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1.
Fluids Barriers CNS ; 21(1): 55, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38987813

RESUMEN

BACKGROUND: Studies indicate that brain clearance via the glymphatic system is impaired in idiopathic normal pressure hydrocephalus (INPH). This has been suggested to result from reduced cerebrospinal fluid (CSF) turnover, which could be caused by a reduced CSF formation rate. The aim of this study was to determine the formation rate of CSF in a cohort of patients investigated for INPH and compare this to a historical control cohort. METHODS: CSF formation rate was estimated in 135 (75 ± 6 years old, 64/71 men/women) patients undergoing investigation for INPH. A semiautomatic CSF infusion investigation (via lumbar puncture) was performed. CSF formation rate was assessed by downregulating and steadily maintaining CSF pressure at a zero level. During the last 10 min, the required outflow to maintain zero pressure, i.e., CSF formation rate, was continuously measured. The values were compared to those of a historical reference cohort from a study by Ekstedt in 1978. RESULTS: Mean CSF formation rate was 0.45 ± 0.15 ml/min (N = 135), equivalent to 27 ± 9 ml/hour. There was no difference in the mean (p = 0.362) or variance (p = 0.498) of CSF formation rate between the subjects that were diagnosed as INPH (N = 86) and those who were not (N = 43). The CSF formation rate in INPH was statistically higher than in the reference cohort (0.46 ± 0.15 vs. 0.40 ± 0.08 ml/min, p = 0.005), but the small difference was probably not physiologically relevant. There was no correlation between CSF formation rate and baseline CSF pressure (r = 0.136, p = 0.115, N = 135) or age (-0.02, p = 0.803, N = 135). CONCLUSIONS: The average CSF formation rate in INPH was not decreased compared to the healthy reference cohort, which does not support reduced CSF turnover. This emphasizes the need to further investigate the source and routes of the flow in the glymphatic system and the cause of the suggested impaired glymphatic clearance in INPH.


Asunto(s)
Líquido Cefalorraquídeo , Sistema Glinfático , Hidrocéfalo Normotenso , Humanos , Masculino , Femenino , Sistema Glinfático/fisiopatología , Hidrocéfalo Normotenso/líquido cefalorraquídeo , Hidrocéfalo Normotenso/fisiopatología , Anciano , Líquido Cefalorraquídeo/fisiología , Anciano de 80 o más Años , Estudios de Cohortes , Punción Espinal , Presión del Líquido Cefalorraquídeo/fisiología , Persona de Mediana Edad
2.
Fluids Barriers CNS ; 21(1): 57, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39020364

RESUMEN

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.


Asunto(s)
Encéfalo , Hidrocefalia , Hipertensión Intracraneal , Humanos , Hidrocefalia/fisiopatología , Hipertensión Intracraneal/fisiopatología , Encéfalo/fisiopatología , Presión del Líquido Cefalorraquídeo/fisiología , Líquido Cefalorraquídeo/fisiología , Presión Intracraneal/fisiología , Ventrículos Cerebrales/fisiopatología , Ventrículos Cerebrales/diagnóstico por imagen
3.
Sci Rep ; 14(1): 12717, 2024 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-38830910

RESUMEN

Chiari type 1 malformation is a neurological disorder characterized by an obstruction of the cerebrospinal fluid (CSF) circulation between the brain (intracranial) and spinal cord (spinal) compartments. Actions such as coughing might evoke spinal cord complications in patients with Chiari type 1 malformation, but the underlying mechanisms are not well understood. More insight into the impact of the obstruction on local and overall CSF dynamics can help reveal these mechanisms. Therefore, our previously developed computational fluid dynamics framework was used to establish a subject-specific model of the intracranial and upper spinal CSF space of a healthy control. In this model, we emulated a single cough and introduced porous zones to model a posterior (OBS-1), mild (OBS-2), and severe posterior-anterior (OBS-3) obstruction. OBS-1 and OBS-2 induced minor changes to the overall CSF pressures, while OBS-3 caused significantly larger changes with a decoupling between the intracranial and spinal compartment. Coughing led to a peak in overall CSF pressure. During this peak, pressure differences between the lateral ventricles and the spinal compartment were locally amplified for all degrees of obstruction. These results emphasize the effects of coughing and indicate that severe levels of obstruction lead to distinct changes in intracranial pressure.


