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1.
Nature ; 627(8002): 165-173, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38326613

RESUMO

The arachnoid barrier delineates the border between the central nervous system and dura mater. Although the arachnoid barrier creates a partition, communication between the central nervous system and the dura mater is crucial for waste clearance and immune surveillance1,2. How the arachnoid barrier balances separation and communication is poorly understood. Here, using transcriptomic data, we developed transgenic mice to examine specific anatomical structures that function as routes across the arachnoid barrier. Bridging veins create discontinuities where they cross the arachnoid barrier, forming structures that we termed arachnoid cuff exit (ACE) points. The openings that ACE points create allow the exchange of fluids and molecules between the subarachnoid space and the dura, enabling the drainage of cerebrospinal fluid and limited entry of molecules from the dura to the subarachnoid space. In healthy human volunteers, magnetic resonance imaging tracers transit along bridging veins in a similar manner to access the subarachnoid space. Notably, in neuroinflammatory conditions such as experimental autoimmune encephalomyelitis, ACE points also enable cellular trafficking, representing a route for immune cells to directly enter the subarachnoid space from the dura mater. Collectively, our results indicate that ACE points are a critical part of the anatomy of neuroimmune communication in both mice and humans that link the central nervous system with the dura and its immunological diversity and waste clearance systems.


Assuntos
Aracnoide-Máter , Encéfalo , Dura-Máter , Animais , Humanos , Camundongos , Aracnoide-Máter/anatomia & histologia , Aracnoide-Máter/irrigação sanguínea , Aracnoide-Máter/imunologia , Aracnoide-Máter/metabolismo , Transporte Biológico , Encéfalo/anatomia & histologia , Encéfalo/irrigação sanguínea , Encéfalo/imunologia , Encéfalo/metabolismo , Dura-Máter/anatomia & histologia , Dura-Máter/irrigação sanguínea , Dura-Máter/imunologia , Dura-Máter/metabolismo , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Perfilação da Expressão Gênica , Imageamento por Ressonância Magnética , Camundongos Transgênicos , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/irrigação sanguínea , Espaço Subaracnóideo/imunologia , Espaço Subaracnóideo/metabolismo , Líquido Cefalorraquidiano/metabolismo , Veias/metabolismo
2.
Acta Neuropathol ; 137(1): 151-165, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30306266

RESUMO

The relationships between cerebrospinal fluid (CSF) and brain interstitial fluid are still being elucidated. It has been proposed that CSF within the subarachnoid space will enter paravascular spaces along arteries to flush through the parenchyma of the brain. However, CSF also directly exits the subarachnoid space through the cribriform plate and other perineural routes to reach the lymphatic system. In this study, we aimed to elucidate the functional relationship between CSF efflux through lymphatics and the potential influx into the brain by assessment of the distribution of CSF-infused tracers in awake and anesthetized mice. Using near-infrared fluorescence imaging, we showed that tracers quickly exited the subarachnoid space by transport through the lymphatic system to the systemic circulation in awake mice, significantly limiting their spread to the paravascular spaces of the brain. Magnetic resonance imaging and fluorescence microscopy through the skull under anesthetized conditions indicated that tracers remained confined to paravascular spaces on the surface of the brain. Immediately after death, a substantial influx of tracers occurred along paravascular spaces extending into the brain parenchyma. We conclude that under normal conditions a rapid CSF turnover through lymphatics precludes significant bulk flow into the brain.


Assuntos
Encéfalo/irrigação sanguínea , Líquido Cefalorraquidiano , Líquido Extracelular/metabolismo , Espaço Subaracnóideo/irrigação sanguínea , Animais , Transporte Biológico/fisiologia , Imageamento por Ressonância Magnética/métodos , Camundongos
3.
J Stroke Cerebrovasc Dis ; 27(10): 2792-2796, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30064869

