1
|
Hladky SB, Barrand MA. Alterations in brain fluid physiology during the early stages of development of ischaemic oedema. Fluids Barriers CNS 2024; 21:51. [PMID: 38858667 PMCID: PMC11163777 DOI: 10.1186/s12987-024-00534-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 03/22/2024] [Indexed: 06/12/2024] Open
Abstract
Oedema occurs when higher than normal amounts of solutes and water accumulate in tissues. In brain parenchymal tissue, vasogenic oedema arises from changes in blood-brain barrier permeability, e.g. in peritumoral oedema. Cytotoxic oedema arises from excess accumulation of solutes within cells, e.g. ischaemic oedema following stroke. This type of oedema is initiated when blood flow in the affected core region falls sufficiently to deprive brain cells of the ATP needed to maintain ion gradients. As a consequence, there is: depolarization of neurons; neural uptake of Na+ and Cl- and loss of K+; neuronal swelling; astrocytic uptake of Na+, K+ and anions; swelling of astrocytes; and reduction in ISF volume by fluid uptake into neurons and astrocytes. There is increased parenchymal solute content due to metabolic osmolyte production and solute influx from CSF and blood. The greatly increased [K+]isf triggers spreading depolarizations into the surrounding penumbra increasing metabolic load leading to increased size of the ischaemic core. Water enters the parenchyma primarily from blood, some passing into astrocyte endfeet via AQP4. In the medium term, e.g. after three hours, NaCl permeability and swelling rate increase with partial opening of tight junctions between blood-brain barrier endothelial cells and opening of SUR1-TPRM4 channels. Swelling is then driven by a Donnan-like effect. Longer term, there is gross failure of the blood-brain barrier. Oedema resolution is slower than its formation. Fluids without colloid, e.g. infused mock CSF, can be reabsorbed across the blood-brain barrier by a Starling-like mechanism whereas infused serum with its colloids must be removed by even slower extravascular means. Large scale oedema can increase intracranial pressure (ICP) sufficiently to cause fatal brain herniation. The potentially lethal increase in ICP can be avoided by craniectomy or by aspiration of the osmotically active infarcted region. However, the only satisfactory treatment resulting in retention of function is restoration of blood flow, providing this can be achieved relatively quickly. One important objective of current research is to find treatments that increase the time during which reperfusion is successful. Questions still to be resolved are discussed.
Collapse
Affiliation(s)
- Stephen B Hladky
- Department of Pharmacology, Tennis Court Rd., Cambridge, CB2 1PD, UK.
| | - Margery A Barrand
- Department of Pharmacology, Tennis Court Rd., Cambridge, CB2 1PD, UK
| |
Collapse
|
2
|
Kaur J, Boyd ED, Ding G, Zhang L, Luo H, Li Q, Li L, Wei M, Landschoot-Ward J, Chopp M, Zhang Z, Jiang Q. The Association between Glymphatic System and Perivascular Macrophages in Brain Waste Clearance. Diagnostics (Basel) 2024; 14:731. [PMID: 38611644 PMCID: PMC11011895 DOI: 10.3390/diagnostics14070731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 04/14/2024] Open
Abstract
The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging. Furthermore, perivascular macrophages (PVMs), which are immune cells located within perivascular spaces, have not been thoroughly explored for their association with the glymphatic system. Therefore, we investigated tracer uptake by PVMs in the perivascular spaces of both the arteries/arterioles and veins/venules and the potential association of PVMs in assisting the glymphatic system for interstitial waste clearance. Our findings demonstrated that both convective bulk flow and diffusion are responsible for the clearance of interstitial waste solutes from the brain parenchyma. Furthermore, our results suggested that PVMs may play an important function in glymphatic system-mediated interstitial waste clearance. The glymphatic system and PVMs could be targeted to enhance interstitial waste clearance in patients with waste-associated neurological conditions and aging.
Collapse
Affiliation(s)
- Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
| | - Edward D. Boyd
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Hao Luo
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Lian Li
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Min Wei
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Julie Landschoot-Ward
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
| |
Collapse
|
3
|
Kovacs MA, Babcock IW, Royo Marco A, Sibley LA, Kelly AG, Harris TH. Vascular Endothelial Growth Factor-C Treatment Enhances Cerebrospinal Fluid Outflow during Toxoplasma gondii Brain Infection but Does Not Improve Cerebral Edema. THE AMERICAN JOURNAL OF PATHOLOGY 2024; 194:225-237. [PMID: 38065361 PMCID: PMC10835445 DOI: 10.1016/j.ajpath.2023.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 10/02/2023] [Accepted: 11/06/2023] [Indexed: 01/22/2024]
Abstract
Cerebral edema frequently develops in the setting of brain infection and can contribute to elevated intracranial pressure, a medical emergency. How excess fluid is cleared from the brain is not well understood. Previous studies have shown that interstitial fluid is transported out of the brain along perivascular channels that collect into the cerebrospinal fluid (CSF)-filled subarachnoid space. CSF is then removed from the central nervous system through venous and lymphatic routes. The current study tested the hypothesis that increasing lymphatic drainage of CSF would promote clearance of cerebral edema fluid during infection with the neurotropic parasite Toxoplasma gondii. Fluorescent microscopy and magnetic resonance imaging was used to show that C57BL/6 mice develop vasogenic edema 4 to 5 weeks after infection with T. gondii. Tracer experiments were used to evaluate how brain infection affects meningeal lymphatic function, which demonstrated a decreased rate in CSF outflow in T. gondii-infected mice. Next, mice were treated with a vascular endothelial growth factor (VEGF)-C-expressing viral vector, which induced meningeal lymphangiogenesis and improved CSF outflow in chronically infected mice. No difference in cerebral edema was observed between mice that received VEGF-C and those that rececived sham treatment. Therefore, although VEGF-C treatment can improve lymphatic outflow in mice infected with T. gondii, this effect does not lead to increased clearance of edema fluid from the brains of these mice.
Collapse
Affiliation(s)
- Michael A Kovacs
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Isaac W Babcock
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Ana Royo Marco
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Lydia A Sibley
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Abigail G Kelly
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia
| | - Tajie H Harris
- Center for Brain Immunology and Glia, Department of Neuroscience, University of Virginia, Charlottesville, Virginia.
| |
Collapse
|
4
|
Kaur J, Boyd E, Ding G, Zhang L, Luo H, Li Q, Li L, Wei M, Landschoot-Ward J, Chopp M, Zhang Z, Jiang Q. The Association between Glymphatic System and Perivascular Macrophages in Brain Waste Clearance. RESEARCH SQUARE 2023:rs.3.rs-3390074. [PMID: 37886481 PMCID: PMC10602168 DOI: 10.21203/rs.3.rs-3390074/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging. Furthermore, perivascular macrophages (PVMs), which are immune cells located within perivascular spaces, have not been thoroughly explored for their association with the glymphatic system. Therefore, we investigated tracer uptake by PVMs in the perivascular spaces of both the arteries/arterioles and veins/venules and the potential association of PVMs in assisting the glymphatic system for interstitial waste clearance. Our findings demonstrated that both convective bulk flow and diffusion are responsible for the clearance of interstitial waste solutes from the brain parenchyma. Furthermore, our results suggested that PVMs play an important function in glymphatic system-mediated interstitial waste clearance. The glymphatic system and PVMs could be targeted to enhance interstitial waste clearance in patients with waste-associated neurological conditions and aging.
Collapse
Affiliation(s)
- Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
| | - Edward Boyd
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
| | - Hao Luo
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Lian Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Min Wei
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | | | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| |
Collapse
|
5
|
Rümenapp JE, Sendel M, Kersebaum D, Larsen N, Jansen O, Baron R. Impaired glymphatic flow as a potential driver of pain chronification. Pain 2023; 164:2191-2195. [PMID: 37433183 DOI: 10.1097/j.pain.0000000000002979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/27/2023] [Indexed: 07/13/2023]
Affiliation(s)
- Johanna Elisabeth Rümenapp
- Division of Neurological Pain Research and Therapy, Clinic for Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Manon Sendel
- Division of Neurological Pain Research and Therapy, Clinic for Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Dilara Kersebaum
- Division of Neurological Pain Research and Therapy, Clinic for Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Naomi Larsen
- Clinic for Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Olav Jansen
- Clinic for Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Ralf Baron
- Division of Neurological Pain Research and Therapy, Clinic for Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
6
|
Purohit P, Dutta P, Roy PK. Empirically validated theoretical analysis of visual-spatial perception under change of nervous system arousal. Front Comput Neurosci 2023; 17:1136985. [PMID: 37251600 PMCID: PMC10213702 DOI: 10.3389/fncom.2023.1136985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/03/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction Visual-spatial perception is a process for extracting the spatial relationship between objects in the environment. The changes in visual-spatial perception due to factors such as the activity of the sympathetic nervous system (hyperactivation) or parasympathetic nervous system (hypoactivation) can affect the internal representation of the external visual-spatial world. We formulated a quantitative model of the modulation of visual-perceptual space under action by hyperactivation or hypoactivation-inducing neuromodulating agents. We showed a Hill equation based relationship between neuromodulator agent concentration and alteration of visual-spatial perception utilizing the metric tensor to quantify the visual space. Methods We computed the dynamics of the psilocybin (hyperactivation-inducing agent) and chlorpromazine (hypoactivation-inducing agent) in brain tissue. Then, we validated our quantitative model by analyzing the findings of different independent behavioral studies where subjects were assessed for alterations in visual-spatial perception under the action of psilocybin and under chlorpromazine. To validate the neuronal correlates, we simulated the effect of the neuromodulating agent on the computational model of the grid-cell network, and also performed diffusion MRI-based tractography to find the neural tracts between the cortical areas involved: V2 and the entorhinal cortex. Results We applied our computational model to an experiment (where perceptual alterations were measured under psilocybin) and found that for n (Hill-coefficient) = 14.8 and k = 1.39, the theoretical prediction followed experimental observations very well (χ2 test robustly satisfied, p > 0.99). We predicted the outcome of another psilocybin-based experiment using these values (n = 14.8 and k = 1.39), whereby our prediction and experimental outcomes were well corroborated. Furthermore, we found that also under hypoactivation (chlorpromazine), the modulation of the visual-spatial perception follows our model. Moreover, we found neural tracts between the area V2 and entorhinal cortex, thus providing a possible brain network responsible for encoding visual-spatial perception. Thence, we simulated the altered grid-cell network activity, which was also found to follow the Hill equation. Conclusion We developed a computational model of visuospatial perceptual alterations under altered neural sympathetic/parasympathetic tone. We validated our model using analysis of behavioral studies, neuroimaging assessment, and neurocomputational evaluation. Our quantitative approach may be probed as a potential behavioral screening and monitoring methodology in neuropsychology to analyze perceptual misjudgment and mishaps by highly stressed workers.
Collapse
Affiliation(s)
- Pratik Purohit
- School of Biomedical Engineering, Indian Institute of Technology (BHU), Varanasi, India
| | - Prasun Dutta
- Department of Physics, Indian Institute of Technology (BHU), Varanasi, India
| | - Prasun K. Roy
- School of Biomedical Engineering, Indian Institute of Technology (BHU), Varanasi, India
- Department of Life Sciences, Shiv Nadar University (SNU), Greater Noida, India
| |
Collapse
|
7
|
Wan Y, Holste KG, Hua Y, Keep RF, Xi G. Brain edema formation and therapy after intracerebral hemorrhage. Neurobiol Dis 2023; 176:105948. [PMID: 36481437 PMCID: PMC10013956 DOI: 10.1016/j.nbd.2022.105948] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/28/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022] Open
Abstract
Intracerebral hemorrhage (ICH) accounts for about 10% of all strokes in the United States of America causing a high degree of disability and mortality. There is initial (primary) brain injury due to the mechanical disruption caused by the hematoma. There is then secondary injury, triggered by the initial injury but also the release of various clot-derived factors (e.g., thrombin and hemoglobin). ICH alters brain fluid homeostasis. Apart from the initial hematoma mass, ICH causes blood-brain barrier disruption and parenchymal cell swelling, which result in brain edema and intracranial hypertension affecting patient prognosis. Reducing brain edema is a critical part of post-ICH care. However, there are limited effective treatment methods for reducing perihematomal cerebral edema and intracranial pressure in ICH. This review discusses the mechanisms underlying perihematomal brain edema formation, the effects of sex and age, as well as how edema is resolved. It examines progress in pharmacotherapy, particularly focusing on drugs which have been or are currently being investigated in clinical trials.