Asunto(s)
Malformación de Arnold-Chiari , Líquido Cefalorraquídeo , Tos , Hidrodinámica , Malformación de Arnold-Chiari/líquido cefalorraquídeo , Malformación de Arnold-Chiari/fisiopatología , Malformación de Arnold-Chiari/complicaciones , Tos/fisiopatología , Humanos , Simulación por Computador , Presión del Líquido Cefalorraquídeo/fisiología , Médula Espinal/fisiopatología , Femenino
4.
J Child Neurol ; 39(5-6): 195-200, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38748539

RESUMEN

Cerebrospinal fluid opening pressure values are associated with various neurologic diseases; however, numerous factors can modify this measurement. This study aims to describe factors related to modifications in opening pressure measurements in pediatric patients. Methods: A retrospective analysis of lumbar punctures in pediatric patients conducted by the neuropediatrics group with institutional standardization. Bivariate and linear regression analyses were performed to determine the association between opening pressure and variables included in the study. Results: 544 events, median age 107 months, median opening pressure 19.7 cm H2O. Bivariate analysis found no association with medication use; anesthetics that increased opening pressure were remifentanil (P = .02) and propofol (P = .05), along with a positive linear correlation between opening pressure and age (P < .0001). Multiple linear regression analysis revealed that age, BMI, male gender, and remifentanil use were associated with an increase in opening pressure, whereas corticosteroid withdrawal was associated with a reduction in opening pressure. There is an interaction between age and headache, with an association with increased opening pressure up to around 140 months. Conclusion: This study identifies factors associated with changes in opening pressure, crucial for estimating normal opening pressure values in children. Headaches, anesthetic use, and corticosteroid withdrawal are confirmed as significant factors.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Cefalea , Punción Espinal , Humanos , Masculino , Femenino , Niño , Estudios Retrospectivos , Presión del Líquido Cefalorraquídeo/fisiología , Preescolar , Adolescente , Cefalea/fisiopatología , Lactante , Punción Espinal/métodos , Factores de Edad
6.
Turk J Ophthalmol ; 54(2): 83-89, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38645613

RESUMEN

Objectives: To review the current literature related to the correlation between translaminar pressure difference (TLPD) and glaucoma. Materials and Methods: In this article, we conducted a literature review using MEDLINE via PubMed, Cochrane Eyes and Vision, and Google Scholar from 01/01/2010 to 31/12/2022. Search terms included "glaucoma", "intraocular pressure", "translaminar cribrosa pressure gradient/difference", "intracranial pressure", and "cerebrospinal fluid pressure". Of 471 results, 8 articles were selected for the meta-analysis. Results: Our meta-analysis demonstrated significantly higher intraocular pressure, lower cerebrospinal fluid pressure (CSFp), and greater TLPD in high-tension and normal-tension glaucoma groups compared to healthy groups. Conclusion: The differences in CSFp and TLPD between glaucoma and healthy people detected in current studies suggests a potential relationship between TLPD and glaucoma.


Asunto(s)
Presión Intraocular , Enfermedades del Nervio Óptico , Humanos , Presión Intraocular/fisiología , Enfermedades del Nervio Óptico/diagnóstico , Enfermedades del Nervio Óptico/etiología , Enfermedades del Nervio Óptico/fisiopatología , Presión del Líquido Cefalorraquídeo/fisiología , Glaucoma/fisiopatología , Tonometría Ocular , Glaucoma de Baja Tensión/fisiopatología , Glaucoma de Baja Tensión/diagnóstico
7.
Pediatr Neurol ; 153: 92-95, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38354628

RESUMEN

BACKGROUND: Currently no guidelines for repeating a lumbar puncture to guide management in primary intracranial hypertension (PIH) exist. METHODS: An institutional database of patients 18 years and younger followed in the institution's pediatric intracranial hypertension clinic was examined for opening pressure changes in PIH at diagnosis, before medication wean, and following medication wean, as well as to examine whether measurements at the time of diagnosis differed between those with and without disease recurrence. RESULTS: Forty-two patients were included in this study; 36% were male and the mean age at diagnosis was 11.01 years. Treatment duration averaged 9.68 months in those without recurrence and 8.5 months in those with recurrence. Average body mass index percentile of patients with disease recurrence was 83.7 and 72.1 in those without recurrence (P = 0.16). Average opening pressure values of all patients at diagnosis, prewean, and postwean was 36.53 cm H2O, 30.7 cm H2O, and 31.1 cm H2O, respectively. There was no statistically significant difference in opening pressures across these time points (P = 0.14). The change in opening pressure from diagnosis to postwean was statistically significant with a reduction of 5.18 cm H2O (P = 0.04). There was no statistical difference between change in opening pressure at diagnosis versus postwean between those with and without recurrence (P = 0.17). CONCLUSIONS: This clinical observational study suggests that mean opening pressure measurements in patients with PIH remain elevated both before and after medication wean despite papilledema resolution and patient-reported PIH symptoms. Clinically, this suggests that other features such as signs of optic disc edema and symptoms should be used to inform a clinical determination of disease recurrence and treatment course.


