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Sanker V, Kundu M, El Kassem S, El Nouiri A, Emara M, Maaz ZA, Nazir A, Bekele BK, Uwishema O. Posttraumatic hydrocephalus: Recent advances and new therapeutic strategies. Health Sci Rep 2023; 6:e1713. [PMID: 38028696 PMCID: PMC10652704 DOI: 10.1002/hsr2.1713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 10/28/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
Background Hydrocephalus or ventriculomegaly is a condition brought on by an overabundance of cerebrospinal fluid (CSF) in the ventricular system. The major contributor to posttraumatic hydrocephalus (PTH) is traumatic brain injuries (TBIs), especially in individuals with occupations set in industrial settings. A variety of criteria have been employed for the diagnosis of PTH, including the combination of neurological symptoms like nerve deficits and headache, as well as an initial improvement followed by a worsened relapse of altered consciousness and neurological deterioration, which is detected by computed tomography-brain imaging that reveals gradual ventriculomegaly. Aim In this article, we discuss and summarize briefly the current understandings and advancements in the management of PTH. Methods The available literature for this review was searched on various bibliographic databases using an individually verified, prespecified approach. The level of evidence of the included studies was considered as per the Centre for Evidence-Based Medicine recommendations. Results The commonly practiced current treatment modality involves shunting CSF but is often associated with complications and recurrence. The lack of a definitive management strategy for PTH warrants the utilization of novel and innovative modalities such as stem cell transplantations and antioxidative stress therapies. Conclusion One of the worst complications of a TBI is PTH, which has a high morbidity and mortality rate. Even though there hasn't been a successful method in stopping PTH from happening, hemorrhage-derived blood, and its metabolic by-products, like iron, hemoglobin, free radicals, thrombin, and red blood cells, may be potential targets for PTH hindrance and management. Also, using stem cell transplantations in animal models and antioxidative stress therapies in future studies can lower PTH occurrence and improve its outcome. Moreover, the integration of clinical trials and theoretical knowledge should be encouraged in future research projects to establish effective and updated management guidelines for PTH.
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Affiliation(s)
- Vivek Sanker
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Society of Brain Mapping and TherapeuticsLos AngelesCaliforniaUSA
| | - Mrinmoy Kundu
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Institute of Medical Sciences and SUM HospitalBhubaneswarIndia
| | - Sarah El Kassem
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Faculty of MedicineBeirut Arab UniversityBeirutLebanon
| | - Ahmad El Nouiri
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Faculty of MedicineBeirut Arab UniversityBeirutLebanon
| | - Mohamed Emara
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- College of MedicineUniversity of SharjahSharjahUnited Arab Emirates
| | - Zeina Al Maaz
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Faculty of MedicineBeirut Arab UniversityBeirutLebanon
| | - Abubakar Nazir
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
| | - Bezawit Kassahun Bekele
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- School of MedicineAddis Ababa UniversityAddis AbabaEthiopia
- Milken Institute of Public HealthGeorge Washington UniversityWashingtonDistrict of ColumbiaUSA
| | - Olivier Uwishema
- Oli Health Magazine Organization, Research and EducationKigaliRwanda
- Department of medicineClinton Global Initiative UniversityNew YorkNew YorkUSA
- Faculty of MedicineKaradeniz Technical UniversityTrabzonTurkey
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Deopujari C, Mohanty C, Agrawal H, Jain S, Chawla P. A comparison of Adult and Pediatric Hydrocephalus. Neurol India 2022; 69:S395-S405. [PMID: 35102995 DOI: 10.4103/0028-3886.332283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.
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Affiliation(s)
- Chandrashekhar Deopujari
- Department of Neurosurgery, Bombay Hospital Institute of Medical Sciences; B J Wadia Hospital for Children, Mumbai, Maharashtra, India
| | - Chandan Mohanty
- Department of Neurosurgery, Bombay Hospital Institute of Medical Sciences; B J Wadia Hospital for Children, Mumbai, Maharashtra, India
| | | | - Sonal Jain
- B J Wadia Hospital for Children, Mumbai, Maharashtra, India
| | - Pawan Chawla
- B J Wadia Hospital for Children, Mumbai, Maharashtra, India
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Wang C, Wang X, Tan C, Wang Y, Tang Z, Zhang Z, Liu J, Xiao G. Novel therapeutics for hydrocephalus: Insights from animal models. CNS Neurosci Ther 2021; 27:1012-1022. [PMID: 34151523 PMCID: PMC8339528 DOI: 10.1111/cns.13695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/09/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023] Open
Abstract
Hydrocephalus is a cerebrospinal fluid physiological disorder that causes ventricular dilation with normal or high intracranial pressure. The current regular treatment for hydrocephalus is cerebrospinal fluid shunting, which is frequently related to failure and complications. Meanwhile, considering that the current nonsurgical treatments of hydrocephalus can only relieve the symptoms but cannot eliminate this complication caused by primary brain injuries, the exploration of more effective therapies has become the focus for many researchers. In this article, the current research status and progress of nonsurgical treatment in animal models of hydrocephalus are reviewed to provide new orientations for animal research and clinical practice.