RESUMO

BACKGROUND: Spontaneous spinal subarachnoid hemorrhage (SSAH) is a rare but serious condition that can lead to a variety of medical complications. METHODS: Using the Mayo Clinic Rochester database, consecutive patients admitted to the Mayo Clinic Rochester, Minnesota hospital with spontaneous SSAH (not iatrogenic or traumatic) between January 2000 and December 2015 were retrospectively reviewed. Demographic and clinical data and functional outcomes as categorized by the modified Rankin Scale (mRS) score at the time of discharge and at postadmission follow-up were assessed. RESULTS: Eight patients (median age 70 years, range 51-87) were identified. Seven patients presented with acute back pain or headache. Seven patients had poorly controlled chronic hypertension. Two patients had vasculitis and 1 had an arteriovenous malformation. Complications included cord compression (n = 4), hyponatremia (n = 5), sulcal subarachnoid hemorrhage (n = 2), chronic arachnoiditis (n = 1), vasospasm (n = 1), ischemic infarct (n = 1), and late cord ischemia (n = 1). All patients were managed medically including blood pressure control and repeat imaging. One patient had an aneurysm, which was embolized, and 2 received steroids for vasculitis. One patient died during hospitalization and 1 died within a week of discharge. Five patients had improved and 1 had unchanged mRS score at posthospitalization follow-up. CONCLUSIONS: SSAH should be considered in patients with sudden onset of severe back pain and headache, especially if as associated with lower extremity weakness or urinary retention. Our findings suggest that older patients with poorly controlled hypertension are at particular risk for spontaneous SSAH. In our study vascular anomalies were found in 25% of patients, vasculitis in 25%, hyponatremia in 63%, and cord compression in 50%. Cord compression may be managed conservatively. Mortality was 25% in the 3 months following the initial event, primarily due to other medical comorbidities.


Assuntos
Hemorragia Subaracnóidea/diagnóstico , Hemorragia Subaracnóidea/terapia , Espaço Subaracnóideo/irrigação sanguínea , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Bases de Dados Factuais , Avaliação da Deficiência , Feminino , Mortalidade Hospitalar , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Minnesota , Valor Preditivo dos Testes , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , Hemorragia Subaracnóidea/mortalidade , Hemorragia Subaracnóidea/fisiopatologia , Fatores de Tempo , Resultado do Tratamento
4.
Microvasc Res ; 113: 16-21, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28365218

RESUMO

During apnoea, the pial artery is subjected to two opposite physiological processes: vasoconstriction due to elevated blood pressure and vasorelaxation driven by rising pH in the brain parenchyma. We hypothesized that the pial artery response to apnoea may vary, depending on which process dominate. Apnoea experiments were performed in a group of 19 healthy, non-smoking volunteers (9 men and 10 women). The following parameters were obtained for further analysis: blood pressure, the cardiac (from 0.5 to 5.0Hz) and slow (<0.5Hz) components of subarachnoid space width, heart rate, mean cerebral blood flow velocity in the internal carotid artery, pulsatility and resistivity index, internal carotid artery diameter, blood oxygen saturation and end-tidal carbon dioxide. The experiment consisted of three apnoeas, sequentially: 30s, 60s and maximal apnoea. The breath-hold was separated for 5minute rest. The control process is sophisticated, involving internal cross-couplings and cross-dependences. The aim of work was to find a mathematical dependence between data. Unexpectedly, the modelling revealed two different reactions, on the same experimental procedure. As a consequence, there are two subsets of cardiac subarachnoid space width responses to breath-hold in humans. A positive cardiac subarachnoid space width change to apnoea depends on changes in heart rate and cerebral blood flow velocity. A negative cardiac subarachnoid space width change to apnoea is driven by heart rate, mean arterial pressure and pulsatility index changes. The described above two different reactions to experimental breath-hold provides new insights into our understanding of the complex mechanisms governing the adaptation to apnoea in humans. We proposed a mathematical methodology that can be used in further clinical research.


