Lumbar Puncture Opening Pressure Research Articles

Concordance between venous sinus pressure and intracranial pressure in patients investigated for idiopathic intracranial hypertension

BackgroundIdiopathic intracranial hypertension (IIH) is a cause of chronic headaches that are probably driven by raised intracranial pressure (ICP). Cerebral venous sinus pressure is thought to play a role in the underlying pathology, but its relation with intracranial pressure requires further investigation. We aimed to evaluate the concordance between lumbar puncture opening pressure (LPOP) as indicator of the ICP and cerebral venous sinus pressure in patients investigated for IIH.MethodsIn this case-series replication study, all patients with IIH suspicion and who underwent cerebral venous sinus pressure measurement followed immediately by LP opening pressure (LPOP) measurement were retrospectively included. Pearson’s correlation and measurement agreement (Bland-Altman plots) between venous pressure and LPOP were analyzed.Results52 consecutive patients (46 women; median age, 31 years [IQR = 25–42]) were included. The mean pressure in the superior sagittal sinus (SSS) and in the torcular were 20.9mmHg (SD ± 7.3) and 20.8 mmHg (SD ± 6.8), respectively. The mean LPOP was 22mmHg (SD ± 6.4). Pressure measured in the transverse venous sinus, the torcular, and the SSS correlated with LPOP (p < 0.001). Bland-Altman plots showed that torcular pressure strongly agreed with LPOP (mean difference of 1.7mmHg). The limit of agreement (LOA) (mean difference ± 1.96SD) contained 98.1% of the differences between the two methods, confirming the concordance between the two measures. Torcular pressure and LPOP were consistent in patients with a trans-stenotic pressure gradient ≥ or < to 8 mmHg (mean difference: 1mmHg and 2.4mmHg, respectively), and for those with a LP OP ≥ or < to 18mmHg (mean difference: 1.8mmHg and 1.95mmHg, respectively).ConclusionsIn patients investigated for IIH, the ICP measured at the LP is correlated and concordant with the torcular pressure. These results confirm previous findings and further corroborate the hypothesis that cerebral venous system plays a major role in CSF dynamics and ICP.

Endoscopic Repair of Cerebrospinal Fluid Leak

BACKGROUND AND IMPORTANCE: The evolution of endoscopic techniques in spine has allowed novel approaches to various pathologies. We describe the use of endoscopy for repair of refractory cerebrospinal fluid (CSF) leak after lumbar puncture (LP). CLINICAL PRESENTATION: A 31-year-old female presented with refractory postural headaches after undergoing LP. The patient underwent 4 total epidural blood patches (EBPs) with minimal symptomatic relief. The LP opening pressure was found to be 18 cm of water, inconsistent with underlying pseudotumor cerebri. A myelogram demonstrated persistent CSF leak and contrast accumulation within the dorsal epidural space at L2-3. Endoscopic exploration was ultimately performed, which demonstrated well-placed EBPs; however, continuous CSF egressed from a pinhole site. This was repaired with coagulation using a radiofrequency probe, DuraSeal (Integra LifeSciences) and DuraGen (Integra LifeSciences). Postoperatively, the patient noted resolution of debilitating intracranial hypotension symptoms and was able to return to work. CONCLUSION: Postdural puncture headaches occur in about 1/3 of patients after LP. Symptoms are often debilitating and can include nausea, neck pain, dizziness, tinnitus, visual changes, and hearing loss. Multiple pharmacological and invasive treatments, such as EBP, have been used historically with success, but Postdural puncture headaches refractory to these interventions can put patients at risk for serious complications including seizures and subdural hematomas. We present the first reported case of an endoscopic approach to repair refractory CSF leak in the lumbar spine. Our approach highlights the potential of minimally invasive endoscopic techniques in the repair of refractory CSF leak from the puncture site after LP.

Venous sinus stenting versus ventriculoperitoneal shunting: comparing clinical outcomes for idiopathic intracranial hypertension

BackgroundVenous sinus stenting (VSS) has been shown to reduce intracranial venous pressures and improve symptoms in patients with idiopathic intracranial hypertension (IIH). However, long-term follow-up data are limited, raising concerns...