Asunto(s)
Hipertensión Intracraneal , Papiledema , Seudotumor Cerebral , Humanos , Masculino , Niño , Femenino , Seudotumor Cerebral/complicaciones , Seudotumor Cerebral/diagnóstico , Seudotumor Cerebral/terapia , Presión del Líquido Cefalorraquídeo , Estudios Retrospectivos , Hipertensión Intracraneal/diagnóstico , Hipertensión Intracraneal/etiología , Hipertensión Intracraneal/terapia , Papiledema/diagnóstico , Presión Intracraneal
8.
Fluids Barriers CNS ; 21(1): 20, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38419077

RESUMEN

BACKGROUND: Impaired cerebrospinal fluid (CSF) dynamics is involved in the pathophysiology of neurodegenerative diseases of the central nervous system and the optic nerve (ON), including Alzheimer's and Parkinson's disease, as well as frontotemporal dementia. The smallness and intricate architecture of the optic nerve subarachnoid space (ONSAS) hamper accurate measurements of CSF dynamics in this space, and effects of geometrical changes due to pathophysiological processes remain unclear. The aim of this study is to investigate CSF dynamics and its response to structural alterations of the ONSAS, from first principles, with supercomputers. METHODS: Large-scale in-silico investigations were performed by means of computational fluid dynamics (CFD) analysis. High-order direct numerical simulations (DNS) have been carried out on ONSAS geometry at a resolution of 1.625 µm/pixel. Morphological changes on the ONSAS microstructure have been examined in relation to CSF pressure gradient (CSFPG) and wall strain rate, a quantitative proxy for mass transfer of solutes. RESULTS: A physiological flow speed of 0.5 mm/s is achieved by imposing a hydrostatic pressure gradient of 0.37-0.67 Pa/mm across the ONSAS structure. At constant volumetric rate, the relationship between pressure gradient and CSF-accessible volume is well captured by an exponential curve. The ONSAS microstructure exhibits superior mass transfer compared to other geometrical shapes considered. An ONSAS featuring no microstructure displays a threefold smaller surface area, and a 17-fold decrease in mass transfer rate. Moreover, ONSAS trabeculae seem key players in mass transfer. CONCLUSIONS: The present analysis suggests that a pressure drop of 0.1-0.2 mmHg over 4 cm is sufficient to steadily drive CSF through the entire subarachnoid space. Despite low hydraulic resistance, great heterogeneity in flow speeds puts certain areas of the ONSAS at risk of stagnation. Alterations of the ONSAS architecture aimed at mimicking pathological conditions highlight direct relationships between CSF volume and drainage capability. Compared to the morphological manipulations considered herein, the original ONSAS architecture seems optimized towards providing maximum mass transfer across a wide range of pressure gradients and volumetric rates, with emphasis on trabecular structures. This might shed light on pathophysiological processes leading to damage associated with insufficient CSF flow in patients with optic nerve compartment syndrome.


Asunto(s)
Hidrodinámica , Presión Intraocular , Humanos , Nervio Óptico/patología , Nervio Óptico/fisiología , Espacio Subaracnoideo/fisiología , Presión del Líquido Cefalorraquídeo/fisiología , Líquido Cefalorraquídeo/fisiología
9.
World Neurosurg ; 184: e299-e306, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38286322

RESUMEN

OBJECTIVE: Cerebrospinal fluid (CSF) hypovolemia presents with orthostatic headaches due to CSF leakage. However, a direct association between the lack of CSF and clinical symptoms has not been found. CSF hypovolemia can be improved by refilling CSF. Therefore, we assessed the validity of a CSF refill test. METHODS: From November 2019 to August 2021, we included 10 patients (≥18 years old) with potential CSF hypovolemia, clear orthostatic headaches, and a CSF opening pressure <10 cmH2O. In the CSF refill test, 10 mL of artificial CSF was injected intrathecally. The primary outcome was improvement in orthostatic headache assessed using a visual analog scale (VAS), while the secondary outcomes were the 10-m walk time and adverse events. When the symptoms temporarily improved after intrathecal injection, the patients underwent radiologic imaging to identify the CSF leak, and an epidural blood patch was proposed accordingly. RESULTS: All patients showed post-test improvements in the VAS score (median [interquartile range], pretest 63.0 [50.3-74.3] vs. post-test 1.5 [0.0-26.0]). The 10-m walk time also significantly improved (9.5 [8.5-10.2] s vs. 8.2 [7.9-8.7] s). One patient experienced temporary right leg numbness associated with a lumbar puncture. After radiologic investigation, 9 patients underwent epidural blood patches, of which 6 were completely cured, and 3 revealed partial improvement. CONCLUSIONS: The cerebrospinal fluid (CSF) refill test was safe and effective in demonstrating the direct association between the lack of CSF and clinical symptoms and may help predict the outcome of an epidural blood patch.