Collapse
Affiliation(s)
- Yingfeng Wan
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | | | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA.
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
8
|
Han M, Seo H, Choi H, Lee EH, Park J. Localized Modification of Water Molecule Transport After Focused Ultrasound-Induced Blood-Brain Barrier Disruption in Rat Brain. Front Neurosci 2021; 15:685977. [PMID: 34393708 PMCID: PMC8358078 DOI: 10.3389/fnins.2021.685977] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 07/09/2021] [Indexed: 12/21/2022] Open
Abstract
Interstitial solutes can be removed by various overlapping clearance systems, including blood-brain barrier (BBB) transport and glymphatic clearance. Recently, focused ultrasound (FUS)-induced BBB disruption (BBBD) has been applied to visualize glymphatic transport. Despite evidence that FUS-BBBD might facilitate glymphatic transport, the nature of fluid movement within the sonication region is yet to be determined. In this study, we sought to determine whether FUS-BBBD may facilitate the local movement of water molecules. Two different FUS conditions (0.60-0.65 MPa and 0.75-0.80 MPa) were used to induce BBBD in the caudate-putamen and thalamus regions of healthy Sprague-Dawley rats. The water diffusion caused by FUS-BBBD was analyzed using the apparent diffusion coefficient (ADC), axial diffusivity, radial diffusivity (RD), and fractional anisotropy, obtained at 5 min, 24 and 48 h, as well as the water channel expression of aquaporin-4 (AQP-4) immunostaining at 48 h after FUS-induced BBBD. In addition, hematoxylin and eosin histopathology and Fluoro-Jade C (FJC) immunostaining were performed to analyze brain damage. The signal changes in ADC and RD in the sonication groups showed significant and transient reduction at 5 min, with subsequent increases at 24 and 48 h after FUS-induced BBBD. When we applied higher sonication conditions, the ADC and RD showed enhancement until 48 h, and became comparable to contralateral values at 72 h. AQP-4 expression was upregulated after FUS-induced BBBD in both sonication conditions at 48 h. The results of this study provide preliminary evidence on how mechanical forces from FUS alter water dynamics through diffusion tensor imaging (DTI) measures and AQP4 expression.
Collapse
Affiliation(s)
- Mun Han
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Hyeon Seo
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Hyojin Choi
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Eun-Hee Lee
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| | - Juyoung Park
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, South Korea
| |
Collapse
|
9
|
Mestre H, Hablitz LM, Xavier AL, Feng W, Zou W, Pu T, Monai H, Murlidharan G, Castellanos Rivera RM, Simon MJ, Pike MM, Plá V, Du T, Kress BT, Wang X, Plog BA, Thrane AS, Lundgaard I, Abe Y, Yasui M, Thomas JH, Xiao M, Hirase H, Asokan A, Iliff JJ, Nedergaard M. Aquaporin-4-dependent glymphatic solute transport in the rodent brain. eLife 2018; 7:40070. [PMID: 30561329 PMCID: PMC6307855 DOI: 10.7554/elife.40070] [Citation(s) in RCA: 342] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 12/17/2018] [Indexed: 02/06/2023] Open
Abstract
The glymphatic system is a brain-wide clearance pathway; its impairment contributes to the accumulation of amyloid-β. Influx of cerebrospinal fluid (CSF) depends upon the expression and perivascular localization of the astroglial water channel aquaporin-4 (AQP4). Prompted by a recent failure to find an effect of Aqp4 knock-out (KO) on CSF and interstitial fluid (ISF) tracer transport, five groups re-examined the importance of AQP4 in glymphatic transport. We concur that CSF influx is higher in wild-type mice than in four different Aqp4 KO lines and in one line that lacks perivascular AQP4 (Snta1 KO). Meta-analysis of all studies demonstrated a significant decrease in tracer transport in KO mice and rats compared to controls. Meta-regression indicated that anesthesia, age, and tracer delivery explain the opposing results. We also report that intrastriatal injections suppress glymphatic function. This validates the role of AQP4 and shows that glymphatic studies must avoid the use of invasive procedures.
Collapse
Affiliation(s)
- Humberto Mestre
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | - Anna Lr Xavier
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Weixi Feng
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Wenyan Zou
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Tinglin Pu
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Hiromu Monai
- RIKEN Center for Brain Science, Wako, Japan.,Ochanomizu University, Tokyo, Japan
| | - Giridhar Murlidharan
- Gene Therapy Center, The University of North Carolina, Chapel Hill, United States
| | | | - Matthew J Simon
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, United States
| | - Martin M Pike
- Advanced Imaging Research Center, Oregon Health and Science University, Portland, United States
| | - Virginia Plá
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | - Ting Du
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | - Benjamin T Kress
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | | | - Benjamin A Plog
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States
| | - Alexander S Thrane
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Ophthalmology, Haukeland University Hospital, Bergen, Norway
| | - Iben Lundgaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States.,Department of Experimental Medical Science, Lund University, Lund, Sweden.,Wallenberg Center for Molecular Medicine, Lund University, Lund, Sweden
| | - Yoichiro Abe
- Department of Pharmacology,School of Medicine, Keio University, Tokyo, Japan
| | - Masato Yasui
- Department of Pharmacology,School of Medicine, Keio University, Tokyo, Japan
| | - John H Thomas
- Department of Mechanical Engineering, University of Rochester, Rochester, United States.,Department of Physics and Astronomy, University of Rochester, Rochester, United States
| | - Ming Xiao
- Jiangsu Province Key Laboratory of Neurodegeneration, Center for Global Health, Nanjing Medical University, Nanjing, China
| | - Hajime Hirase
- RIKEN Center for Brain Science, Wako, Japan.,Brain and Body System Science Institute, Saitama University, Saitama, Japan
| | - Aravind Asokan
- Gene Therapy Center, The University of North Carolina, Chapel Hill, United States.,Department of Molecular Genetics and Microbiology, Duke University School of Medicine, North Carolina, United States.,Department of Surgery, Duke University School of Medicine, Durham, United States
| | - Jeffrey J Iliff
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, United States.,Knight Cardiovascular Institute, Oregon Health and Science University, Portland, United States
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, United States.,Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
10
|
Vinokurova D, Zakharov AV, Lebedeva J, Burkhanova GF, Chernova KA, Lotfullina N, Khazipov R, Valeeva G. Pharmacodynamics of the Glutamate Receptor Antagonists in the Rat Barrel Cortex. Front Pharmacol 2018; 9:698. [PMID: 30018551 PMCID: PMC6038834 DOI: 10.3389/fphar.2018.00698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/08/2018] [Indexed: 02/01/2023] Open
Abstract
Epipial application is one of the approaches for drug delivery into the cortex. However, passive diffusion of epipially applied drugs through the cortical depth may be slow, and different drug concentrations may be achieved at different rates across the cortical depth. Here, we explored the pharmacodynamics of the inhibitory effects of epipially applied ionotropic glutamate receptor antagonists CNQX and dAPV on sensory-evoked and spontaneous activity across layers of the cortical barrel column in urethane-anesthetized rats. The inhibitory effects of CNQX and dAPV were observed at concentrations that were an order higher than in slices in vitro, and they slowly developed from the cortical surface to depth after epipial application. The level of the inhibitory effects also followed the surface-to-depth gradient, with full inhibition of sensory evoked potentials (SEPs) in the supragranular layers and L4 and only partial inhibition in L5 and L6. During epipial CNQX and dAPV application, spontaneous activity and the late component of multiple unit activity (MUA) during sensory-evoked responses were suppressed faster than the short-latency MUA component. Despite complete suppression of SEPs in L4, sensory-evoked short-latency multiunit responses in L4 persisted, and they were suppressed by further addition of lidocaine suggesting that spikes in thalamocortical axons contribute ∼20% to early multiunit responses. Epipial CNQX and dAPV also completely suppressed sensory-evoked very fast (∼500 Hz) oscillations and spontaneous slow wave activity in L2/3 and L4. However, delta oscillations persisted in L5/6. Thus, CNQX and dAPV exert inhibitory actions on cortical activity during epipial application at much higher concentrations than in vitro, and the pharmacodynamics of their inhibitory effects is characterized by the surface-to-depth gradients in the rate of development and the level of inhibition of sensory-evoked and spontaneous cortical activity.
Collapse
Affiliation(s)
- Daria Vinokurova
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.,Mediterranean Institute of Neurobiology - National Institute of Health and Medical Research, Aix-Marseille University, UMR1249, Marseille, France
| | | | - Julia Lebedeva
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| | | | | | - Nailya Lotfullina
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.,Mediterranean Institute of Neurobiology - National Institute of Health and Medical Research, Aix-Marseille University, UMR1249, Marseille, France
| | - Rustem Khazipov
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.,Mediterranean Institute of Neurobiology - National Institute of Health and Medical Research, Aix-Marseille University, UMR1249, Marseille, France
| | - Guzel Valeeva
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| |
Collapse
|
11
|
Abbott NJ, Pizzo ME, Preston JE, Janigro D, Thorne RG. The role of brain barriers in fluid movement in the CNS: is there a 'glymphatic' system? Acta Neuropathol 2018; 135:387-407. [PMID: 29428972 DOI: 10.1007/s00401-018-1812-4] [Citation(s) in RCA: 341] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/16/2018] [Accepted: 01/24/2018] [Indexed: 12/15/2022]
Abstract
Brain fluids are rigidly regulated to provide stable environments for neuronal function, e.g., low K+, Ca2+, and protein to optimise signalling and minimise neurotoxicity. At the same time, neuronal and astroglial waste must be promptly removed. The interstitial fluid (ISF) of the brain tissue and the cerebrospinal fluid (CSF) bathing the CNS are integral to this homeostasis and the idea of a glia-lymph or 'glymphatic' system for waste clearance from brain has developed over the last 5 years. This links bulk (convective) flow of CSF into brain along the outside of penetrating arteries, glia-mediated convective transport of fluid and solutes through the brain extracellular space (ECS) involving the aquaporin-4 (AQP4) water channel, and finally delivery of fluid to venules for clearance along peri-venous spaces. However, recent evidence favours important amendments to the 'glymphatic' hypothesis, particularly concerning the role of glia and transfer of solutes within the ECS. This review discusses studies which question the role of AQP4 in ISF flow and the lack of evidence for its ability to transport solutes; summarizes attributes of brain ECS that strongly favour the diffusion of small and large molecules without ISF flow; discusses work on hydraulic conductivity and the nature of the extracellular matrix which may impede fluid movement; and reconsiders the roles of the perivascular space (PVS) in CSF-ISF exchange and drainage. We also consider the extent to which CSF-ISF exchange is possible and desirable, the impact of neuropathology on fluid drainage, and why using CSF as a proxy measure of brain components or drug delivery is problematic. We propose that new work and key historical studies both support the concept of a perivascular fluid system, whereby CSF enters the brain via PVS convective flow or dispersion along larger caliber arteries/arterioles, diffusion predominantly regulates CSF/ISF exchange at the level of the neurovascular unit associated with CNS microvessels, and, finally, a mixture of CSF/ISF/waste products is normally cleared along the PVS of venules/veins as well as other pathways; such a system may or may not constitute a true 'circulation', but, at the least, suggests a comprehensive re-evaluation of the previously proposed 'glymphatic' concepts in favour of a new system better taking into account basic cerebrovascular physiology and fluid transport considerations.