Radiological signs supporting idiopathic intracranial hypertension in symptomatic patients with lumbar puncture opening pressure < 250 mm

Lumbar puncture opening pressure (LPOP) exceeding 250mmH2O is key in diagnosing idiopathic intracranial hypertension (IIH), per revised Friedman’s criteria. Some patients do not meet LPOP criteria (with or without papilledema), despite having IIH-related symptoms and neuroimaging findings. This study aimed to investigate the radiological findings and clinical symptoms in patients suspected of having IIH without meeting the LPOP criteria. We retrospectively evaluated cerebral venous sinus stenosis using the conduit Farb score (CFS) and other radiological findings suggestive of IIH by computed tomography venography and magnetic resonance venography in females ≥ 18 years-old with chronic headaches, suspected IIH, and LPOP < 250 mm. Eighty-eight women (56 with LPOP < 200 mm H2O and 32 with LPOP ranging between 200 and 250mmH2O) were included. Among patients with LPOP 200–250mmH2O, 40% (12) exhibited three or more radiological findings supporting IIH, compared to 17% (8) in the LPOP < 200 mmH2O group (p = 0.048). Cerebral venous stenosis (CFS ≤ 5) was observed in 80% (24) of those with LPOP 200–250 mmH2O, contrasting with 40% (19) of those with LPOP < 200 mmH2O (p < 0.001). Cerebral venous stenosis was significantly more common in patients with LPOP 200–250 mmH2O than < 200 mmH2O, suggesting that they may benefit from IIH treatment.

Severe Spaceflight-Associated Neuro-Ocular Syndrome in an Astronaut With 2 Predisposing Factors

Understanding potential predisposing factors associated with spaceflight-associated neuro-ocular syndrome (SANS) may influence its management. To describe a severe case of SANS associated with 2 potentially predisposing factors. Ocular testing of and blood collections from a female astronaut were completed preflight, inflight, and postflight in the setting of the International Space Station (ISS). Weightlessness throughout an approximately 6-month ISS mission. Mean carbon dioxide (CO2) partial pressure decreased from 2.6 to 1.3 mm Hg weeks before the astronaut's flight day (FD) 154 optical coherence tomography (OCT) session. In response to SANS, 4 B-vitamin supplements (vitamin B6, 100 mg; L-methylfolate, 5 mg; vitamin B12, 1000 μg; and riboflavin, 400 mg) were deployed, unpacked on FD153, consumed daily through FD169, and then discontinued due to gastrointestinal discomfort. Refraction, distance visual acuity (DVA), optic nerve, and macular assessment on OCT. Cycloplegic refraction was -1.00 diopter in both eyes preflight and +0.50 - 0.25 × 015 in the right eye and +1.00 diopter in the left eye 3 days postflight. Uncorrected DVA was 20/30 OU preflight, 20/16 or better by FD90, and 20/15 OU 3 days postflight. Inflight peripapillary total retinal thickness (TRT) peaked between FD84 and FD126 (right eye, 401 μm preflight, 613 μm on FD84; left eye, 404 μm preflight, 636 μm on FD126), then decreased. Peripapillary choroidal folds, quantified by surface roughness, peaked at 12.7 μm in the right eye on FD154 and 15.0 μm in the left eye on FD126, then decreased. Mean choroidal thickness increased throughout the mission. Genetic analyses revealed 2 minor alleles for MTRR 66 and 2 major alleles for SHMT1 1420 (ie, 4 of 4 SANS risk alleles). One-week postflight, lumbar puncture opening pressure was normal, at 19.4 cm H2O. To the authors' knowledge, no other report of SANS documented as large of a change in peripapillary TRT or hyperopic shift during a mission as in this astronaut, and this was only 1 of 4 astronauts to experience chorioretinal folds approaching the fovea. This case showed substantial inflight improvement greater than the sensitivity of the measure, possibly associated with B-vitamin supplementation and/or reduction in cabin CO2. However, as a single report, such improvement could be coincidental to these interventions, warranting further evaluation.