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Affiliation(s)
- Chuansen Wang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Xiaoqiang Wang
- Department of Pediatric NeurosurgeryXinhua HospitalShanghai Jiaotong University School of MedicineShanghaiChina
| | - Changwu Tan
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Yuchang Wang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Zhi Tang
- Department of NeurosurgeryHunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of MedicineCentral South UniversityChangshaHunanChina
| | - Zhiping Zhang
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Jingping Liu
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
| | - Gelei Xiao
- Department of NeurosurgeryXiangya HospitalCentral South UniversityChangshaHunanChina
- Diagnosis and Treatment Center for HydrocephalusXiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric DisordersXiangya HospitalCentral South UniversityChangshaHunanChina
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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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Renjen P, Gupta C, Chaudhari D, Mishra A. Diagnosis, pathophysiology, and treatment of normal pressure hydrocephalus: A review of current perspectives. APOLLO MEDICINE 2020. [DOI: 10.4103/am.am_7_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Oliveira LM, Nitrini R, Román GC. Normal-pressure hydrocephalus: A critical review. Dement Neuropsychol 2019; 13:133-143. [PMID: 31285787 PMCID: PMC6601311 DOI: 10.1590/1980-57642018dn13-020001] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/20/2019] [Indexed: 12/13/2022] Open
Abstract
Normal-pressure hydrocephalus (NPH) is a potentially reversible syndrome characterized by enlarged cerebral ventricles (ventriculomegaly), cognitive impairment, gait apraxia and urinary incontinence. A critical review of the concept, pathophysiology, diagnosis, and treatment of both idiopathic and secondary NPH was conducted. We searched Medline and PubMed databases from January 2012 to December 2018 using the keywords "normal-pressure hydrocephalus" / "idiopathic normal-pressure hydrocephalus" / "secondary normal-pressure hydrocephalus" / "NPH" / "ventriculoperitoneal shunt". The initial search produced 341 hits. After careful selection, a total of 54 articles were chosen and additional relevant studies were included during the process of writing this article. NPH is an important cause of potentially reversible dementia, frequent falls and recurrent urinary infections in the elderly. The clinical and imaging features of NPH may be incomplete or nonspecific, posing a diagnostic challenge for medical doctors and often requiring expert assessment to minimize unsuccessful surgical treatments. Recent advances resulting from the use of non-invasive MRI methods for quantifying cerebral blood flow, in particular arterial spin-labeling (ASL), and the frequent association of NPH and obstructive sleep apnea (OSA), offer new avenues to understand and treat NPH.
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Affiliation(s)
- Louise Makarem Oliveira
- Medical Student, School of Medicine, Federal University of Amazonas
(UFAM), Manaus, AM, Brazil
| | - Ricardo Nitrini
- Professor of Neurology, Department of Neurology, University of São
Paulo Medical School, São Paulo, SP, Brazil
| | - Gustavo C. Román
- The Jack S. Blanton Distinguished Endowed Chair, Neurological
Institute Houston, Methodist Hospital, Professor of Neurology Weill Cornell Medical
College Methodist Neurological Institute, USA
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Tuniz F, Vescovi MC, Bagatto D, Drigo D, De Colle MC, Maieron M, Skrap M. The role of perfusion and diffusion MRI in the assessment of patients affected by probable idiopathic normal pressure hydrocephalus. A cohort-prospective preliminary study. Fluids Barriers CNS 2017; 14:24. [PMID: 28899431 PMCID: PMC5596479 DOI: 10.1186/s12987-017-0072-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 09/02/2017] [Indexed: 01/12/2023] Open
Abstract
Background Invasive tests measuring resistance to cerebral spinal fluid (CSF) outflow and the effect of temporary drainage of CSF are used to select candidates affected by idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery. Neither test, however, completely excludes patients from treatment. Perfusion and diffusion magnetic resonance imaging (MRI) are non-invasive techniques that might be of value in selecting patients for surgical treatment and understanding brain changes in iNPH patients. The aim of this study was to understand the role of perfusion and diffusion MRI in selecting candidates for shunt surgery and to investigate the relationship between cerebral perfusion and possible microstructural changes in brain tissue before and after invasive tests, and after ventricular-peritoneal (VP) shunt implantation, to better clarify pathophysiological mechanisms underlying iNPH. Methods Twenty-three consecutive patients with probable iNPH were included in this study. Patients underwent a clinical and neuroradiological evaluation before and after invasive tests, and after surgery. Only patients who showed a positive result in at least one of the invasive tests were submitted for VP shunt implantation. Perfusion and diffusion magnetic resonance imaging (MRI) was performed before and after invasive tests and after shunt surgery. Results Thirteen patients underwent surgery and all showed clinical improvement after VP shunt implantation and a significant increase in perfusion in both periventricular white matter (PVWM) and basal ganglia (BG) regions. The 10 patients that did not have surgery showed after invasive tests, a significant reduction in perfusion in both PVWM and BG regions. Comparing the changes in perfusion with those of diffusion in positive patients we found a significant positive correlation in BG and a significant inverse correlation in PVWM area. Conclusions Perfusion MRI is a non-invasive technique that could be useful together with invasive tests in selecting patients for surgical treatment. Furthermore, the relationship between perfusion and diffusion data could better clarify pathophysiological mechanisms underlying iNPH. In PVWM area we suggest that interstitial edema could reduce microvascular blood flow and interfere with the blood supply to these regions. In BG regions we suggest that a chronic hypoxic insult caused by blood hypo-perfusion produces a chronic cytotoxic edema. Both in PVWM and in BG regions, pathophysiological mechanisms could be modified after VP-shunt implantation.