Assuntos
Apneia/fisiopatologia , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular , Hemodinâmica , Modelos Cardiovasculares , Pia-Máter/irrigação sanguínea , Espaço Subaracnóideo/irrigação sanguínea , Adaptação Fisiológica , Pressão Arterial , Velocidade do Fluxo Sanguíneo , Suspensão da Respiração , Feminino , Frequência Cardíaca , Humanos , Masculino , Fluxo Pulsátil , Fluxo Sanguíneo Regional , Vasoconstrição , Vasodilatação
5.
J Comput Assist Tomogr ; 38(1): 33-5, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24424554

RESUMO

Perivascular spaces (PVSs) surrounding the walls of arteries, arterioles, and venules do not directly communicate with subarachnoid spaces. There are a few reports exhibiting subarachnoid hemorrhage (SAH) and intracerebral hematomas extending to the PVSs by leakage of the leptomeninges that surround arteries. In this report, we present 4 patients of whom 3 had SAH extending into the PVSs in the bilateral basal ganglia and 1 had extension of contrast medium to the PVSs after injection of the contrast medium into the lumbar subarachnoid space. The hemorrhage extending to the PVSs in our 3 patients with SAH could be explained by leakage of the leptomeninges surrounding the arteries. However, how the contrast medium extends to the PVSs is not clear. We think that, although speculative, incomplete or complete defect at the leptomeninges surrounding the arteries resulting in direct continuity between the subarachnoid space and the PVS allows that blood or contrast media to extend to the PVSs.


Assuntos
Hemorragia Subaracnóidea/diagnóstico por imagem , Espaço Subaracnóideo/irrigação sanguínea , Idoso , Gânglios da Base/irrigação sanguínea , Angiografia Cerebral , Meios de Contraste , Extravasamento de Materiais Terapêuticos e Diagnósticos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
6.
Childs Nerv Syst ; 28(12): 2041-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22890472

RESUMO

INTRODUCTION: Spinal cord injury is a complex result of primary mechanical damage and the secondary vascular compromise and inflammatory reactions. Depending on timing, different treatment modalities may have various effects. CONCLUSIONS: We review the latest advances in terms of non-pharmacological experimental treatments.


Assuntos
Traumatismos da Medula Espinal/terapia , Animais , Drenagem , Dura-Máter/cirurgia , Terapia por Estimulação Elétrica , Campos Eletromagnéticos , Humanos , Oxigenoterapia Hiperbárica , Procedimentos Neurocirúrgicos , Fluxo Sanguíneo Regional/fisiologia , Traumatismos da Medula Espinal/líquido cefalorraquidiano , Espaço Subaracnóideo/irrigação sanguínea
7.
Neurosurg Focus ; 32(5): E15, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22537124

RESUMO

Spinal dural arteriovenous fistula (DAVF) is an uncommon condition that can be difficult to diagnose. This often results in misdiagnosis and treatment delay. Although conventional MRI plays an important role in the initial screening for the disease, the typical MRI findings may be absent. In this article, the authors present a series of 4 cases involving patients with angiographically proven spinal DAVFs who demonstrated cord T2 prolongation on conventional MRI but without abnormal subarachnoid flow voids or enhancement. These cases suggest that spinal DAVF cannot be excluded in symptomatic patients with cord edema based on conventional MRI findings alone. Dynamic Gd-enhanced MR angiography (MRA) was successful in demonstrating abnormal spinal vasculature in all 4 cases. This limited experience provides support for the role of spinal MRA in patients with abnormal cord signal and symptoms suggestive of DAVF even when typical MRI findings of a DAVF are absent.


Assuntos
Fístula Arteriovenosa/diagnóstico , Dura-Máter/irrigação sanguínea , Imageamento por Ressonância Magnética , Medula Espinal/irrigação sanguínea , Espaço Subaracnóideo/irrigação sanguínea , Idoso , Meios de Contraste , Feminino , Gadolínio , Humanos , Masculino , Pessoa de Meia-Idade
8.
Acta Neurol Scand ; 119(2): 100-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18616621

