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Gholampour S, Frim D, Yamini B. Long-term recovery behavior of brain tissue in hydrocephalus patients after shunting. Commun Biol 2022; 5:1198. [PMID: 36344582 PMCID: PMC9640582 DOI: 10.1038/s42003-022-04128-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/18/2022] [Indexed: 11/11/2022] Open
Abstract
The unpredictable complexities in hydrocephalus shunt outcomes may be related to the recovery behavior of brain tissue after shunting. The simulated cerebrospinal fluid (CSF) velocity and intracranial pressure (ICP) over 15 months after shunting were validated by experimental data. The mean strain and creep of the brain had notable changes after shunting and their trends were monotonic. The highest stiffness of the hydrocephalic brain was in the first consolidation phase (between pre-shunting to 1 month after shunting). The viscous component overcame and damped the input load in the third consolidation phase (after the fifteenth month) and changes in brain volume were stopped. The long-intracranial elastance (long-IE) changed oscillatory after shunting and there was not a linear relationship between long-IE and ICP. We showed the long-term effect of the viscous component on brain recovery behavior of hydrocephalic brain. The results shed light on the brain recovery mechanism after shunting and the mechanisms for shunt failure.
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Affiliation(s)
| | - David Frim
- Department of Neurological Surgery, University of Chicago, Chicago, IL, USA
| | - Bakhtiar Yamini
- Department of Neurological Surgery, University of Chicago, Chicago, IL, USA.
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Hagen SM, Eftekhari S, Hamann S, Juhler M, Jensen RH. Intracranial pressure and optic disc changes in a rat model of obstructive hydrocephalus. BMC Neurosci 2022; 23:29. [PMID: 35606718 PMCID: PMC9128145 DOI: 10.1186/s12868-022-00716-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 05/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The kaolin induced obstructive hydrocephalus (OHC) model is well known for its ability to increase intracranial pressure (ICP) in experimental animals. Papilledema (PE) which is a predominant hallmark of elevated ICP in the clinic has not yet been studied in this model using high-resolution digital fundus microscopy. Further, the long-term effect on ICP and optic nerve head changes have not been fully demonstrated. In this study we aimed to monitor epidural ICP after induction of OHC and to examine changes in the optic disc. In addition, we validated epidural ICP to intraventricular ICP in this disease model. METHOD Thirteen male Sprague-Dawley rats received an injection into the cisterna magna containing either kaolin-Ringer's lactate suspension (n = 8) or an equal amount of Ringer's lactate solution (n = 5). Epidural ICP was recorded post-operatively, and then continuously overnight and followed up after 1 week. The final epidural ICP value after 1 week was confirmed with simultaneous ventricular ICP measurement. Optic disc photos (ODP) were obtained preoperatively at baseline and after one week and were assessed for papilledema. RESULTS All animals injected with kaolin developed OHC and had significant higher epidural ICP (15.49 ± 2.47 mmHg) compared to control animals (5.81 ± 1.33 mmHg) on day 1 (p < 0.0001). After 1 week, the epidural ICP values were subsided to normal range in hydrocephalus animals and there was no significant difference in epidural ICP between the groups. Epidural ICP after 1 week correlated with the ventricular ICP with a Pearson's r = 0.89 (p < 0.0001). ODPs from both groups showed no signs of acute papilledema, but 5 out of 8 (62.5%) of the hydrocephalus animals were identified with peripapillary changes. CONCLUSIONS We demonstrated that the raised ICP at day 1 in the hydrocephalus animals was completely normalized within 1 week and that epidural ICP measurements are valid method in this model. No acute papilledema was identified in the hydrocephalus animals, but the peripapillary changes indicate a potential gliosis formation or an early state of a growing papilledema in the context of lateral ventricle dilation and increased ICP.
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Affiliation(s)
- Snorre Malm Hagen
- Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark.
| | - Sajedeh Eftekhari
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark.
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet, University of Copenhagen, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.
| | - Marianne Juhler
- Department of Neurosurgery, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100, Copenhagen Ø, Denmark.
| | - Rigmor H Jensen
- Danish Headache Center, Department of Neurology, Glostrup Research Institute, Rigshospitalet, University of Copenhagen, Nordstjernevej 42, 2600, Glostrup, Denmark.