Dural venous sinus angioplasty and stenting for treatment of idiopathic intracranial hypertension: a single-center experience with 20 consecutive cases

Background: Dural venous sinus stenosis has been shown to be a potential cause or aggravating factor of idiopathic intracranial hypertension (IIH). Endovascular therapy for angioplasty of venous sinus stenosis is emerging as a potential alternative to treat IIH. Objective: This article aims to present the results of a cases series representing the experience of a single center in treating this disease. Materials and Methods: We retrospectively reviewed the angiographic and manometric data of patients undergoing angioplasty and stenting for the treatment of IIH with venous sinus stenosis on magnetic resonance angiography. All patients had failed conventional medical treatment. Data on demographic features, clinical and radiologic presentation, and outcomes were collected retrospectively. Results: 20 female patients, with persistent headache and papilledema, underwent venous sinus angioplasty and stenting. Mean age was 35.9 (SD, 10) years. Eighteen patients (90%) had clinical improvement after the procedure. Of these, all showed resolution (17 patients, 94%) or partial improvement (1 patient, 6%) of papilledema within 6 months. Two patients had persistent moderate-to-severe headache (intensity &gt; 6 on a 10-point pain scale), with continued papilledema despite stable visual acuity on visual field testing. The mean pre-procedure lumbar puncture opening pressure was 30.1 (SD, 4) mm Hg, decreasing to 16.2 (SD, 4) mm Hg after the procedure. Only 4 patients experienced complications directly or indirectly related to the procedure, with no impact on outcome. Conclusion: Angioplasty and stenting of the stenotic segment may effectively and safely treat IIH associated with focal venous sinus stenosis, with a high technical success rate and an acceptable complication rate.

Magnetic Resonance Imaging Signs of Idiopathic Intracranial Hypertension

The magnetic resonance imaging (MRI) criteria currently used to diagnose idiopathic intracranial hypertension (IIH) are based on expert opinion and have limited accuracy. Additional neuroimaging signs have been proposed and used with contradictory results; thus, prospective evidence is needed to improve diagnostic accuracy. To provide evidence-based, accurate MRI signs for IIH diagnosis. This prospective cohort study was conducted from January 2018 to May 2021 with 3 validation cohorts at 2 Danish headache centers and with 3 independent international cohorts. Consecutive patients with suspected IIH were enrolled. Eligibility required the clinical suspicion of IIH, age 18 years or older, and written informed consent. The validation cohorts comprised patients with confirmed IIH from Austria and the US, and patients without IIH from the US. Data analysis was performed from December 2021 to August 2023. Standardized diagnostic workup was performed to classify cases according to current criteria, and blinded evaluation of cerebral radiological diagnostics and papilledema was performed. The primary outcomes were MRI signs associated with IIH as assessed by univariate analyses. An MRI score estimating papilledema was calculated using machine learning. Internal validation of associations with lumbar puncture opening pressure and outcome and external validation of accuracy were performed in 3 cohorts. Of 192 eligible patients (185 women [96.4%]; median [IQR] age, 28.0 [23.0-35.0] years), 110 were classified as having IIH, 4 as having probable IIH, and 1 as having suspected IIH without papilledema; 77 did not have IIH and served as controls, with corresponding age, sex, and weight. Papilledema at diagnosis was associated with perioptic subarachnoid space distension (56 patients [68.3%] vs 21 patients [41.2%]), posterior globe flattening (53 patients [66.3%] vs 10 patients [21.3%]), optic nerve disc protrusion (35 patients [30.4%] vs 2 patients [2.3%]), and transverse sinus venous stenosis (75 patients [79.8%] vs 29 patients [46.8%]). The papilledema-estimating MRI score showed optimal balance between sensitivity (49%) and specificity (87%) when 2 of the 3 latter signs were present and was associated with the lumbar puncture opening pressure and ophthalmological outcome. The score showed strong diagnostic accuracy in the external validation cohorts (587 patients; area under the receiver operating characteristic curve, 0.86) and outperformed the current (2013) diagnostic MRI criteria. The findings of this cohort study of patients with IIH and controls suggest that an evidence-based MRI score including posterior globe flattening, optic nerve disc protrusion, and transverse sinus stenosis can estimate the presence of papilledema more accurately than the current diagnostic criteria.

Intracranial Hypertension in a Person Infected with Influenza A: An Accidental Diagnosis

Idiopathic intracranial hypertension (ICH) is a neurological syndrome determined by a rise in intracranial pressure without a specific cause. The exact pathophysiology of this disease is unknown. Intake of retinoids, steroid hormones, high body mass index, release of cytokines, and adipokine levels could be possible causal or associated factors. The association of influenza with ICH has been observed rarely in adults. The clinical symptoms can be headache, disturbance of vision, diplopia, and tinnitus, which can be very well missed during an acute flu attack as the symptoms overlap. Even though papilledema is considered the most specific sign, it is rarely found. Neuroradiological signs on magnetic resonance imaging may suggest the diagnosis of idiopathic ICH. Ophthalmological evaluation is mandatory to find out complications and sequelae in the form of visual loss. Lumbar puncture and cerebrospinal fluid opening pressure measurement are helpful in establishing a diagnosis as well as relieving pressures as part of the management. Influenza is a preventable disease with the administration of a yearly vaccine against specific strains of the virus for the year and region, as released by the Center for Disease Control.