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Affiliation(s)
- Francesco Tuniz
- Department of Neurosurgery, AOU-UD "Santa Maria della Misericordia", Piazzale S.M. della Misericordia, 33100, Udine, Italy
| | - Maria Caterina Vescovi
- Department of Neurosurgery, AOU-UD "Santa Maria della Misericordia", Piazzale S.M. della Misericordia, 33100, Udine, Italy.
| | - Daniele Bagatto
- Department of Neuroradiology, AOU-UD "Santa Maria della Misericordia", Udine, Italy
| | - Daniela Drigo
- Institute of Epidemiology, AOU-UD "Santa Maria della Misericordia", Udine, Italy
| | | | - Marta Maieron
- Department of Physics, AOU-UD "Santa Maria della Misericordia", Udine, Italy
| | - Miran Skrap
- Department of Neurosurgery, AOU-UD "Santa Maria della Misericordia", Piazzale S.M. della Misericordia, 33100, Udine, Italy
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Environmental enrichment reduces brain damage in hydrocephalic immature rats. Childs Nerv Syst 2017; 33:921-931. [PMID: 28382436 DOI: 10.1007/s00381-017-3403-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 03/27/2017] [Indexed: 01/12/2023]
Abstract
PURPOSE We investigate the effects of environmental enrichment (EE) on morphological alterations in different brain structures of pup rats submitted to hydrocephalus condition. METHODS Hydrocephalus was induced in 7-day-old pup rats by injection of 20% kaolin into the cisterna magna. Ventricular dilatation and magnetization transfer to analyze myelin were assessed by magnetic resonance. Hydrocephalic and control rats exposed to EE (n = 10 per group) were housed in cages with a tunnel, ramp, and colored plastic balls that would emit sound when touched. The walls of the housing were decorated with colored adhesive tape. Moreover, tactile and auditory stimulation was performed daily throughout the experiment. Hydrocephalic and control rats not exposed to EE (n = 10 per group) were allocated singly in standard cages. All animals were weighed daily and exposed to open-field conditions every 2 days until the end of the experiment when they were sacrificed and the brains removed for histology and immunohistochemistry. Solochrome cyanine staining was performed to assess the thickness of the corpus callosum. The glial fibrillary acidic protein method was used to evaluate reactive astrocytes, and the Ki67 method to assess cellular proliferation in the subventricular zone. RESULTS The hydrocephalic animals exposed to EE showed better performance in Open Field tests (p < 0.05), while presenting lower weight gain. In addition, these animals showed better myelination as revealed by magnetization transfer (p < 0.05). Finally, the EE group showed a reduction in reactive astrocytes by means of glial fibrillary acidic protein immunostaining and preservation of the proliferation potential of progenitor cells. CONCLUSION The results suggest that EE can protect the developing brain against damaging effects caused by hydrocephalus.
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Shaw R, Mahant N, Jacobson E, Owler B. A Review of Clinical Outcomes for Gait and Other Variables in the Surgical Treatment of Idiopathic Normal Pressure Hydrocephalus. Mov Disord Clin Pract 2016; 3:331-341. [PMID: 30363503 PMCID: PMC6178707 DOI: 10.1002/mdc3.12335] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 01/07/2016] [Accepted: 01/09/2016] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Idiopathic normal pressure hydrocephalus (INPH) is a treatable cause of gait disturbance, cognitive impairment, and urinary incontinence. This clinical triad of symptoms occurs in association with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. Although the treatment outcomes after CSF shunting for INPH have improved significantly since its first description in 1965, shortcomings in our understanding still remain. Not all INPH patients exhibit clinical improvement after shunting, and it is challenging to identify patients who are more likely to benefit from shunting. METHODS The Cochrane Library, Medline, Embase, and PubMed databases were searched for English-language publications between 1965 and October 2015. Reference lists of publications were also manually searched for additional publications. RESULTS The findings of this review indicate that, despite efforts to improve patient selection, the degree of clinical improvement after shunting continues to demonstrate significant variability both within and between studies. These discrepancies in treatment outcomes are the result of controversies in 3 distinct but interrelated domains: the underlying pathophysiology of INPH, the diagnosis of INPH, and the identification of likely shunt-responders. CONCLUSIONS This review focuses on these 3 areas and their relation to surgical treatment outcomes. Despite the limitations of published outcome studies and limitations in our understanding of INPH pathophysiology, shunting is a safe and effective means of achieving meaningful clinical improvement in most patients with INPH.
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Affiliation(s)
- Richard Shaw
- Faculty of MedicineUniversity of New South WalesSydneyAustralia
| | - Neil Mahant
- Department of NeurologyWestmead HospitalSydneyAustralia
- Western Clinical School: Medicine (Westmead)University of SydneySydneyAustralia
| | - Erica Jacobson
- Department of NeurosurgeryPrince of Wales HospitalSydneyAustralia
| | - Brian Owler
- Department of NeurosurgerySydney Adventist HospitalSydneyAustralia
- Department of SurgeryUniversity of SydneySydneyAustralia
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Raybaud C. MR assessment of pediatric hydrocephalus: a road map. Childs Nerv Syst 2016; 32:19-41. [PMID: 26337698 DOI: 10.1007/s00381-015-2888-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/11/2015] [Indexed: 12/12/2022]
Abstract
PURPOSE This study was conducted to design a rational approach to the MR diagnosis of hydrocephalus based on a pathophysiologic reevaluation of its possible mechanisms and to apply it to the different etiological contexts. METHOD A review of the literature reports describing new physiologic models of production and absorption and of the hydrodynamics of the CSF was made. RESULTS Besides the secretion of CSF by the choroid plexuses, and its passive, pressure-dependent transdural absorption (arachnoid villi, dural clefts, cranial, and spinal nerve sheaths), water transporters, aquaporins, allow water (if not ions and organic molecules) to exchange freely between the brain parenchyma and the CSF spaces across the ependymal and the pial interfaces (including the Virchow-Robin spaces). Consequently, the CSF bulk flow is not necessarily global, and situations of balanced absorption-secretion may occur separately in different CSF compartments such as the ventricular, intracranial, or intraspinal CSF spaces. This means that rather than from a hypothetical pressure gradient from the plexuses to the dural sinuses, the dynamics of the CSF depend on the force provided in those different compartments by the arterial systolic pulsation of the pericerebral (mostly), intracerebral, and intraventricular (choroid plexuses) vascular beds. CONCLUSION Using MR imaging, diverse varieties of hydrocephalus may tentatively be explained by applying those concepts to the correspondingly diverse causal diseases. Hopefully, this may have an impact on the choice of the treatment strategies also.