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MR Elastography demonstrates reduced white matter shear stiffness in early-onset hydrocephalus. NEUROIMAGE-CLINICAL 2021; 30:102579. [PMID: 33631603 PMCID: PMC7905205 DOI: 10.1016/j.nicl.2021.102579] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 12/08/2020] [Accepted: 01/21/2021] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Hydrocephalus that develops early in life is often accompanied by developmental delays, headaches and other neurological deficits, which may be associated with changes in brain shear stiffness. However, noninvasive approaches to measuring stiffness are limited. Magnetic Resonance Elastography (MRE) of the brain is a relatively new noninvasive imaging method that provides quantitative measures of brain tissue stiffness. Herein, we aimed to use MRE to assess brain stiffness in hydrocephalus patients compared to healthy controls, and to assess its associations with ventricular size, as well as demographic, shunt-related and clinical outcome measures. METHODS MRE was collected at two imaging sites in 39 hydrocephalus patients and 33 healthy controls, along with demographic, shunt-related, and clinical outcome measures including headache and quality of life indices. Brain stiffness was quantified for whole brain, global white matter (WM), and lobar WM stiffness. Group differences in brain stiffness between patients and controls were compared using two-sample t-tests and multivariable linear regression to adjust for age, sex, and ventricular volume. Among patients, multivariable linear or logistic regression was used to assess which factors (age, sex, ventricular volume, age at first shunt, number of shunt revisions) were associated with brain stiffness and whether brain stiffness predicts clinical outcomes (quality of life, headache and depression). RESULTS Brain stiffness was significantly reduced in patients compared to controls, both unadjusted (p ≤ 0.002) and adjusted (p ≤ 0.03) for covariates. Among hydrocephalic patients, lower stiffness was associated with older age in temporal and parietal WM and whole brain (WB) (beta (SE): -7.6 (2.5), p = 0.004; -9.5 (2.2), p = 0.0002; -3.7 (1.8), p = 0.046), being female in global and frontal WM and WB (beta (SE): -75.6 (25.5), p = 0.01; -66.0 (32.4), p = 0.05; -73.2 (25.3), p = 0.01), larger ventricular volume in global, and occipital WM (beta (SE): -11.5 (3.4), p = 0.002; -18.9 (5.4), p = 0.0014). Lower brain stiffness also predicted worse quality of life and a higher likelihood of depression, controlling for all other factors. CONCLUSIONS Brain stiffness is reduced in hydrocephalus patients compared to healthy controls, and is associated with clinically-relevant functional outcome measures. MRE may emerge as a clinically-relevant biomarker to assess the neuropathological effects of hydrocephalus and shunting, and may be useful in evaluating the effects of therapeutic alternatives, or as a supplement, of shunting.
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Neural stem cell therapy of foetal onset hydrocephalus using the HTx rat as experimental model. Cell Tissue Res 2020; 381:141-161. [PMID: 32065263 DOI: 10.1007/s00441-020-03182-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/28/2020] [Indexed: 01/01/2023]
Abstract
Foetal onset hydrocephalus is a disease starting early in embryonic life; in many cases it results from a cell junction pathology of neural stem (NSC) and neural progenitor (NPC) cells forming the ventricular zone (VZ) and sub-ventricular zone (SVZ) of the developing brain. This pathology results in disassembling of VZ and loss of NSC/NPC, a phenomenon known as VZ disruption. At the cerebral aqueduct, VZ disruption triggers hydrocephalus while in the telencephalon, it results in abnormal neurogenesis. This may explain why derivative surgery does not cure hydrocephalus. NSC grafting appears as a therapeutic opportunity. The present investigation was designed to find out whether this is a likely possibility. HTx rats develop hereditary hydrocephalus; 30-40% of newborns are hydrocephalic (hyHTx) while their littermates are not (nHTx). NSC/NPC from the VZ/SVZ of nHTx rats were cultured into neurospheres that were then grafted into a lateral ventricle of 1-, 2- or 7-day-old hyHTx. Once in the cerebrospinal fluid, neurospheres disassembled and the freed NSC homed at the areas of VZ disruption. A population of homed cells generated new multiciliated ependyma at the sites where the ependyma was missing due to the inherited pathology. Another population of NSC homed at the disrupted VZ differentiated into βIII-tubulin+ spherical cells likely corresponding to neuroblasts that progressed into the parenchyma. The final fate of these cells could not be established due to the protocol used to label the grafted cells. The functional outcomes of NSC grafting in hydrocephalus remain open. The present study establishes an experimental paradigm of NSC/NPC therapy of foetal onset hydrocephalus, at the etiologic level that needs to be further explored with more analytical methodologies.