Are the ICHD-3 criteria for headache attributed to idiopathic intracranial hypertension valid? Headache phenotyping and field-testing in newly diagnosed idiopathic intracranial hypertension.

Headache burden is substantial in idiopathic intracranial hypertension. The classification of idiopathic intracranial hypertension headache by the International Classification of Headache Disorders (ICHD) is an important tool for research and clinical purposes. We phenotyped headaches and tested sensitivity and specificity of the ICHD-3 criteria for idiopathic intracranial hypertension headache in a prospective cohort of patients suspected of idiopathic intracranial hypertension at two tertiary headache centers. Sensitivity was 93% and specificity was 100% of ICHD-3 criteria for idiopathic intracranial hypertension-related headache validated in idiopathic intracranial hypertension (n = 140) and patients in whom idiopathic intracranial hypertension was suspected but disproven (n = 103). The phenotype of new/worsened headaches related to idiopathic intracranial hypertension suspicion was equally migraine-like (p = 0.76) and tension-type-like (p = 0.08). Lumbar puncture opening pressure was higher (p < 0.0001) and pulsatile tinnitus more frequent (p < 0.0001) in idiopathic intracranial hypertension patients, but neither improved the applicability of the headache criteria, nor did papilledema. Headache phenotype is not distinct in idiopathic intracranial hypertension. ICHD-3 criteria for idiopathic intracranial hypertension headache are sensitive and specific, but simplicity can be improved without compromising accuracy. We propose that a new or worsened headache temporally related to active idiopathic intracranial hypertension is a sufficient criterion for idiopathic intracranial hypertension headache regardless of headache phenotype or accompanying symptoms, and that elements of idiopathic intracranial hypertension diagnostics (papilledema and opening pressure) be segregated from headache criteria.Trial Registration: ClinicalTrials.gov Identifier: NCT04032379.

Clinical and Radiological Characteristics of Non-Obese Female Patients with Idiopathic Intracranial Hypertension.

While the typical patient with idiopathic intracranial hypertension (IIH) is an obese female of childbearing age, there are unique patient populations, such as non-obese females, that have not been well studied. Characterizing this subpopulation may increase awareness our of it, which may prevent underdiagnosis and improve our understanding of IIH's underlying pathophysiology. We retrospectively reviewed electronic medical records and compared the clinical and radiological characteristics of non-obese (BMI < 30) and obese (BMI > 30) female patients with IIH. Two hundred and forty-six patients (age 32.3 ± 10) met our inclusion criteria. The non-obese patients (n = 59, 24%) were significantly younger than the obese patients (29.4 ± 9.9 vs. 33.2 ± 10.2, p = 0.004) and had higher rates of severe papilledema (Friesen 4-5; 25.4% vs. 11.8%, p = 0.019), scleral flattening (62.7% vs. 36.9%, p = 0.008), and optic nerve dural ectasia (78.0% vs. 55.6%, p = 0.044). Non-obese patients also had a tendency to have a higher lumbar puncture opening pressure (368 ± 92.7 vs. 344 ± 76.4, p = 0.062). Non-obese patients were three times more likely to present with a combination of scleral flattening and optic nerve dural ectasia (OR = 3.00, CI: 1.57-5.72, χ2 = 11.63, α < 0.001). Overall, non-obese females with IIH were found to have a more fulminant presentation, typified by higher rates of severe papilledema and radiological findings typical for IIH.

The Relationship between Lumbar Puncture Opening Pressure and Retinal Nerve Fiber Layer Thickness in the Diagnosis of Idiopathic Intracranial Hypertension: Is a Lumbar Puncture Always Necessary?

Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without an identified cause. Today, lumbar puncture (LP) is the most common method used for diagnosis by measuring cerebrospinal fluid (CSF) pressure to reflect intracranial pressure. This invasive examination has significant disadvantages, such as complications and negative experiences for patients. Therefore, noninvasive methods for ICP measurement are desired. Optical coherence tomography (OCT) is widely used for the diagnosis and follow-up of IIH patients as it reflects papilledema. The aim of this study is to investigate the relationship between CSF pressure and OCT parameters and the ability of OCT in the diagnostic approach. In our study, patients who were followed up with a diagnosis of IIH with complete neuro-ophthalmological examinations, including visual acuity (VA), visual field, and OCT imaging within 24 hours before lumbar puncture, were retrospectively evaluated. CSF pressure, visual acuity LogMAR, mean deviation of visual fields, retinal nerve fiber layer (RNFL) thickness measured by OCT, and treatment protocols were obtained from our hospital data system. A total of 42 eyes of 21 patients were enrolled in the study. A statistically significant positive and moderate correlation was found between CSF pressure values and average RNFL thickness (r=0.507; P=0.001). The same relationship was demonstrated in all 4 quadrants: inferior, superior, nasal, and temporal. Increased peripapillary RNFL thickness in optic nerve head OCT may be correlated with increased ICP in IIH patients. A larger number of patients are needed to better understand the correlation between OCT parameters and CSF pressure in patients with IIH.

The impact of eating disorders on idiopathic intracranial hypertension.

Idiopathic intracranial hypertension (IIH) occurs more frequently in obese females of childbearing age. A link between eating disorders and poor outcome has been suggested but remains unproven. This prospective field study at two tertiary headache centers included patients with clinically suspected IIH after standardized diagnostic work-up. Eating disorders were evaluated using validated questionnaires (EDQs). Primary outcome was the impact of eating disorders on IIH severity and outcome, secondary outcome was the prevalence and type of eating disorders in IIH compared to controls. We screened 326 patients; 143 patients replied to the EDQs and were classified as 'IIH' or 'non-IIH' patients. The demographic profile of EDQ-respondents and non-respondents was similar. Presence of an eating disorder did not impact IIH severity (lumbar puncture opening pressure (p = 0.63), perimetric mean deviation (p = 0.18), papilledema (Frisén grad 1-3; p = 0.53)) nor IIH outcome (optic nerve atrophy (p = 0.6), impaired visual fields (p = 0.18)). Moreover, we found no differences in the prevalence and type of eating disorders when comparing IIH with non-IIH patients (p = 0.09). Eating disorders did not affect IIH severity or outcome. We found the same prevalence and distribution pattern of eating disorders in IIH and non-IIH patients advocating against a direct link between IIH and eating disorders.

Diffusion-Weighted Imaging Reveals Impaired Glymphatic Clearance in Idiopathic Intracranial Hypertension.

The pathophysiology underlying idiopathic intracranial hypertension (IIH) remains incompletely understood. While one theory postulates impaired cerebral glymphatic clearance in IIH, there is a paucity of methods to quantify glymphatic activity in human brains. The purpose of this study was to use advanced diffusion-weighed imaging to evaluate the glymphatic clearance of IIH patients and how it may relate to clinical severity. DWI was used to separately evaluate the diffusivity along the cerebral perivascular spaces and lateral association and projection fibers, with the degree of diffusivity used as a surrogate for glymphatic function (diffusion tensor image analysis along the perivascular space. Patients with IIH were compared with normal controls. Glymphatic clearance was correlated with several clinical metrics, including lumbar puncture opening pressure and Frisen papilledema grade (low grade: 0-2; high grade: 3-5). In total, 99 patients with IIH were identified and compared with 6 healthy controls. Overall, patients with IIH had significantly lower glymphatic clearance based on DWI-derived diffusivity compared with controls (P = .005). Additionally, in patients with IIH, there was a significant association between declining glymphatic clearance and increasing Frisen papilledema grade (P = .046) but no correlation between opening pressure and glymphatic clearance (P = .27). Furthermore, healthy controls had significantly higher glymphatic clearance compared with patients with IIH and low-grade papilledema (P = .015) and high-grade papilledema (P = .002). Lastly, patients with IIH and high-grade papilledema had lower glymphatic clearance compared with patients with IIH and low-grade papilledema (P = .005). Patients with IIH possess impaired glymphatic clearance, which is directly related to the extent of clinical severity. The DWI-derived parameters can be used for clinical diagnosis or to assess response to treatment.