Asunto(s)
Hipotensión Intracraneal , Humanos , Adolescente , Hipotensión Intracraneal/diagnóstico , Hipotensión Intracraneal/terapia , Pérdida de Líquido Cefalorraquídeo/diagnóstico , Pérdida de Líquido Cefalorraquídeo/terapia , Presión del Líquido Cefalorraquídeo , Parche de Sangre Epidural/métodos , Cefalea/diagnóstico , Cefalea/etiología , Cefalea/terapia , Líquido Cefalorraquídeo
10.
Clin Neuroradiol ; 34(2): 391-401, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38277058

RESUMEN

PURPOSE: To quantify the effects of CSF pressure alterations on intracranial venous morphology and hemodynamics in idiopathic intracranial hypertension (IIH) and spontaneous intracranial hypotension (SIH) and assess reversibility when the underlying cause is resolved. METHODS: We prospectively examined venous volume, intracranial venous blood flow and velocity, including optic nerve sheath diameter (ONSD) as a noninvasive surrogate of CSF pressure changes in 11 patients with IIH, 11 age-matched and sex-matched healthy controls and 9 SIH patients, before and after neurosurgical closure of spinal dural leaks. We applied multiparametric MRI including 4D flow MRI, time-of-flight (TOF) and T2-weighted half-Fourier acquisition single-shot turbo-spin echo (HASTE). RESULTS: Sinus volume overlapped between groups at baseline but decreased after treatment of intracranial hypotension (p = 0.067) along with a significant increase of ONSD (p = 0.003). Blood flow in the middle and dorsal superior sagittal sinus was remarkably lower in patients with higher CSF pressure (i.e., IIH versus controls and SIH after CSF leak closure) but blood flow velocity was comparable cross-sectionally between groups and longitudinally in SIH. CONCLUSION: We were able to demonstrate the interaction of CSF pressure, venous volumetry, venous hemodynamics and ONSD using multiparametric brain MRI. Closure of CSF leaks in SIH patients resulted in symptoms suggestive of increased intracranial pressure and caused a subsequent decrease of intracranial venous volume and of blood flow within the superior sagittal sinus while ONSD increased. In contrast, blood flow parameters from 4D flow MRI did not discriminate IIH, SIH and controls as hemodynamics at baseline overlapped at most vessel cross-sections.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Circulación Cerebrovascular , Hipotensión Intracraneal , Seudotumor Cerebral , Humanos , Femenino , Masculino , Adulto , Hipotensión Intracraneal/diagnóstico por imagen , Hipotensión Intracraneal/fisiopatología , Circulación Cerebrovascular/fisiología , Seudotumor Cerebral/fisiopatología , Seudotumor Cerebral/diagnóstico por imagen , Seudotumor Cerebral/cirugía , Presión del Líquido Cefalorraquídeo/fisiología , Venas Cerebrales/diagnóstico por imagen , Venas Cerebrales/fisiopatología , Persona de Mediana Edad , Angiografía por Resonancia Magnética/métodos , Velocidad del Flujo Sanguíneo/fisiología , Imagenología Tridimensional/métodos , Estudios Prospectivos , Reproducibilidad de los Resultados , Imagen por Resonancia Magnética/métodos , Sensibilidad y Especificidad , Hemodinámica/fisiología , Hipertensión Intracraneal/fisiopatología , Hipertensión Intracraneal/diagnóstico por imagen
11.
Neurol Med Chir (Tokyo) ; 64(2): 93-99, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38220165

RESUMEN

The pathophysiology of syringomyelia remains poorly understood. Two prevailing challenges stand out: the need for a comprehensive understanding of its diverse types and the yet-to-be-explained mechanism of cerebrospinal fluid (CSF) retention in the syrinx despite its higher pressure than that in the adjacent subarachnoid space. Expanding on our previous proposal that direction-selective resistance to subarachnoid CSF flow drives syringomyelia genesis, this study uses a computer model to explore this mechanism further. We developed a computer simulation model to study spinal CSF dynamics, employing a lumped parameter approach with multiple compartments. This model replicated the to-and-fro movement of CSF in the spinal subarachnoid space and within an intraspinal channel. Subsequently, a direction-selective resistance-opposing only the caudal subarachnoid CSF flow-was introduced at a specific location within the subarachnoid space. Following the introduction of the direction-selective resistance, a consistent pressure increase was observed in the intraspinal channel downstream of the resistance. Importantly, this increase in pressure accumulated with every cycle of to-and-fro CSF flow. The accumulation results from the pressure drop across the resistance, and its effect on the spinal cord matrix creates a pumping action in the intraspinal channel. Our findings elucidate the mechanisms underlying our hypothesis that a direction-selective resistance to subarachnoid CSF flow causes syringomyelia. This comprehensively explains the various types of syringomyelia and resolves the puzzle of CSF retention in the syrinx despite a pressure gradient.


