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1.
Neurology ; 93(12): e1205-e1211, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31409736

RESUMO

OBJECTIVE: To determine the hemodynamic conditions associated with optimal neurologic improvement in individuals with acute traumatic spinal cord injury (SCI) who had lumbar intrathecal catheters placed to measure CSF pressure (CSFP). METHODS: Ninety-two individuals with acute SCI were enrolled in this multicenter prospective observational clinical trial. We monitored mean arterial pressure (MAP) and CSFP during the first week after injury and assessed neurologic function at baseline and 6 months after injury. We used relative risk iterations to determine transition points at which the likelihood of either improving neurologically or remaining unchanged neurologically was equivalent. These transition points guided our analyses in which we examined the linear relationships between time spent within target hemodynamic ranges (i.e., clinical adherence) and neurologic recovery. RESULTS: Relative risk transition points for CSFP, MAP, and spinal cord perfusion pressure (SCPP) were linearly associated with neurologic improvement and directed the identification of key hemodynamic target ranges. Clinical adherence to the target ranges was positively and linearly related to improved neurologic outcomes. Adherence to SCPP targets, not MAP targets, was the best indicator of improved neurologic recovery, which occurred with SCPP targets of 60 to 65 mm Hg. Failing to maintain the SCPP within the target ranges was an important detrimental factor in neurologic recovery, particularly if the target range is set lower. CONCLUSION: We provide an empirical, data-driven approach to aid institutions in setting hemodynamic management targets that accept the real-life challenges of adherence to specific targets. Our results provide a framework to guide the development of widespread institutional management guidelines for acute traumatic SCI.


Assuntos
Pressão Sanguínea/fisiologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia , Medula Espinal/irrigação sanguínea , Medula Espinal/fisiologia , Cateterismo/métodos , Vértebras Cervicais/lesões , Gerenciamento Clínico , Feminino , Hemodinâmica/fisiologia , Humanos , Vértebras Lombares/lesões , Estudos Prospectivos , Traumatismos da Medula Espinal/diagnóstico , Vértebras Torácicas/lesões
2.
Pediatr. aten. prim ; 21(81): 15-20, ene.-mar. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-184523

RESUMO

Introducción: se analizan las características de la hipertensión intracraneal idiopática; clínica al inicio, pruebas realizadas, tratamiento y evolución que presentaron. Material y métodos: estudio descriptivo retrospectivo de los pacientes diagnosticados de hipertensión intracraneal idiopática en los últimos siete años (2011-2017) en un hospital de tercer nivel. Resultados: se estudiaron 40 pacientes (55% mujeres) con una edad media de 9,6 años. Como factores asociados, el 5% seguían tratamiento con hormona del crecimiento. Solo el 25% presentaban sobrepeso u obesidad. El síntoma principal fue cefalea opresiva, asociando vómitos (27,5%) o alteraciones visuales (22%). Tres pacientes presentaron hallazgo casual de papiledema bilateral. La exploración física fue anodina (65%), se observó estrabismo por parálisis del VI par craneal (35%). Presentaron papiledema el 62,5%. La campimetría solo se realizó en el 55% de los pacientes y estaba alterada en el 50% de estos. El tiempo hasta el diagnóstico fue 44,8 días. Obtuvimos una presión de apertura media 29,7 cm H2O (± 8,2). Se realizó tomografía computarizada al 85% de los pacientes y fue normal en el 88,2% de estos. Se hizo resonancia magnética craneal al 7,5%, y fue normal en el 70% de estos. Se practico angio-RM al 5%, y fue normal en todos los casos. Se solicitó analítica, con función renal y hepática (62,5%, todos normal), hormonal (65%), estudio de trombofilias y autoinmunidad (10% y 20% respectivamente, anodinas). Se inició tratamiento con acetazolamida (95%), y hubo que añadir corticoterapia por falta de respuesta en el 24% de los casos. En el 5% se autolimitó espontáneamente. Como último escalón, el 7,5% requirió válvula de derivación lumboperitoneal. Evolucionaron favorablemente el 95%, con recidivas en el 15% de los casos. El tiempo medio hasta la resolución fue de 3,9 meses. Conclusión: el diagnóstico y tratamiento precoz de la hipertensión intracraneal idiopática es importante para evitar posibles secuelas irreversibles. El estudio oftalmológico, especialmente la campimetría, es esencial para el diagnóstico, seguimiento y determinación de la agresividad del tratamiento


