Elevated Cerebrospinal Fluid Pressure Research Articles

Thecaloscopy Reduces the Risk of Recurrent Perineural (Tarlov) Cysts after Microsurgical Resection.

Sacral Tarlov cysts (TCs), often asymptomatic, can cause significant pain and severe neurological dysfunction. Conventional treatments are generally associated with high recurrence and complication rates. Specifically, the substantial recurrence rates, which can reach as high as 50%, significantly impact long-term outcomes. Recent evidence increasingly supports the hypothesis that the formation of Tarlov cysts (TCs) may be associated with inflammatory processes within the nerve root sheath, further exacerbated by elevated cerebrospinal fluid (CSF) pressure. This retrospective study explores thecaloscopy, combined with surgical techniques, as a more effective alternative. We observed a total of 78 patients, 48 of whom underwent endoscopic fenestration of the arachnoid sheath in addition to microsurgical resection of the TC. We found that the fenestration of the arachnoid sheath at the level of lumbosacral spinal nerve root entry led to a significantly decreased risk of developing recurrent TCs (5/48 vs. 9/30). Only one of the patients suffered from a persistent new bladder dysfunction after microsurgical resection. This presented technique provides a promising treatment path for the future management of TCs, offering a safe and more effective treatment option compared to previous methods. Additionally, the advantages of the thecaloscopy provide pathophysiological implications regarding the development of perineural cysts.

Systemic steroids in pediatric pseudotumor cerebri - A case report

Study design: Case report. Purpose: To study the efficacy of systemic steroids in pediatric pseudotumor cerebri. Introduction: Pseudotumor cerebri is a condition caused by elevated intracranial pressure presenting most commonly with headache. It is a diagnosis of exclusion. Methods: A 15-year-old girl presented in our outpatient department with a headache for 3 months, more in the posterior aspect, continuous type with severe intensity, non-radiating. On examination, the best corrected visual acuity in her right eye was 6/9, and her left eye was 6/6 parts. She had a normal anterior segment and normal Intraocular Pressure (IOP). Fundoscopy showed both optic discs edematous, pink in color with blurry disc margins, tortuous disc vessels, and edematous peripapillary area. The rest of the retina was normal. Lumbar puncture showed elevated opening CSF pressure and normal CSF composition. Hence she was diagnosed with IIH. She was started on oral prednisolone 1mg/kgbw once a day dosage, oral acetazolamide 250 mg once a day, topical nepafenac 0.1% one drop thrice a day and timolol 0.5% eye drops twice a day. Discussion: The main goals of treatment are alleviation of symptoms, including headache, and preservation of vision. Steroids were commonly used for treating IIH in the past, but cause significant long-term side effects, such as weight gain, that are undesirable in IIH patients. Furthermore, withdrawal of steroids can cause rebound intracranial hypertension. Thus, steroids should not be used routinely for IIH treatment. Results: By the end of one month, the patient was relieved of symptoms, best corrected visual acuity was 6/6 in both eyes with normal IOP, normal optic disc in both eyes. Conclusion: Steroids are an effective way of managing idiopathic intracranial hypertension in pediatric patients.

96 The Proportion of Patients with Cerebrospinal Fluid Biomarkers Consistent with Alzheimer’s Disease in a Cohort with Suspected Normal Pressure Hydrocephalus