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Sherrod BA, Yoon NK, Anzai Y, Schmidt RH, Couldwell WT, Hawryluk GWJ. Delayed Cerebrospinal Fluid Cleft Formation Through the Midbrain and Thalamus Following Hemicraniectomy and Cranioplasty for Acute Subdural Hematoma. Oper Neurosurg (Hagerstown) 2019; 18:E88-E94. [DOI: 10.1093/ons/opz124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/19/2019] [Indexed: 11/14/2022] Open
Affiliation(s)
- Brandon A Sherrod
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah
| | - Nam K Yoon
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah
| | - Yoshimi Anzai
- Department of Radiology, Division of Neuroradiology, University of Utah, Salt Lake City, Utah
| | - Richard H Schmidt
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah
| | | | - Gregory W J Hawryluk
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah
- Department of Neurology, University of Utah, Salt Lake City, Utah
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Emery SP, Greene S, Murdoch G, Wiley CA. Histologic Appearance of Iatrogenic Obstructive Hydrocephalus in the Fetal Lamb Model. Fetal Diagn Ther 2019; 47:7-14. [PMID: 30974442 DOI: 10.1159/000497360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 01/29/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Documentation of histologic findings associated with congenital hydrocephalus in the fetal lamb model is a critical step in evaluating the efficacy of ventriculoamniotic shunting in the human fetus. METHODS Four fetal sheep had hydrocephalus induced at approximately 95 days' gestation. Two co-twins remained as controls. The ewes were euthanized at term. The lamb brains were fixed in formalin, paraffin-embedded, stained, and analyzed for markers of neuropathology. Astrocytosis, microgliosis, and axonal loss were assessed with immunocytochemistry for glial fibrillary acidic protein, ionized calcium-binding adapter, and neurofilament/amyloid precursor protein, respectively. Cortical gray matter extracellular matrix was assessed with staining for the lectin Wisteria Floribunda agglutinin. RESULTS Hydrocephalic lamb brains demonstrated deep white matter damage with loss of projecting axonal tracts in regions physically distorted by hydrocephalus, similar to that seen in hydrocephalic humans. There was no evidence of abnormal neocortical neuronal migration; however, there was evidence for delayed maturation of the neocortical gray matter, possibly from increased intracerebral pressure and subsequent ischemia. Control lamb brains demonstrated none of the above findings. CONCLUSION This histological approach can be used to further define the mechanism of brain damage associated with hydrocephalus and interpret the efficacy of ventriculoamniotic shunting on fetal lamb brain neuroanatomy.
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Affiliation(s)
- Stephen P Emery
- Department of Obstetrics, Gynecology and Reproductive Sciences, Magee-Womens Hospital of the University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA,
| | - Stephanie Greene
- Department of Neurological Surgery, Children's Hospital of the University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Geoffrey Murdoch
- Division of Neuropathology, Department of Pathology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Clayton A Wiley
- Division of Neuropathology, Department of Pathology, University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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da Silva SC, Feres O, da Silva Beggiora P, Machado HR, Menezes-Reis R, Araújo JE, Brandão RA, da Silva Lopes L. Hyperbaric oxygen therapy reduces astrogliosis and helps to recovery brain damage in hydrocephalic young rats. Childs Nerv Syst 2018; 34:1125-1134. [PMID: 29671042 DOI: 10.1007/s00381-018-3803-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/10/2018] [Indexed: 01/29/2023]
Abstract
PURPOSE We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus. METHODS Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies. RESULTS The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group. CONCLUSION The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.