Introduction: the characteristics of idiopathic intracranial hypertension are analyzed; epidemiology, clinic at the beginning, tests performed, treatment and evolution that presented the analyzed cases. Material and methods: a retrospective descriptive study was conducted on patients with idiopathic intracra­nial hypertension in the last seven years (2011-2017), in a third level hospital. Results: forty patients (55% women) were studied, with a mean age of 9.6 years. As associated factors, 5% had a treatment with growth hormone. It is important to note that only 25% were overweight or obese. The main symptom was oppressive headache, without predominance hours, associating vomiting (27.5%), or visual alterations (22%). Three asymptomatic patients presented a chance finding of bilateral papilledema. The physical examination was anodyne (65%), showing strabismus due to cranial nerve palsy VI (35%). 62,5% presented papilledema, and the campimetry was only performed in 55% of the patients, altered in 50% of them. The time to diagnosis was 44.8 days. We obtained an average opening pressure of 29.7 cm H2O (± 8.2). CT was performed (85%), being normal (88.2%). MRI of the skull (7.5%), normal (70%). Angio-NMR (5%), all normal. Analytical was requested, with renal and hepatic function (62.5%, all normal), hormonal (65%), thrombophilic study and autoimmunity (10% and 20% respectively, anodyne). Treatment was started with acetazolamide (95%), requiring the addition of corticotherapy due to lack of response 24%. In 5%, it spontaneously self-limited. As a last step, 7.5% required a lumboperitoneal bypass valve. They evolved favora­bly 95%, relapsing 15%. Redialing the average time to resolution was 3.9 months. Conclusion: idiopathic intracranial hypertension is rare, but its diagnosis and early treatment is essential to avoid possible irreversible sequelae. The ophthalmological study, by fundus and especially campimetry, is es­sential for the diagnosis, monitoring and determination of the aggressiveness of the treatment


Assuntos
Humanos , Masculino , Feminino , Criança , Pseudotumor Cerebral/epidemiologia , Hipertensão Intracraniana/diagnóstico , Papiledema/diagnóstico , Pressão do Líquido Cefalorraquidiano/fisiologia , Diagnóstico Diferencial , Testes de Campo Visual/estatística & dados numéricos , Estudos Retrospectivos , Hormônio do Crescimento/uso terapêutico
3.
Neurocrit Care ; 30(2): 421-428, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30328047

RESUMO

BACKGROUND/OBJECTIVES: We recently developed techniques to monitor intraspinal pressure (ISP) and spinal cord perfusion pressure (SCPP) from the injury site to compute the optimum SCPP (SCPPopt) in patients with acute traumatic spinal cord injury (TSCI). We hypothesized that ISP and SCPPopt can be predicted using clinical factors instead of ISP monitoring. METHODS: Sixty-four TSCI patients, grades A-C (American spinal injuries association Impairment Scale, AIS), were analyzed. For 24 h after surgery, we monitored ISP and SCPP and computed SCPPopt (SCPP that optimizes pressure reactivity). We studied how well 28 factors correlate with mean ISP or SCPPopt including 7 patient-related, 3 injury-related, 6 management-related, and 12 preoperative MRI-related factors. RESULTS: All patients underwent surgery to restore normal spinal alignment within 72 h of injury. Fifty-one percentage had U-shaped sPRx versus SCPP curves, thus allowing SCPPopt to be computed. Thirteen percentage, all AIS grade A or B, had no U-shaped sPRx versus SCPP curves. Thirty-six percentage (22/64) had U-shaped sPRx versus SCPP curves, but the SCPP did not reach the minimum of the curve, and thus, an exact SCPPopt could not be calculated. In total 5/28 factors were associated with lower ISP: older age, excess alcohol consumption, nonconus medullaris injury, expansion duroplasty, and less intraoperative bleeding. In a multivariate logistic regression model, these 5 factors predicted ISP as normal or high with 73% accuracy. Only 2/28 factors correlated with lower SCPPopt: higher mean ISP and conus medullaris injury. In an ordinal multivariate logistic regression model, these 2 factors predicted SCPPopt as low, medium-low, medium-high, or high with only 42% accuracy. No MRI factors correlated with ISP or SCPPopt. CONCLUSIONS: Elevated ISP can be predicted by clinical factors. Modifiable factors that may lower ISP are: reducing surgical bleeding and performing expansion duroplasty. No factors accurately predict SCPPopt; thus, invasive monitoring remains the only way to estimate SCPPopt.


Assuntos
Circulação Sanguínea/fisiologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Monitorização Neurofisiológica/métodos , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/fisiopatologia , Medula Espinal/irrigação sanguínea , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Traumatismos da Medula Espinal/cirurgia , Adulto Jovem
4.
J Neurointerv Surg ; 11(3): 307-312, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30389898

RESUMO

BACKGROUND: Venous stenting has been proven to be a safe and effective therapeutic option for patients with idiopathic intracranial hypertension (IIH) and cerebral venous sinus stenosis (CVSS). However, its use in patients with cerebral venous sinus thrombosis-related CVSS has been less reported. PURPOSE: To explore the safety and efficacy of stenting for patients with cerebral venous sinus thrombosis (CVST)-related CVSS. METHODS: The clinical presentation, treatment, and outcome of patients with CVST-related CVSS received venous stenting in the chronic stage after failed medical treatment were retrospectively evaluated. RESULTS: A total of 17 patients with CVST-related CVSS were included. Mean pressure gradient across the CVSS decreased from 11.5±4.2 mmHg prior to stenting to 2.1±1.1 mmHg post- stenting. Mean CSF opening pressure decreased from 33.1±5.5 cmH2O to 18.7±1.7 cmH2O. Both headache and visual disturbance improved or resolved in 78% and 92% of the patients, respectively. Complications included lethal cerebellar hematoma in one case and bilateral occipital epidural hematoma in another case. One of the patients received retreatment with ventriculo-peritoneal shunting due to recurrent headache. CONCLUSION: Restoring the patency of stenotic sinuses with stents in patients of CVST-related CVSS unresponsive to medical therapy in the chronic stage may improve symptoms in the majority of the patients. However, a relatively higher cerebral hemorrhage rate was observed and may be related to this pathology. Stenting in this subgroup of CVSS patients may require further evaluation with a larger and long-term study, and should be used with caution at this time.


