Changes of cerebrospinal fluid pressure gradient in different body positions under experimental impairment of cerebrospinal fluid pathway: new insight into hydrocephalus development.

It is generally accepted that hydrocephalus is a consequence of the disbalance between cerebrospinal fluid (CSF) secretion and absorption which should in turn lead to CSF pressure gradient development and ventricular enlargement. To test CSF pressure gradient role in hydrocephalus development, we experimentally caused CSF system impairment at two sites in cats. In the first group of animals, we caused Sylvian aqueduct obstruction and recorded CSF pressure changes pre and post obstruction at three measuring sites (lateral ventricle -LV, cortical-CSS and lumbar subarachnoid space -LSS) during 15 min periods and in different body positions over 360 degrees. In the second group of experiments, we caused cervical stenosis by epidural plastic semiring implantation and monitored CSF pressure changes pre and post stenosis implantation at two measuring sites (lateral ventricle and lumbar subarachnoid space) during 15 min periods in different body positions over 360 degrees. Both groups of experimental animals had similar CSF pressures before stenosis or obstruction at all measuring points in the horizontal position. During head-up verticalization, CSF pressures inside the cranium gradually became more subatmospheric with no significant difference between LV and CSS, as they are measured at the same hydrostatic level, while CSF pressure inside LSS became more positive, causing the development of a large hydrostatic gradient between the cranial and the spinal space. With cervical stenosis, CSF pressure inside the cranium is positive during head-up verticalization, while in cats with aqueductal obstruction CSF pressure inside the CSS remains negative, as it was during control period. Concomitantly, CSF pressure inside LV becomes less negative, thus creating a small hydrostatic gradient between LV and CSS. Since CSF pressure and gradient changes occur only by shifting body position from the horizontal plane, our results indicate that cervical stenosis in a head-up vertical position reduces blood perfusion of the whole brain, while aqueductal obstruction impairs only the perfusion of the local periventricular brain tissue. It seems that, for evolutionary important bipedal activity, free craniospinal communication and good spinal space compliance represent crucial biophysical parameters for adequate cerebral blood perfusion and prevention of pathophysiological changes leading to the development of hydrocephalus.

Antibiotics-Induced Intracranial Hypertension: A Case Report With Literature Review.

Idiopathic intracranial hypertension (IIH) is a rare condition characterized by increased intracranial pressure, with an unknown cause. However, the pathophysiology of antibiotic-induced IIH remains unclear. The clinical symptoms include headache, visual disturbances, and vomiting. The diagnosis is confirmed by an elevated intracranial pressure (ICP) with normal CSF study and cerebral imaging. Management includes discontinuing the offending antibiotic and reducing ICP with medications such as acetazolamide or diuretics. Therefore, surgical intervention may be necessary in severe cases. In this article, we report the case of a 19-year-old patient, admitted with symptoms of intracranial hypertension syndrome, occurring three days after receiving antibiotics (gentamicin, penicillin). Physical examination revealed bilateral optic disc edema. Cerebral magnetic resonance imaging (MRI) revealed indirect signs of intracranial hypertension. The CSF pressure measurement was approximately 290 mmHg, while CSF and other laboratory blood tests were normal. The patient received methylprednisolone bolus and topiramate (50 mg/day). A month later, the clinical outcome showed regression of headaches and regression of the papilledema.

Value of CT in targeted CT-guided epidural blood patching: Predictors for successful epidural punctures.