Collapse
Affiliation(s)
- N Joan Abbott
- Faculty of Life Sciences and Medicine, Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building 3.82, 150 Stamford St, London, SE1 9NH, UK.
| | - Michelle E Pizzo
- Division of Pharmaceutical Sciences, University of Wisconsin-Madison School of Pharmacy, Madison, WI, USA
- Clinical Neuroengineering Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Jane E Preston
- Faculty of Life Sciences and Medicine, Institute of Pharmaceutical Science, King's College London, Franklin Wilkins Building 3.82, 150 Stamford St, London, SE1 9NH, UK
| | - Damir Janigro
- Flocel Inc., Cleveland, OH, USA
- Department of Physiology, Case Western Reserve University, Cleveland, OH, USA
| | - Robert G Thorne
- Division of Pharmaceutical Sciences, University of Wisconsin-Madison School of Pharmacy, Madison, WI, USA.
- Clinical Neuroengineering Training Program, University of Wisconsin-Madison, Madison, WI, USA.
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA.
- Cellular and Molecular Pathology Graduate Training Program, University of Wisconsin-Madison, Madison, WI, USA.
- Institute for Clinical and Translational Research, University of Wisconsin-Madison, Madison, WI, USA.
- , 5113 Rennebohm Hall, 777 Highland Avenue, Madison, WI, 53705, USA.
| |
Collapse
|
12
|
Coles JA, Myburgh E, Brewer JM, McMenamin PG. Where are we? The anatomy of the murine cortical meninges revisited for intravital imaging, immunology, and clearance of waste from the brain. Prog Neurobiol 2017; 156:107-148. [PMID: 28552391 DOI: 10.1016/j.pneurobio.2017.05.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 04/25/2017] [Accepted: 05/08/2017] [Indexed: 12/15/2022]
Abstract
Rapid progress is being made in understanding the roles of the cerebral meninges in the maintenance of normal brain function, in immune surveillance, and as a site of disease. Most basic research on the meninges and the neural brain is now done on mice, major attractions being the availability of reporter mice with fluorescent cells, and of a huge range of antibodies useful for immunocytochemistry and the characterization of isolated cells. In addition, two-photon microscopy through the unperforated calvaria allows intravital imaging of the undisturbed meninges with sub-micron resolution. The anatomy of the dorsal meninges of the mouse (and, indeed, of all mammals) differs considerably from that shown in many published diagrams: over cortical convexities, the outer layer, the dura, is usually thicker than the inner layer, the leptomeninx, and both layers are richly vascularized and innervated, and communicate with the lymphatic system. A membrane barrier separates them and, in disease, inflammation can be localized to one layer or the other, so experimentalists must be able to identify the compartment they are studying. Here, we present current knowledge of the functional anatomy of the meninges, particularly as it appears in intravital imaging, and review their role as a gateway between the brain, blood, and lymphatics, drawing on information that is scattered among works on different pathologies.
Collapse
Affiliation(s)
- Jonathan A Coles
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Sir Graeme Davis Building, University of Glasgow, Glasgow, G12 8TA, United Kingdom.
| | - Elmarie Myburgh
- Centre for Immunology and Infection Department of Biology, University of York, Wentworth Way, Heslington, York YO10 5DD, United Kingdom
| | - James M Brewer
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Sir Graeme Davis Building, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Paul G McMenamin
- Department of Anatomy & Developmental Biology, School of Biomedical and Psychological Sciences and Monash Biomedical Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, 10 Chancellor's Walk, Clayton, Victoria, 3800, Australia
| |
Collapse
|
13
|
Piazza M, Munasinghe J, Murayi R, Edwards N, Montgomery B, Walbridge S, Merrill M, Chittiboina P. Simulating vasogenic brain edema using chronic VEGF infusion. J Neurosurg 2017; 127:905-916. [PMID: 28059647 DOI: 10.3171/2016.9.jns1627] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE To study peritumoral brain edema (PTBE), it is necessary to create a model that accurately simulates vasogenic brain edema (VBE) without introducing a complicated tumor environment. PTBE associated with brain tumors is predominantly a result of vascular endothelial growth factor (VEGF) secreted by brain tumors, and VEGF infusion alone can lead to histological blood-brain barrier (BBB) breakdown in the absence of tumor. VBE is intimately linked to BBB breakdown. The authors sought to establish a model for VBE with chronic infusion of VEGF that can be validated by serial in-vivo MRI and histological findings. METHODS Male Fischer rats (n = 182) underwent stereotactic striatal implantation of MRI-safe brain cannulas for chronic infusion of VEGF (2-20 µg/ml). Following a preinfusion phase (4-6 days), the rats were exposed to VEGF or control rat serum albumin (1.5 µl/hr) for as long as 144 hours. Serial MRI was performed during infusion on a high-field (9.4-T) machine at 12-24, 24-36, 48-72, and 120-144 hours. Rat brains were then collected and histological analysis was performed. RESULTS Control animals and animals infused with 2 µg/ml of VEGF experienced no neurological deficits, seizure activity, or abnormal behavior. Animals treated with VEGF demonstrated a significantly larger volume (42.90 ± 3.842 mm3) of T2 hyper-attenuation at 144 hours when compared with the volume (8.585 ± 1.664 mm3) in control animals (mean difference 34.31 ± 4.187 mm3, p < 0.0001, 95% CI 25.74-42.89 mm3). Postcontrast T1 enhancement in the juxtacanalicular region indicating BBB breakdown was observed in rats undergoing infusion with VEGF. At the later time periods (120-144 hrs) the volume of T1 enhancement (34.97 ± 8.99 mm3) was significantly less compared with the region of edema (p < 0.0001). Histologically, no evidence of necrosis or inflammation was observed with VEGF or control infusion. Immunohistochemical analysis demonstrated astrocyte activation, vascular remodeling, and increased claudin-5 expression in juxtacanalicular regions. Aquaporin-4 expression was increased in both control and VEGF animals in the juxtacanalicular regions. CONCLUSIONS The results of this study show that chronic brain infusion of VEGF creates a reliable model of VBE. This model lacks necrosis and inflammation that are characteristic of previous models of VBE. The model allows for a precise investigation into the mechanism of VBE formation. The authors also anticipate that this model will allow for investigation into the mechanism of glucocorticoid action in abrogating VBE, and to test novel therapeutic strategies targeting PTBE.
Collapse
Affiliation(s)
- Martin Piazza
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | | | - Roger Murayi
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | - Nancy Edwards
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | - Blake Montgomery
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | - Stuart Walbridge
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | - Marsha Merrill
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| | - Prashant Chittiboina
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, and
| |
Collapse
|
14
|
Muro K, Das S, Raizer JJ. Convection-Enhanced and Local Delivery of Targeted Cytotoxins in the Treatment of Malignant Gliomas. Technol Cancer Res Treat 2016; 5:201-13. [PMID: 16700617 DOI: 10.1177/153303460600500304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Despite advances in our knowledge about the genesis, molecular biology, and natural history of malignant gliomas and the use of a multi-disciplinary approach to their treatment, patients harboring this diagnosis continue to face a grim prognosis. At the time of diagnosis, patients typically undergo surgery for the establishment of a histologic diagnosis, the reduction of tumor burden, and the relief of mass effect, with the maintenance of the patient's neurological function in mind. This is followed by the administration of adjuvant therapeutics, including radiation therapy and chemotherapy. Many investigational agents with laboratory evidence of efficacy against malignant gliomas have not met their promise in the clinical setting, largely due to the barriers that they must overcome to reach the tumor at a therapeutically meaningful concentration for a durable period of time. The relevant aspects of the blood-brain barrier, blood-tumor barrier, and blood-cerebrospinal fluid barrier, as they pertain to the delivery of agents to the tumor, will be discussed along with the strategies devised to circumvent them. This discussion will be followed by a description of agents currently in preclinical and clinical development, many of which are the result of intense ongoing research into the molecular biology of gliomas.
Collapse
Affiliation(s)
- Kenji Muro
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Abbott Hall, Suite 1123, 710 N Lake Shore Drive, Chicago, Illinois 60611, USA
| | | | | |
Collapse
|
15
|
Hammer C, Daou B, Chalouhi N, Starke RM, Ya'qoub L, Mouchtouris N, Koduri S, Tjoumakaris S, Rosenwasser RH, Jabbour P. Decreased CSF output as a clinical indicator of cerebral vasospasm following aneurysmal subarachnoid hemorrhage. Clin Neurol Neurosurg 2016; 144:101-4. [PMID: 27037865 DOI: 10.1016/j.clineuro.2016.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/22/2016] [Accepted: 03/27/2016] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Vasospasm is a significant cause of morbidity and mortality among those with aneurysmal subarachnoid hemorrhage (aSAH). Treating increased intracranial pressure by drainage of cerebral spinal fluid through an external ventriculostomy is routine practice. The objective of this study is to evaluate the trends of CSF output in patients who experience vasospasm. METHODS Electronic medical charts were reviewed to identify two groups of patients with aSAH, 75 consecutive patients who developed vasospasm and 75 matched patients who did not develop vasospasm. CSF output was recorded within 3 days before and 3 days after the occurrence of vasospasm. CSF output was recorded for the same days after SAH in matched patients with no vasospasm. RESULTS Total CSF output was lower in patients with vasospasm as compared to patients without vasospasm matched for the same day (p<0.001). In patients with vasospasm, CSF output recordings were significantly higher prior to the occurrence of vasospasm (438ml/day) than the period following vasospasm (325.7ml/day), with a consistent decrease in CSF drainage from day 3 before vasospasm to day 3 after vasospasm (p=0.012). Decreasing CSF output was significantly associated with the occurrence of vasospasm (p=0.017). Youden indices demonstrated that daily CSF drainage <160ml was significantly associated with the occurrence of vasospasm. The sensitivity of this test was 64.79% and the specificity was 55.38%. CONCLUSIONS In addition to clinical exam findings, observation of a CSF output decline to less than 160ml/day may be used as additional support for the diagnosis of vasospasm.
Collapse
Affiliation(s)
- Christine Hammer
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Badih Daou
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Nohra Chalouhi
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Robert M Starke
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Lina Ya'qoub
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Nikolaos Mouchtouris
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Sravanthi Koduri
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Stavropoula Tjoumakaris
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Robert H Rosenwasser
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
| | - Pascal Jabbour
- Department of Neurological Surgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA.
| |
Collapse
|
16
|
Stokum JA, Gerzanich V, Simard JM. Molecular pathophysiology of cerebral edema. J Cereb Blood Flow Metab 2016; 36:513-38. [PMID: 26661240 PMCID: PMC4776312 DOI: 10.1177/0271678x15617172] [Citation(s) in RCA: 357] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/21/2015] [Accepted: 10/22/2015] [Indexed: 12/25/2022]
Abstract
Advancements in molecular biology have led to a greater understanding of the individual proteins responsible for generating cerebral edema. In large part, the study of cerebral edema is the study of maladaptive ion transport. Following acute CNS injury, cells of the neurovascular unit, particularly brain endothelial cells and astrocytes, undergo a program of pre- and post-transcriptional changes in the activity of ion channels and transporters. These changes can result in maladaptive ion transport and the generation of abnormal osmotic forces that, ultimately, manifest as cerebral edema. This review discusses past models and current knowledge regarding the molecular and cellular pathophysiology of cerebral edema.