Assuntos
Cavidades Cranianas/diagnóstico por imagem , Cavidades Cranianas/cirurgia , Trombose dos Seios Intracranianos/diagnóstico por imagem , Trombose dos Seios Intracranianos/cirurgia , Stents , Adulto , Veias Cerebrais/diagnóstico por imagem , Veias Cerebrais/cirurgia , Pressão do Líquido Cefalorraquidiano/fisiologia , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
5.
Br J Neurosurg ; 33(1): 71-75, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28934871

RESUMO

INTRODUCTION: Headaches, visual problems and tinnitus are symptoms of Idiopathic Intracranial Hypertension (IIH) which resolve with reduction of CSF pressure. Impaired cranial venous outflow has been implicated in the pathogenesis and there is evidence of good treatment results in IIH using venous sinus stenting. We are currently initiating a multi-centre randomised controlled trial, the VISION study (Venous Intervention versus Shunting in IIH for Optic Disc Swelling) comparing radiological (venous sinus stenting) to surgical intervention (CSF shunting). As part of the preparations for VISION we made a basic questionnaire available to members of the website IIH UK ( www.iih.org.uk ). METHODS: 10-point questionnaire pertaining to IIH diagnosis, symptoms and management using www.surveymonkey.com . RESULTS: 250 questionnaires were returned. 95.6% of respondents were female, mostly ≤40 years of age. 70% were diagnosed in the last 5 years, but only 35% were diagnosed less than a year after onset of symptoms. 59.4% of patients had not undergone any radiological/surgical intervention, 34.9% had had CSF diversion, 3.6% venous stenting and 2.0% had stent plus shunt. 16.8% indicated their lives were most affected by tinnitus and 18.1% by visual problems, but 49.6% said they were most affected by their headaches. 81% of patients indicated they would be happy to participate in a randomised trial comparing the two treatment options of venous stenting and CSF shunting. CONCLUSION: IIH patients want to be actively involved in their treatment and are favourably disposed towards clinical research. Variation exists in treatment modalities offered. There are individual differences regarding impact of symptoms.


Assuntos
Pseudotumor Cerebral/cirurgia , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Pressão do Líquido Cefalorraquidiano/fisiologia , Derivações do Líquido Cefalorraquidiano/métodos , Feminino , Transtornos da Cefaleia/etiologia , Transtornos da Cefaleia/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Procedimentos Neurocirúrgicos/psicologia , Nervo Óptico/cirurgia , Aceitação pelo Paciente de Cuidados de Saúde , Participação do Paciente , Pseudotumor Cerebral/psicologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Stents , Zumbido/etiologia , Zumbido/cirurgia , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/psicologia , Transtornos da Visão/etiologia , Transtornos da Visão/cirurgia , Adulto Jovem
7.
Neurología (Barc., Ed. impr.) ; 33(7): 449-458, sept. 2018. ilus
Artigo em Espanhol | IBECS | ID: ibc-175953

RESUMO

Introducción: Desde la descripción hace 5 décadas de la hidrocefalia crónica del adulto idiopática (HCAi), su fisiopatología ha sido considerada básicamente relacionada con el efecto que la dilatación ventricular ejerce sobre las estructuras adyacentes al sistema ventricular. Sin embargo, las alteraciones en el flujo sanguíneo cerebral (FSC) y, sobre todo, la reducción en el recambio licuoral parecen emerger como componentes fisiopatológicos principales de esta enfermedad. Desarrollo: En la HCAi se observa una compresión del tracto piramidal, de los circuitos cortico-subcorticales fronto-estriatales y fronto-reticulares, y de las fibras profundas del fascículo longitudinal superior. En el cuerpo calloso se objetiva un descenso en el número de fibras comisurales, que son reemplazadas por gliosis. El FSC se encuentra alterado, con un patrón de última pradera en la región subcortical adyacente a los ventrículos, correspondiente a la intersección entre las arterias subependimarias y las arterias perforantes dependientes de los grandes troncos arteriales de la circulación anterior. El recambio diario del LCR se ve disminuido en un 75%, lo que conlleva una reducción del aclaramiento de neurotóxicos y la interrupción de las señalizaciones neuroendocrinas y paracrinas que ocurren a través del LCR. Conclusiones: La HCAi emerge como una entidad nosológica compleja, en la que los efectos de la microangiopatía subcortical y la disminución del recambio de LCR desempeñan un papel fundamental. Esta base fisiopatológica aleja la HCAi del concepto clásico de hidrocefalia y la acerca al perfil de otras enfermedades neurodegenerativas, como la enfermedad de Alzheimer o la enfermedad de Binswanger