Objective:Normal pressure hydrocephalus (NPH) is characterized by pathologically enlarged ventricles without elevated cerebrospinal fluid (CSF) pressure along with a triad of clinical symptoms including gait disturbances, urinary incontinence, and cognitive impairment. NPH is evaluated with lumbar drain trials (LDTs) where CSF is removed over several days to determine if patients would benefit from ventricular shunting. Candidate selection and success for these surgeries remains challenging because other diseases such as Alzheimer’s disease (AD) share common features with NPH in cognitive impairment and enlarged ventricles. Prior research has found that 20%-40% of presumed NPH cases have AD pathology as determined by brain biopsy or autopsy. CSF biomarkers of AD can be altered in NPH and are not always conclusive, complicating the interpretation of results when formulating diagnoses and prognoses. Studies to refine the analyses of AD CSF biomarkers in NPH are needed. We aimed to examine the frequency of CSF biomarker results among patients presenting for NPH evaluations with LDTs.Participants and Methods:62 patients presented for LDTs upon physician recommendations. CSF specimens were sent to Mayo Clinic Laboratories for Alzheimer Disease Evaluation (ADEVL) that utilizes Elecsys (Lenexa, KS) CSF electrochemiluminescence immunoassays (Roche Diagnostics, Basel, Switzerland) to measure levels of amyloid-beta 42 (Aβ42), total tau (t-tau), and phosphorylatedtau (p-tau), and p-tau:Aβ42 ratio. Results were classified based on interpretation through the Amyloid/Tau/Neurodegeneration (ATN) framework1: 1) AD - biomarker profile consistent with AD pathologic change, 2) non-AD profile - biomarker levels normal or inconsistent with AD pathologic change, or 3) indeterminate - biomarkers were incongruous with only one or two abnormal levels of Aβ42, t-tau, p-tau, or ptau: Aβ42. Indeterminate cases may represent altered protein levels due to CSF dynamics or AD-related pathologic change. In reviewing recent research on CSF dynamics and AD biomarkers in NPH2 a p-tau threshold of 15 pg/mL was derived and implemented such that cases with Aß42 <=1026 pg/mL and p-tau <15 pg/mL were designated as suspected non-AD, and those with Aß42 <=1026 pg/mL and p-tau >15 pg/mL were designated suspected AD.Results:Of the 62 LDT cases, 12 (19.35%) were classified as AD, 31 (50%) were indeterminate and 22 (35.48%) were non-AD. Of the 31 indeterminate cases, 21 (33.87% of the overall sample) were suspected non-AD and 7 (11.29% of the full sample) were categorized as suspected AD.Conclusions:Our findings show that 20%-30% of patients presenting for LDT showed evidence for AD-type pathologic change, consistent with prior reports of AD pathology in cases of possible NPH. Half of all LDT cases had indeterminate AD CSF biomarker results, the interpretations of which were confounded by the potential alterations of CSF biomarkers levels due to NPH independent of AD. Our findings emphasize the need to establish better approaches to interpreting CSF AD biomarkers in evaluating NPH. Future research should examine the discriminative utility of CSF AD biomarkers and the selected p-tau threshold in indeterminate cases for predicting response to LDT and shunting.

Dynamics of cerebrospinal fluid pressure alterations and bilateral transverse-sigmoid sinus morphologies in Asian patients with venous pulsatile tinnitus.

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). 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. The mean ICP was 212.5 ± 47.3 mmH2O. The median was 130 (range, 55-150) mmH2O. The was linearly correlated with the open lumbar pressure, and a significant difference was found between patients with normal and elevated cerebrospinal fluid pressure. The was linearly correlated with the and . was linearly correlated with 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.

Correlation between retinal vein pulse amplitude, estimated intracranial pressure, and postural change

Spaceflight associated neuro-ocular syndrome (SANS) is common amongst astronauts on long duration space missions and is associated with signs consistent with elevated cerebrospinal fluid (CSF) pressure. Additionally, CSF pressure has been found to be elevated in a significant proportion of astronauts in whom lumbar puncture was performed after successful mission completion. We have developed a retinal photoplethysmographic technique to measure retinal vein pulsation amplitudes. This technique has enabled the development of a non-invasive CSF pressure measurement apparatus. We tested the system on healthy volunteers in the sitting and supine posture to mimic the range of tilt table extremes and estimated the induced CSF pressure change using measurements from the CSF hydrostatic indifferent point. We found a significant relationship between pulsation amplitude change and estimated CSF pressure change (p < 0.0001) across a range from 2.7 to 7.1 mmHg. The increase in pulse amplitude was highest in the sitting posture with greater estimated CSF pressure increase (p < 0.0001), in keeping with physiologically predicted CSF pressure response. This technique may be useful for non-invasive measurement of CSF pressure fluctuations during long-term space voyages.

Abstract Number ‐ 12: First‐In‐Human Endovascular Treatment of Idiopathic Intracranial Hypertension Using a Miniature Biomimetic Transdural Shunt.