Emergent cerebral venous stenting: A valid treatment option for fulminant idiopathic intracranial hypertension

BackgroundFulminant idiopathic intracranial hypertension (FIIH) is characterized by rapid, severe, progressive vision loss and often treated surgically. Cerebral transverse venous stenting (CTVS) is efficacious in IIH patients, but emergent CTVS in FIIH is rarely reported. We present our experience with emergent CTVS in patients with FIIH. MethodsSince 01/2019, an institutional protocol allowed emergent CTVS in FIIH patients with bilateral transverse sinus stenosis and gradient pressure > 15 on digital subtraction angiography (DSA). We retrospectively analyzed a prospective registry of all IIH patients with details of neurological and neuro-ophthalmological assessments before and after treatment, and subjective assessments of headache and tinnitus were made pre-and post-procedure. Results259 IIH patients, including 49 who underwent CTVS, were registered. Among them, five female patients met inclusion criteria for FIIH and underwent emergent CTVS. FIIH patients were younger (18.8 ± 1.64 vs 27.7 ± 4.85, p < 0.01), mean BMI was lower (30.8 ± 10.57 vs 34.6 ± 4.3, p < 0.01), and lumbar puncture opening pressure higher (454 ± vs 361 ± 99.4, p < 0.01) than that of IIH patients. They presented with acute visual loss, severe headache, papilledema, significant bilateral transverse sinus stenosis on CT-venography, and mean dominant side gradient pressure of 26.4 ± 6.2 on DSA. CTVS was performed without significant complications, resulting in remarkable improvement in headache, optical coherence tomography, and visual fields within 1 week. At 1-year follow-up (four patients) and 6-month follow-up (1 patient), there was complete resolution of papilledema and headache, and marked improvement in visual acuity. ConclusionsIn these patients, emergent-CTVS was a safe and effective treatment option for FIIH. Further evaluation is warranted.

The clinical findings to notice mild elevation of intracranial pressure in an otology clinic

Mildly elevated intracranial pressure appears to be a distinct pathology separate from idiopathic increased intracranial pressure and migraine. Many patients present with head fullness-pressure and dizziness, which is often suggestive of a clinical diagnosis of vestibular migraine. These patients may additionally have episodic vertigo as seen in endolymphatic hydrops and positional vertigo in addition to feeling dizzy. In most cases, hearing is normal. A long duration of the condition or a presence of associated ear pathologies, i.e., dehiscence, fistula, hypermobile footplate, or history of chronic ear infections can add hearing loss to clinical presentations. Low-pitch pulsatile tinnitus, when present, is an important symptom. The neuroimaging findings such as partially empty sella, blockage of the dural venous sinus or sigmoid sinus wall defects are frequently observed. The condition is diagnosed by measuring the lumbar puncture opening pressure. Typically, patients have normal cerebrospinal fluid chemistry and microscopy. Lowering the pressure during the lumbar puncture will resolve the patient's symptoms temporarily. Medical therapy is typically successful using carbonic anhydrase inhibitors and corrections of medical disorders that may be contributing to the increased pressure. A few require shunting or stenting procedures. In this review article, we define the condition in detail with illustrative cases that we collected from our practices.

Long-term monitoring of children with Pseudo Tumor Cerebri Syndrome by transbulbar sonography.

Determination of optic nerve sheath diameter (ONSD) with transbulbar sonography has become an easily accessible and time-effective tool in the assessment of increased intracranial pressure. The aim of our study was to evaluate the usefulness of transbulbar sonography in the initial diagnosis and in follow-up examinations of children and adolescents with the diagnosis of pseudotumor cerebri syndrome (PTCS). We retrospectively reviewed imaging results of 24 patients aged 0.75-17 years with PTCS. Serial transbulbar sonography examinations were performed between 2011 and 2021. Sonographic evaluation included the ONSD, papilledema and subarachnoid space. 240 sonographic measurements taken at 108 time points in 17 patients met the inclusion criteria. All patients underwent serial lumbar punctures and routine fundoscopy in close relation to transbulbar sonography. We found that ONSD values remained high in all patients. The longest follow-up period was dated 2498 days (6.84 years) after initial diagnosis. Papilledema resolved in close correlation to fundoscopy normalization. In 16/17 patients the subarachnoid space remained cystic in appearance. These findings were independent of clinical symptoms and lumbar puncture opening pressure. We conclude that transbulbar sonography is a useful diagnostic tool in the initial diagnostic workup of children with PTCS. On follow-up however ONSD values and the cystic transformation of the subarachnoid space remained pathologic in the majority of cases while papilledema resolved parallel to fundoscopy findings. Serial measurements of ONSD are therefore of limited value in the follow-up of patients with PTCS and cannot be considered a reliable tool in subsequent therapeutic decisions.