Introduction: Since its description five decades ago, the pathophysiology of idiopathic chronic adult hydrocephalus (iCAH) has been traditionally related to the effect that ventricular dilatation exerts on the structures surrounding the ventricular system. However, altered cerebral blood flow, especially a reduction in the CSF turnover rate, are starting to be considered the main pathophysiological elements of this disease. Development: Compression of the pyramidal tract, the frontostriatal and frontoreticular circuits, and the paraventricular fibres of the superior longitudinal fasciculus have all been reported in iCAH. At the level of the corpus callosum, gliosis replaces a number of commissural tracts. Cerebral blood flow is also altered, showing a periventricular watershed region limited by the subependymal arteries and the perforating branches of the major arteries of the anterior cerebral circulation. The CSF turnover rate is decreased by 75%, leading to the reduced clearance of neurotoxins and the interruption of neuroendocrine and paracrine signalling in the CSF. Conclusions: iCAH presents as a complex nosological entity, in which the effects of subcortical microangiopathy and reduced CSF turnover play a key role. According to its pathophysiology, it is simpler to think of iCAH more as a neurodegenerative disease, such as Alzheimer disease or Binswanger disease than as the classical concept of hydrocephalus


Assuntos
Humanos , Hidrocefalia de Pressão Normal/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Ventrículos Cerebrais/fisiopatologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Circulação Cerebrovascular/fisiologia , Doença Crônica , Hidrocefalia de Pressão Normal/diagnóstico , Hidrocefalia de Pressão Normal/líquido cefalorraquidiano , Doenças Neurodegenerativas/líquido cefalorraquidiano , Doenças Neurodegenerativas/diagnóstico
8.
J Neurotrauma ; 35(24): 2947-2956, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30101641

RESUMO

To guide management of patients with acute spinal cord injuries, we developed intraspinal pressure monitoring from the injury site. Here, we examine the complex fluctuations in the intraspinal pressure signal using network theory. We analyzed 7097 h of intraspinal pressure data from 58 patients with severe cord injuries. Intraspinal pressure signals were split into hourly windows. Each window was mapped into a visibility graph as follows. Vertical bars were drawn at 0.1 Hz representing signal amplitudes. Each bar produced a node, thus totalling 360 nodes per graph. Two nodes were linked with an edge if the straight line through the nodes did not intersect a bar. We computed several topological metrics for each graph including diameter, modularity, eccentricity, and small-worldness. Patients were followed up for 20 months on average. Our data show that the topological structure of intraspinal pressure visibility graphs is highly sensitive to pathological events at the injury site, including cord compression (high intraspinal pressure), ischemia (low spinal cord perfusion pressure), and deranged autoregulation (high spinal pressure reactivity index). These pathological changes correlate with long graph diameter, high modularity, high eccentricity and reduced small-worldness. In a multivariate logistic regression model, age, neurological status on admission, and average node eccentricity were independent predictors of neurological improvement. We conclude that analysis of intraspinal pressure fluctuations after spinal cord injury as graphs, rather than as time series, captures clinically important information. Our novel technique may be applied to other signals recorded from injured central nervous system (CNS); for example, intracranial pressure, tissue metabolite, and oxygen levels.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Monitorização Fisiológica/métodos , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Clin Neurol Neurosurg ; 173: 154-158, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30142621

RESUMO

OBJECTIVES: Hydrocephalus can be defined as clinically symptomatic dilatation of the internal ventricular system at the expense of brain and blood volume. Shunt insertion is the mainstay of therapy for communicating hydrocephalus. One of the most frequently used valves is the programmable Codman Medos Hakim valve which enables the pressure level to be adjusted from 30 to 200 mmH2O. The problem of functional over- or underdrainage and the associated complications should be significantly reduced if not excluded. Especially in the clinical application of the Codman Medos Hakim Shunt System in hydrocephalus of other etiology only a few studies can be found. This study aims to increase knowledge of both the safety of Codman Medos valves with SiphonGuard in the clinical application as well as the correct choice of the pressure level for different indications. PATIENTS AND METHODS: In this retrospective study, 101 patients were included who underwent surgery with the adjustable "Codman Medos Hakim" valve with "SiphonGuard" between January 2010 and July 2013. We analyzed the patient files and imaging (CCT, cMRT) data. The statistical examinations were performed using the WINStat program for Excel. RESULTS: Our results show that an initial pressure level of 120mmH2O proved to be suitable in all subgroups. After optimization of the initial pressure level 70.3% of the valves (71 valves) had a pressure level of 120mmH2O. Importantly, only in the SAH subgroup the clinical improvement was correlated with a reduction in the measured indices. But in all subgroups a clinical deterioration was associated with an increased ventricular size. CONCLUSION: Overall, the clinical data show that an initial pressure level of 120mmH2O seems to be appropriate for most patients treated in this series. Measured indices from the cranial imaging can provide valuable indications for the presence of a suboptimal valve setting for the individual patient.