Collapse
Affiliation(s)
- Jesse A Stokum
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA
| | - J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, USA Department of Pathology, University of Maryland School of Medicine, Baltimore, USA Department of Physiology, University of Maryland School of Medicine, Baltimore, USA
| |
Collapse
|
17
|
Yazdan-Shahmorad A, Diaz-Botia C, Hanson T, Kharazia V, Ledochowitsch P, Maharbiz M, Sabes P. A Large-Scale Interface for Optogenetic Stimulation and Recording in Nonhuman Primates. Neuron 2016; 89:927-39. [DOI: 10.1016/j.neuron.2016.01.013] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 07/28/2015] [Accepted: 01/05/2016] [Indexed: 12/15/2022]
|
18
|
Diem AK, Tan M, Bressloff NW, Hawkes C, Morris AWJ, Weller RO, Carare RO. A Simulation Model of Periarterial Clearance of Amyloid-β from the Brain. Front Aging Neurosci 2016; 8:18. [PMID: 26903861 PMCID: PMC4751273 DOI: 10.3389/fnagi.2016.00018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 01/25/2016] [Indexed: 11/25/2022] Open
Abstract
The accumulation of soluble and insoluble amyloid-β (Aβ) in the brain indicates failure of elimination of Aβ from the brain with age and Alzheimer's disease (AD). There is a variety of mechanisms for elimination of Aβ from the brain. They include the action of microglia and enzymes together with receptor-mediated absorption of Aβ into the blood and periarterial lymphatic drainage of Aβ. Although the brain possesses no conventional lymphatics, experimental studies have shown that fluid and solutes, such as Aβ, are eliminated from the brain along 100 nm wide basement membranes in the walls of cerebral capillaries and arteries. This lymphatic drainage pathway is reflected in the deposition of Aβ in the walls of human arteries with age and AD as cerebral amyloid angiopathy (CAA). Initially, Aβ diffuses through the extracellular spaces of gray matter in the brain and then enters basement membranes in capillaries and arteries to flow out of the brain. Although diffusion through the extracellular spaces of the brain has been well characterized, the exact mechanism whereby perivascular elimination of Aβ occurs has not been resolved. Here we use a computational model to describe the process of periarterial drainage in the context of diffusion in the brain, demonstrating that periarterial drainage along basement membranes is very rapid compared with diffusion. Our results are a validation of experimental data and are significant in the context of failure of periarterial drainage as a mechanism underlying the pathogenesis of AD as well as complications associated with its immunotherapy.
Collapse
Affiliation(s)
- Alexandra K Diem
- Institute for Complex Systems Simulation, School of Electronics and Computer Science, University of SouthamptonSouthampton, UK; Computational Engineering and Design, Faculty of Engineering and the Environment, University of SouthamptonSouthampton, UK
| | - Mingyi Tan
- Fluid Structure Interactions, Faculty of Engineering and the Environment, University of Southampton Southampton, UK
| | - Neil W Bressloff
- Computational Engineering and Design, Faculty of Engineering and the Environment, University of Southampton Southampton, UK
| | - Cheryl Hawkes
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton Southampton, UK
| | - Alan W J Morris
- Clinical and Experimental Sciences, Faculty of Medicine, University of SouthamptonSouthampton, UK; Institute for Life Sciences, University of SouthamptonSouthampton, UK
| | - Roy O Weller
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton Southampton, UK
| | - Roxana O Carare
- Clinical and Experimental Sciences, Faculty of Medicine, University of SouthamptonSouthampton, UK; Institute for Life Sciences, University of SouthamptonSouthampton, UK
| |
Collapse
|
19
|
Thrane AS, Rangroo Thrane V, Nedergaard M. Drowning stars: reassessing the role of astrocytes in brain edema. Trends Neurosci 2014; 37:620-8. [PMID: 25236348 DOI: 10.1016/j.tins.2014.08.010] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 11/18/2022]
Abstract
Edema formation frequently complicates brain infarction, tumors, and trauma. Despite the significant mortality of this condition, current treatment options are often ineffective or incompletely understood. Recent studies have revealed the existence of a brain-wide paravascular pathway for cerebrospinal (CSF) and interstitial fluid (ISF) exchange. The current review critically examines the contribution of this 'glymphatic' system to the main types of brain edema. We propose that in cytotoxic edema, energy depletion enhances glymphatic CSF influx, whilst suppressing ISF efflux. We also argue that paravascular inflammation or 'paravasculitis' plays a critical role in vasogenic edema. Finally, recent advances in diagnostic imaging of glymphatic function may hold the key to defining the edema profile of individual patients, and thus enable more targeted therapy.
Collapse
Affiliation(s)
- Alexander S Thrane
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York 14642, USA; Department of Ophthalmology, Haukeland University Hospital, Bergen 5021, Norway; Letten Centre, Institute of Basic Medical Sciences, Department of Physiology, University of Oslo, 0317 Oslo, Norway.
| | - Vinita Rangroo Thrane
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York 14642, USA; Department of Ophthalmology, Haukeland University Hospital, Bergen 5021, Norway; Letten Centre, Institute of Basic Medical Sciences, Department of Physiology, University of Oslo, 0317 Oslo, Norway
| | - Maiken Nedergaard
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, New York 14642, USA
| |
Collapse
|
20
|
Abstract
The brain is one of the most protected organs in the body. There are two key barriers that control the access of endogenous substances and xenobiotics (drugs or toxins) to the CNS. These physiological structures are the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier. The BBB represents the main determinant of the effective delivery of drugs to the CNS. Good access through the BBB is essential if the target site is located within the CNS or, in contrast, can be a disadvantage if adverse reactions occur at central level. The development of new drugs targeted to the CNS requires a better knowledge of the factors affecting BBB permeation as well as in vitro and in silico predictive tools to optimize screening, and to reduce the attrition rate at later stages of drug development. This review discusses the particular characteristics of the biology and physiology of the BBB with respect to the permeation and distribution of drugs into the brain. The factors affecting rate, extent and distribution into the brain are discussed and a brief description of the in silico, in vitro, in situ and in vivo methods used to measure BBB transport are presented. Finally, the lastest proposals and strategies to enhance transport across the BBB of new CNS drugs are summarized.
Collapse
|
21
|
Corem-Salkmon E, Ram Z, Daniels D, Perlstein B, Last D, Salomon S, Tamar G, Shneor R, Guez D, Margel S, Mardor Y. Convection-enhanced delivery of methotrexate-loaded maghemite nanoparticles. Int J Nanomedicine 2011; 6:1595-602. [PMID: 21904449 PMCID: PMC3160945 DOI: 10.2147/ijn.s23025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Convection-enhanced delivery (CED) is a novel approach for delivering drugs directly into brain tumors by intracranial infusion, enabling the distribution of high drug concentrations over large tissue volumes. This study was designed to present a method for binding methotrexate (MTX) to unique crystalline, highly ordered and superparamagnetic maghemite nanoparticles via human serum albumin (HSA) coating, optimized for CED treatments of gliomas. Naked nanoparticles and HSA- or polyethylene glycol (PEG)-coated nanoparticles with/without MTX were studied. In vitro results showed no toxicity and a similar cell-kill efficacy of the MTX-loaded particles via HSA coating to that of free MTX, while MTX-loaded particles via PEG coating showed low efficacy. In vivo, the PEG-coated nanoparticles provided the largest distributions in normal rat brain and long clearance times, but due to their low efficacy in vitro, were not considered optimal. The naked nanoparticles provided the smallest distributions and shortest clearance times. The HSA-coated nanoparticles (with/without MTX) provided good distributions and long clearance times (nearly 50% of the distribution volume remained in the brain 3 weeks post treatment). No MTX-related toxicity was noted. These results suggest that the formulation in which HSA was bound to our nanoparticles via a unique precipitation method, and MTX was bound covalently to the HSA, could enable efficient and stable drug loading with no apparent toxicity. The cell-kill efficacy of the bound MTX remained similar to that of free MTX, and the nanoparticles presented efficient distribution volumes and slow clearance times in vivo, suggesting that these particles are optimal for CED.
Collapse
Affiliation(s)
- Enav Corem-Salkmon
- The Institute of Nanotechnology and Advanced Materials, Department of Chemistry, Bar-Ilan University, Ramat-Gan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Postmortem image analysis of sheep cortical leptomeningeal space and vasculature: theoretical implications on brain surface dialysis. ASAIO J 2011; 57:388-94. [PMID: 21709544 DOI: 10.1097/mat.0b013e318224e1f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The vascular surface distribution of the subarachnoid space has not been studied extensively. The aim of our study was to develop a method of computer-assisted estimation of the distribution of the vascular network in the cortical leptomeninges and subarachnoid space and model it to aid the study of the physiology of brain surface dialysis. Nine sheets of leptomeningeal tissue were obtained from adult sheep. Fourteen image sample areas of 4 cm² each were acquired and processed with ImageJ. The vascular and nonvascular areas of the cortical subarachnoid space were identified using a "projected surface" approach. The modeling equations were used to predict the behavior of brain surface dialysis processes. The mean surface area of identified subarachnoid vessels was 0.354 ± 0.02 cm² per 1 cm² of tissue. The mean meningeal area with unidentified vessels was 0.646 ± 0.02 cm²/1 cm², and the difference between these surfaces was significant (p < 0.0001). The modeling equations used predict that modifying the vessel diameter of the subarachnoid space could alter the efficiency of brain surface dialysis. The computer-assisted modeling of the vascular surface of the cortical subarachnoid space may be a useful tool in depicting its morphology and assessing the physiology during brain surface dialysis.
Collapse
|
23
|
Kotsarini C, Griffiths PD, Wilkinson ID, Hoggard N. A systematic review of the literature on the effects of dexamethasone on the brain from in vivo human-based studies: implications for physiological brain imaging of patients with intracranial tumors. Neurosurgery 2011; 67:1799-815; discussion 1815. [PMID: 21107211 DOI: 10.1227/neu.0b013e3181fa775b] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Among glucocorticoids, dexamethasone is most widely used for treatment of cerebral edema because of its long biological half-life and its low mineralocorticoid activity (sodium retaining). OBJECTIVE A systematic review of the literature on the effects of dexamethasone on the brain from in vivo studies in humans. METHODS A MEDLINE database search (via the PubMed interface) and an EMBASE database search (via the Dialog interface) of the past 35 years was performed. Every article relating to human use reported in English was included. In addition, references of all eligible articles were searched to identify other possible sources. RESULTS Twenty-four articles matched the eligibility criteria. There were disparate methodologies and conflicting results, although they tended to indicate a decrease in blood-tumor barrier permeability, decreased tumoral perfusion, decreased tumoral diffusivity, and the possibility of decreased perfusion in contralateral normal-appearing brain tissue. CONCLUSION Treatment with dexamethasone may alter imaging parameters from cerebral perfusion studies used in the management of brain tumors. In adequately powered studies, it may be possible to assess the longer term effects of dexamethasone on normal brain tissue to help optimize use with longer term survivors that are emerging as improvements in glioma treatment are made.
Collapse
Affiliation(s)
- Christina Kotsarini
- Academic Unit of Radiology, University of Sheffield, and Royal Hallamshire Hospital, Sheffield, United Kingdom
| | | | | | | |
Collapse
|
24
|
Basak S, Brogan D, Dietrich H, Ritter R, Dacey RG, Biswas P. Transport characteristics of nanoparticle-based ferrofluids in a gel model of the brain. Int J Nanomedicine 2009; 4:9-26. [PMID: 19421367 PMCID: PMC2720738 DOI: 10.2147/ijn.s4114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A current advance in nanotechnology is the selective targeting of therapeutics by external magnetic field-guided delivery. This is an important area of research in medicine. The use of magnetic forces results in the formation of agglomerated structures in the field region. The transport characteristics of these agglomerated structures are explored. A nonintrusive method based on in situ light-scattering techniques is used to characterize the velocity of such particles in a magnetic field gradient. A transport model for the chain-like agglomerates is developed based on these experimental observations. The transport characteristics of magnetic nanoparticle drug carriers are then explored in gel-based simulated models of the brain. Results of such measurements demonstrate decreased diffusion of magnetic nanoparticles when placed in a high magnetic field gradient.