BACKGROUND AND PURPOSE: Differentiating epidural from intrathecal punctures before computed tomography (CT)-guided epidural blood patching (EBP) is subjective, relying on operator experience. This study aimed to investigate CT findings for epidural and intrathecal punctures and identify reliable predictors for successful epidural punctures before targeted CT-guided EBP. MATERIALS AND METHODS: We included 65 patients with low-cerebrospinal fluid (CSF)-pressure headache receiving targeted CT-guided EBP between January 2021 and October 2022 in this retrospective study. We analyzed clinical data, technical information, and CT features before EBP. Fisher's exact test was used for discrete variables, while Mann-Whitney U test was used for continuous variables. Positive (PLR) and negative likelihood ratios (NLR) were calculated to identify predictors for confirming epidural punctures. RESULTS: We confirmed 43 patients as epidural punctures and 22 patients as intrathecal punctures. Before contrast injection, epidural fat at the needle tip in the epidural group was higher than the intrathecal group (37.2 % [16/43] vs. 4.5 % [1/22], p = 0.006). After contrast injection, the "contrast-needle tip connection" sign was mostly observed in the epidural group than the intrathecal group (95.3 % [41/43] vs. 9.1 % [2/22], p < 0.001). Additionally, the epidural group had significantly higher boomerang-shaped contrast morphology than the intrathecal group (65.1 % [28/43] vs. 9.1 % [2/22], p < 0.001). The "contrast-needle tip connection" sign had the highest PLR (10.49) and lowest NLR (0.05). CONCLUSION: Identifying epidural fat at the needle tip, "contrast-needle tip connection" sign, and boomerang-shaped contrast morphology on CT scans are useful for confirming proper placement of the needle tip within the epidural space.

Hipotensión intracraneal espontánea. Una puesta al día

Introducción: La hipotensión intracraneal espontánea es un síndrome causado por la disminución del volumen de líquido cefalorraquídeo consecuencia de su fuga al espacio extradural. Aunque la ICHD-3 proporciona un alto nivel de especificidad diagnóstica, esta enfermedad puede manifestarse de forma atípica. Hasta en un 30% no es posible establecer el punto de escape, pero con el refinamiento de los exámenes de imágenes este porcentaje se ha reducido a un 15%-20%. Actualmente, su manejo no se encuentra estandarizado y las recomendaciones se basan en evidencia de limitada calidad metodológica, además de la variabilidad de protocolos entre distintos centros. Desarrollo En esta revisión actualizamos los procedimientos diagnósticos y terapéuticos. Por un lado, analizamos el rol de la resonancia nuclear magnética de encéfalo y médula espinal completa como primer paso diagnóstico y, por otro lado, señalamos los exámenes destinados a determinar la fuga de líquido cefalorraquídeo. Tal es el caso de la mielo-resonancia, la mielo-tomografía computarizada, tanto estándar, dinámica y por sustracción digital, además de la cisternografía con 111-Indium-DPTA. Sin embargo, determinar cuál de estos exámenes es el óptimo es objeto de debate. Lo mismo ocurre con el tratamiento: reposo; parche sanguíneo epidural a ciegas, parche guiado por fluoroscopia o tomografía computarizada, parche de fibrina; o cirugía. Conclusiones Se requiere de una mayor investigación, especialmente con trabajos multicéntricos controlados, para una mejor comprensión de la fisiopatología, el diagnóstico por imágenes, los enfoques terapéuticos y evaluación objetiva de los resultados clínicos. Solo así se establecerán pautas diagnósticas y de tratamiento validadas.

Introducction: Spontaneous intracranial hypotension is a syndrome caused by decreased CSF volume secondary to its leakage into the extradural space Although ICHD-3 provides a high level of diagnostic specificity, manifestations may be atypical, making diagnosis challenging. The site of leakage may be undetermined in point Up to 30% of cases, although with recent refinement of imaging, this percentage has been reduced to 15-20%. Currently, management is not standardized and recommendations are based on inconclusive evidence, with variability of protocols between centres. Development. In this review, we update diagnostic and therapeutic procedures. We analyse the role of whole brain and spinal cord MRI as a first investigation and review tests aimed at determining cerebrospinal fluid leakage, such as MRI myelography, conventional CT myelography, dynamic CT myelography, and digital subtraction CT myelography, as well as 111-Indium-DPTA cisternography. Determining optimal use of these investigations remains a matter of debate. The same is true for treatment: rest, blind epidural blood patch, fluoroscopy or CT-guided epidural blood patch, fibrin patch and surgery are discussed. Conclusión: Further research, especially multicentre controlled studies, is required to improve understanding of pathophysiology, diagnostic imaging, therapeutic approaches and to objectively assess clinical outcomes. Only then will diagnostic and treatment guidelines be evidence-based.