Assuntos
Derivações do Líquido Cefalorraquidiano , Hidrocefalia/cirurgia , Complicações Pós-Operatórias/etiologia , Próteses e Implantes , Adolescente , Adulto , Pressão do Líquido Cefalorraquidiano/fisiologia , Derivações do Líquido Cefalorraquidiano/instrumentação , Criança , Pré-Escolar , Desenho de Equipamento , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Invest Ophthalmol Vis Sci ; 59(8): 3394-3404, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-30025070

RESUMO

Purpose: To examine the early glial reactivity and neuron damage in response to short-term cerebrospinal fluid pressure (CSFp) reduction, as compared with intraocular pressure (IOP) elevation. Methods: The experiment included 54 male Sprague-Dawley rats with elevated translaminar cribrosa pressure difference (TLPD), defined as IOP minus CSFp. These rats underwent either continuous CSF drainage for 6 hours (n = 18), or unilateral IOP elevation to 40 mm Hg for 6 hours (n = 18). For control, 18 normal rats were anesthetized for 6 hours. Orthograde axonal transport was examined by intravitreal injection of 3% rhodamine-ß-isothiocyanate. We also used transmission electron microscopy to display the ultrastructural features of retinal ganglion cell axons in the optic nerve head. Early glial reactivity in the retina, lateral geniculate nucleus (LGN), and superior colliculus (SC) was detected by immunostaining and Western blot for the glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS). We also observed the glial reactivity in the inferior colliculus and hippocampus to rule out possible influences of CSF dynamics and composition. Results: Anterograde staining with 3% rhodamine-ß-isothiocyanate revealed decreased fluorescence intensity of the SC and LGN projected from both lower CSFp and higher IOP eyes. Transmission electron microscopy showed loss of axons from the optic nerve head in the high-IOP group, but not in the low-CSFp group. Compared with the anesthesia control group, GFAP expression was significantly increased in the retina, LGN, and SC, whereas GS expression was only increased in the retina following CSFp reduction. However, their expressions were not significantly elevated in the inferior colliculus and hippocampus. In the high-IOP group, expressions of GFAP and GS were significantly increased in the retina, LGN, and SC. Conclusions: Visual system neurons may be much more sensitive than other nervous tissues. Following short-term CSFp reduction, early glial reactivity may precede axonal loss. Changes of translaminar cribrosa pressure difference in both experimental low-CSFp and high-IOP groups induce selective early glial reactivity. The neuron damage from abnormally low CSFp may be pathogenetically similar to high IOP.


Assuntos
Axônios/patologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Neuroglia/patologia , Disco Óptico/patologia , Doenças do Nervo Óptico/fisiopatologia , Células Ganglionares da Retina/patologia , Vias Visuais/patologia , Animais , Axônios/ultraestrutura , Western Blotting , Técnica Indireta de Fluorescência para Anticorpo , Corpos Geniculados/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Glutamato-Amônia Ligase/metabolismo , Pressão Intraocular/fisiologia , Masculino , Microscopia Eletrônica de Transmissão , Disco Óptico/ultraestrutura , Ratos , Ratos Sprague-Dawley , Células Ganglionares da Retina/ultraestrutura , Colículos Superiores/metabolismo
12.
Eur J Cardiothorac Surg ; 54(1): 149-156, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29917121

RESUMO

OBJECTIVES: Anterior radiculomedullary arteries (ARMAs) link dorsal segmental arteries and the intraspinal compartment of the spinal collateral network. The number of thoracic ARMA is highly variable from one person to another. The impact of the number of ARMAs on spinal cord perfusion during thoracic aortic procedures is unknown. We investigated the influence of the number of thoracic ARMAs on spinal cord perfusion in an aortic surgical large animal model. METHODS: Twenty-six pigs were included (20 treatment animals, 6 sham animals, weight 34 ± 3 kg). The animals underwent ligation of the left subclavian artery and the thoracic segmental arteries via a left lateral thoracotomy with normothermia. After sacrifice, complete body perfusion with coloured cast resin was performed and the number of thoracic ARMAs was documented at autopsy. End points were spinal cord perfusion pressure, cerebrospinal fluid pressure, spinal cord blood flow (microspheres) and neurological outcome. Observation time was 3 h post-ligation. RESULTS: The numbers of thoracic ARMAs ranged between 3 (n = 1) and 13 (n = 1). The mean number was 8. Animals were grouped according to number of thoracic ARMA: 6-7 (5 animals), 8-10 (8 animals) and 11-13 (5 animals). A large number of thoracic ARMAs was linked to (i) a lower drop in spinal cord blood flow from baseline to post-clamp, (ii) the presence and increased magnitude of hyperaemia evident 3 h post-clamp (P < 0.001) and (iii) the presence of early hyperaemia starting immediately post-clamp in animals with 11 or more ARMA (P < 0.001). CONCLUSIONS: We showed that a large number of thoracic ARMA protects against spinal cord injury during descending aortic surgical procedures.1.


Assuntos
Aorta Torácica/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Isquemia do Cordão Espinal/prevenção & controle , Animais , Pressão do Líquido Cefalorraquidiano/fisiologia , Modelos Animais de Doenças , Monitorização Intraoperatória/métodos , Fluxo Sanguíneo Regional , Medula Espinal/irrigação sanguínea , Isquemia do Cordão Espinal/etiologia , Sus scrofa
13.
AJNR Am J Neuroradiol ; 39(6): 1185-1190, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29724759