Asunto(s)
Siringomielia , Humanos , Siringomielia/etiología , Siringomielia/líquido cefalorraquídeo , Simulación por Computador , Presión del Líquido Cefalorraquídeo/fisiología , Espacio Subaracnoideo , Líquido Cefalorraquídeo/fisiología , Imagen por Resonancia Magnética
12.
BMC Neurol ; 24(1): 35, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38243235

RESUMEN

BACKGROUND: The relationship between cerebrospinal fluid pressure (CSFP) and cognition has received little research attention. The purpose of this study was to explore the relationship between CSFP and cognition in patients with Alzheimer's disease (AD) and patients with Lewy body dementia (LBD). METHOD: We included 178 participants, including 137 patients with AD and 41 patients with LBD (including dementia with Lewy bodies (DLBs) and Parkinson's disease dementia (PDD)). CSFP was measured by lumbar puncture, and a patient-reported history and laboratory test data were collected. Logistic and linear regression analyses were used to evaluate the associations between CSFP and cognition, the cerebrospinal fluid (CSF) / serum albumin ratio (Qalb), and CSF biomarkers of AD. RESULTS: The mean age of the included patients was 63.58 ± 8.77 years old, and the mean CSFP was 121 ± 33.72 mmH2O. A total of 76.9% of the patients had a CSFP distribution of [90-170) mmH2O, 46 patients (25.8%) had severe dementia, 83 patients (46.6%) had moderate dementia, 28 patients (15.7%) had mild dementia, and 21 patients (11.8%) had mild cognitive impairment (MCI) (including 16 patients with MCI due to AD and 5 patients with MCI due to LBD). In all patients (p value < 0.001) and in patients with AD (p value = 0.01), the mean cerebrospinal fluid pressure (CSFP) was higher in patients with MCI than in patients with dementia. In multivariate analysis, in all patients (OR: 6.37, 95% confidential interval (CI): 1.76-23.04, p = 0.005) and patients with AD (odds ratio (OR): 5.43, 95% CI: 1.41-20.87, p = 0.005), a CSFP in the lowest quartile ([50-90) mmH2O) was associated with a higher level of severe dementia than a CSFP in the highest quartile ([170-210) mmH2O). In addition, there was a significant linear correlation between CSFP and the Mini-Mental State Examination (MMSE) score in all patients with dementia (r = 0.43, p = 0.04, Durbin-Watson test (D-W test) = 0.75). CONCLUSION: In patients with AD, the mean cerebrospinal fluid pressure was higher in patients with MCI than in patients with dementia, and the decrease in CSFP was related to a more serious dementia level. However, no such relationship was found in patients with LBD.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Demencia , Enfermedad por Cuerpos de Lewy , Enfermedad de Parkinson , Humanos , Persona de Mediana Edad , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Demencia/complicaciones , Enfermedad por Cuerpos de Lewy/complicaciones , Proteínas tau/líquido cefalorraquídeo , Enfermedad de Parkinson/complicaciones , Cognición , Disfunción Cognitiva/diagnóstico , Biomarcadores/líquido cefalorraquídeo , Presión del Líquido Cefalorraquídeo , Péptidos beta-Amiloides/líquido cefalorraquídeo
13.
Sci Rep ; 13(1): 20989, 2023 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-38017027

RESUMEN

In Alligator mississippiensis the spinal dura is surrounded by a venous sinus; pressure waves can propagate in the spinal venous blood, and these spinal venous pressures can be transmitted to the spinal cerebrospinal fluid (CSF). This study was designed to explore pressure transfer between the spinal venous blood and the spinal CSF. At rest the cardiac-related CSF pulsations are attenuated and delayed, while the ventilatory-related pulsations are amplified as they move from the spinal venous blood to the spinal CSF. Orthostatic gradients resulted in significant alterations of both cardiac- and ventilatory-related CSF pulsations. Manual lateral oscillations of the alligator's tail created pressure waves in the spinal CSF that propagated, with slight attenuation but no delay, to the cranial CSF. Oscillatory pressure pulsations in the spinal CSF and venous blood had little influence on the underlying ventilatory pulsations, though the same oscillatory pulsations reduced the ventilatory- and increased the cardiac-related pulsations in the cranial CSF. In Alligator the spinal venous anatomy creates a more complex pressure relationship between the venous and CSF systems than has been described in humans.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Duramadre , Humanos , Presión Venosa , Líquido Cefalorraquídeo/fisiología , Presión Sanguínea/fisiología
14.
J Int Med Res ; 51(8): 3000605231187949, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37548322