Spontaneous intracranial hypotension: a case series and literature review.

Spontaneous intracranial hypotension (SIH) is a condition of negative intracranial pressure resulting from cerebrospinal fluid (CSF) leakage from the dural sac and is a well-known cause of orthostatic headache. Diagnosis and management can be difficult, often requiring coordination between multiple disciplines. Low CSF pressure and diffuse meningeal enhancement on brain MRI are the major instrumental features of the classic syndrome. Neuroimaging plays a key role in diagnosing SIH, particularly in atypical clinical presentations, by recognizing the specific findings of brain sagging on MRI and detecting the level of CSF leak on spinal imaging, thus guiding therapy accordingly. Since SIH could present with such a heterogeneous clinical picture, careful history taking and increased awareness of atypical presentations are of utmost importance. We review the existing SIH literature, illustrate management, clinical and neuroimaging findings of four consecutive patients with atypical SIH, who were recently referred to our hospital for evaluation to simplify and streamline the management of SIH.

Neurophysiological visual assessment in patients with idiopathic intracranial hypertension: visual evoked potential and multifocal field electroretinography.

BACKGROUND: Determining the cause of visual deterioration in idiopathic intracranial hypertension (IIH) patients is of clinical necessity. This study aimed to study the effect of chronic increased ICP on the retina and optic nerve through objective electrophysiological measures in chronic IIH patients. METHODS: Thirty patients with chronic IIH and thirty age and sex-matched healthy controls were included in this study. Papilledema grade and CSF pressure were evaluated in the patients' group. Both groups were submitted to visual evoked potentials (VEP) and multifocal electroretinogram (mfERG). RESULT: The mean value of P100 latencies of the right and left on two check sizes, 1 deg and 15m in chronic IIH patients, was significantly delayed than controls (P-value < 0.001 for each). Chronic IIH patients showed a significantly lower amplitude of the right and left R1, R2, R3, R4 & R5 compared to controls (P-value < 0.001, < 0.001) (P-value < 0.001, < 0.001) (P-value < 0.001, < 0.001) (P-value < 0.001, = 0.001) (P-value = 0.002, < 0.001), respectively. Also, patients showed a significantly delayed peak time of the right and left R1 and R2 compared to controls (P-value < 0.001, < 0.001) (P-value = 0.001, = 0.009), respectively. There was a significant positive correlation between each of CSF pressure and papilledema grade with right and left PVEP latencies. In contrast, there was no statistically significant correlation between either CSF pressure or papilledema grade and PVEP amplitudes in both eyes. CONCLUSION: In chronic IIH patients, both optic nerve dysfunction and central retinal changes were identified, supported by VEP and the mfERG findings.

Pituitary enlargement in patients with cerebrospinal fluid drainage due to ventricular shunt insertion: know the condition and do not mistake for adenoma.