RESUMO

BACKGROUND AND PURPOSE: Idiopathic intracranial hypertension is a complex neurologic disorder resulting from increased intracranial pressure. Our aim was to determine whether a correlation exists between the CSF pressure-volume relationship, specifically the craniospinal elastance and pressure-volume index, in patients with idiopathic intracranial hypertension and whether opening pressure affects this relationship. MATERIALS AND METHODS: Lumbar punctures performed for suspected idiopathic intracranial hypertension from 2006 to 2017 were identified. Opening and closing pressures, CSF volume removed, and clinical diagnosis of idiopathic intracranial hypertension were obtained from the medical records. The craniospinal elastance (pressure change per milliliter of CSF removed) and pressure-volume index were calculated, and the Pearson correlation coefficients between both the craniospinal elastance and pressure-volume index and opening pressure were determined. Linear regression models of craniospinal elastance and the pressure-volume index and interaction terms with opening pressure were assessed for covariate influence on this association. RESULTS: One hundred sixteen patients were included in the final analysis. The mean craniospinal elastance according to opening pressure group was 0.52 ± 0.18 for <20 cm H2O, 0.57 ± 0.20 for 20-29 cm H2O, 0.91 ± 0.28 for 30-39 cm H2O, and 1.20 ± 0.25 for ≥40 cm H2O. There was a positive linear association between opening pressure and craniospinal elastance with a 0.28 cm H2O/mL increase in craniospinal elastance (standard error = 0.03, P < .001) for every 10 cm H2O increase in opening pressure. Of the covariables analyzed, only age older than 50 years and total volume of CSF removed affected this association. CONCLUSIONS: As opening pressure increases, the craniospinal elastance increases in a linear fashion while the pressure-volume index decreases. Further studies are needed to determine whether these changes relate to the underlying pathophysiology of idiopathic intracranial hypertension or simply represent established CSF volume pressure dynamics.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Pseudotumor Cerebral/fisiopatologia , Adulto , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Punção Espinal
14.
World Neurosurg ; 116: e830-e839, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29803060

RESUMO

BACKGROUND: Morphometric analysis or examination of symptoms in patients with Chiari malformation type I (CM-I) with various associations does not suffice for evaluation of surgical outcome of these patients. We assessed the relationship of morphologic changes in brain and spinal cord and disease symptoms with changes in cerebrospinal fluid (CSF) hydrodynamic parameters in patients with CM-I. METHODS: The study included 41 patients in 3 groups of CM-I, CM-I/occipitoatlantoaxial joint instability, and CM-I/tethered cord syndrome and 18 normal subjects. Phase-contrast magnetic resonance imaging and computational fluid dynamics analysis were done for all samples. RESULTS: Maximum CSF velocities and pressures in patients had an increase of 17.1%-23.2% and 41.5%-56.8%, respectively, compared with normal subjects. The data dispersion of maximum CSF velocity was >3.1 times that of the maximum pressure. Results showed that maximum CSF pressure is a more appropriate hydrodynamic parameter than maximum CSF velocity for assessing the condition of patients. Results also showed that CSF and PCF volumes had declined 57% and 11.3%, respectively, in CM-I. These declines were greater in CM-I than in the other 2 groups. CONCLUSIONS: Maximum CSF pressure regardless of the group the patients belonged to was similar in patients with symptoms of similar intensity. The correlation between maximum CSF pressure with CSF and PCF volumes decreased secondary to the disease. PCF volume was more favorable than CSF volume for assessing intensity of disease symptoms. Furthermore, in a constant pressure change, sensitivity of PCF volume in CM-I/occipitoatlantoaxial joint instability and CM-I/tethered cord syndrome groups was more than in the CM-I group.


Assuntos
Malformação de Arnold-Chiari/líquido cefalorraquidiano , Malformação de Arnold-Chiari/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Pressão do Líquido Cefalorraquidiano/fisiologia , Hidrodinâmica , Medula Espinal/diagnóstico por imagem , Adulto , Malformação de Arnold-Chiari/fisiopatologia , Líquido Cefalorraquidiano/fisiologia , Feminino , Humanos , Masculino
15.
J Biomech ; 76: 16-26, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-29801662

RESUMO

The dorsal root ganglion (DRG) that is embedded in the foramen of the cervical vertebra can be injured during a whiplash motion. A potential cause is that whilst the neck bends in the whiplash motion, the changes of spinal canal volume induce impulsive pressure transients in the venous blood outside the dura mater (DM) and in the cerebrospinal fluid (CSF) inside the DM. The fluids can dynamically interact with the DRG and DM, which are deformable. In this work, the interaction is investigated numerically using a strong-coupling partitioned method that synchronize the computations of the fluid and structure. It is found that the interaction includes two basic processes, i.e., the pulling and pressing processes. In the pulling process, the DRG is stretched towards the spinal canal, and the venous blood is driven into the canal via the foramen. This process results from negative pressure in the fluids. In contrast, the pressing process is caused by positive pressure that leads to compression of the DRG and the outflow of the venous blood from the canal. The largest pressure gradient is observed at the foramen, where the DRG is located at. The DRG is subject to prominent von Mises stress near its end, which is fixed without motions. The negative internal pressure is more efficient to deform the DRG than the positive internal pressure. This indicates that the most hazardous condition for the DRG is the pulling process.