RESUMO

OBJECTIVES: To investigate the effect of early aneurysm surgery (<72 h) on outcome in patients with subarachnoid haemorrhage (SAH). MATERIALS AND METHODS: We studied two consecutive series of patients with aneurysmal SAH [postponed surgery (PS) cohort, n = 118, 1989-1992: surgery was planned on day 12 and early surgery (ES) cohort, n = 85, 1996-1998: ES was performed only in patients with Glasgow Coma Scale (GCS) >13]. We used multivariable logistic regression analysis to assess outcome at 3 months. RESULTS: Favourable outcome (Glasgow Outcome Scale 4 or 5) was similar in both cohorts. Cerebral ischemia occurred significantly more often in the ES cohort. The occurrence of rebleeds was similar in both cohorts. External cerebrospinal fluid (CSF) drainage was performed more often in the ES cohort (51% vs 19%). Patients with cisternal sum score (CSS) of subarachnoid blood <15 on admission [adjusted odds ratio (OR) for favourable outcome: 6.4, 95% confidence interval (CI) 1.0-39.8] and patients with both CSS <15 and GCS > 12 on admission benefited from the strategy including ES (OR 10.5, 95% CI 1.1-99.4). CONCLUSIONS: Our results support the widely adopted practice of ES in good-grade SAH patients.


Assuntos
Aneurisma Intracraniano/cirurgia , Hemorragia Subaracnóidea/cirurgia , Adulto , Isquemia Encefálica/etiologia , Estudos de Coortes , Drenagem , Feminino , Escala de Resultado de Glasgow , Humanos , Aneurisma Intracraniano/líquido cefalorraquidiano , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Hemorragia Subaracnóidea/líquido cefalorraquidiano , Espaço Subaracnóideo/irrigação sanguínea , Resultado do Tratamento
9.
J Cereb Blood Flow Metab ; 38(4): 719-726, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29039724

RESUMO

Clearance of waste products from the brain is of vital importance. Recent publications suggest a potential clearance mechanism via paravascular channels around blood vessels. Arterial pulsations might provide the driving force for paravascular flow, but its flow pattern remains poorly characterized. In addition, the relationship between paravascular flow around leptomeningeal vessels and penetrating vessels is unclear. In this study, we determined blood flow and diameter pulsations through a thinned-skull cranial window. We observed that microspheres moved preferentially in the paravascular space of arteries rather than in the adjacent subarachnoid space or around veins. Paravascular flow was pulsatile, generated by the cardiac cycle, with net antegrade flow. Confocal imaging showed microspheres distributed along leptomeningeal arteries, while their presence along penetrating arteries was limited to few vessels. These data suggest that paravascular spaces around leptomeningeal arteries form low resistance pathways on the surface of the brain that facilitate cerebrospinal fluid flow.


Assuntos
Encéfalo/fisiologia , Líquido Cefalorraquidiano/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Volume Sanguíneo , Encéfalo/anatomia & histologia , Artérias Cerebrais/fisiologia , Circulação Cerebrovascular/fisiologia , Pressão Intracraniana/fisiologia , Masculino , Meninges/irrigação sanguínea , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microesferas , Espaço Subaracnóideo/irrigação sanguínea , Espaço Subaracnóideo/fisiologia
10.
Lik Sprava ; (5-6): 40-2, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16396290

RESUMO

Morphological and histochemical investigations on dura mater spinalis of the lumbar site in 5 women of reproductive age dead from accidents and 5 women dead during deliveries due to hemorrhage were carried out. It was found that one of the etiological factors of head-aches after subarachnoid anesthesia was functional reduction of mechanic and supporting function of dura mater spinalis along with elasticity loss of fibrous tissue, edema and friability. The stable non-healing postpuncture defect of dura mater spinalis resulted in liquorrhea with subsequent development of the "liquorrhea hypotension" syndrome.


Assuntos
Acidentes/mortalidade , Lesões Encefálicas , Traumatismos Craniocerebrais , Parto Obstétrico/efeitos adversos , Dura-Máter/patologia , Adulto , Anestésicos Locais/efeitos adversos , Fenômenos Biomecânicos , Lesões Encefálicas/etiologia , Lesões Encefálicas/mortalidade , Lesões Encefálicas/patologia , Traumatismos Craniocerebrais/etiologia , Traumatismos Craniocerebrais/mortalidade , Traumatismos Craniocerebrais/patologia , Dura-Máter/metabolismo , Feminino , Histocitoquímica , Humanos , Região Lombossacral , Gravidez , Espaço Subaracnóideo/irrigação sanguínea , Espaço Subaracnóideo/patologia
11.
Stroke ; 34(8): 1886-91, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12829863