OBJECTIVE: Childhood hydrocephalus patients treated by ventriculo-peritoneal (v.-p.) shunting are sometimes referred years after this therapy for evaluation of suspicious pituitary enlargement. Since pituitary size has been shown to depend on cerebrospinal fluid (CSF) pressure, we assume this phenomenon to be caused by shunt overdrainage. Therefore, we studied pituitary size and morphology in shunted hydrocephalus patients with radiological signs of high CSF drainage. PATIENTS AND METHODS: Retrospective study of pituitary size and morphology in 15 shunted patients with non-tumoral hydrocephalus and 7 shunted hydrocephalus patients due to childhood brain tumor compared to a population mean. In five brain tumor patients also pre- and postsurgical comparisons were performed. RESULTS: Pituitary mid-sagittal size and pituitary volume were significantly higher in both hydrocephalus groups, compared to the population mean (midsagittal size t = 5.91; p < 0.001; pituitary volume, t = 3.03; p = 0.006). In patients available for pre- and postoperative comparison, there was also a significant increase in pituitary size and volume postoperatively (mean preoperative midsagittal height 2.54 ± 1.0 mm vs. 6.6 ± 0.7 mm post-surgery; mean pre-operative pituitary volume 120.5 ± 69.2 mm3 vs. 368.9 ± 57.9 mm3 post-surgery). CONCLUSION: Our results confirmed a significant increase in pituitary size and volume, mimicking pituitary pathology, after v.-p. shunt insertion. This phenomenon can be explained by the Monro-Kellie doctrine, stating that intracranial depletion of CSF-as caused by v.p. shunting-leads to compensatory intracranial hyperemia, especially in the venous system, with the consequence of engorged venous sinuses, most likely responsible for enlargement of the pituitary gland.

Current perspectives on the recognition and diagnosis of low CSF pressure headache syndromes.

INTRODUCTION: Headaches occur when cerebrospinal fluid (CSF) pressure drops following dural puncture or trauma or spontaneously. As the features of these headaches and their accompanying symptoms might not be typical, low CSF pressure headache syndromes, and spontaneous intracranial hypotension in particular, are often misdiagnosed and underdiagnosed. AREAS COVERED: The aim of this narrative review is to summarize the most recent evidence regarding the clinical presentation and the diagnosis of low CSF pressure headache syndromes. EXPERT OPINION: The clinical spectrum low CSF pressure headache syndromes varies significantly and key signs might be missing. Low CSF pressure headache syndromes should be included in the differential diagnosis of any case of refractory headache, even when the headache is not orthostatic, or there are normal neuroimaging findings, and/or lumbar puncture opening pressure is within normal limits. Future research should focus on controlled interventional studies on the treatment of low CSF pressure headache syndromes, which are currently lacking.

Management of long-term cryptococcal meningitis neoformans in a surviving patient: A case report.

Cryptococcal meningitis is a common fungal infection of the central nervous system with high mortality and disability rates. A prominent clinical manifestation is persistent and severe cranial hypertension, which is one of the most critical outcome determinants in patients with cryptococcal meningoencephalitis. Herein, we report and discuss a case of cryptococcal meningitis treated by an inadequate course of medical therapy and placement of a ventriculoperitoneal shunt in a patient who survived for more than 10 years.

Cerebrospinal fluid micro-volume changes inside the spinal space affect intracranial pressure in different body positions of animals and phantom.

Interpersonal differences can be observed in the human cerebrospinal fluid pressure (CSFP) in the cranium in an upright body position, varying from positive to subatmospheric values. So far, these changes have been explained by the Monroe-Kellie doctrine according to which CSFP should increase or decrease if a change in at least one of the three intracranial volumes (brain, blood, and CSF) occurs. According to our hypothesis, changes in intracranial CSFP can occur without a change in the volume of intracranial fluids. To test this hypothesis, we alternately added and removed 100 or 200 µl of fluid from the spinal CSF space of four anesthetized cats and from a phantom which, by its dimensions and biophysical characteristics, imitates the cat cerebrospinal system, subsequently comparing CSFP changes in the cranium and spinal space in both horizontal and vertical positions. The phantom was made from a rigid "cranial" part with unchangeable volume, while the "spinal" part was made of elastic material whose modulus of elasticity was in the same order of magnitude as those of spinal dura. When a fluid volume (CSF or artificial CSF) was removed from the spinal space, both lumbar and cranial CSFP pressures decreased by 2.0-2.5 cm H2O for every extracted 100 µL. On the other hand, adding fluid volume to spinal space causes an increase in both lumbar and cranial CSFP pressures of 2.6-3.0 cm H2O for every added 100 µL. Results observed in cats and phantoms did not differ significantly. The presented results on cats and a phantom suggest that changes in the spinal CSF volume significantly affect the intracranial CSFP, but regardless of whether we added or removed the CSF volume, the hydrostatic pressure difference between the measuring sites (lateral ventricle and lumbar subarachnoid space) was always constant. These results suggest that intracranial CSFP can be increased or decreased without significant changes in the volume of intracranial fluids and that intracranial CSFP changes in accordance with the law of fluid mechanics.