Collapse
Affiliation(s)
- Soubir Basak
- Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical, Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | | | | | | | | | | |
Collapse
|
25
|
Pronin IN, McManus KA, Holodny AI, Peck KK, Kornienko VN. Quantification of dispersion of Gd-DTPA from the initial area of enhancement into the peritumoral zone of edema in brain tumors. J Neurooncol 2009; 94:399-408. [PMID: 19330483 DOI: 10.1007/s11060-009-9872-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 03/16/2009] [Indexed: 11/26/2022]
Abstract
To evaluate Gd-DTPA contrast enhancement of brain tumors over time and to describe the dispersion of contrast into the zone of peritumoral edema. We performed MR imaging with a dose of 0.4 mmol Gd-DTPA/kg on eleven patients diagnosed with 5 different supratentorial tumors. MR imaging was done at five intervals between 5 min and 6 h. The change in zone of enhancement was measured for each time point, and a linear measurement was made of the furthest dispersion of contrast from the original volume of enhancement. An increase in the zone of enhancement over time was seen for all tumors; the average increase in volume of contrast was 14.76 +/- 3.35 cm(3) (mean +/- standard deviation). The largest changes in the zone of contrast enhancement, 18.6 +/- 4.63 cm(3), were seen in glioblastoma multiforme. The expansion of contrast enhancement assumed the morphology of the surrounding edema. The dispersion of Gd-DTPA over time into the zone of peritumoral edema is a potential source of error in clinical settings when there is a delay between Gd-DTPA injection and scanning.
Collapse
Affiliation(s)
- Igor N Pronin
- Department of Neuroradiology, Burdenko Institute of Neurosurgery, Moscow, Russia
| | | | | | | | | |
Collapse
|
26
|
Pan HC, Sun MH, Chen CCC, Chen CJ, Lee CH, Sheehan J. Neuroimaging and quality-of-life outcomes in patients with brain metastasis and peritumoral edema who undergo Gamma Knife surgery. J Neurosurg 2009; 109 Suppl:90-8. [PMID: 19123894 DOI: 10.3171/jns/2008/109/12/s15] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Gamma Knife surgery (GKS) has been shown to be effective for treating many patients with brain metastasis. Some brain metastases demonstrate significant peritumoral edema; radiation may induce cerebral edema or worsening preexisting edema. This study was conducted to evaluate the imaging and neurobehavioral outcomes in patients with preexisting peritumoral edema who then undergo GKS. METHODS Between August 2003 and January 2008, 63 cases of brain metastasis with significant peritumoral edema (> 20 cm(3)) were prospectively studied. The study inclusion criteria were as follows: 1) a single metastatic lesion with significant edema (perilesional edema signal volume on FLAIR > 20 cm(3)); and 2) inclusion of only 1 lesion > 20 cm(3) in the study (in cases of multiple lesions noted on FLAIR images). All patients received MR imaging with pulse sequences including T1-weighted imaging and FLAIR with or without contrast and T2-weighted imaging at an interval of 3 months. A neurological assessment and Brain Cancer Module (BCM-20) questionnaire were obtained every 2-3 months. Kaplan-Meier, Cox regression, and logistic regression were used for analysis of survival and associated factors. RESULTS At the time of GKS, the median Karnofsky Performance Scale (KPS) score was 70 (range 50-90), and the mean BCM-20 score was 45.5 +/- 6.1. The mean tumor volume (+/- standard deviation) was 5.2 +/- 4.6 cm(3) with corresponding T2-weighted imaging and FLAIR volumes of 59.25 +/- 37.3 and 62.1 +/- 38.8 cm(3), respectively (R(2) = 0.977, p < 0.001). The mean edema index (volume of peritumoral edema/tumor volume) was 17.5 +/- 14.5. The mean peripheral and maximum GKS doses were 17.4 +/- 2.3 and 35 +/- 4.7 Gy, respectively. The median survival was 11 months. The longer survival was related to KPS scores >or= 70 (p = 0.008), age < 65 years (p = 0.022), and a reduction of > 6 in BCM-20 score (p = 0.007), but survival was not related to preexisting edema or tumor volume. A reduction in BCM-20 score of > 6 was related to decreased volume in T1-weighted and FLAIR imaging (p < 0.001). Thirty-eight (79.2%) of 48 patients demonstrated decreased tumor volume and accompanied by decreased T2-weighted imaging and FLAIR volume. Eight (16.7%) of the 48 patients exhibited increased or stable tumor volume. A margin dose > 18 Gy was more likely to afford tumor reduction and resolution of peritumoral edema (p = 0.005 and p = 0.006, respectively). However, prior external-beam radiation therapy correlated with worsened preexisting peritumoral edema (p = 0.013) and longer maintenance of corticosteroids (p < 0.001). CONCLUSIONS Patients demonstrating a reduction in the BCM-20 score > 6, age < 65 years, and KPS score >or= 70 exhibited longer survival. Significant preexisting edema did not influence the tumor response or clinical outcome. The resolution of edema was related to better quality of life but not to longer survival.
Collapse
Affiliation(s)
- Hung-Chuan Pan
- Department of Neurosurgery, Taichung Veterans General Hospital, Taichung, Taiwan
| | | | | | | | | | | |
Collapse
|
27
|
Goldberg L, Ocherashvilli A, Daniels D, Last D, Cohen ZR, Tamar G, Kloog Y, Mardor Y. Salirasib (farnesyl thiosalicylic acid) for brain tumor treatment: a convection-enhanced drug delivery study in rats. Mol Cancer Ther 2008; 7:3609-16. [PMID: 19001442 DOI: 10.1158/1535-7163.mct-08-0488] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our aim was to assess the ability of convection-enhanced drug delivery (CED), a novel approach of direct delivery of drugs into brain tissue and brain tumors, to treat brain tumors using salirasib (farsnesyl thiosalicylic acid). CED was achieved by continuous infusion of drugs via intracranial catheters, thus enabling convective distribution of high drug concentrations over large volumes while avoiding systemic toxicity. Several phase II/III CED-based trials are currently in progress but have yet to overcome two major pitfalls of this methodology (the difficulty in attaining efficient CED and the significant nonspecific neurotoxicity caused by high drug doses in the brain). In this study, we addressed both issues by employing our previously described novel CED imaging and increased efficiency methodologies to exclusively target the activated form of the Ras oncogene in a 9L gliosarcoma rat model. The drug we used was salirasib, a highly specific Ras inhibitor shown to exert its suppressive effects on growth and migration of proliferating tumor cells in in vitro and in vivo models, including human glioblastoma, without affecting normal tissues. The results show a significant decrease in tumor growth rate in salirasib-treated rats relative to vehicle-treated rats as well as a significant correlation between CED efficacy and tumor growth rate with no observed toxicity despite drug concentrations an order of magnitude higher than previously detected in the brain. The results show that CED of salirasib is efficient and nontoxic for the treatment of glioblastoma in a rat model, thus suggesting that it may be considered for clinical application.
Collapse
Affiliation(s)
- Liat Goldberg
- Department of Neurobiochemistry, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Diffusion in the extracellular space (ECS) of the brain is constrained by the volume fraction and the tortuosity and a modified diffusion equation represents the transport behavior of many molecules in the brain. Deviations from the equation reveal loss of molecules across the blood-brain barrier, through cellular uptake, binding, or other mechanisms. Early diffusion measurements used radiolabeled sucrose and other tracers. Presently, the real-time iontophoresis (RTI) method is employed for small ions and the integrative optical imaging (IOI) method for fluorescent macromolecules, including dextrans or proteins. Theoretical models and simulations of the ECS have explored the influence of ECS geometry, effects of dead-space microdomains, extracellular matrix, and interaction of macromolecules with ECS channels. Extensive experimental studies with the RTI method employing the cation tetramethylammonium (TMA) in normal brain tissue show that the volume fraction of the ECS typically is approximately 20% and the tortuosity is approximately 1.6 (i.e., free diffusion coefficient of TMA is reduced by 2.6), although there are regional variations. These parameters change during development and aging. Diffusion properties have been characterized in several interventions, including brain stimulation, osmotic challenge, and knockout of extracellular matrix components. Measurements have also been made during ischemia, in models of Alzheimer's and Parkinson's diseases, and in human gliomas. Overall, these studies improve our conception of ECS structure and the roles of glia and extracellular matrix in modulating the ECS microenvironment. Knowledge of ECS diffusion properties is valuable in contexts ranging from understanding extrasynaptic volume transmission to the development of paradigms for drug delivery to the brain.
Collapse
Affiliation(s)
- Eva Syková
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | |
Collapse
|
29
|
Perlstein B, Ram Z, Daniels D, Ocherashvilli A, Roth Y, Margel S, Mardor Y. Convection-enhanced delivery of maghemite nanoparticles: Increased efficacy and MRI monitoring. Neuro Oncol 2008; 10:153-61. [PMID: 18316474 DOI: 10.1215/15228517-2008-002] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Convection-enhanced drug delivery (CED) is a novel approach to delivering drugs into brain tissue. Drugs are delivered continuously via a catheter, enabling large volume distributions of high drug concentrations with minimum systemic toxicity. Previously we demonstrated that CED formation/extent of small molecules may be significantly improved by increasing infusate viscosities. In this study we show that the same methodology can be applied to monodispersed maghemite nanoparticles (MNPs). For this purpose we used a normal rat brain model and performed CED of MNPs over short infusion times. By adding 3% sucrose or 3%-6% polyethylene glycol (PEG; molecular weight 400) to saline containing pristine MNPs, we increased infusate viscosity and obtained increased CED efficacy. Further, we show that CED of dextran-coated MNPs (dextran-MNPs) resulted in increased efficacy over pristine MNPs (p < 0.007). To establish the use of MRI for reliable depiction of MNP distribution, CED of fluorescent dextran-MNPs was performed, demonstrating a significant correlation between the distributions as depicted by MRI and spectroscopic images (r(2) = 0.74, p < 0.0002). MRI follow-up showed that approximately 80%-90% of the dextran-MNPs were cleared from the rat brain within 40 days of CED; the rest remained in the brain for more than 4 months. MNPs have been tested for applications such as targeted drug delivery and controlled drug release and are clinically used as a contrast agent for MRI. Thus, combining the CED method with the advantages of MNPs may provide a powerful tool to treat and monitor brain tumors.
Collapse
Affiliation(s)
- Benny Perlstein
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | | | | | | | | | | | | |
Collapse
|
30
|
Rite I, Machado A, Cano J, Venero JL. Intracerebral VEGF injection highly upregulates AQP4 mRNA and protein in the perivascular space and glia limitans externa. Neurochem Int 2008; 52:897-903. [DOI: 10.1016/j.neuint.2007.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 10/04/2007] [Accepted: 10/08/2007] [Indexed: 01/05/2023]
|
31
|
Abstract
Object
Brain edema resulting from traumatic brain injury (TBI) or ischemia if uncontrolled exhausts volume reserve and leads to raised intracranial pressure and brain herniation. The basic types of edema—vasogenic and cytotoxic—were classified 50 years ago, and their definitions remain intact.
Methods
In this paper the author provides a review of progress over the past several decades in understanding the pathophysiology of the edematous process and the success and failures of treatment. Recent progress focused on those manuscripts that were published within the past 5 years.
Results
Perhaps the most exciting new findings that speak to both the control of production and resolution of edema in both trauma and ischemia are the recent studies that have focused on the newly described “water channels” or aquaporins. Other important findings relate to the predominance of cellular edema in TBI.
Conclusions
Significant new findings have been made in understanding the pathophysiology of brain edema; however, less progress has been made in treatment. Aquaporin water channels offer hope for modulating and abating the devastating effects of fulminating brain edema in trauma and stroke.