RESUMEN

OBJECTIVE: This study was performed to investigate the dynamics of intracranial pressure (ICP) alterations and bilateral transverse-sigmoid sinus morphologies in patients with venous pulsatile tinnitus (PT). METHODS: This retrospective study involved 27 patients with venous PT associated with sigmoid sinus wall anomalies. ICP and ICP metrics were measured by cerebrospinal fluid manometry and internal jugular vein compression tests. Correlation analysis was performed to determine the statistical correlation between ICP and the morphological metrics. RESULTS: The mean ICP was 212.5 ± 47.3 mmH2O. The median ΔICPtotal was 130 (range, 55-150) mmH2O. The ΔICPtotal was linearly correlated with the open lumbar pressure, and a significant difference was found between patients with normal and elevated cerebrospinal fluid pressure. The ΔICPdifference was linearly correlated with the Lendifference and Voldifference. ΔICP was linearly correlated with Lendifference. CONCLUSIONS: Complete obstruction of flow patency should be avoided in patients with low ICP and large volumetric/patency differences in the bilateral transverse-sigmoid sinus systems.


Asunto(s)
Acúfeno , Senos Transversos , Humanos , Estudios Retrospectivos , Senos Transversos/anomalías , Senos Craneales , Presión del Líquido Cefalorraquídeo
15.
Sci Rep ; 13(1): 12405, 2023 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-37524734

RESUMEN

Recent studies have linked spreading depolarization (SD, an electro-chemical wave in the brain following stroke, migraine, traumatic brain injury, and more) with increase in cerebrospinal fluid (CSF) flow through the perivascular spaces (PVSs, annular channels lining the brain vasculature). We develop a novel computational model that couples SD and CSF flow. We first use high order numerical simulations to solve a system of physiologically realistic reaction-diffusion equations which govern the spatiotemporal dynamics of ions in the extracellular and intracellular spaces of the brain cortex during SD. We then couple the SD wave with a 1D CSF flow model that captures the change in cross-sectional area, pressure, and volume flow rate through the PVSs. The coupling is modelled using an empirical relationship between the excess potassium ion concentration in the extracellular space following SD and the vessel radius. We find that the CSF volumetric flow rate depends intricately on the length and width of the PVS, as well as the vessel radius and the angle of incidence of the SD wave. We derive analytical expressions for pressure and volumetric flow rates of CSF through the PVS for a given SD wave and quantify CSF flow variations when two SD waves collide. Our numerical approach is very general and could be extended in the future to obtain novel, quantitative insights into how CSF flow in the brain couples with slow waves, functional hyperemia, seizures, or externally applied neural stimulations.


Asunto(s)
Trastornos Migrañosos , Accidente Cerebrovascular , Humanos , Encéfalo/fisiología , Presión del Líquido Cefalorraquídeo/fisiología , Espacio Extracelular , Líquido Cefalorraquídeo/fisiología
16.
Mol Neurobiol ; 60(10): 5770-5788, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37347366

RESUMEN

Low intracranial pressure (LICP)-induced translaminar cribrosa pressure difference (TLCPD) elevation has been proven as a risk factor in glaucomatous neurodegeneration, whereas the underlying retinal immune features of LICP-induced retinal ganglion cells (RGC) injury remain elusive. Here, we identified the retinal immune characteristics of LICP rats, and minocycline (Mino) treatment was utilized to analyze its inhibitory role in glia-mediated retinal inflammation of LICP rats. The results showed that retrograde axonal transport was decreased in LICP rats without significant RGC loss, indicating the RGC injury was at an early stage before the morphological loss. The activation of retinal microglia and astrocytes with morphologic and M1 or A1-marker alternations was detected in TLCPD elevation rats, the activation level is more dramatic in HIOP rats than in the LICP rats (P<0.05). Besides, we detected reduced retinal tight junction protein expressions, accompanied by specific imbalance patterns of T lymphocytes in the retina of both LICP and HIOP rats (P<0.05). Further Mino treatment showed an effective inhibitory role in glia-driven inflammatory responses in LICP rats, including improving retrograde axonal transport, inhibiting retinal glial activation and proinflammatory subtype polarization, and alleviating the blood-retina barrier compromise. This study identified the glia-mediated retinal inflammation features triggered by LICP stimulus, and Mino application exhibited an effective role in the inhibition of retinal glia-mediated inflammation in LICP-induced TLCPD elevation rats.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Enfermedades de la Retina , Células Ganglionares de la Retina , Neuroglía/metabolismo , Enfermedades de la Retina/metabolismo , Inflamación/metabolismo , Células Ganglionares de la Retina/metabolismo , Masculino , Animales , Ratas , Ratas Sprague-Dawley , Transducción de Señal , Linfocitos T/metabolismo
17.
Acta Neurochir (Wien) ; 165(8): 2309-2319, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37354286