Evaluation of Clinical Findings with MRI Venography in Patients with Idiopatic Intracranial Hypertension.

OBJECTIVES: To evaluate clinical data and Magnetic Resonance Venography (MRV) findings together in patients with idiopathic intracranial hypertension (IIH). MATERIALS AND METHODS: In this retrospective study between January 2009 and February 2021, conventional MRI and MRV examinations were performed on 30 patients who were admitted to the neurology service of Erciyes University Medical Faculty with the pre-diagnosis of IIH, cerebrospinal fluid (CSF) pressure was measured in these patients to confirm the diagnosis of IIH. Transverse Sinus Stenosis Ratio (TS SR), Superior Sagittal Sinus (SSS) diameter, Sinus Rectus (SR) diameter, Stenosis Segment Length (SSL) were studied. RESULTS: High CSF pressure was detected in 22 of 30 patients with IIH pre-diagnosis. CSF pressure was normal in 8 cases. TS SR was compared in all groups, right TS SR 0.63 ± 0.16, Left TS SR 0.55 ± 0.16 in the patient group with IIH, right TS SR 0.55 ±0.16 in the CSF pressure normal patient group, Right TS SR 0.28 ± 0.07 Left TS SR 0.31 ± 0.07 in the control group Right TS SR It was 0.28 ± 0.09, Sol TS SR was 0.30 ± 0.07. CONCLUSION: Before LP, the cranial venous system must be monitored. TS SR and CSF pressure are directly proportional. The stenosis rate is important for IIH rather than SSL.

Incidence of dural sac puncture during neuraxial anesthesia in cats: an observational, retrospective study.

OBJECTIVES: The aim of this study was to determine the occurrence of dural puncture, indicated by cerebrospinal fluid (CSF) outflow, in cats receiving neuraxial anesthesia through a lumbosacral injection guided by a pop sensation method. METHODS: This was an observational, retrospective study. Cats that were scheduled for lumbosacral neuraxial anesthesia were included. Medical records were analyzed to investigate: (1) demographic data; (2) neuraxial anesthesia performed (epidural/spinal); (3) type of needle used, including gauge and length; (4) presence of CSF (yes/no) and/or blood (yes/no) in the hub of the needle; and (5) flicking of the tail during needle advancement (yes/no). RESULTS: A total of 94 medical records were analyzed. A 22 G 50 mm Tuohy needle was used in all cats scheduled for an epidural injection (n = 60), whereas a 22 G 40 mm Quincke needle was used in all cats scheduled for an intrathecal injection (n = 34). CSF outflow was detected in 55/60 (91.7%) cats in which a Tuohy needle was used, and 34/34 (100%) of the cats in which a Quincke needle was used (P = 0.15). Flicking of the tail was detected in 41/60 (68.3%) and in 24/34 (70.6%) injections with Tuohy and Quincke needles, respectively (P >0.99). Traces of blood, but not active blood outflow, were detected via staining of the first drops of CSF in 2/34 cats in which Quincke needles were used and in none of the cats in which Tuohy needles were used (P = 0.12). CONCLUSIONS AND RELEVANCE: This study shows that the lumbosacral approach for neuraxial anesthesia in cats may result in a dural sac puncture when 22 G Quincke or Tuohy needles are used. The pop sensation method should be deemed effective in predicting intrathecal but not epidural needle placement.