RESUMO

BACKGROUND AND PURPOSE: Hyperintense vessel sign (HVS) on fluid-attenuated inversion recovery (FLAIR) has been described in hyperacute stroke patients with arterial occlusion. We sought to determine whether HVS was more frequent in patients with intracerebral arterial stenoses than in those without stenosis regardless of the presence of a brain infarct. METHODS: In this case-control study (19 symptomatic patients with multiple intracerebral arterial stenoses compared with 19 age-matched asymptomatic patients without stenosis), we looked for HVS (ie, focal or tubular hyperintensities in the subarachnoid space) on FLAIR images. We compared the proportion of HVS-positive patients in the 2 groups and evaluated the concordance between the arterial distribution of stenoses on angiogram and that of HVS on FLAIR. RESULTS: HVS was found in 13 of 19 patients (68%) in the study group and 1 of 19 control patients (5.2%) (P<0.0001). The concordance between the territorial distribution of stenoses on angiogram and HVS on FLAIR was higher for the right and left middle cerebral artery (kappa=0.6 and 0.63, respectively) compared with the right and left anterior cerebral artery (kappa=0.35 and 0.2, respectively). HVSs were observed in 1 of 7 patients with posterior cerebral artery stenoses on angiogram. HVSs were seen equally in patients with acute focal (7 of 10) or diffuse (6 of 9) cerebral involvement. In the 6 HVS-positive patients with acute stroke confirmed by MRI, additional HVSs were observed in a different arterial territory than that of the stroke lesion. CONCLUSIONS: Although their significance remains unclear, multiple HVSs are more frequently observed in symptomatic patients with multiple intracerebral stenoses than in asymptomatic patients without stenosis.


Assuntos
Doenças Arteriais Cerebrais/diagnóstico , Constrição Patológica/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Angiografia Digital , Estudos de Casos e Controles , Angiografia Cerebral , Doenças Arteriais Cerebrais/complicações , Circulação Cerebrovascular , Constrição Patológica/complicações , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Valores de Referência , Reprodutibilidade dos Testes , Estudos Retrospectivos , Espaço Subaracnóideo/irrigação sanguínea , Vasculite do Sistema Nervoso Central/complicações , Vasculite do Sistema Nervoso Central/diagnóstico
12.
J Cereb Blood Flow Metab ; 11(3): 353-60, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2016343

RESUMO

We used confocal laser scanning microscopy (CLSM) to investigate the morphology and three-dimensional relationships of the microcirculation of the superficial layers of the rat brain cortex in vivo. In anesthetized rats equipped with a closed cranial window (dura mater removed), after i.v. injection of 3 mg/100 g of body weight of fluorescein in 0.5 ml of saline, serial optical sections of the brain cortex intraparenchymal microcirculation were taken. Excitation was at a wavelength of 488 nm (argon laser), and emission was collected above 515 nm. CLSM provided images of brain vessels with sufficient signal-to-noise ratio for three-dimensional reconstructions down to a depth of 250 microns beneath the surface of the brain. Compared to conventional fluorescence microscopy, CLSM has a much higher axial resolution and higher depth of penetration. Laser light-induced intravascular aggregates, irregularities of erythrocyte flow, or microvascular occlusions ("light and dye injury") were not apparent in the current experimental paradigm. CLSM is a promising new tool for in vivo visualization of the cerebral microcirculation. Future studies have to characterize the potential damage to the tissue dye mechanisms.


Assuntos
Córtex Cerebral/irrigação sanguínea , Microcirculação/anatomia & histologia , Animais , Capilares/anatomia & histologia , Processamento de Imagem Assistida por Computador , Masculino , Microscopia/métodos , Microscopia de Fluorescência , Lobo Parietal/irrigação sanguínea , Pia-Máter/irrigação sanguínea , Ratos , Ratos Endogâmicos , Espaço Subaracnóideo/irrigação sanguínea
13.
Brain Res ; 463(2): 259-67, 1988 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-3196917