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Affiliation(s)
- Charles Raybaud
- Division of Neuroradiology, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
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Ziegelitz D, Starck G, Kristiansen D, Jakobsson M, Hultenmo M, Mikkelsen IK, Hellström P, Tullberg M, Wikkelsø C. Cerebral perfusion measured by dynamic susceptibility contrast MRI is reduced in patients with idiopathic normal pressure hydrocephalus. J Magn Reson Imaging 2013; 39:1533-42. [PMID: 24006249 DOI: 10.1002/jmri.24292] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/29/2013] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To demonstrate in idiopathic normal pressure hydrocephalus (iNPH) patients by dynamic susceptibility contrast MRI a reduced preoperative cerebral blood flow (CBF) which correlates with the severity of clinical symptoms and predicts shunt outcome. MATERIALS AND METHODS In cortical, subcortical, periventricular regions and along peri-and paraventricular profiles absolute perfusion values were estimated by multi-slice DSC MRI in 21 iNPH patients and 16 age-matched healthy individuals (HI). Relative CBF (rCBF), calculated with the occipital cortex as internal reference, was used for comparison between groups and for correlation analysis between regional rCBF and symptoms or outcome. RESULTS iNPH patients showed significantly decreased rCBF in the basal medial frontal cortex, hippocampus, lentiform nucleus, periventricular white matter (PVWM), central grey matter and the global parenchyma as compared to HI. iNPH patients with higher preoperative rCBF in the PVWM performed better in clinical tests. A lower overall preoperative function resulted in a more obvious recovery after shunt insertion. Shunt-responders had higher rCBF values in the basal medial frontal cortex than non-responders. CONCLUSION DSC MRI perfusion is a potentially useful diagnostic tool in iNPH and perfusion based criteria might be possible predictors of shunt response.
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Affiliation(s)
- Doerthe Ziegelitz
- Department of Neuroradiology, Institute of Clinical Sciences, Gothenburg, Sweden
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Biel M, Kramer M, Forterre F, Jurina K, Lautersack O, Failing K, Schmidt MJ. Outcome of ventriculoperitoneal shunt implantation for treatment of congenital internal hydrocephalus in dogs and cats: 36 cases (2001-2009). J Am Vet Med Assoc 2013; 242:948-58. [PMID: 23517207 DOI: 10.2460/javma.242.7.948] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To examine outcome data for cats and dogs with congenital internal hydrocephalus following treatment via ventriculoperitoneal shunting to determine treatment-associated changes in neurologic signs, the nature and incidence of postoperative complications, and survival time. DESIGN Retrospective multicenter case series. ANIMALS 30 dogs and 6 cats with congenital internal hydrocephalus (confirmed via CT or MRI). PROCEDURES Medical records for dogs and cats with internal hydrocephalus that underwent unilateral ventriculoperitoneal shunt implantation from 2001 through 2009 were evaluated. Data collected included the nature and incidence of postoperative complications, change in clinical signs following surgery, and survival time. To compare pre- and postoperative signs, 2-way frequency tables were analyzed with a 1-sided exact McNemar test. RESULTS 8 of 36 (22%) animals developed postoperative complications, including shunt malfunction, shunt infection, and seizure events. Three dogs underwent shunt revision surgery. Thirteen (36%) animals died as a result of hydrocephalus-related complications or were euthanized. Following shunt implantation, clinical signs resolved in 7 dogs and 2 cats; overall, 26 (72%) animals had an improvement of clinical signs. After 18 months, 20 animals were alive, and the longest follow-up period was 9.5 years. Most deaths and complications occurred in the first 3 months after shunt placement. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that ventriculoperitoneal shunt implantation is a viable option for treatment of dogs or cats with congenital hydrocephalus. Because complications are most likely to develop in the first 3 months after surgery, repeated neurologic and imaging evaluations are warranted during this period.
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Affiliation(s)
- Miriam Biel
- Small Animal Clinic, Department of Veterinary Clinical Sciences, Justus Liebig University, 35392 Giessen, Germany.
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Cerebral white matter oxidation and nitrosylation in young rodents with kaolin-induced hydrocephalus. J Neuropathol Exp Neurol 2012; 71:274-88. [PMID: 22437339 DOI: 10.1097/nen.0b013e31824c1b44] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Hydrocephalus is associated with reduced blood flow in periventricular white matter. To investigate hypoxic and oxidative damage in the brains of rats with hydrocephalus, kaolin was injected into the cisterna magna of newborn 7- and 21-day-old Sprague-Dawley rats, and ventricle size was assessed by magnetic resonance imaging at 7, 21, and 42 days of age. In-situ evidence of hypoxia in periventricular capillaries and glial cells was shown by pimonidazole hydrochloride binding. Biochemical assay of thiobarbituric acid reaction and immunohistochemical detection of malondialdehyde and 4-hydroxy-2-nonenal indicated the presence of lipid peroxidation in white matter. Biochemical assay of nitrite indicated increased nitric oxide production. Nitrotyrosine immunohistochemistry showed nitrosylated proteins in white matter reactive microglia and astrocytes. Activities of the antioxidant enzymes catalase and glutathione peroxidase were not increased, and altered hypoxia-inducible factor 1α was not detected by quantitative reverse transcription-polymerase chain reaction. Cerebral vascular endothelial growth factor expression determined by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay was not changed, but vascular endothelial growth factor immunoreactivity was increased in reactive astrocytes of hydrocephalic white matter. To determine if nitric oxide synthase is involved in the pathogenesis, we induced hydrocephalus in 7-day-old wild-type and neuronal nitric oxide synthase-deficient mice. At 7 days, the wild-type and mutant mice exhibited equally severe ventriculomegaly and no behavioral differences, although increased glial fibrillary acidic protein was less in the mutant mice. We conclude that hypoxia, via peroxidation and nitrosylation, contributes to brain changes in young rodents with hydrocephalus and that compensatory mechanisms are negligible.