The Effect of Periocular Negative Pressure Application on Intraocular and Retrobulbar Pressure in Human Cadaver Eyes.

INTRODUCTION: To investigate the effect of applying negative pressure (vacuum) to the periocular space on intraocular pressure (IOP) and retrobulbar pressure (RBP) by use of the Multi-Pressure Dial (MPD) system (Equinox Ophthalmic, Inc.). METHODS: Two eyes of two full body cadavers were studied. In each subject, the retrobulbar space, posterior segment and intra-goggle space were cannulated to provide direct IOP, RBP and intra-goggle pressure measurements via a pressure transducer data acquisition system. The goggles of the MPD system were placed over the eyes of each subject, and multiple test runs were performed, with negative pressure settings programmed to 5, 10 and 20 mmHg. IOP and RBP measurements were continuously obtained during each run and plotted against time for analysis. RESULTS: For both subjects, the mean reduction (± standard deviation) in IOP was 1.6 ± 0.9 (10%), 3.5 ± 1.8 (23%) and 5.6 ± 2.0 (37%) mmHg at programmed negative pressure levels of - 5, - 10 and - 20 mmHg, respectively. The overall mean change in RBP (mmHg) during negative pressure application was 0.02 ± 0.14 at - 5 mmHg, 0.03 ± 0.19 at - 10 mmHg and - 0.01 ± 0.18 at - 20 mmHg. In both subjects, the magnitude of RBP change during application of negative pressure fell below the uncertainty of the measurement system. CONCLUSIONS: The application of negative pressure to the periocular space with the MPD decreases IOP but does not affect RBP.

How do presentation age and CSF opening pressure level affect long-term prognosis of pseudotumor cerebri syndrome in children? Experience of a single tertiary clinic.

BACKGROUND: Diagnosis and treatment of pseudotumor cerebri syndrome in children is still a challenge for clinicians. The aim of this study is to reveal the influence of presentation age and CSF opening pressure on long-term prognosis of pseudotumor cerebri and share our clinical data of the very young age (≤ 5-year) group. METHOD: This retrospective study includes the patients followed by the Marmara University Pediatric Neurology Clinic between years 2012 and 2020 diagnosed with definite, probable, or suggestive pseudotumor cerebri syndrome according to modified Friedman criteria. Patients were classified into three groups according to presentation age: group 1: ≤ 5 years old; group 2: 6-10 years; and group 3 > 10 years old. CSF opening pressure was also categorized into three groups as CSF < 20 cmH20; CSF 20-30 cmH20; and CSF > 30 cmH20. RESULTS: One hundred three patients, 62.1% female (n = 64), were enrolled in the study. Group 1 consisted of 16 patients (60% male), group 2 consisted of 30 patients (63.3% female), and group 3 consisted of 57 patients (66.7% female). The mean CSF opening pressure did not differ between the three age groups in our study (p > 0.05). Treatment response was not correlated with CSF opening pressure. Papilledema presence and level of CSF opening pressure were independent of age (p > 0.05). CONCLUSIONS: Age at presentation and CSF opening pressure at diagnosis are not any predictive factors that influence long-term prognosis of pseudotumor cerebri syndrome in children. Evaluation and follow-up of children should be done in personalized approach.

Evaluation of the IOP-Lowering Effect of a Multi-Pressure Dial at Different Negative Pressure Settings.