Seizures as the initial manifestation of Idiopathic Intracranial Hypertension (P2-9.001)

<h3>Objective:</h3> To describe the clinical and radiologic characteristics of 5 patients with seizure as a symptom of idiopathic intracranial hypertension (IIH). <h3>Background:</h3> Patients with IIH may have atypical presentations and may not meet the classic IIH diagnostic criteria. Recent reports suggest an association between IIH and seizures in patients with temporal encephaloceles, which are frequently observed in temporal lobe epilepsy and might be an epileptogenic focus. The aim of this study is to report patients with presumed IIH and seizures associated with encephaloceles. <h3>Design/Methods:</h3> NA <h3>Results:</h3> We report 5 patients (34–79 years old; 4 women, 1 man; body mass index mean 44.6 (25.6–60.6)) with generalized or focal epilepsy associated with encephaloceles in the basal frontal lobe or inferomedial temporal lobe. Three patients with temporal lobe encephaloceles had interictal epileptiform activity or focal temporal slowing in one or both temporal lobes. Other radiological findings included signs of chronic intracranial hypertension. Three patients had rhinorrhea from spontaneous cerebrospinal fluid (CSF) leak; all denied visual symptoms. One patient had mild papilledema, and 4 patients had chronic peripapillary changes suggesting previous papilledema. Three patients had a lumbar puncture opening pressure between 26 and 28 cm H₂O. <h3>Conclusions:</h3> These cases suggest that seizures related to basal encephaloceles likely result from untreated chronic intracranial hypertension, as can be seen in untreated or chronic IIH. Skull base meningoencephaloceles and spontaneous CSF leak are two manifestations of the same bony defects that are likely part of the expanding IIH spectrum. The diagnosis of IIH remains presumptive, especially without papilledema. Radiological findings of chronic intracranial hypertension in patients with isolated seizures should prompt funduscopic examination looking for papilledema and skull base imaging screening for basal encephaloceles that may help guide epilepsy treatment. <b>Disclosure:</b> Dr. Bouthour has nothing to disclose. Dr. Al-Balushi has nothing to disclose. Dr. Dattilo has nothing to disclose. Dr. Newman has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for GenSight. Dr. Newman has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Chiesi. Dr. Newman has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Neurophoenix. Dr. Newman has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Stoke. Dr. Newman has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Avidity. Dr. Newman has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for Neurodiem. The institution of Dr. Newman has received research support from GenSight. The institution of Dr. Newman has received research support from Chiesi/Santhera. The institution of Dr. Newman has received research support from NINDS/NIH. Dr. Newman has received publishing royalties from a publication relating to health care. Dr. Newman has received publishing royalties from a publication relating to health care. Dr. Newman has received publishing royalties from a publication relating to health care. Dr. Biousse has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Gensights Biologic. Dr. Biousse has received personal compensation in the range of $0-$499 for serving as a Consultant for Neurophoenix. The institution of Dr. Biousse has received research support from NIH. Dr. Biousse has received publishing royalties from a publication relating to health care. Dr. Biousse has received publishing royalties from a publication relating to health care.

Elevated neurofilament light chain CSF/serum ratio indicates impaired CSF outflow in idiopathic intracranial hypertension