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Steinman MQ, Knight JA, Trainor BC. Effects of photoperiod and food restriction on the reproductive physiology of female California mice. Gen Comp Endocrinol 2012; 176:391-9. [PMID: 22245263 PMCID: PMC3334427 DOI: 10.1016/j.ygcen.2011.12.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 12/24/2011] [Accepted: 12/27/2011] [Indexed: 12/21/2022]
Abstract
Many temperate-zone animals use changes in photoperiod to time breeding. Shorter term cues, like food availability, are integrated with photoperiod to adjust reproductive timing under unexpected conditions. Many mice of the genus Peromyscus breed in the summer. California mice (Peromyscus californicus), however, can breed year round, but tend to begin breeding in the winter. Glial cells may be involved in transduction of environmental signals that regulate gonadotrophin releasing hormone I (GnRH) activity. We examined the effects of diet and photoperiod on reproduction in female California mice. Mice placed on either short days (8L:16D) or long days (16L:8D) were food restricted (80% of normal intake) or fed ad libitum. Short day-food restricted mice showed significant regression of the reproductive system. GnRH-immunoreactivity was increased in the tuberal hypothalamus of long day-food restricted mice. This may be associated with the sparing effect long days have when mice are food restricted. The number of GFAP-immunoreactive fibers in proximity to GnRH nerve terminals correlated negatively with uterine size in ad libitum but not food restricted mice, suggesting diet may alter glial regulation of the reproductive axis. There was a trend towards food restriction increasing uterine expression of c-fos mRNA, an estrogen dependent gene. Similar to other seasonally breeding rodents, short days render the reproductive system of female California mice more susceptible to effects of food restriction. This may be vestigial, or it may have evolved to mitigate consequences of unexpectedly poor winter food supplies.
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Affiliation(s)
- Michael Q Steinman
- Molecular, Cellular and Integrative Physiology Graduate Group, University of California, Davis, CA 95616, USA.
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15
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Neocortical capillary flow pulsatility is not elevated in experimental communicating hydrocephalus. J Cereb Blood Flow Metab 2012; 32:318-29. [PMID: 21934694 PMCID: PMC3272598 DOI: 10.1038/jcbfm.2011.130] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
While communicating hydrocephalus (CH) is often characterized by increased pulsatile flow of cerebrospinal fluid (CSF) in the cerebral aqueduct, a clear-cut explanation for this phenomenon is lacking. Increased pulsatility of the entire cerebral vasculature including the cortical capillaries has been suggested as a causative mechanism. To test this theory, we used two-photon microscopy to measure flow pulsatility in neocortical capillaries 40 to 500 μm below the pial surface in adult rats with CH at 5 to 7 days (acute, n=8) and 3 to 5 weeks (chronic, n=5) after induction compared with intact controls (n=9). Averaging over all cortical depths, no increase in capillary pulsatility occurred in acute (pulsatility index (PI): 0.15±0.06) or chronic (0.14±0.05) CH animals compared with controls (0.18±0.07; P=0.07). More specifically, PI increased significantly with cortical depth in controls (r=0.35, P<0.001), but no such increase occurred in acute (r=0.06, P=0.3) or chronic (r=0.05, P=0.5) CH. Pulsatile CSF aqueductal flow, in contrast, was elevated 10- to 500-fold compared with controls. We conclude that even in the presence of markedly elevated pulsatile CSF flow in the aqueduct, there is no concurrent increase in microvascular pulsatile flow.
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Karbowski J. Scaling of brain metabolism and blood flow in relation to capillary and neural scaling. PLoS One 2011; 6:e26709. [PMID: 22053202 PMCID: PMC3203885 DOI: 10.1371/journal.pone.0026709] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/02/2011] [Indexed: 11/18/2022] Open
Abstract
Brain is one of the most energy demanding organs in mammals, and its total metabolic rate scales with brain volume raised to a power of around 5/6. This value is significantly higher than the more common exponent 3/4 relating whole body resting metabolism with body mass and several other physiological variables in animals and plants. This article investigates the reasons for brain allometric distinction on a level of its microvessels. Based on collected empirical data it is found that regional cerebral blood flow CBF across gray matter scales with cortical volume as , brain capillary diameter increases as , and density of capillary length decreases as . It is predicted that velocity of capillary blood is almost invariant (), capillary transit time scales as , capillary length increases as , and capillary number as , where is typically a small correction for medium and large brains, due to blood viscosity dependence on capillary radius. It is shown that the amount of capillary length and blood flow per cortical neuron are essentially conserved across mammals. These results indicate that geometry and dynamics of global neuro-vascular coupling have a proportionate character. Moreover, cerebral metabolic, hemodynamic, and microvascular variables scale with allometric exponents that are simple multiples of 1/6, rather than 1/4, which suggests that brain metabolism is more similar to the metabolism of aerobic than resting body. Relation of these findings to brain functional imaging studies involving the link between cerebral metabolism and blood flow is also discussed.