Assuntos
Pressão Sanguínea/fisiologia , Pressão do Líquido Cefalorraquidiano/fisiologia , Vértebras Cervicais/fisiologia , Gânglios Espinais/fisiologia , Traumatismos em Chicotada/fisiopatologia , Humanos , Pescoço/fisiologia , Canal Vertebral/fisiologia
16.
PLoS One ; 13(4): e0196216, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29708982

RESUMO

3D fluid-structure interaction modelling was utilized for simulation of 13 normal subjects, 11 non-communicating hydrocephalus (NCH) patients at pre-treatment phase, and 3 patients at five post-treatment phases. Evaluation of ventricles volume and maximum CSF pressure (before shunting) following results validation indicated that these parameters were the most proper hydrodynamic indices and the NCH type doesn't have any significant effect on changes in two indices. The results confirmed an appropriate correlation between these indices although the correlation decreased slightly after the occurrence of disease. NCH raises the intensity of vortex and pulsatility (2.4 times) of CSF flow while the flow remains laminar. On day 18 after shunting, the CSF pressure decreased 81.0% and all clinical symptoms of patients vanished except for headache. Continuing this investigation during the treatment process showed that maximum CSF pressure is the most sensitive parameter to patients' clinical symptoms. Maximum CSF pressure has decreased proportional to the level of decrease in clinical symptoms and has returned close to the pressure range in normal subjects faster than other parameters and simultaneous with disappearance of patients' clinical symptoms (from day 81 after shunting). However, phase lag between flow rate and pressure gradient functions and the degree of CSF pulsatility haven't returned to normal subjects' conditions even 981 days after shunting and NCH has also caused a permanent volume change (of 20.1%) in ventricles. Therefore, patients have experienced a new healthy state in new hydrodynamic conditions after shunting and healing. Increase in patients' intracranial compliance was predicted with a more accurate non-invasive method than previous experimental methods up to more than 981 days after shunting. The changes in hydrodynamic parameters along with clinical reports of patients can help to gain more insight into the pathophysiology of NCH patients.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Simulação por Computador , Hidrocefalia/patologia , Hidrodinâmica , Pressão Intracraniana , Derivação Ventriculoperitoneal , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Hidrocefalia/líquido cefalorraquidiano , Hidrocefalia/epidemiologia , Hidrocefalia/cirurgia , Imagem Tridimensional/métodos , Irã (Geográfico)/epidemiologia , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
17.
Acta Ophthalmol ; 96(5): e570-e576, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29575652

RESUMO

PURPOSE: To compare the orbital cerebral spinal fluid pressure (CSFP) and trans-lamina cribrosa pressure difference (TLCPD) determined noninvasively in ocular hypertensive (OH) subjects and controls. METHODS: Cross-sectional observational study. Magnetic resonance imaging was used to measure orbital subarachnoid space width (OSASW). The CSFP (mm Hg) was estimated from a published formula as 17.54 × MRI derived OSASW at 15 mm behind the globe + 0.47 × body mass index + 0.13 × mean arterial blood pressure -21.52. Estimated TLCPD was calculated as IOP- CSFP. RESULTS: The orbital subarachnoid space width was significantly wider (p = 0.01) in the OH group than in the control group at all three measurement locations. The MRI derived CSFP value in OH (14.9 ± 2.9 mm Hg) was significantly higher than in the normal group (12.0 ± 2.8 mm Hg; p < 0.01). The estimated TLCPD value in OH (9.0 ± 4.2 mm Hg) was significantly higher than in controls (3.6 ± 3.0 mm Hg; p < 0.01). CONCLUSION: The wider OSASW and higher estimated CSFP in OH subjects suggest a higher orbital CSFP. Despite a higher orbital CSFP that could be protective, the higher TLCPD in OH may play a significant role in the risk of developing glaucoma.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Pressão Intraocular/fisiologia , Hipertensão Ocular/fisiopatologia , Adulto , Pressão Sanguínea/fisiologia , Estudos Transversais , Feminino , Gonioscopia , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Hipertensão Ocular/diagnóstico , Disco Óptico/diagnóstico por imagem , Disco Óptico/patologia , Nervo Óptico/diagnóstico por imagem , Nervo Óptico/patologia , Órbita/diagnóstico por imagem , Órbita/patologia , Espaço Subaracnóideo/diagnóstico por imagem , Tomografia de Coerência Óptica , Tonometria Ocular , Acuidade Visual/fisiologia , Testes de Campo Visual
18.
Acta Ophthalmol ; 96(5): e562-e569, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29532640

RESUMO

PURPOSE: To investigate the cerebrospinal fluid (CSF) dynamics along the entire optic nerve (ON) in patients with normal-tension glaucoma (NTG). METHODS: Retrospective analysis of computed tomographic (CT) cisternographies in Caucasian patients with NTG. Fifty-six patients (99 of 112 eyes) fulfilled the diagnostic criteria of NTG and underwent CT-cisternography. Twelve subjects without NTG (24 eyes) served as controls. Contrast-loaded cerebrospinal fluid (CLCSF) density measurements in Hounsfield units (HU) were performed at four defined regions along the ON and in the basal cistern. RESULTS: In NTG patients, the mean density CLCSF in the bulbar segment measured 76 ± 49 HU right and 88 ± 74 HU left, in the mid-orbital segment 117 ± 92 HU right and 119 ± 73 HU left, in the intracanalicular ON portion 209 ± 88 HU right and 216 ± 101 HU left, in the intracranial ON portion 290 ± 106 HU right and 286 ± 118 HU left and in the basal cistern 517 ± 213 HU. The distribution of CLCSF along the ON showed a statistically significant reduction in the intraorbital ON segments in NTG patients compared to controls without NTG with the far largest difference within the retrobulbar segment (-150 HU right and -117 HU left; right: p < 0.001, left: p < 0.001). CONCLUSION: This study demonstrates a gradual reduction in CLCSF towards the retrobulbar segment in NTG, while in controls without NTG, no reduction in CLCSF was measured within the orbital segments. Impaired CSF dynamics along the ON may contribute to the pathophysiology of NTG.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Líquido Cefalorraquidiano/fisiologia , Glaucoma de Baixa Tensão/líquido cefalorraquidiano , Idoso , Idoso de 80 Anos ou mais , Feminino , Gonioscopia , Humanos , Hidrodinâmica , Pressão Intraocular , Glaucoma de Baixa Tensão/diagnóstico , Glaucoma de Baixa Tensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mielografia/métodos , Oftalmoscopia , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Tomografia Computadorizada por Raios X
19.
Neuroradiology ; 60(4): 413-419, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29470603