RESUMO

We have analyzed rabbit cerebrospinal fluid for neuropeptide Y (NPY)-like immunoreactivity, using high performance liquid chromatography (HPLC) and radioimmunoassay (RIA) and examined the anatomical relationship of NPY-containing fibers to the cerebral vasculature and the third cerebral ventricle. Cerebrospinal fluid (CSF) obtained from the cisterna magna of rabbits was injected into a C18 column and subjected to HPLC. The fractions were collected, dried and reconstituted in buffer for NPY radioimmunoassay. A single peak of NPY immunoreactivity was obtained which corresponded in retention time to synthetic porcine NPY. Analysis of CSF samples produced displacement curves parallel to the standard curve. Immunohistochemistry revealed numerous NPY-labeled fibers which penetrated the ependymal lining of the third cerebral ventricle and directly bordered the ventricular lumen. Other fibers were observed in the pia which lines the ventral aspect of the hypothalamus. The basilar artery, its branches and other cerebral vessels were surrounded by NPY-labeled fibers. The results show that: (1) approximately 1 ng/ml of NPY immunoreactivity which corresponds chromatographically to synthetic porcine NPY is present in rabbit CSF; (2) NPY-containing fibers surround the basilar artery and other cerebral vessels; (3) NPY may be released into the CSF from axons in the pia and from axons which penetrate the ependymal lining of the third ventricle. These observations form the basis for our analysis of the vasoconstrictor effects of NPY and its role in cerebrovasospasm after experimental subarachnoid hemorrhage.


Assuntos
Artérias Cerebrais/inervação , Ventrículos Cerebrais/metabolismo , Neuropeptídeo Y/líquido cefalorraquidiano , Espaço Subaracnóideo/metabolismo , Animais , Ventrículos Cerebrais/irrigação sanguínea , Imuno-Histoquímica , Masculino , Neuropeptídeo Y/metabolismo , Coelhos , Espaço Subaracnóideo/irrigação sanguínea
14.
J Neurol ; 226(1): 43-52, 1981.
Artigo em Inglês | MEDLINE | ID: mdl-6181215

RESUMO

Pleocytosis in cerebrospinal fluid and infiltration of the leptomeningeal tissue have been studied after injection of ferritin into the subarachnoid space (SAS) of cats. The most important source of granulocytes in the leptomeninges are the relatively large veins of the pia mater, which have very thin walls. Passing between the lining cells of the pia mater the granulocytes leave the connective tissue space of the pia mater and reach the SAS. Leukodiapedesis has also been observed in veins crossing the SAS. During this process, gaps between the lining cells of the perivascular leptomeningeal sheath may develop. There are two possible ways for the granulocytes to pass from the vascular pia mater to the avascular arachnoidea: either they migrate actively on the surface of the leptomeningeal trabeculae or they reach the arachnoidea passively by the circulation of the cerebrospinal fluid. Leukodiapedesis in the vessels of the dura mater occurs relatively seldom and would not be able to cause the occasionally massive infiltration of the arachnoidea.


Assuntos
Aracnoide-Máter/citologia , Leucócitos/fisiologia , Pia-Máter/citologia , Espaço Subaracnóideo/citologia , Animais , Gatos , Movimento Celular , Dura-Máter/citologia , Espaço Subaracnóideo/irrigação sanguínea , Veias/citologia
15.
Neurosurgery ; 29(2): 232-8, 1991 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1886661