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Affiliation(s)
- Jan Karbowski
- Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
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Wagshul ME, Eide PK, Madsen JR. The pulsating brain: A review of experimental and clinical studies of intracranial pulsatility. Fluids Barriers CNS 2011; 8:5. [PMID: 21349153 PMCID: PMC3042979 DOI: 10.1186/2045-8118-8-5] [Citation(s) in RCA: 258] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 01/18/2011] [Indexed: 02/01/2023] Open
Abstract
The maintenance of adequate blood flow to the brain is critical for normal brain function; cerebral blood flow, its regulation and the effect of alteration in this flow with disease have been studied extensively and are very well understood. This flow is not steady, however; the systolic increase in blood pressure over the cardiac cycle causes regular variations in blood flow into and throughout the brain that are synchronous with the heart beat. Because the brain is contained within the fixed skull, these pulsations in flow and pressure are in turn transferred into brain tissue and all of the fluids contained therein including cerebrospinal fluid. While intracranial pulsatility has not been a primary focus of the clinical community, considerable data have accrued over the last sixty years and new applications are emerging to this day. Investigators have found it a useful marker in certain diseases, particularly in hydrocephalus and traumatic brain injury where large changes in intracranial pressure and in the biomechanical properties of the brain can lead to significant changes in pressure and flow pulsatility. In this work, we review the history of intracranial pulsatility beginning with its discovery and early characterization, consider the specific technologies such as transcranial Doppler and phase contrast MRI used to assess various aspects of brain pulsations, and examine the experimental and clinical studies which have used pulsatility to better understand brain function in health and with disease.
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Affiliation(s)
- Mark E Wagshul
- Albert Einstein College of Medicine, Department of Radiology, Bronx, NY 10461, USA.
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Yang J, Dombrowski SM, Deshpande A, Krajcir N, Luciano MG. VEGF/VEGFR-2 changes in frontal cortex, choroid plexus, and CSF after chronic obstructive hydrocephalus. J Neurol Sci 2010; 296:39-46. [PMID: 20619858 DOI: 10.1016/j.jns.2010.06.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 05/15/2010] [Accepted: 06/10/2010] [Indexed: 12/21/2022]
Abstract
Chronic hydrocephalus (CH) is often associated with decreased cerebral blood flow (CBF) and oxygen levels. While the exact pathophysiology is not clear, vascular endothelial growth factor (VEGF) and its receptor-2 (VEGFR-2) may be involved. Because the choroid plexus (CP) is involved in cerebrospinal fluid (CSF) production and secretes numerous growth factors including VEGF, it is important to understand VEGF/VEGFR-2 levels in the CP-CSF circulatory system. Our results showed significant decreases in CBF and VEGFR-2 levels in frontal cortex (FC) in CH compared with SC; there were no significant changes in VEGF levels. CBF change in FC was positively correlated with VEGFR-2 levels (P=0.024). Immunohistochemistry (IHC) showed robust expression of VEGF/VEGFR-2 in CP. After CH induction, ventricular CSF volume and VEGF levels significantly increased. These results suggest that the decreased VEGFR-2 levels in FC may be contributed to decreased CBF and increased ventricular CSF-VEGF levels possibly reflected a hypoxic response and/or accumulation of VEGF from CP secretion after blockage of CSF outlet. Further investigation into CSF-VEGF levels in different sites may provide a better understanding of VEGF/VEGFR-2 modulation in the normal and hydrocephalic brain, and may represent a feasible approach to potential therapeutic options for hydrocephalus.
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Affiliation(s)
- Jun Yang
- Department of Neurological Surgery, Section of Pediatric and Congenital Neurological Surgery, CSF Physiology Laboratory, Neurological Institute, Cleveland Clinic, S-60, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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Abstract
In the context of spina bifida, hydrocephalus is usually caused by crowding of the posterior fossa with obstruction to cerebrospinal fluid flow from the forth ventricle, and less often by malformation of the cerebral aqueduct. Enlargement of the cerebral ventricles causes gradual destruction of periventricular white matter axons. Motor, sensory, visual, and memory systems may be disturbed through involvement of the long projection axons, periventricular structures including the corpus callosum, and the fimbria-fornix pathway. Secondary changes occur in neuronal cell bodies and synapses, but there is minimal death of neurons. The clinical syndrome of hydrocephalic brain dysfunction is thus due to subcortical disconnection. Some of the brain dysfunction is reversible by shunting, probably through restoration of cerebral blood flow and normalization of the extracellular environment. However, destroyed axons cannot be restored.
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Affiliation(s)
- Marc R Del Bigio
- Department of Pathology, University of Manitoba, and Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada.