RESUMO

PURPOSE: Intravoxel incoherent motion (IVIM) in diffusion-weighted magnetic resonance imaging (DW-MRI) attributes the signal attenuation to the molecular diffusion and to a faster pseudo-diffusion. Purpose of the study was to demonstrate the feasibility of IVIM for the investigation of intracranial cerebrospinal fluid (CSF) dynamics. METHODS: Cardiac-gated DW-MRI images with fifteen b-values (0-1300s/mm2) along three orthogonal directions (mediolateral (ML), anteroposterior (AP), and craniocaudal (CC)) were acquired during maximum systole and diastole in 10 healthy volunteers (6 males, mean age 36 ± 15 years). A pixel-wise bi-exponential fitting with an iterative nonparametric algorithm was carried out to calculate the following parameters: diffusion coefficient (D), fast diffusion coefficient (D*), and fraction of fast diffusion (f). Region of interest measurements were performed in both lateral ventricles. Comparison of IVIM parameters was performed among two cardiac cycle acquisitions and among the diffusion-encoding directions using a paired Student's t test. RESULTS: f significantly (p < 0.05) depended on the diffusion-encoding direction and on the cardiac cycle (diastole AP 0.30 ± 0.13, ML 0.22 ± 0.12, CC 0.26 ± 0.17; systole AP 0.45 ± 0.17, ML 0.34 ± 0.15, CC 0.40 ± 0.21). Neither a cardiac cycle nor a direction dependency was found among mean D values (which is in line with the expected intraventricular isotropic diffusion) and D* values (p > 0.05 each). CONCLUSION: The fraction of fast diffusion from IVIM is feasible to detect a direction-dependent and cardiac-dependent pulsatile CSF flow within the lateral ventricles allowing for quantitative monitoring of CSF dynamics. This technique might provide opportunities to further investigate the pathophysiology of various neurological disorders involving altered CSF dynamics.


Assuntos
Técnicas de Imagem de Sincronização Cardíaca/métodos , Pressão do Líquido Cefalorraquidiano/fisiologia , Imagem de Difusão por Ressonância Magnética/métodos , Ventrículos Laterais/diagnóstico por imagem , Ventrículos Laterais/fisiologia , Adulto , Estudos de Viabilidade , Feminino , Voluntários Saudáveis , Humanos , Hidrodinâmica , Masculino
20.
Med Hypotheses ; 110: 150-154, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29317060

RESUMO

Fibromyalgia (FM) is a debilitating, widespread pain disorder that is assumed to originate from inappropriate pain processing in the central nervous system. Psychological and behavioral factors are both believed to underlie the pathogenesis and complicate the treatment. This hypothesis, however, has not yet been sufficiently supported by scientific evidence and accumulating evidence supports a peripheral neurological origin of the symptoms. We postulate that FM and several unexplained widespread pain syndromes are caused by chronic postural idiopathic cerebrospinal hypertension. Thus, the symptoms originate from the filling of nerve root sleeves under high pressure with subsequent polyradiculopathy from the compression of the nerve root fibers (axons) inside the sleeves. Associated symptoms, such as bladder and bowel dysfunction, result from compression of the sacral nerve root fibers, and facial pain and paresthesia result from compression of the cranial nerve root fibers. Idiopathic Intracranial Hypertension, Normal Pressure Hydrocephalus and the clinical entity of symptomatic Tarlov cysts share similar central and peripheral neurological symptoms and are likely other manifestations of the same condition. The hypothesis presented in this article links the characteristics of fibromyalgia and unexplained widespread pain to cerebrospinal pressure dysregulation with support from scientific evidence and provides a conclusive explanation for the multitude of symptoms associated with fibromyalgia.


Assuntos
Pressão do Líquido Cefalorraquidiano/fisiologia , Fibromialgia/líquido cefalorraquidiano , Fibromialgia/fisiopatologia , Dor/líquido cefalorraquidiano , Dor/fisiopatologia , Humanos , Modelos Biológicos , Modelos Neurológicos , Síndromes de Compressão Nervosa/líquido cefalorraquidiano , Síndromes de Compressão Nervosa/fisiopatologia , Neuralgia/líquido cefalorraquidiano , Neuralgia/fisiopatologia , Doenças do Sistema Nervoso Periférico/líquido cefalorraquidiano , Doenças do Sistema Nervoso Periférico/fisiopatologia
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