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Affiliation(s)
- Stephanya Covas da Silva
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil.
| | - Omar Feres
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil
| | - Pâmella da Silva Beggiora
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil
| | - Hélio Rubens Machado
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil
| | - Rafael Menezes-Reis
- Department of Biomechanics, Medicine and Rehabilitation, Ribeirão Preto Medical School, University of São Paulo, 3900 Av. dos Bandeirantes, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - João Eduardo Araújo
- Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, Ribeirão Preto Medical School, University of São Paulo, 3900 Av. dos Bandeirantes, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Ricardo Andrade Brandão
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil
| | - Luiza da Silva Lopes
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo - USP, Bandeirantes Av., 3900, Ribeirão Preto, São Paulo, 14049-090, Brazil
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Garcia CAB, Catalão CHR, Machado HR, Júnior IM, Romeiro TH, Peixoto-Santos JE, Santos MV, da Silva Lopes L. Edaravone reduces astrogliosis and apoptosis in young rats with kaolin-induced hydrocephalus. Childs Nerv Syst 2017; 33:419-428. [PMID: 27988876 DOI: 10.1007/s00381-016-3313-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 12/01/2016] [Indexed: 01/17/2023]
Abstract
PURPOSE We investigated the possible neuroprotective effects of the free radical scavenger edaravone in experimental hydrocephalus. METHODS Seven-day-old Wistar rats were divided into three groups: control group (C), untreated hydrocephalic (H), and hydrocephalic treated with edaravone (EH). The H and EH groups were subjected to hydrocephalus induction by 20% kaolin intracisternal injection. The edaravone (20 mg/kg) was administered daily for 14 days from the induction of hydrocephalus. All animals were daily weighed and submitted to behavioral test and assessment by magnetic resonance imaging. After 14 days, the animals were sacrificed and the brain was removed for histological, immunohistochemical, and biochemical studies. RESULTS The gain weight was similar between groups from the ninth post-induction day. The open field test performance of EH group was better (p < 0.05) as compared to untreated hydrocephalic animals. Hydrocephalic animals (H and EH) showed ventricular ratio values were higher (p < 0.05), whereas magnetization transfer values were lower (p < 0.05), as compared to control animals. Astrocyte activity (glial fibrillary acidic protein) and apoptotic cells (caspase-3) of EH group were decreased on the corpus callosum (p > 0.01), germinal matrix (p > 0.05), and cerebral cortex (p > 0.05), as compared to H group. CONCLUSIONS We have demonstrated that administration of edaravone for 14 consecutive days after induction of hydrocephalus reduced astrocyte activity and that it has some beneficial effects over apoptotic cell death.
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Affiliation(s)
- Camila Araújo Bernardino Garcia
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil
| | - Carlos Henrique Rocha Catalão
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Hélio Rubens Machado
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil
| | - Ivair Matias Júnior
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil
| | - Thais Helena Romeiro
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil
| | - José Eduardo Peixoto-Santos
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Marcelo Volpon Santos
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil
| | - Luiza da Silva Lopes
- Department of Surgery and Anatomy, Division of Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, 3900 Av. dos Bandeirantes, Ribeirao Preto, SP, 14049-900, Brazil.
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Chen LJ, Wang YJ, Chen JR, Tseng GF. Hydrocephalus compacted cortex and hippocampus and altered their output neurons in association with spatial learning and memory deficits in rats. Brain Pathol 2016; 27:419-436. [PMID: 27411167 DOI: 10.1111/bpa.12414] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/04/2016] [Indexed: 12/29/2022] Open
Abstract
Hydrocephalus is a common neurological disorder in children characterized by abnormal dilation of cerebral ventricles as a result of the impairment of cerebrospinal fluid flow or absorption. Clinical presentation of hydrocephalus varies with chronicity and often shows cognitive dysfunction. Here we used a kaolin-induction method in rats and studied the effects of hydrocephalus on cerebral cortex and hippocampus, the two regions highly related to cognition. Hydrocephalus impaired rats' performance in Morris water maze task. Serial three-dimensional reconstruction from sections of the whole brain freshly froze in situ with skull shows that the volumes of both structures were reduced. Morphologically, pyramidal neurons of the somatosensory cortex and hippocampus appear to be distorted. Intracellular dye injection and subsequent three-dimensional reconstruction and analyses revealed that the dendritic arbors of layer III and V cortical pyramid neurons were reduced. The total dendritic length of CA1, but not CA3, pyramidal neurons was also reduced. Dendritic spine densities on both cortical and hippocampal pyramidal neurons were decreased, consistent with our concomitant findings that the expressions of both synaptophysin and postsynaptic density protein 95 were reduced. These cortical and hippocampal changes suggest reductions of excitatory connectivity, which could underlie the learning and memory deficits in hydrocephalus.