RESUMO

To gain a better understanding of cerebrospinal fluid (CSF) hydrodynamics and their relationship to the cerebrovascular system, normal and naturally hydrocephalic dogs were studied to determine transmantle [lateral ventricle (LV) to subarachnoid space] and transparenchymal [LV to cortical vein (CV)] pressures. Pressure was also measured in the sagittal sinus, cisterna magna, and femoral artery. CV pressure has not previously been measured in hydrocephalus. Ventricular volume was determined by computed tomography. Four groups of animals were studied. In Group 1 (n = 5) transmantle pressure was measured; in Group 2 (n = 5), transparenchymal pressure in normal animals was measured. In Group 3 (n = 5) was measured all the pressures in spontaneously normal animals, and in Group 4 (n = 6) was measured the pressures in hydrocephalic animals. The pressure-volume index and CSF outflow resistance were also measured. LV volume in the normal dogs was 1.3 +/- 0.7 ml and in the hydrocephalic dogs was 5.1 +/- 2.7 ml (P less than 0.005). Although LV, subarachnoid space, and sagittal sinus pressures were elevated in the hydrocephalic dogs (15.1 versus 10.2, 16.4 versus 10.5, and 8.4 versus 5.2 mm Hg, respectively), the transmantle pressure and subarachnoid space to sagittal sinus gradients were not significantly altered. CV pressure was markedly elevated in the hydrocephalic animals (21.5 versus 11.7 mm Hg, P less than 0.005). The pressure-volume index and outflow resistance were not significantly different. These results suggest that an elevated CV pressure plays a role in the development and/or maintenance of hydrocephalus, and that the pathway for CSF absorption includes transcapillary or transvenular absorption of CSF from the interstitial space.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Veias Cerebrais/fisiopatologia , Hidrocefalia/fisiopatologia , Animais , Ventrículos Cerebrais/irrigação sanguínea , Ventriculografia Cerebral , Cães , Hidrocefalia/líquido cefalorraquidiano , Hidrocefalia/diagnóstico por imagem , Pulso Arterial/fisiologia , Espaço Subaracnóideo/irrigação sanguínea , Tomografia Computadorizada por Raios X , Pressão Venosa/fisiologia
16.
Neurosurgery ; 35(3): 472-81; discussion 481-3, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7800139

RESUMO

The use of cranial base approaches to aneurysm surgery is illustrated by means of patient examples. Over a 9-year period, cranial base approaches were used to expose and treat 38 aneurysms involving the anterior communicating artery complex, proximal internal carotid artery, basilar artery, or vertebral artery. The approaches included orbital osteotomy, orbitozygomatic osteotomy, petrous apicectomy, presigmoid petrosectomy, and extreme lateral transcondylar methods. Complications related to the approaches included one partial ptosis and two cerebrospinal fluid leaks, which resolved with treatment. The technique of three-dimensional computed tomographic angiography was useful in delineating the vascular anatomy and its relation to the cranial base structures. This helped the surgeon plan the appropriate approach to the aneurysm. Cranial base approaches, used selectively, can provide improved exposure of deep-seated aneurysms and large or giant aneurysms, while minimizing brain retraction.


Assuntos
Craniotomia/métodos , Aneurisma Intracraniano/cirurgia , Aneurisma Roto/diagnóstico , Aneurisma Roto/cirurgia , Artéria Basilar/cirurgia , Artéria Carótida Interna/cirurgia , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Aneurisma Intracraniano/diagnóstico , Complicações Pós-Operatórias/etiologia , Espaço Subaracnóideo/irrigação sanguínea , Tomografia Computadorizada por Raios X , Artéria Vertebral/cirurgia
17.
J Neurosurg ; 48(2): 173-8, 1978 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-624965

RESUMO

Measurements were made at eight predetermined positions on 627 sets of angiograms from 293 patients with aneurysms. A ratio between the sum of the vessel diameters in the subarachnoid space to the sum in the base of skull and neck was calculated and plotted against time. Vasospasm has its onset in man about Day 3 after subarachnoid hemorrhage, is maximal at Days 6 to 8, and is gone by Day 12. There is a tendency for patients in poor clinical grades to have more vasospasm. The patients with most vasospasm have a significantly higher mortality than those with the least.


Assuntos
Artéria Carótida Interna/patologia , Artérias Cerebrais/patologia , Aneurisma Intracraniano/complicações , Espasmo/etiologia , Hemorragia Subaracnóidea/complicações , Espaço Subaracnóideo/irrigação sanguínea , Doenças Vasculares/etiologia , Angiografia Cerebral , Humanos , Aneurisma Intracraniano/patologia , Hemorragia Subaracnóidea/patologia , Fatores de Tempo
18.
J Neurosurg ; 82(2): 196-200, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7815146