RESUMEN

INTRODUCTION: The cerebrospinal fluid (CSF) production rate in humans is not clearly defined but is estimated to be 18-24 ml/h (Trevisi et al Croat Med J 55(4):377-387 (24); Casey and Vries Childs Nerv Syst 5(5):332-334 (8)). A frequent clinical observation is that patients often drain higher volumes of CSF than can be explained by the assumed 'normal' CSF production rate (PRcsf). In the National Hospital for Neurology and Neurosurgery PRcsf was recorded in a variety of common neurosurgical pathologies using LiquoGuard7, an automated peristaltic pump that accurately controls CSF drainage and maintains a pre-set CSF pressure. METHODS: A prospective observational study was performed from September 2021 onwards, on all patients in the National Hospital for Neurology and Neurosurgery who required CSF drainage as part of their ongoing treatment. The external drain was connected to a LiquoGuard7 pump (Möller Medical GmbH, Fulda, Germany), and the internal software of LiquoGuard7 was used to measure PRcsf. Statistical analysis used SPSS (version 25.0, IBM) by paired t test, comparing measured rates to hypothetical 'normal' CSF production rates calculated and published by Ekstedt (16-34ml/h) (Ekstedt J Neurol Neurosurg Psychiatry 41(4):345-353 (14)), assuming a similar distribution. RESULTS: PRcsf was calculated in 164 patients. Suspected normal pressure hydrocephalus (n=41): PRcsf of 79ml/h±20SD (p<0.0001). Post-surgical CSF leak (n=26): PRcsf of 90ml/h±20SD (p<0.0001). Subarachnoid haemorrhage (n=34): PRcsf of 143ml/h±9SD (p<0.0001). Intracerebral haemorrhage (n=22): PRcsf of 137ml/h±20SD (p<0.0001). Spinal lesions (n=7): PRcsf of 130ml/h±20SD (p<0.0032). Pituitary adenomas (n=10): PRcsf of 29 ml/h±9SD (p<0.049). Idiopathic intracranial hypertension (n=15): PRcsf of 86ml/h±10SD (p<0.0001). Decompensated long-standing overt ventriculomegaly (n=4): PRcsf of 65ml/h±10SD (p<0.0001). Cerebral infection (n=5): PRcsf of 90ml/h±20SD (p<0.0001). CONCLUSION: Net CSF production rate may be higher than expected in many conditions, as measured with new device LiquoGuard7 through the study of net flow rate, which may have implications for clinical decisions on CSF diversion. The conventional understanding of CSF production and circulation does not explain the findings of this study. More extensive studies are needed to validate this technique.


Asunto(s)
Hidrocéfalo Normotenso , Hidrocefalia , Hemorragia Subaracnoidea , Humanos , Hidrocefalia/cirugía , Presión del Líquido Cefalorraquídeo , Pérdida de Líquido Cefalorraquídeo , Estudios Prospectivos , Líquido Cefalorraquídeo
18.
Acta Neurochir (Wien) ; 165(6): 1533-1543, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37079108

RESUMEN

PURPOSE: Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. METHOD: Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). RESULTS: Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. CONCLUSION: This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Punción Espinal , Humanos , Anciano , Presión Sanguínea , Constricción Patológica , Presión
19.
Neurorehabil Neural Repair ; 37(4): 171-182, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36919616

RESUMEN

BACKGROUND: Sufficient and timely spinal cord decompression is a critical surgical objective for neurological recovery in spinal cord injury (SCI). Residual cord compression may be associated with disturbed cerebrospinal fluid pressure (CSFP) dynamics. OBJECTIVES: This study aims to assess whether intrathecal CSFP dynamics in SCI following surgical decompression are feasible and safe, and to explore the diagnostic utility. METHODS: Prospective cohort study. Bedside lumbar CSFP dynamics and cervical MRI were obtained following surgical decompression in N = 9 with mostly cervical acute-subacute SCI and N = 2 patients with non-traumatic SCI. CSFP measurements included mean CSFP, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp), Valsalva maneuver, and Queckenstedt's test (firm pressure on jugular veins, QT). From QT, proxies for cerebrospinal fluid pulsatility curve were calculated (ie, relative pulse pressure coefficient; RPPC-Q). CSFP metrics were compared to spine-healthy patients. computer tomography (CT)-myelography was done in 3/8 simultaneous to CSFP measurements. RESULTS: Mean age was 45 ± 9 years (range 17-67; 3F), SCI was complete (AIS A, N = 5) or incomplete (AIS B-D, N = 6). No adverse events related to CSFP assessments. CSFP rise during QT was induced in all patients [range 9.6-26.6 mmHg]. However, CSFPp was reduced in 3/11 (0.1-0.3 mmHg), and in 3/11 RPPC-Q was abnormal (0.01-0.05). Valsalva response was reduced in 8/11 (2.6-23.4 mmHg). CSFP dynamics corresponded to CT-myelography. CONCLUSIONS: Comprehensive bedside lumbar CSFP dynamics in SCI following decompression are safe, feasible, and can reveal distinct patterns of residual spinal cord compression. Longitudinal studies are required to define critical thresholds of impaired CSFP dynamics that may impact neurological recovery and requiring surgical revisions.