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Affiliation(s)
- Li-Jin Chen
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
| | - Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien City, Taiwan
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Ezerarslan H, Beriat GK, Nurhat RH, Kazancı B, Çelikkan FT, Sabuncuoğlu B, Sabuncuoğlu H. Non-invasive detection and monitoring of experimental hydrocephalus with distortion product otoacoustic emissions. Auris Nasus Larynx 2016; 43:404-11. [DOI: 10.1016/j.anl.2015.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/08/2015] [Accepted: 11/16/2015] [Indexed: 11/25/2022]
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Jugé L, Pong AC, Bongers A, Sinkus R, Bilston LE, Cheng S. Changes in Rat Brain Tissue Microstructure and Stiffness during the Development of Experimental Obstructive Hydrocephalus. PLoS One 2016; 11:e0148652. [PMID: 26848844 PMCID: PMC4743852 DOI: 10.1371/journal.pone.0148652] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 01/21/2016] [Indexed: 11/18/2022] Open
Abstract
Understanding neural injury in hydrocephalus and how the brain changes during the course of the disease in-vivo remain unclear. This study describes brain deformation, microstructural and mechanical properties changes during obstructive hydrocephalus development in a rat model using multimodal magnetic resonance (MR) imaging. Hydrocephalus was induced in eight Sprague-Dawley rats (4 weeks old) by injecting a kaolin suspension into the cisterna magna. Six sham-injected rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before, and at 3, 7 and 16 days post injection. T2-weighted MR images were collected to quantify brain deformation. MR elastography was used to measure brain stiffness, and diffusion tensor imaging (DTI) was conducted to observe brain tissue microstructure. Results showed that the enlargement of the ventricular system was associated with a decrease in the cortical gray matter thickness and caudate-putamen cross-sectional area (P < 0.001, for both), an alteration of the corpus callosum and periventricular white matter microstructure (CC+PVWM) and rearrangement of the cortical gray matter microstructure (P < 0.001, for both), while compression without gross microstructural alteration was evident in the caudate-putamen and ventral internal capsule (P < 0.001, for both). During hydrocephalus development, increased space between the white matter tracts was observed in the CC+PVWM (P < 0.001), while a decrease in space was observed for the ventral internal capsule (P < 0.001). For the cortical gray matter, an increase in extracellular tissue water was significantly associated with a decrease in tissue stiffness (P = 0.001). To conclude, this study characterizes the temporal changes in tissue microstructure, water content and stiffness in different brain regions and their association with ventricular enlargement. In summary, whilst diffusion changes were larger and statistically significant for majority of the brain regions studied, the changes in mechanical properties were modest. Moreover, the effect of ventricular enlargement is not limited to the CC+PVWM and ventral internal capsule, the extent of microstructural changes vary between brain regions, and there is regional and temporal variation in brain tissue stiffness during hydrocephalus development.