Collapse
Affiliation(s)
- Anthony Marmarou
- Department of Neurosurgery, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298-0508, USA.
| |
Collapse
|
32
|
McGirt MJ, Woodworth G, Coon AL, Thomas G, Williams MA, Rigamonti D. Diagnosis, treatment, and analysis of long-term outcomes in idiopathic normal-pressure hydrocephalus. Neurosurgery 2006; 57:699-705; discussion 699-705. [PMID: 16239882 DOI: 10.1093/neurosurgery/57.4.699] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE The response to shunt surgery for idiopathic normal-pressure hydrocephalus (INPH) is variable because INPH is difficult to distinguish from other conditions causing the same symptoms. To date, no clinical picture or diagnostic test can distinguish INPH or predict response to cerebrospinal fluid (CSF) shunt surgery. We reviewed our 10-year experience with INPH to characterize long-term outcome and to identify independent predictors of outcome after shunt surgery. METHODS Patients were classified as having INPH only if they had: 1) ventriculomegaly, 2) two or more INPH clinical features, 3) no risk factor for secondary normal-pressure hydrocephalus, 4) A- or B-waves on CSF pressure monitoring, and 5) clinical improvement during a 3-day CSF drainage trial via a spinal catheter. Independent predictors of outcome were assessed via a multivariate proportional hazards regression analysis. RESULTS One hundred thirty-two patients underwent 179 shunt surgeries. Forty-four (33%), 79 (60%), and 99 (75%) patients demonstrated objective improvement 3, 6, and 24 months after shunt surgery, respectively. Gait improved first in 88 (93%) patients. Dementia and urinary incontinence were twofold less likely to improve. Radiological evidence of corpus callosum distension, gait impairment as the primary symptom, and shorter duration of INPH symptoms predicted improvement. Duration of symptoms and gait as the primary symptom were independent predictors by multivariate analysis. CONCLUSION INPH can be diagnosed accurately with CSF pressure monitoring and CSF drainage via a spinal catheter. CSF shunting is safe and effective for INPH with a long-term shunt response rate of 75%. Independent predictors of improvement are the presence of gait impairment as the dominant symptom and shorter duration of symptoms.
Collapse
Affiliation(s)
- Matthew J McGirt
- Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, Maryland 21287, USA
| | | | | | | | | | | |
Collapse
|
33
|
McGirt MJ, Woodworth G, Coon AL, Thomas G, Williams MA, Rigamonti D. Diagnosis, Treatment, and Analysis of Long-term Outcomes in Idiopathic Normal-Pressure Hydrocephalus. Neurosurgery 2005. [DOI: 10.1227/01.neu.0000175724.00147.10] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Matthew J. McGirt
- Department of Neurosurgery and The Adult Hydrocephalus Program, The Johns Hopkins Hospital, Baltimore, Maryland
| | - Graeme Woodworth
- The Adult Hydrocephalus Program, The Johns Hopkins Hospital, and The Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Alexander L. Coon
- Department of Neurosurgery and The Adult Hydrocephalus Program, The Johns Hopkins Hospital, Baltimore, Maryland
| | - George Thomas
- Department of Neurosurgery and The Adult Hydrocephalus Program, The Johns Hopkins Hospital, Baltimore, Maryland
| | - Michael A. Williams
- Department of Neurosurgery and The Adult Hydrocephalus Program, The Johns Hopkins Hospital, Baltimore, Maryland
| | - Daniele Rigamonti
- Department of Neurosurgery and The Adult Hydrocephalus Program, The Johns Hopkins Hospital, Baltimore, Maryland
| |
Collapse
|
34
|
Rothstein RP, Levison SW. Gray matter oligodendrocyte progenitors and neurons die caspase-3 mediated deaths subsequent to mild perinatal hypoxic/ischemic insults. Dev Neurosci 2005; 27:149-59. [PMID: 16046849 PMCID: PMC1351040 DOI: 10.1159/000085987] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2004] [Accepted: 03/09/2005] [Indexed: 11/19/2022] Open
Abstract
With significant improvements in neonatal care, fewer infants sustain severe injury as a consequence of hypoxia/ischemia (H/I). However, the majority of experimental studies have inflicted moderate to severe injuries, or they have assessed damage to the caudal forebrain; therefore, to better understand how a mild H/I episode affects the structures and cells of the rostral forebrain, we assessed the relative vulnerabilities of cells in the neocortex, striatum, corpus callosum, choroid plexus and subventricular zone (SVZ). To inflict mild H/I injury, the right common carotid artery was ligated followed by 1 h of hypoxia (8% O(2)) at 37 degrees C. Regional vulnerabilities were assessed using TUNEL, active caspase-3 and hematoxylin and eosin staining at 24 and 48 h of recovery. Scattered columns of cell death were observed in the neocortex with deep-layer neurons more vulnerable than more superficial neurons. The majority of these dying neurons appeared to be dying apoptotic rather than necrotic deaths. In addition, approximately 1/3 of the apoptotic cells in the neocortex were O4+ oligodendrocyte progenitors. We also observed a decrease in NG2 staining within the affected regions of the forebrain. By contrast, active caspase-3+/S-100beta+ astrocytes were not observed. Neurons and O4+ oligodendrocyte progenitors also died apoptotic deaths within the striatum. The lining cells of the choroid plexus also sustained damage. Elevated numbers of apoptotic cells were observed in the most lateral region of the SVZ and some of these dying cells were O4+. The most novel finding of this study, that oligodendrocyte progenitors in the gray matter are damaged and eliminated as a consequence of perinatal H/I, provides new insights into the histopathology and neurological deficits observed in infants who sustain mild H/I brain injuries.
Collapse
Affiliation(s)
- Raymond P Rothstein
- Department of Neurology and Neuroscience, Laboratory for Regenerative Neurobiology, UMDNJ-New Jersey Medical School, Newark, NJ, USA
| | | |
Collapse
|
35
|
Mardor Y, Rahav O, Zauberman Y, Lidar Z, Ocherashvilli A, Daniels D, Roth Y, Maier SE, Orenstein A, Ram Z. Convection-Enhanced Drug Delivery: Increased Efficacy and Magnetic Resonance Image Monitoring. Cancer Res 2005; 65:6858-63. [PMID: 16061669 DOI: 10.1158/0008-5472.can-05-0161] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Convection-enhanced drug delivery (CED) is a novel approach to directly deliver drugs into brain tissue and brain tumors. It is based on delivering a continuous infusion of drugs via intracranial catheters, enabling convective distribution of high drug concentrations over large volumes of the target tissue while avoiding systemic toxicity. Efficient formation of convection depends on various physical and physiologic variables. Previous convection-based clinical trials showed significant diversity in the extent of convection among patients and drugs. Monitoring convection has proven to be an essential, yet difficult task. The current study describes the application of magnetic resonance imaging for immediate assessment of convection efficiency and early assessment of cytotoxic tissue response in a rat brain model. Immediate assessment of infusate distribution was obtained by mixing Gd-diethylenetriaminepentaacetic acid in the infusate prior to infusion. Early assessment of cytotoxic tissue response was obtained by subsequent diffusion-weighted magnetic resonance imaging. In addition, the latter imaging methodologies were used to establish the correlation between CED extent and infusate's viscosity. It was found that low-viscosity infusates tend to backflow along the catheter track, whereas high-viscosity infusates tend to form efficient convection. These results suggest that CED formation and extent may be significantly improved by increasing the infusate's viscosities, thus increasing treatment effects.
Collapse
Affiliation(s)
- Yael Mardor
- Advanced Technology Center, Neurosurgery Department, Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Ramat Gan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Abbott NJ. Evidence for bulk flow of brain interstitial fluid: significance for physiology and pathology. Neurochem Int 2004; 45:545-52. [PMID: 15186921 DOI: 10.1016/j.neuint.2003.11.006] [Citation(s) in RCA: 517] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Accepted: 11/12/2003] [Indexed: 11/24/2022]
Abstract
This review surveys evidence for the flow of brain interstitial fluid (ISF) via preferential pathways through the brain, and its relation to cerebrospinal fluid (CSF). Studies over >100 years have raised several controversial points, not all of them resolved. Recent studies have usefully combined a histological and a mathematical approach. Taken together the evidence indicates an ISF bulk flow rate of 0.1-0.3 microl min(-1) g(-1) in rat brain along preferential pathways especially perivascular spaces and axon tracts. The main source of this fluid is likely to be the brain capillary endothelium, which has the necessary ion transporters, channels and water permeability to generate fluid at a low rate, c1/100th of the rate per square centimeter of CSF secretion across choroid plexus epithelium. There is also evidence that a proportion of CSF may recycle from the subarachnoid space into arterial perivascular spaces on the ventral surface of the brain, and join the circulating ISF, draining back via venous perivascular spaces and axon tracts into CSF compartments, and out both through arachnoid granulations and along cranial nerves to the lymphatics of the neck. The bulk flow of ISF has implications for non-synaptic cell:cell communication (volume transmission); for drug delivery, distribution, and clearance; for brain ionic homeostasis and its disturbance in brain edema; for the immune function of the brain; for the clearance of beta-amyloid deposits; and for the migration of cells (malignant cells, stem cells).
Collapse
Affiliation(s)
- N Joan Abbott
- Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
| |
Collapse
|
37
|
Lidar Z, Mardor Y, Jonas T, Pfeffer R, Faibel M, Nass D, Hadani M, Ram Z. Convection-enhanced delivery of paclitaxel for the treatment of recurrent malignant glioma: a Phase I/II clinical study. J Neurosurg 2004; 100:472-9. [PMID: 15035283 DOI: 10.3171/jns.2004.100.3.0472] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. A minority of patients with recurrent glioblastomas multiforme (GBMs) responds to systemic chemotherapy. The authors investigated the safety and efficacy of intratumoral convection-enhanced delivery (CED) of paclitaxel in patients harboring histologically confirmed recurrent GBMs and anaplastic astrocytomas.
Methods. Fifteen patients received a total of 20 cycles of intratumoral CED of paclitaxel. The patients were observed daily by performing diffusion-weighted (DW) magnetic resonance (MR) imaging to assess the convective process and routine diagnostic MR imaging to identify the tumor response. Effective convection was determined by the progression of the hyperintense signal within the tumor on DW MR images, which corresponded to a subsequent lytic tumor response displayed on conventional MR images. Of the 15 patients, five complete responses and six partial responses were observed, giving a response rate of 73%. The antitumor effect was confirmed by one biopsy and three en bloc resections of tumors, which showed a complete response, and by one tumor resection, which demonstrated a partial response. Lack of convection and a poor tumor response was associated with leakage of the convected drug into the subarachnoid space, ventricles, and cavities formed by previous resections, and was seen in tumors containing widespread necrosis. Complications included transient chemical meningitis in six patients, infectious complications in three patients, and transient neurological deterioration in four patients (presumably due to increased peritumoral edema).
Conclusions. On the basis of our data we suggest that CED of paclitaxel in patients with recurrent malignant gliomas is associated with a high antitumor response rate, although it is associated with a significant incidence of treatment-associated complications. Diffusion-weighted MR images may be used to predict a response by demonstrating the extent of convection during treatment. Optimization of this therapeutic approach to enhance its efficacy and reduce its toxicity should be explored further.