Asunto(s)
Presión del Líquido Cefalorraquídeo , Traumatismos de la Médula Espinal , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Estudios Prospectivos , Estudios de Factibilidad , Presión del Líquido Cefalorraquídeo/fisiología , Traumatismos de la Médula Espinal/diagnóstico por imagen , Traumatismos de la Médula Espinal/cirugía , Traumatismos de la Médula Espinal/líquido cefalorraquídeo , Descompresión Quirúrgica/efectos adversos , Descompresión Quirúrgica/métodos , Médula Espinal
20.
Cephalalgia ; 43(4): 3331024231157694, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36856002

RESUMEN

BACKGROUND: Headache with neurologic deficits and cerebrospinal fluid lymphocytosis, previously also termed pseudomigraine with temporary neurologic symptoms and lymphocytic pleocytosis, is a self-limiting syndrome characterized by moderate to severe headache associated with focal neurological deficits occurring in the context of lymphocytosis in the cerebrospinal fluid. As a consequence of its rarity, data regarding headache with neurologic deficits and cerebrospinal fluid lymphocytosis is sparse. Therefore, we conducted this review to analyze data related to 93 patients of headache with neurologic deficits and cerebrospinal fluid lymphocytosis, to characterize their demographics, clinical manifestations, investigations and treatment options. METHODS: We performed a systematic review of cases reported through PubMed and Google scholar database, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Keywords used were 'Headache with Neurologic Deficits and cerebrospinal fluid lymphocytosis', 'Headache with neurologic deficits and cerebrospinal fluid lymphocytosis syndrome'. The quality of the included studies was assessed using the Joanna Briggs Institute Critical Appraisal Tool. RESULTS: We analyzed a total of 93 cases of headache with neurologic deficits and cerebrospinal fluid lymphocytosis with a mean age of 28.8 years at onset. Seventy patients (75.2%) were adults, while 23 (24.7%) belonged to the pediatric age group. Comparing these groups, mean age at onset was 32.5 years and 14.3 years, respectively. The average duration of follow-up was 11.08 months. Thirty percent of patients experienced relapsing episodes of headache with neurologic deficits and cerebrospinal fluid lymphocytosis symptoms. The most common type of headache reported was unilateral severe throbbing episodic headache. Other associated symptoms included sensory deficit (60%) and motor deficits (54.8%). The least common symptoms were nystagmus and agraphia, which were reported in one patient each. Antiviral agents were a common treatment option in the acute phase (n = 23 patients [23.6%]), while Flunarizine was the most commonly used agent in the chronic setting (n = 3 patients [3.2%]). While most of the patients had normal brain magnetic resonance imaging, 20 patients had magnetic resonance imaging abnormalities, including (but not limited to) non-specific white matter lesions (eight patients) and meningeal enhancement (six patients). The most common electroencephalographic findings included diffuse and focal slowing. The mean cerebrospinal fluid opening-pressure was 240.5 mmH2O. Cerebrospinal fluid protein was elevated in 59 (63.4%) patients, with a mean value of 114 mg/dL. Two patients in our cohort were found to have cerebrospinal fluid oligoclonal bands. CONCLUSION: Headache with neurologic deficits and cerebrospinal fluid lymphocytosis tends to affect young individuals with a slight male predominance. Unilateral severe throbbing episodic headache with associated hemi-paresthesia and hemiparesis were the most common symptoms based on our review. Elevated cerebrospinal fluid opening-pressure can be seen in headache with neurologic deficits and cerebrospinal fluid lymphocytosis syndrome. Early recognition of the syndrome is paramount. Antivirals were found to be among the most widely used treatments in the acute setting. Magnetic resonance imaging of the brain is mostly normal. Diffuse and focal slowing were among the most common electroencephalographic findings. Cerebral flow abnormalities on perfusion scans are not uncommon in headache with neurologic deficits and cerebrospinal fluid lymphocytosis. Prospective studies with a larger sample size are needed to validate our findings and guide the clinical care of these patients.


Asunto(s)
Linfocitosis , Adulto , Humanos , Masculino , Niño , Femenino , Linfocitosis/complicaciones , Estudios Prospectivos , Cefalea/epidemiología , Presión del Líquido Cefalorraquídeo , Encéfalo
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