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20
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Eide PK, Stanisic M. Cerebral microdialysis and intracranial pressure monitoring in patients with idiopathic normal-pressure hydrocephalus: association with clinical response to extended lumbar drainage and shunt surgery. J Neurosurg 2010; 112:414-24. [PMID: 19538048 DOI: 10.3171/2009.5.jns09122] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT This study was performed in patients with idiopathic normal-pressure hydrocephalus (iNPH) to monitor cerebral metabolism with microdialysis (MD) and intracranial pressure (ICP) readings, and relate to the clinical responses to extended lumbar drainage (ELD) and shunt surgery. METHODS The baseline levels of MD metabolites and ICP were monitored overnight in 40 consecutive patients with iNPH. In a subset of 28 patients, monitoring was continued during 3 days of ELD. Thirty-one patients received a ventriculoperitoneal shunt. The clinical severity of iNPH was determined before and then 3 and 6-12 months after shunt surgery. RESULTS Altered levels of MD markers (lactate, pyruvate, lactate/pyruvate ratio, glutamate, and/or glycerol) were seen in all patients at baseline; these improved during ELD. Despite normal static ICP (mean ICP), the pulsatile ICP (the ICP wave amplitude) was increased in 24 patients (60%). Only the level of the ICP wave amplitude differentiated the ELD and/or shunt responders from nonresponders. CONCLUSIONS The MD monitoring indicated low-grade cerebral ischemia in patients with iNPH; during ELD, cerebral metabolism improved. The pulsatile ICP (the ICP wave amplitude) was the only variable differentiating the clinical responders from the nonresponders. The authors suggest that the pulsatile ICP reflects the intracranial compliance and that CSF diversion improves the biophysical milieu of the nerve cells, which subsequently may improve their biochemical milieu.
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Affiliation(s)
- Per K Eide
- Department of Neurosurgery, Division of Clinical Neuroscience, Rikshospitalet University Hospital, Oslo, Norway.
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Dissociation between vascular endothelial growth factor receptor-2 and blood vessel density in the caudate nucleus after chronic hydrocephalus. J Cereb Blood Flow Metab 2009; 29:1806-15. [PMID: 19675561 DOI: 10.1038/jcbfm.2009.98] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic hydrocephalus (CH) is characterized by the presence of ventricular enlargement, decreased cerebral blood flow (CBF), and brain tissue oxygen delivery. Although the underlying pathophysiological role of vascular endothelial growth factor (VEGF) is not clear, ischemic-hypoxic events in CH are known to trigger its release. Previously, we have shown increased VEGF receptor-2 (VEGFR-2) and blood vessel density (BVd) in the hippocampus after CH. We investigated changes in neuronal and glial VEGFR-2 density and BVd in the caudate nucleus in an experimental model of CH. Animals with CH were divided into short term (ST, 2 to 4 weeks) and long term (LT, 12 to 16 weeks) and were compared with surgical controls (SCs, 12 to 16 weeks). The cellular and BVds were estimated using immunohistochemical and stereological counting methods. Overall, percentage (%)VEGFR-2 neurons were approximately two times greater in CH (ST, LT) than in SC. By comparison, glial cell %VEGFR-2 was greater by 10% to 17% in ST and 4% to 11% lower in LT compared with that in SC. Blood vessel density was significantly lower in CH than in SC in the superficial caudate. Changes in cerebrospinal fluid ventricular volume and pressure, as well as in CBF did not correlate with either VEGFR-2 or BVd. These observed findings suggest that destructive forces may outweigh angiogenic forces and possibly show a disassociation between VEGFR-2 and BV expressions.
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Mecha M, Rabadán MA, Peña-Melián A, Valencia M, Mondéjar T, Blanco MJ. Expression of TGF-betas in the embryonic nervous system: analysis of interbalance between isoforms. Dev Dyn 2008; 237:1709-17. [PMID: 18498095 DOI: 10.1002/dvdy.21558] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) is a family of growth factors with essential and multiple roles during embryonic development. In mammals, three isoforms (TGF-beta1, TGF-beta2, TGF-beta3) have been described. In the nervous system, the presence of TGF-beta1 has remained undetectable in other structures than meninges and choroids plexus, while TGF-beta2 and TGF-beta3 were considered as the neural members of the family. In the present study, we have analysed the expression pattern of the three isoforms in the neural tube, brain, and spinal cord during development in both mouse and chicken. The data reveal specific patterns for each isoform. This work also shows that both TGF-beta1 and TGF-beta3 are expressed in neural crest cells. In addition, we demonstrate the existence of interbalance between TGF-beta1 and TGF-beta3 with possible functional implications, which, together with the expression of TGF-beta1 in the CNS, represents one of the most important contributions of this work.
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Affiliation(s)
- M Mecha
- Departamento de Anatomía y Embriología Humana I, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
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Dombrowski SM, Deshpande A, Dingwall C, Leichliter A, Leibson Z, Luciano MG. Chronic hydrocephalus-induced hypoxia: increased expression of VEGFR-2+ and blood vessel density in hippocampus. Neuroscience 2007; 152:346-59. [PMID: 18262364 DOI: 10.1016/j.neuroscience.2007.11.049] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 11/09/2007] [Accepted: 11/29/2007] [Indexed: 12/11/2022]
Abstract
Chronic hydrocephalus (CH) is a neurological disease characterized by increased cerebrospinal fluid volume and pressure that is often associated with impaired cognitive function. By and large, CH is a complex and heterogeneous cerebrospinal fluid (CSF) disorder where the exact site of brain insult is uncertain. Several mechanisms including neural compression, fiber stretch, and local or global hypoxia have been implicated in the underlying pathophysiology of CH. Specifically, the hippocampus, which plays a significant role in memory processing and is in direct contact with expanding CSF ventricles, may be involved. Using our model of chronic hydrocephalus, we quantified the density of vascular endothelial growth factor receptor 2 (VEGFR-2(+)) neurons, glial, endothelial cells, and blood vessels in hippocampal regions CA1, CA2-3, dentate gyrus and hilus using immunohistochemical and stereological methods. Density and %VEGFR-2(+) cell populations were estimated for CH animals (2-3 weeks vs. 12-16 weeks) and surgical controls (SC). Overall, we found approximately six- to eightfold increase in the cellular density of VEGFR-2(+) and more than double blood vessel density (BVd) in the hippocampus of CH compared with SC. There were no significant regional differences in VEGFR-2(+) cellular and BVd expression in the CH group. VEGFR-2(+) and BVds were significantly related to changes in CSF volume (P<or=0.05), and not intracranial pressure (ICP). The %VEGFR-2(+) was significantly greater in CH than SC (P<or=0.05), and was significantly correlated with BVd (P<or=0.05). These results showed that CH elicited a profound increase in VEGFR-2(+) in hippocampus that corresponded to increased BVd. It was unclear whether increased VEGFR-2(+) and blood vessel expression was related to focal compression alone or in combination with global ischemia/hypoxia conditions as previously described. These findings suggest that VEGFR-2 may play an adaptive role in angiogenesis after CH-induced hypoxia. Modulation of vascular endothelial growth factor/VEGFR-2(+) may be important in developing treatments for hypoxic conditions including hydrocephalus and other forms of cerebral ischemia.