Collapse
Affiliation(s)
- Zvi Lidar
- Department of Neurosurgery, Advanced Technology Center, The Chaim Sheba Medical Center, Tel Hashomer, Israel
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
Insulin-like growth factor-1 (IGF-1) is a naturally occurring neurotrophic factor that plays an important role in promoting cell proliferation and differentiation during normal brain development and maturation. The present review examines recent evidence that endogenous IGF-1 also plays a significant role in recovery from insults such as hypoxia-ischemia and that giving additional exogenous IGF-1 can actively ameliorate damage. It is now well established that neurons and other cell types die many hours or even days after initial injury due to activation of programmed cell death pathways. IGF-1 and its binding proteins and receptors are intensely induced within damaged brain regions following brain injury, suggesting a possible a role for IGF-1 in brain recovery. Exogenous administration of IGF-1 within a few hours after brain injury is now known to be protective in both gray and white matter and leads to improved somatic function. In contrast, pre-treatment is ineffective, likely reflecting limited intracerebral penetration of IGF-1 into the uninjured brain. The neuroprotective effects of IGF-1 are mediated by IGF-1 receptors and its binding proteins and are specific to particular cellular phenotypes and brain regions. The window of opportunity for treatment with IGF-1 is limited to a few hours after normothermic brain injury, reflecting its specific actions on early, intracellular events in the apoptotic cascade. However, injury-associated mild post-hypoxic hypothermia, which delays the development of cell death, can shift and dramatically extend the window of opportunity for delayed treatment with IGF-1. Such a combined approach is likely to be essential for any clinical treatment.
Collapse
Affiliation(s)
- J Guan
- Faculty of Medicine and Health Sciences, The Liggins Institute, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | | | | | | |
Collapse
|
39
|
Ter Minassian A. [Treatment of cerebral oedema]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2003; 22:336-48. [PMID: 12818327 DOI: 10.1016/s0750-7658(03)00056-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Progress in brain imaging, monitoring and physiopathology allows the identification of brain oedema from brain swelling, determination of its interstitial or intracellular nature, as well as blood-brain barrier permeability and the evaluation of the impact on cerebral haemodynamic. Common treatment of all types of cerebral oedema is based on prevention of self-sustained disorders due to increased intracranial pressure resulting in ischemic cerebral oedema. The specific treatment of each type of cerebral oedema is reviewed. Optimization of conventional anti-oedematous strategies is based on the precise determination of the nature of the cerebral oedema and of the blood-brain barrier status.
Collapse
Affiliation(s)
- A Ter Minassian
- Département d'anesthésie-réanimation, CHU d'Angers, 4, rue Larrey, 49033 cedex, Angers, France
| |
Collapse
|
40
|
Abstract
A number of mechanisms seem to be involved in edema formation after an ICH. At least three phases of edema are involved in ICH. These include a very early phase (first several hours) involving hydrostatic pressure and clot retraction, a second phase (first 2 days) involving the activation of the coagulation cascade and thrombin production, and a third phase (after 3 days) involving RBC lysis and hemoglobin-induced neuronal toxicity. Activation of the complement system in brain parenchyma also plays an important role in the second and third phases. There are potential therapeutic strategies to address each of these mechanisms. Because the adverse effect of an ICH seems to result from a toxic effect of blood components on brain tissue, early clot removal may be the best strategy, because it results in the removal of all the toxic components [93]. Hematoma aspiration after tissue plasminogen activator (tPA) infusion has also been shown to be relatively safe and effective in animal models. Kaufman et al [94] reported that tPA lysed the hematoma in minutes and did not cause inflammation or bleeding in rabbits. Because clots lysed with tPA can be aspirated through a needle or catheter, mechanical brain injury by this method is minimized. In a rat model, aspiration of clot with tPA reduced clot volume and brain injury [95,96]. Recently, Wagner et al [97] infused tPA into hematomas in a porcine model at 3 hours after induction and aspirated the liquified clots 1 hour later. Clot removal after tPA treatment resulted in a 72% reduction in hematoma volume compared with untreated controls. Clot removal also reduced brain edema volume and BBB disruption and improved cerebral tissue pressure [93]. Six randomized trials have been accomplished, but surgical evacuation of the clot remains controversial [98-103]. Recently, thrombolysis and aspiration under CT guidance reduced the hematoma volume effectively [104]. Infusion of tPA directly into the hematoma before clot aspiration has also been used in human beings. Up to 90% of the original hematoma volume can be removed [105, 106]. Schaller et al [107] injected tPA directly into a hematoma 72 hours after the ictus in patients. The hematomas were lysed, and the liquified clots were drained in 14 patients. Two patients died, but none had recurrent hemorrhage. In conclusion, much has been learned about the basic mechanisms involved in edema formation after ICH. Animal models indicate that a number of components of blood are capable of inducing brain injury and brain edema. Now, it is time to translate that basic information into clinical trials.
Collapse
Affiliation(s)
- Guohua Xi
- Department of Neurosurgery, University of Michigan, MC, TC 2128, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0338, USA
| | | | | |
Collapse
|
41
|
Abstract
OBJECT Convection-enhanced delivery (CED) can be used safely to achieve high local infusate concentrations within the brain and spinal cord. The use of CED in the brainstem has not been previously reported and may offer an alternative method for treating diffuse pontine gliomas. In the present study the authors tested CED within the rat brainstem to assess its safety and establish distribution parameters. METHODS Eighteen rats underwent stereotactic cannula placement into the pontine nucleus oralis without subsequent infusions. Twenty rats underwent stereotactic cannula placement followed by infusion of fluorescein isothiocyanate (FITC)-dextran at a constant rate (0.1 microl/minute) until various total volumes of infusion (V(i)s) were reached: 0.5, 1, 2, and 4 microl. Additional rats underwent FITC-dextran infusion (V, 4 microl) and were observed for 48 hours (five animals) or 14 days (five animals). Serial (20-microm thick) brain sections were imaged using confocal microscopy with ultraviolet illumination, and the volume of distribution (Vd) was calculated using computer image analysis. Histological analysis was performed on adjacent sections. No animal exhibited a postoperative neurological deficit, and there was no histological evidence of tissue disruption. The Vd increased linearly (range 15.4-55.8 mm3) along with increasing Vi, with statistically significant correlations for all groups that were compared (p < 0.022). The Va/Vi ratio ranged from 14 to 30.9. The maximum cross-sectional area of fluorescence (range 9.8-20.9 mm2) and the craniocaudal extent of fluorescence (range 2.8-5.1 mm) increased with increasing Vi. CONCLUSIONS Convection-enhanced delivery can be safely applied to the rat brainstem with substantial and predictable V(d)s. This study provides the basis for investigating delivery of various candidate agents for the treatment of diffuse pontine gliomas.
Collapse
Affiliation(s)
- David I Sandberg
- Department of Neurosurgery, Weill Medical College of Cornell University, New York, NY, USA
| | | | | |
Collapse
|
42
|
Holtmannspötter M, Schoch A, Baethmann A, Reulen HJ, Uhl E. Intracranial hypertension influences the resolution of vasogenic brain edema following intracerebral hemorrhage. ACTA NEUROCHIRURGICA. SUPPLEMENT 2001; 76:497-9. [PMID: 11450077 DOI: 10.1007/978-3-7091-6346-7_104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Aim of the current study was to investigate the influence of intracranial hypertension on the resolution of vasogenic brain edema following intracerebral hemorrhage. An intracerebral hematoma was induced by 500 microliters of blood injected into the left frontal lobe of rabbits (n = 25). Na(+)-fluorescein (MW376) and Texas-Red-albumin (MW67.000) were administered intravenously as edema markers. By using a closed cranial window for superfusion of the brain surface and a ventriculo-cisternal perfusion the clearance of both fluorescence markers was measured in the CSF-effluates up to 8 hours using spectrophotometry. ICP was adjusted between 2-6 mmHg (low pressure, n = 10), 8-12 mmHg (moderate pressure, n = 10) or 14-20 mmHg (high pressure, n = 5). In all groups Na(+)-fluorescein started to accumulate at 60 min after induction of the hematoma in the subarachnoid space, while at 90 min in the ventricular system. In the low intracranial pressure group Na(+)-fluorescein (mean +/- SEM) in the ventricular system amounted to 1.47 +/- 0.42 nmol as compared to 1.34 +/- 0.41 nmol in the moderate, or 0.38 +/- 0.11 nmol in the high intracranial pressure group. In the subarachnoid space the marker reached 1.96 +/- 0.57 nmol, 4.15 +/- 1.28 nmol, or 0.96 +/- 0.32 nmol, respectively. In conclusion, the data demonstrate that vasogenic edema induced by an intracerebral hematoma is cleared into both CSF compartments, albeit with delay into the ventricular system. Edema resorption occurred earlier and to a higher extent into the subarachnoid space as compared to the ventricular system. Further, edema resorption is influenced by the actual intracranial pressure, with marked inhibition by a high intracranial pressure.
Collapse
Affiliation(s)
- M Holtmannspötter
- Department of Neurosurgery, Klinikum Grosshadern, University of Munich, Germany
| | | | | | | | | |
Collapse
|
43
|
Haar PJ, Stewart JE, Gillies GT, Prabhu SS, Broaddus WC. Quantitative three-dimensional analysis and diffusion modeling of oligonucleotide concentrations after direct intraparenchymal brain infusion. IEEE Trans Biomed Eng 2001; 48:560-9. [PMID: 11341530 DOI: 10.1109/10.918595] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We compared quantitative experimental results on the diffusion of 35S-labeled phosphorothioate oligonucleotide (PS-ODN) after intraparenchymal infusion in rat brain, with the distributions predicted by Fick's second law of diffusion. Fischer 344 rats underwent identical intracerebral infusions of 36S-PS-ODN. After 0, 5, 11, 23, and 47 h, groups of animals were sacrificed and sequential brain cryosections subjected to autoradiography. The resulting experimental data were compared to the predicted distributions, for estimation of the apparent free diffusion coefficient, D*. Volumes of distribution and total content of 36 S-PS-ODN in the parenchyma were also computed, to monitor loss of total material. The values for D* were within the expected range for the 21-mer PS-ODN used, but a progressive decrease in D* over time was noted. The model requires D* to remain constant and, thus, does not adequately explain the spread of 35S-PS-ODN following infusion. The progressive slowing of spread over time suggests that at later time points, 35S-PS-ODN may be fixed by tissue binding or cellular uptake in the brain. Loss of material via vascular and CSF clearance may also contribute to the lack of fit. Our results highlight issues to be addressed in the modeling and experimental design of the intraparenchymal infusion process.
Collapse
Affiliation(s)
- P J Haar
- Division of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, West Hospital, Richmond 23298, USA
| | | | | | | | | |
Collapse
|
44
|
Bruce JN, Falavigna A, Johnson JP, Hall JS, Birch BD, Yoon JT, Wu EX, Fine RL, Parsa AT. Intracerebral clysis in a rat glioma model. Neurosurgery 2000; 46:683-91. [PMID: 10719865 DOI: 10.1097/00006123-200003000-00031] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE Intracerebral clysis (ICC) is a new term we use to describe convection-enhanced microinfusion into the brain. This study establishes baseline parameters for preclinical, in vivo, drug investigations using ICC in a rat glioma model. METHODS Intracranial pressure was measured, with an intraparenchymal fiber-optic catheter, in male Fischer rats 10, 15, 20, and 25 days after implantation of C6 glioma cells in the right frontal lobe (n = 80) and in control rats without tumor (n = 20), before and during ICC. A 25% albumin solution (100 microl) was infused through an intratumoral catheter at 0.5, 1.0, 2.0, 3.0, and 4.0 microl/min. Infusate distribution was assessed by infusion of fluorescein isothiocyanate-dextran (Mr 20,000), using the aforementioned parameters (n = 36). Brains were sectioned and photographed under ultraviolet light, and distribution was calculated by computer analysis (NIH Image for Macintosh). Safe effective drug distribution was demonstrated by measuring tumor sizes and apoptosis in animals treated with N,N'-bis(2-chloroethyl)-N-nitrosourea via ICC, compared with untreated controls. Magnetic resonance imaging noninvasively confirmed tumor growth before treatment. RESULTS Intracranial pressure increased with tumor progression, from 5.5 mm Hg at baseline to 12.95 mm Hg on Day 25 after tumor cell implantation. Intracranial pressure during ICC ranged from 5 to 21 mm Hg and was correlated with increasing infusion volumes and increasing rates of infusion. No toxicity was observed, except at the higher ends of the tumor size and volume ranges. Fluorescein isothiocyanate-dextran distribution was greater with larger infusion volumes (30 microl versus 10 microl, n = 8, P < 0.05). No significant differences in distribution were observed when different infusion rates were compared while the volume was kept constant. At tolerated flow rates, the volumes of distribution were sufficient to promote adequate drug delivery to tumors. N,N'-Bis(2-chloroethyl)-N-nitrosourea treatment resulted in significant decreases in tumor size, compared with untreated controls. CONCLUSION The C6 glioma model can be easily modified to study aspects of interstitial delivery via ICC and the application of ICC to the screening of potential antitumor agents for safety and efficacy.