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Affiliation(s)
- Lauriane Jugé
- Neuroscience Research Australia, Margarete Ainsworth Building, Randwick, Australia
- University of New South Wales, School of Medical Sciences, Wallace Wurth Building, Kensington, Australia
| | - Alice C. Pong
- Neuroscience Research Australia, Margarete Ainsworth Building, Randwick, Australia
| | - Andre Bongers
- University of New South Wales, Biological Resources Imaging Laboratory, Lowy Cancer Research Centre, Kensington, Australia
| | - Ralph Sinkus
- King’s College London, Chair in Biomedical Engineering, Imaging Sciences & Biomedical Engineering Division Kings College, St. Thomas’ Hospital, London, United Kingdom
| | - Lynne E. Bilston
- Neuroscience Research Australia, Margarete Ainsworth Building, Randwick, Australia
- University of New South Wales, Prince of Wales Clinical School, Edmund Blacket Building, Kensington, Australia
| | - Shaokoon Cheng
- Neuroscience Research Australia, Margarete Ainsworth Building, Randwick, Australia
- Macquarie University, Department of Engineering, Faculty of Science, Macquarie University, Sydney, Australia
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Guild SJ, McBryde FD, Malpas SC. Recording of intracranial pressure in conscious rats via telemetry. J Appl Physiol (1985) 2015; 119:576-81. [DOI: 10.1152/japplphysiol.00165.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 07/06/2015] [Indexed: 11/22/2022] Open
Abstract
Although cerebral perfusion pressure (CPP) is known to be fundamental in the control of normal brain function, there have been no previous long-term measurements in animal models. The aim of this study was to explore the stability and viability of long-term recordings of intracranial pressure (ICP) in freely moving rats via a telemetry device. We also developed a repeatable surgical approach with a solid-state pressure sensor at the tip of the catheter placed under the dura and in combination with arterial pressure (AP) measurement to enable the calculation of CPP. Telemeters with dual pressure catheters were implanted in Wistar rats to measure ICP and AP. We found that the signals were stable throughout the 28-day recording period with an average ICP value of 6 ± 0.8 mmHg. Significant light-dark differences were found in AP (3.1 ± 2.7 mmHg, P = 0.02) and HR (58 ± 12 beats/min, P = 0.003), but not ICP (0.3 ± 0.2 mmHg, P >0.05) or CPP (2.6 ± 2.8 mmHg, P > 0.05). Use of kaolin to induce hydrocephalus in several rats demonstrates the ability to measure changes in ICP throughout disease progression, validating this new solution for chronic measurement of ICP, CPP, and AP in conscious rats.
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Affiliation(s)
| | | | - Simon C. Malpas
- Department of Physiology and
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; and
- Millar Ltd, Auckland, New Zealand
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13
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Mehrabian A, Abousleiman YN, Mapstone TB, El-Amm CA. Dual-porosity poroviscoelasticity and quantitative hydromechanical characterization of the brain tissue with experimental hydrocephalus data. J Theor Biol 2015; 384:19-32. [PMID: 26277735 DOI: 10.1016/j.jtbi.2015.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 07/31/2015] [Accepted: 08/03/2015] [Indexed: 12/30/2022]
Abstract
Hydromechanical brain models often involve constitutive relations which must account for soft tissue deformation and creep, together with the interstitial fluid movement and exchange through capillaries. The interaction of rather unknown mechanisms which produce, absorb, and circulate the cerebrospinal fluid within the central nervous system can further add to their complexity. Once proper models for these phenomena or processes are selected, estimation of the associated parameters could be even more challenging. This paper presents the results of a consistent, coupled poroviscoelastic modeling and characterization of the brain tissue as a dual-porosity system. The model draws from Biot's theory of poroviscoelasticity, and adopts the generalized Kelvin's rheological description of the viscoelastic tissue behavior. While the interstitial space serves as the primary porosity through which the bulk flow of the interstitial fluid occurs, a secondary porosity network comprising the capillaries and venous system allows for its partial absorption into the blood. The correspondence principle is used in deriving a time-dependent analytical solution to the proposed model. It allows for identical poroelastic formulation of the original poroviscoelastic problem in the Laplace transform space. Hydrocephalus generally refers to a class of medical conditions which share the ventricles enlargement as a common feature. A set of published data from induced hydrocephalus and follow-up perfusion of cats' brains is used for quantitative characterization of the proposed model. A selected portion of these data including the ventricular volume and rate of fluid absorption from the perfused brain, together with the forward model solution, is utilized via an inverse problem technique to find proper estimations of the model parameters. Results show significant improvement in model predictions of the experimental data. The convoluted and coupled solution results are presented through the time-dependent plots of the ventricular volume undergoing the perfusion experiment. The plots demonstrate the intricate interplay of viscous and poroelastic diffusive time scales, and their competition in reaching the steady state response of the system.