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Affiliation(s)
- S M Dombrowski
- Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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Dombrowski SM, Schenk S, Leichliter A, Leibson Z, Fukamachi K, Luciano MG. Chronic hydrocephalus-induced changes in cerebral blood flow: mediation through cardiac effects. J Cereb Blood Flow Metab 2006; 26:1298-310. [PMID: 16495938 DOI: 10.1038/sj.jcbfm.9600282] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Decreased cerebral blood flow (CBF) in hydrocephalus is believed to be related to increased intracranial pressure (ICP), vascular compression as the result of enlarged ventricles, or impaired metabolic activity. Little attention has been given to the relationship between cardiac function and systemic blood flow in chronic hydrocephalus (CH). Using an experimental model of chronic obstructive hydrocephalus developed in our laboratory, we investigated the relationship between the duration and severity of hydrocephalus and cardiac output (CO), CBF, myocardial tissue perfusion (MTP), and peripheral blood flow (PBF). Blood flow measures were obtained using the microsphere injection method under controlled hemodynamic conditions in experimental CH (n=23) and surgical control (n=8) canines at baseline and at 2, 4, 8, 12, and 16 weeks. Cardiac output measures were made using the Swan-Ganz thermodilution method. Intracranial compliance (ICC) via cerebrospinal fluid (CSF) bolus removal and infusion, and oxygen delivery in CSF and prefrontal cortex (PFC) were also investigated. We observed an initial surgical effect relating to 30% CO reduction and approximately 50% decrease in CBF, MTP, and PBF in both groups 2 weeks postoperatively, which recovered in control animals but continued to decline further in CH animals at 16 weeks. Cerebral blood flow, which was positively correlated with CO (P=0.028), showed no significant relationship with either CSF volume or pressure. Decreased CBF correlated with oxygen deprivation in PFC (P=0.006). Cardiac output was inversely related with ventriculomegaly (P=0.019), but did not correlate with ICP. Decreased CO corresponded to increased ICC, as measured by CSF infusion (P=0.04). Our results suggest that CH may have more of an influence on CO and CBF in the chronic stage than in the early condition, which was dominated by surgical effect. The cause of this late deterioration of cardiac function in hydrocephalus is uncertain, but may reflect cardiac regulation secondary to physiologic response or brain injury. The relationship between cardiac function and CBF should be considered in the pathophysiology and clinical treatment of CH.
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Affiliation(s)
- Stephen M Dombrowski
- Department of Neurological Surgery, Pediatric and Congenital Neurological Surgery, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
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Klinge PM, Samii A, Mühlendyck A, Visnyei K, Meyer GJ, Walter GF, Silverberg GD, Brinker T. Cerebral hypoperfusion and delayed hippocampal response after induction of adult kaolin hydrocephalus. Stroke 2003; 34:193-9. [PMID: 12511773 DOI: 10.1161/01.str.0000048820.17198.15] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE In chronic hydrocephalus, a role for tissue hypoxia resulting from cerebrovascular compression is suggested. The purpose of this study was to evaluate whether changes in cerebral blood flow (CBF) in the time course of adult kaolin-induced hydrocephalus correlated with immunohistochemical neuronal responses. METHODS In 46 adult Sprague-Dawley rats, kaolin hydrocephalus was induced and immunostaining of neurofilament protein (NF68), synaptophysin (SYN38), and neuronal nitric oxide synthase (NOS) was performed at 2 (short term), 4 (intermediate term), and 6 and 8 (long term) weeks. Local CBF was measured quantitatively by [14C]iodoantipyrine ([14C]IAP) autoradiography in the short-term stage and in both long-term stages. RESULTS At 2 weeks, neuronal NOS immunoreactivity was globally increased in cortical areas and within the hippocampus. Four weeks after hydrocephalus induction, a reactive increase of SYN38 and NF68 immunoreactivity in the periventricular cortex was seen. At 6 and 8 weeks, when the ventricular size was decreasing, immunohistochemical changes in the hippocampus became most evident. A maintained toxic NOS reactivity in the CA1 subfield was accompanied by a loss of NF68 staining. In the CA3 subfield, however, focal increases in NF68 and SYN38 immunoreactivity were found. Cortical and hippocampal blood flow showed prolonged decreases of 25% to 55% compared with control animals. At 8 weeks, control levels were reached. CONCLUSIONS The observed temporary CBF decrease appears to correlate with an early global neuronal ischemic response. In addition, it may also account for the delayed selective response of ischemia-vulnerable structures, eg, hippocampus, in chronic adult kaolin-induced hydrocephalus.
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Affiliation(s)
- C E Johanson
- Dept of Clin. Neurosciences, Brown University, School of Medicine, Providence, RI 02903, USA.
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