Collapse
Affiliation(s)
- J N Bruce
- Department of Neurological Surgery, Neurological Institute of New York, New York 10032, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Yoshioka H, Inagawa T, Tokuda Y, Inokuchi F. Chronic hydrocephalus in elderly patients following subarachnoid hemorrhage. SURGICAL NEUROLOGY 2000; 53:119-24; discussion 124-5. [PMID: 10713188 DOI: 10.1016/s0090-3019(99)00185-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND With the aging of the population, surgery for ruptured intracranial aneurysms is increasing among the elderly. We sought to clarify the characteristics of chronic hydrocephalus following aneurysmal subarachnoid hemorrhage (SAH) in elderly patients. METHODS Of the 576 surgically treated patients, 289 were aged 59 years or younger, 169 were 60 to 69, and 118 were 70 years or older. The relationship between chronic hydrocephalus and the causative factors was analyzed for each age group. RESULTS Of the 576 patients, chronic hydrocephalus was observed in 215 (37%), with the incidence increasing significantly with age (p < 0.001) and being the highest in the oldest age group. In elderly patients, the incidence of chronic hydrocephalus was relatively high, even after mild SAH. The incidence of chronic hydrocephalus was high regardless of age in patients with severe SAH, such as in those with H&H grades III-IV, SAH grades III-IV, acute hydrocephalus, symptomatic vasospasm, and intraventricular hemorrhage, and in those with vertebro-basilar artery aneurysms. CONCLUSION In the elderly, the incidence of chronic hydrocephalus following SAH was significantly higher than in younger patients, even after mild SAH. In elderly patients, careful observation and individualized treatment are necessary even if SAH is mild.
Collapse
Affiliation(s)
- H Yoshioka
- Department of Neurosurgery, Shimane Prefectural Central Hospital, Izumo, Japan
| | | | | | | |
Collapse
|
46
|
Andersen C. The effect of glucocorticoids in the normal cerebral hemisphere of brain tumour patients. Acta Neurol Scand 1998; 98:433-8. [PMID: 9875623 DOI: 10.1111/j.1600-0404.1998.tb07326.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To study the potential effects of glucocorticoids (GC) in normal white matter (WM) of the contralateral cerebral hemisphere in brain tumour patients in a prospective protocol. MATERIALS AND METHODS Using MR relaxation time (RT) imaging (T1 and T2-maps), 190 different scanning sessions were performed on 42 brain tumour patients before and after initiation of GC-treatment. RT imaging correlates closely with in vivo tissue water content (reported estimation accuracy error <4%). Repetitive studies were performed in order to study changes as a function of time. RTs were measured in the contralateral frontal and occipital white matter (WM). RESULTS The mean change in T1 after initiation of GC treatment was 1.6+/-1.7% (P = 0.24), and 1.8+/-3.8% in T2. The mean coefficient of variation for the pooled data in all patients was 1.4% for both T1 and T2. There were no differences in effect between different histological types of tumours or sex. CONCLUSION GC treatment does not influence in vivo cerebral water content expressed as relaxation times of apparently normal WM. The neurological effects in brain tumour patients are normally evident within 24 h, but do not seem to correlate with changes in brain water content. The normal biological variation in RTs (and thereby in vivo tissue water content) in normal WM of brain tumour patients is very small and approaches the expected fluctuations in the MRI measurement technique.
Collapse
Affiliation(s)
- C Andersen
- Dept of Neurosurgery, Aarhus University Hospital, MR-Centre, Denmark
| |
Collapse
|
47
|
Wrba E, Nehring V, Baethmann A, Reulen HJ, Uhl E. Resolution of experimental vasogenic brain edema at different intracranial pressures. ACTA NEUROCHIRURGICA. SUPPLEMENT 1998; 71:313-5. [PMID: 9779217 DOI: 10.1007/978-3-7091-6475-4_91] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Resolution of vasogenic brain edema was examined using the infusion edema model in rabbits. Texas Red-albumin (MW 66,000 D) and sodium fluorescein (MW 376 D) dissolved in artificial cerebrospinal fluid (aCSF) were infused into the white matter of the left frontal lobe of the brain. To quantify the edema fluid cleared by the ventricular system, ventriculo-cisternal perfusion was performed with aCSF. A closed cranial window, implanted above the left parietal brain, served for studying resolution of the artificial edema fluid via the subarachnoid space. CSF-samples were collected in 30 minutes-intervals and analysed with a spectrophotometer. Clearance of edema fluid was examined under low (2-5 mm Hg), medium (9-12 mm Hg), or high (14-17 mm Hg) intracranial pressures (ICP). In the low pressure-group, both edema fluid markers were found in the ventriculo-cisternal and subarachnoid perfusate at 60 and 90 min, in the group with moderately increased ICP at 90 and 120 min, respectively. In the high ICP-group both fluorescence dyes appeared not less than 90 min in the ventricular system, while no increase at all could be found in the subarachnoid space. Our results imply that resolution of edema fluid via both the ventricular system and the subarachnoid space depends on the actual ICP level.
Collapse
Affiliation(s)
- E Wrba
- Department of Neurosurgery, Grosshadern University Hospital, University of Munich, Federal Republic of Germany
| | | | | | | | | |
Collapse
|
48
|
Pleines UE, Stover JF, Kossmann T, Trentz O, Morganti-Kossmann MC. Soluble ICAM-1 in CSF coincides with the extent of cerebral damage in patients with severe traumatic brain injury. J Neurotrauma 1998; 15:399-409. [PMID: 9624625 DOI: 10.1089/neu.1998.15.399] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The intercellular adhesion molecule-1 (ICAM-1) expressed by endothelial cells is crucial in promoting adhesion and transmigration of circulating leukocytes across the blood-brain barrier (BBB). Migrated immunocompetent cells, in turn, release mediators that stimulate glial and endothelial cells to express ICAM-1 and release cytokines, possibly sustaining cerebral damage. Following activation, proteolytic cleavage of membrane-anchored ICAM-1 results in measurable levels of a soluble form, sICAM-1. The aims of this study were to investigate the changes of sICAM-1 levels in ventricular CSF and serum and to elucidate the influence of structural brain damage as estimated by computerized tomography (CT) as well as the extent of BBB dysfunction as calculated by the CSF/serum albumin ratio (QA) in patients with severe traumatic brain injury (TBI). All investigated parameters revealed two subgroups. Patients belonging to group A had sICAM-1 levels in CSF above normal range, presented marked cerebral damage and a disturbance of the BBB (range 0.6-24.7 ng/ml, n = 8). In contrast, patients belonging to group B had no elevation of sICAM-1 values in CSF (range 0.3-3.9 ng/ml, n = 5; p < 0.017) and showed minor cerebral damage with an intact BBB in most cases. In addition, overall analysis showed that sICAM-1 in CSF correlated with the extent of BBB damage as indicated by the QA (r = 0.76; p < 0.001). These results suggest that increased sICAM-1 levels in CSF might depict ongoing immunologic activation and that sICAM-1 correlates with the extent of tissue and BBB damage. The origin of soluble ICAM-1 in CSF and its pathophysiologic role after TBI remains to be clarified.
Collapse
Affiliation(s)
- U E Pleines
- Division of Research, University Hospital Zuerich, Switzerland
| | | | | | | | | |
Collapse
|
49
|
Wrba E, Nehring V, Chang RC, Baethmann A, Reulen HJ, Uhl E. Quantitative analysis of brain edema resolution into the cerebral ventricles and subarachnoid space. ACTA NEUROCHIRURGICA. SUPPLEMENT 1998; 70:288-90. [PMID: 9416349 DOI: 10.1007/978-3-7091-6837-0_89] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Resolution of vasogenic brain edema was examined using a model of infusion of fluid into the brain of rabbits. For this purpose infusion of Texas Red-albumin (MW 67.000 D) and sodium fluorescein (MW 376 D) dissolved in artificial cerebrospinal fluid (mock CSF) was made into the white matter of the left frontal lobe of the brain. In order to quantify the portion of edema fluid which was cleared by the ventricular system, a ventriculo-cisternal perfusion was performed with mock CSF. A closed cranial window was implanted above the left parietal brain for superfusion of the cerebral cortex with mock CSF, in order to study resolution of the artificial edema fluid via the subarachnoid space. CSF-samples were collected in 30 minutes-intervals and analysed with a spectrophotometer. The clearance of edema fluid was examined under low (2-5 mmHg) and medium (9-12 mmHg) intracranial pressure (ICP). In the low-pressure group both edema fluid markers were found in the ventriculo-cisternal and subarachnoid perfusate at 60 min and 90 min, respectively, after start of infusion. In the group with moderately increased ICP the markers appeared at 90 min and 120 min, respectively. The amount of clearance of fluorescent dye via the subarachnoid space was the same in both groups and independent of the intracranial pressure.
Collapse
Affiliation(s)
- E Wrba
- Department of Neurosurgery, Grosshadern University Hospital, University of Munich, Federal Republic of Germany
| | | | | | | | | | | |
Collapse
|
50
|
Paczynski RP, He YY, Diringer MN, Hsu CY. Multiple-dose mannitol reduces brain water content in a rat model of cortical infarction. Stroke 1997; 28:1437-43; discussion 1444. [PMID: 9227697 DOI: 10.1161/01.str.28.7.1437] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND PURPOSE Repeated use of mannitol in the setting of ischemic infarction is a controversial and poorly defined therapeutic intervention. The purpose of this study was to examine the effects of repeated mannitol infusions on brain water content and tissue pressure in a well-defined rat model of focal ischemic stroke. METHODS Mannitol infusions (0.5, 1.5, or 2.5 g/kg) were given by intravenous bolus 4 or 24 hours after 90-minute transient cortical ischemia in the territory of the right middle cerebral artery in rats and every 4 hours thereafter for a total of 24 hours. Fluid replacement was limited to 0.5 mL i.v. isotonic saline administered immediately after each mannitol dose. Control rats received 0.5 mL i.v. saline at the same intervals and were otherwise under ad libitum conditions. Water contents (percent H2O) of whole hemispheres and of cortical biopsies were measured with the wet-dry method, and blood samples were analyzed for plasma osmolality and chemistries. In a subgroup of rats, tissue pressure was also measured within the hemisphere ipsilateral to the infarct. RESULTS Repeated mannitol infusions resulted in a dose-dependent increase in plasma osmolality and a dose-dependent decrease in the percent H2O of the ischemic middle cerebral artery cortex and ipsilateral hemisphere. In contrast, percent H2O of the contralateral cortex and hemisphere was significantly decreased only in the groups given the highest dose of mannitol (2.5 g/kg). Mannitol infusions at a dose of 1.5 g/kg begun 24 hours after reperfusion were also associated with a significant reduction of tissue pressure. CONCLUSIONS In a rat model of ischemic cortical infarction, repeated mannitol infusions resulted primarily in a decrease in the percent H2O of the infarct and ipsilateral hemisphere, as well as decreased tissue pressure.
Collapse
Affiliation(s)
- R P Paczynski
- Department of Neurology, Washington University Medical Center, St Louis, Mo. 63110, USA
| | | | | | | |
Collapse
|