Purpose: To evaluate the intraocular pressure (IOP)-lowering effect of a multi-pressure dial (MPD) at targeted negative pressure settings. Methods: Prospective, intrasubject controlled study of 65 healthy subjects randomized to receive no negative pressure for 60 minutes or negative pressure application at designated levels of 25%, 50%, and 75% of baseline IOP for 20 minutes each. The main outcome measure was mean IOP with application of negative pressure. Results: In the study eye group, from a baseline IOP of 15.8 ± 3.6 mm Hg, the mean IOP was 13.5 ± 3.4, 11.5 ± 3.1, and 10.2 ± 2.7 mm Hg with negative pressure settings of 25%, 50% and 75%, respectively. In the control eye group, from a baseline IOP of 15.5 ± 3.0 mm Hg, the mean IOP values at the same time points, without negative pressure, were 15.6 ± 3.0, 15.5 ± 2.5 and 15.3 ± 2.4 mm Hg. The difference between the mean IOPs of the two groups was significantly different at all negative pressure settings (P < 0.001) in comparison with baseline. There was one minor adverse event, a corneal abrasion, that was unrelated to device wear. Conclusions: Negative pressure application to the periocular space with a multi-pressure dial can produce titratable IOP reduction while the device is worn with active negative pressure. To our knowledge, this technology represents the first nonpharmacologic, nonlaser, nonsurgical method for IOP reduction. Translational Relevance: This represents the first study demonstrating the IOP-lowering ability of the multi-pressure dial, a device that uses a novel IOP-lowering strategy by delivering negative pressure to the periocular region.

Transcranial Doppler for Monitoring and Evaluation of Idiopathic Intracranial Hypertension.

Background Idiopathic intracranial hypertension (IIH) is a disorder of unknown origin, characterized by features of raised intracranial pressure (ICP). Existing literature is inconclusive about the role of transcranial Doppler (TCD) in the management of IIH. Objective To study the TCD changes in IIH patients, pre- and post-cerebrospinal fluid (CSF) drainage. Materials and Methods This was a prospective study, conducted between July 2017 and December 2019, in a tertiary care referral center in South India. Sixteen consecutive patients, suspected to have IIH, underwent magnetic resonance imaging ofthe brain, a baseline TCD, and lumbar puncture with CSF drainage and pressure monitoring. Post-CSF drainage, TCD was repeated and mean flow velocities, peak systolic velocities, end-diastolic velocities, and pulsatility index (PI), in the middle cerebral artery (MCA), vertebral artery, and basilar artery (BA) were noted. Thirteen patients had elevated CSF pressure, and fulfilled the diagnostic criteria for IIH. These patients were included in the final analysis and pre- and post-CSF drainage TCD blood flow velocities and PI were compared. Results The mean age of study participants was 29.92 ± 6.92 years. There was a significant reduction in the cerebral flow velocities in bilateral MCA, after CSF drainage and normalization of ICP. Flow velocities in posterior circulation and PI in MCA, PCA, and BA showed an insignificant reduction. Two patients, who did not show any reduction in flow velocities after CSF drainage, developed optic atrophy on follow-up. Conclusion TCD-derived systolic blood flow velocities can be used in the management and follow-up of patients with IIH.

The role of opening CSF pressure in response to treatment for idiopathic intracranial hypertension (IIH).

The aim of the current study was to assess the risk factors, clinical symptoms and Cerebrospinal fluid (CSF) pressure of idiopathic intracranial hypertension (IIH) with emphasis on determining the risk factors which involved in poor response to treatment. We retrospectively included 202 patients who were diagnosed with IIH. Disease severity was classified according to prescribed therapeutic option into 4 groups: acetazolamide (group 1), Acetazolamide plus topiramate or Lasix (group 2), repeated LP (group 3) and surgical intervention (group 4). Being in the higher group was considered as a higher severity of disease and poor response to treatment. Among the evaluated features of IIH, the strongest association were observed between opening CSF pressure and disease severity. So that, the highest CSF pressure was observed in patients who underwent surgery, which represent the highest severity of disease (group 4) and poor response to therapy (mean ± SD: 43.9 ± 21.1 cm H2O). Headache was the most prevalent symptom of IIH in our series which was significantly higher among acetazolamide group. Blurred vision was the second most common symptoms which, unlike the headache was more reported in surgery group. Our results suggested that higher CSF pressure could be the risk factors of poor response to therapy, which may raise need for more intensive treatment. Furthermore, suffering of headache without blurred vision can consider as a prognostic factor for mild severity and good response to treatment.