BackgroundImpaired cerebrospinal fluid (CSF) homeostasis is central to the pathogenesis of idiopathic intracranial hypertension (IIH), although the precise mechanisms involved are still not completely understood. The aim of the current study was to assess the CSF/serum ratio of neurofilament light chain levels (QNfL) as a potential indicator of functional CSF outflow obstruction in IIH patients.MethodsNfL levels were measured by single molecule array in CSF and serum samples of 87 IIH patients and in three control groups, consisting of 52 multiple sclerosis (MS) patients with an acute relapse, 21 patients with an axonal polyneuropathy (PNP), and 41 neurologically healthy controls (HC). QNfL was calculated as the ratio of CSF and serum NfL levels. Similarly, we also assessed the CSF/serum ratio of glial fibrillary acidic protein (QGFAP) levels to validate the QNfL data. Routine CSF parameters including the CSF/serum albumin ratio (QAlb) were determined in all groups. Lumbar puncture opening pressure of IIH patients was measured by manometry.ResultsCSF-NfL levels (r = 0.29, p = 0.008) and QNfL (0.40, p = 0.0009), but not serum NfL (S-NfL) levels, were associated with lumbar puncture opening pressure in IIH patients. CSF-NfL levels were increased in IIH patients, MS patients, and PNP patients, whereas sNfL levels were normal in IIH, but elevated in MS and PNP. Remarkably, QNfL (p < 0.0001) as well as QGFAP (p < 0.01) were only increased in IIH patients. QNfL was positively correlated with CSF-NfL levels (r = 0.51, p = 0.0012) and negatively correlated with S-NfL levels (r = − 0.51, p = 0.0012) in HC, while it was only positively associated with CSF-NfL levels in IIH patients (r = 0.71, p < 0.0001). An increase in blood-CSF barrier permeability assessed by QAlb did not lead to a decrease in QNfL in any cohort.ConclusionsThe observed elevation of QNfL in IIH patients, which was associated with lumbar puncture opening pressure, indicates a reduced NfL transition from the CSF to serum compartment. This supports the hypothesis of a pressure-dependent CSF outflow obstruction to be critically involved in IIH pathogenesis.

Optic nerve head diffusion-weighted magnetic resonance imaging and apparent diffusion coefficient values as measuring tools for papilledema grade in idiopathic intracranial hypertension

Aim The aim of this study was to explore if there is a relationship between the grade of papilledema and MRI diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values of the optic nerve head (ONH) in patients having idiopathic intracranial hypertension (IIH). Patients and methods This is a prospective study that was conducted between March 2020 and June 2022 on 285 patients diagnosed as having IIH, who were subjected to meticulous clinical examination, visual field testing, color vision testing, and orbital MRI done within one week of diagnosis. ONH signal intensity was graded and then compared with papilledema grade, and the results were analyzed. Results The study included 285 patients (156 females and 129 males), with a mean age of 30.8±9.6 years, definitely diagnosed as having IIH with lumbar puncture opening pressure ranging from 18 to 58 cmH2O (mean=35.6±9.8 cmH2O). The papilledema grades were grade I (121 patients), grade II (136 patients), grade III (21 patients), and grade IV (seven patients). ADC values of the ONH were found to be gradually decreased with higher papilledema grades among cases. In addition, according to papilledema grading, in grade I, 67% of the patients showed no DWI changes, whereas in grade II, 97% of the patients showed DWI changes in the ONH. In grades III and IV, all patients showed DWI changes. Conclusion MRI can be considered as a diagnostic tool for papilledema. In addition, low ADC values and diffusion restriction can be used as indicators for the severity of ONH insult in cases of increased intracranial tension.

Elevated lumbar puncture opening pressure in aseptic meningitis

ObjectivesElevated lumbar puncture opening pressure (ELPOP) is a reported but understudied phenomenon in aseptic meningitis. This study aimed to characterize the features of ELPOP in aseptic meningitis patients. MethodsAn observational, retrospective, single-center study was conducted. We included all adult patients diagnosed with aseptic meningitis or meningoencephalitis from October 2015 to May 2017, for whom lumbar puncture opening pressure (LP OP) was measured. OP > 25 cm H2O was documented as ELPOP. Patients’ demographic characteristics, clinical data, laboratory and cerebrospinal fluid (CSF) results, as well as optic disc appearance were analyzed. ResultsAmong 116 patients (61 males) included, 16 patients (14 %) had ELPOP (11 males). The average age of those patients was 32.4 years (SD = 9.8), and the mean OP was 31.7 cm H2O (SD = 6.02) as opposed to the mean normal LPOP (NLPOP) of16.13 cm H2O (SD = 4.15). Body mass index (BMI) was significantly higher in the ELPOP group (p = 0.0081). Funduscopic examination was documented in 15/16 patients in the ELPOP group and revealed swollen optic discs in 6 (40 %) patients. Fundus examination was performed in 62 patients in the NLPOP group, of whom 2 (3.2 %) had a swollen disc. There was no difference in CSF content between groups. ConclusionsThis study fills the void of information lacking on the frequency of ELPOP in aseptic meningitis. Its association with increased BMI may be related to the pathogenesis. LP OP should be measured in all patients with aseptic meningitis. Additional research is needed to determine the threshold of tolerated intracranial pressure (ICP).