RESUMO

To establish if interruption of the intradural draining spinal vein or surgical excision are curative treatments for spinal dural arteriovenous fistulas (AVFs), the medical records and radiographic studies of 19 patients with spinal dural AVFs and progressive myelopathy were reviewed. Spinal arteriograms were obtained before and within 2 weeks after surgery in 19 patients, and after a delay of 4 months or more in 11 patients. The mean clinical and arteriographic follow up was at 37 and 35 months, respectively. In the 11 patients who underwent excision of the dural AVF there was no evidence of a residual lesion upon immediate or delayed postoperative arteriography. Surgery in eight patients consisted of simple interruption of the intradural draining vein as it entered the subarachnoid space. In six of these patients the vein draining the AVF intrathecally provided the only venous drainage of the AVF. In these six patients there was no immediate (six of six) or delayed (four of six) arteriographic evidence of residual or recurrent flow through the AVF. Two patients had an AVF with both intra- and extradural venous drainage; after intradural division of the draining vein there was residual flow through the AVF into the extradural venous system. In one of these two patients intrathecal venous drainage was reestablished, which required additional therapy. In the other patient the extradural AVF spontaneously thrombosed and was not evident on delayed follow-up arteriography. In patients with spinal dural AVFs with only intrathecal medullary venous drainage, which includes most patients with these lesions, surgical interruption of the intradural draining vein provides lasting and curative treatment. In patients with both intra- and extradural drainage of the AVF, complete excision of the fistula or interruption of the intra- and extradural venous drainage of the fistula is indicated. In patients in whom a common vessel supplies the spinal cord and the dural AVF, simple surgical interruption of the vein draining the AVF is the treatment of choice, as it provides lasting obliteration of the fistula and it is the only treatment that does not risk arterial occlusion and cord infarction. Simple interruption of the venous drainage of a spinal dural AVF provides lasting occlusion of the fistula, as it does for cranial dural AVFs, if all pathways of venous drainage are interrupted. This result provides further evidence that the venous approach to the treatment of dural AVFs can be used successfully.


Assuntos
Fístula Arteriovenosa/cirurgia , Dura-Máter/irrigação sanguínea , Medula Espinal/irrigação sanguínea , Adulto , Idoso , Fístula Arteriovenosa/diagnóstico por imagem , Dura-Máter/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Medula Espinal/diagnóstico por imagem , Espaço Subaracnóideo/irrigação sanguínea , Resultado do Tratamento , Veias/cirurgia
19.
J Neurosurg ; 73(5): 688-98, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2213158

RESUMO

In this prospective multicenter study, the authors have examined data derived from the initial computerized tomography (CT) scans of 753 patients with severe head injury. When the CT findings were related to abnormal intracranial pressure and to death, the most important characteristics of the scans were: midline shift: compression or obliteration of the mesencephalic cisterns: and the presence of subarachnoid blood. Diffuse hemispheric swelling was also found to be associated with an early episode of either hypoxia or hypotension.


Assuntos
Lesões Encefálicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Lesões Encefálicas/complicações , Lesões Encefálicas/mortalidade , Hemorragia Cerebral/etiologia , Humanos , Hipotensão/etiologia , Hipóxia/etiologia , Pressão Intracraniana , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Espaço Subaracnóideo/irrigação sanguínea
20.
Neurol Res ; 19(6): 577-87, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9427956

RESUMO

We describe the microanatomy of the perforating arteries arising from the anterior communicating artery complex (5 mm distal of the anterior cerebral artery, the anterior communicating artery, and 5 mm proximal of the distal anterior cerebral artery). Thirteen unfixed human brains were used in this study. The origin and number of perforators are described, as is the site of brain penetration, and results are correlated with previous studies. The hemodynamics of blood flow in relation to the formation of an anterior communicating artery aneurysm and different surgical approaches are mentioned. The neuropsychological outcome after aneurysm clipping with regards to the pattern of blood supply from the anterior cerebral artery complex is also discussed.


Assuntos
Encéfalo/irrigação sanguínea , Artérias Cerebrais/anatomia & histologia , Encéfalo/anatomia & histologia , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/irrigação sanguínea , Corpo Caloso/anatomia & histologia , Corpo Caloso/irrigação sanguínea , Hemodinâmica , Humanos , Aneurisma Intracraniano/etiologia , Aneurisma Intracraniano/fisiopatologia , Quiasma Óptico/anatomia & histologia , Quiasma Óptico/irrigação sanguínea , Fluxo Sanguíneo Regional , Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/irrigação sanguínea
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