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Affiliation(s)
- Amin Mehrabian
- PoroMechanics Institute, Mewbourne School of Petroleum and Geological Engineering, University of Oklahoma, Norman, OK 73019
| | - Younane N Abousleiman
- Mewbourne School of Petroleum and Geological Engineering, School of Geology and Geophysics, School of Civil Engineering and Environmental Science, PoroMechanics Institute, University of Oklahoma, Norman, OK 73019.
| | - Timothy B Mapstone
- School of Medicine and Department of Neurosurgery, University of Oklahoma, Oklahoma City, OK 73104
| | - Christian A El-Amm
- Section of Plastic and Reconstructive Surgery, Department of Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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14
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Shulyakov A, Buist RJ, DiCurzio DL, Del Bigio M. Calcium antagonism effects on cerebral blood flow in rats with acute hydrocephalus. Fluids Barriers CNS 2015. [PMCID: PMC4583159 DOI: 10.1186/2045-8118-12-s1-p49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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15
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Shim JW, Sandlund J, Madsen JR. VEGF: a potential target for hydrocephalus. Cell Tissue Res 2014; 358:667-83. [PMID: 25146955 DOI: 10.1007/s00441-014-1978-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 07/28/2014] [Indexed: 12/13/2022]
Abstract
Growth factors are primarily responsible for the genesis, differentiation and proliferation of cells and maintenance of tissues. Given the central role of growth factors in signaling between cells in health and in disease, it is understandable that disruption of growth factor-mediated molecular signaling can cause diverse phenotypic consequences including cancer and neurological conditions. This review will focus on the specific questions of enlarged cerebral ventricles and hydrocephalus. It is also well known that angiogenic factors, such as vascular endothelial growth factor (VEGF), affect tissue permeability through activation of receptors and adhesion molecules; hence, recent studies showing elevations of this factor in pediatric hydrocephalus led to the demonstration that VEGF can induce ventriculomegaly and altered ependyma when infused in animals. In this review, we discuss recent findings implicating the involvement of biochemical and biophysical factors that can induce a VEGF-mimicking effect in communicating hydrocephalus and pay particular attention to the role of the VEGF system as a potential pharmacological target in the treatment of some cases of hydrocephalus. The source of VEGF secretion in the cerebral ventricles, in periventricular regions and during pathologic events including hydrocephalus following hypoxia and hemorrhage is sought. The review is concluded with a summary of potential non-surgical treatments in preclinical studies suggesting several molecular targets including VEGF for hydrocephalus and related neurological disorders.
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Affiliation(s)
- Joon W Shim
- Department of Biology, Indiana University-Purdue University Indianapolis, 723 W. Michigan Street SL354, Indianapolis, IN, 46202, USA
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16
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Alfasi AM, Shulyakov AV, Del Bigio MR. Intracranial biomechanics following cortical contusion in live rats. J Neurosurg 2013; 119:1255-62. [DOI: 10.3171/2013.7.jns121973] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Object
The goal of this study was to examine the mechanical properties of living rat intracranial contents and corresponding brain structural alterations following parietal cerebral cortex contusion.
Methods
After being anesthetized, young adult rats were subjected to parietal craniotomy followed by cortical contusion using a calibrated weight-drop method. Magnetic resonance imaging was used to visualize the contusion. At the site of contusion, instrumented force-controlled indentation was performed 2 hours to 21 days later on the intact dural surface. The force-deformation (stress-strain) relationship was used to calculate elastic (indentation modulus) and strain changes over time, and constant hold or cyclic stress was used to evaluate viscoelastic deformation. These measurements were followed by histological studies.
Results
At contusion sites, the indentation modulus was significantly decreased at 1–3 days and tended to be above control values at 21 days. Multicycle indentation showed that the brain tended to accumulate more strain (an indicator of viscosity) by 1 day after the contusion. Imaging and histological studies showed local edema and hemorrhage at 6 hours to 3 days and accumulation of reactive astrocytes, which began at 3 days and was pronounced by 21 days.
Conclusions
The viscoelastic properties of living rat brain change following contusion. Initially, edema and tissue necrosis occur, and the brain becomes less elastic and less viscous. Later, along with undergoing reactive astroglial changes, the brain tends to become stiffer than normal. These quantitative data, which are related to the physical changes in the brain following trauma and which reflect subjective impressions upon palpation, will be useful for understanding emerging diagnostic tools such as magnetic resonance elastography.
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Affiliation(s)
| | | | - Marc R. Del Bigio
- 2Pathology, University of Manitoba, Winnipeg, Canada
- 3Manitoba Institute of Child Health, Winnipeg, Canada
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18
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Mattei TA. Small-amplitude cyclic increments in ICP and hydrocephalus. Neurosurgery 2013; 72:E875-7. [PMID: 23381492 DOI: 10.1227/neu.0b013e318289d840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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