Nutcracker syndrome mimicking new daily persistent headache: A case report.

INTRODUCTION: Compression of the duodenum and left renal vein between the aorta and superior mesenteric artery usually leads to symptoms of proximal bowel obstruction or hematuria and, more rarely, nonspecific mild headaches. CASE: A young woman presented with new daily persistent headache refractory to numerous pharmacological treatments, onabotulinumtoxinA, nerve blocks, and occipital nerve stimulation. Following several years of daily severe headache, worsening abdominal pain and intolerance for food intake led to the discovery of aortomesenteric compression. Surgical treatment gave prompt improvement in gastric symptoms but also essentially resolved the headache. CONCLUSION: This is the first description of new daily persistent headache in association with aortomesenteric compression as well as marked improvement of headache following aortomesenteric decompression. In patients with new daily persistent headache and orthostatic symptoms one may consider a differential diagnosis of Nutcracker syndrome, especially in patients with comorbid hypermobility syndromes, hematuria or gastric symptoms.

Coupling of CSF and sagittal sinus pressure in adult patients with pseudotumour cerebri.

OBJECTIVE: Pseudotumour cerebri syndrome (PTCS including idiopathic intracranial hypertension) is characterised by the symptoms and signs of raised cerebrospinal fluid pressure (CSFp) in the absence of ventricular dilatation or an intracranial mass lesion. Its aetiology is unknown in the majority of cases but there is much evidence for impaired CSF absorption. Traditionally, sagittal sinus pressure has been considered to be independent of CSF pressure in adults. However, the discovery of stenoses of intracranial venous sinuses and introduction of venous sinus stenting has highlighted the importance of the venous drainage in PTCS. In this study, we have explored the relationship between CSFp and SSp before and during a CSF infusion test and during CSF drainage. MATERIALS AND METHODS: Ten patients (9 females:1 male) with PTCS underwent infusion studies in parallel with direct retrograde cerebral venography. Both SSp and CSFp were recorded at a baseline and during CSFp elevation in a course of a CSF infusion test. The drainage of CSF after the CSF infusion was performed in 7 patients. In 5 cases, jugular venous pressure was also measured. RESULTS: CSFp and SSp including their amplitudes correlated significantly and strongly both at baseline (R = 0.96; p = 0.001) and during infusion (R = 0.92; p = 0.0026). During drainage, this correlation was maintained until SSp reached a stable value, whereas CSFp continued to decrease. CONCLUSIONS: In this series of ten patients with PTCS, CSFp and SSp were coupled, both at baseline and during infusion. The implications of such coupling for the calculation of CSF outflow resistance are discussed.

Under pressure: Cerebrospinal fluid contribution to the physiological homeostasis of the eye.

The cerebrospinal fluid (CSF) is a waterly, colorless fluid contained within the brain ventricles and the cranial and spinal subarachnoid spaces. CSF physiological functions range from hydromechanical protection of the central nervous system (CNS) to CNS modulation of developmental processes and regulation of interstitial fluid homeostasis. Optic nerve (ON) is surrounded by CSF circulating in the subarachnoid spaces and is exposed to both CSF (CSFP) and intra ocular (IOP) pressures, which converge at the lamina cribrosa (LC) as two opposite forces. The trans-lamina cribrosa pressure gradient (TLPG) is defined as IOP - CSFP and its alterations (due either to an elevation in IOP or a reduction in ICP) could result in structural damaging of the ON, including glaucomatous changes. The purpose of this review is to update the readers on the CSF contribution in controlling the functions/dysfunctions of ON by regulating homeostasis at LC. We also highlight emerging parallelisms regarding the expression of cilia-related genes in the regulation of common functions of body fluids in both brain and eye structures.