Introduction Successful percutaneous transvenous deployment of a miniature valved biomimetic transdural endovascular shunt (CereVasc eShunt, Auburndale, MA, USA) via an inferior petrosal sinus approach was recently described for treatment of post‐subarachnoid hemorrhage communicating hydrocephalus.The endovascular shunt replicates the function of the arachnoid granulation by draining cerebrospinal fluid (CSF) from the cerebello‐pontine angle cistern to the ipsilateral internal jugular vein. Idiopathic intracranial hypertension (IIH), usually resulting from venous transverse sinus stenosis, can be treated with pharmacological inhibition of CSF production, surgical ventriculoperitoneal shunting, or using venous stent angioplasty. In IIH, elevated CSF pressure can act to exacerbate venous sinus stenosis, resulting in worsening CSF reabsorption, thereby perpetuating a vicious cycle. The authors sought to evaluate the role of the minimally invasive eShunt approach in IIH management. Methods A 50‐year‐old male patient with history of dyslipidemia and IIH initially presented 6 years ago with diplopia initially treated with poorly tolerated acetazolamide and periodic lumbar punctures with subsequent symptom improvement. The patient was admitted following rapid evolution of sudden onset horizontal diplopia and headache. Brain magnetic resonance revealed flattening of the posterior sclera, partially empty Sella Turcica, enhancement of the prelaminar optic nerves and enlarged Meckel´s cave. Lumbar puncture was performed with opening pressure of 28 cmH2O. Cerebral angiography with 3D venography confirmed bilateral transverse sinus stenosis, though without a significant pressure gradient. Results The patient declined surgical ventriculoperitoneal shunting and was approved for compassionate use of eShunt by regulatory and bioethics committees.He underwent successful endovascular transdural deployment of the eShunt, which he tolerated well and was discharged at 48 hours post‐procedure with rapid symptomatic headache relief. Upon 30‐day follow‐up repeat brain MRI showed improvement of the prominent subarachnoid space around both optic nerves and sustained improvement of his pre‐procedural headache and diplopia.A repeat lumbar puncture revealed a lowed opening pressure of 20 cmH2O and MRI cisternography confirmed maintained patency of the biomimetic valve with accumulation of Gadolinium‐enhanced CSF drainage through the eShunt into the jugular bulb. Conclusions The current report describes the first‐in‐human use of the eShunt device for treatment of IIH resulting in sustained symptomatic relief along with decrease in CSF pressure and pre‐laminar optic nerve edema. The current results, which require confirmation in a larger cohort with longer follow‐up, are encouraging and suggest a possible role for minimally invasive endovascular transdural eshunt placement in the management of IIH.

The Reliability of Venous Sinus Stenosis Using Non Contrast 3D MRV in Prediction of the Diagnosis of Idiopathic Intracranial Hypertension, a Case Control Study

Abstract Idiopathic intracranial hypertension, or shorty IIH, refers to a clinical syndrome in which there is elevated CSF pressure and papilledema in the lack of any focal neurological signs. It is largely a diagnosis of exclusion, but imaging workup is undertaken routinely in order to rule out other pathologies. In this study we tried to evaluate the prevalence of venous sinus abnormalities using the simpler and less invasive non contrast enhanced 3D TOF MRV in group of patients with IIH, using the combined stenosis score, and compare this score with a group of controls, to assess the accuracy of MRV alone as an individual test in predicting the diagnosis of IIH. The study sample included 44 patients and 25 control subjects, following MRV analysis it was found that a combined severity score of cut of value of 4.5 for the combined conduit score (CCS) was associated with 79% sensitivity and 88.6 specificity for the diagnosis of IIH, and a cut off value of 5.5 for the adjusted score method gives a 83% sensitivity and 88.6 % specificity for the diagnosis. MRV is a valuable in the diagnosis of IIH; non contrast 3D MRV is an efficient test and gives valuable diagnostic information.

Absence of cortical lesions after the first seizure in a patient with anti-myelin oligodendrocyte glycoprotein-associated cortical encephalitis

A 31-year-old man developed headache and generalized convulsions. At the time of the first seizure, there was no distinct MRI abnormality. He was admitted to the hospital with repeated seizures, left-sided hemiparesis, and left-sided neglect. He had a slight fever, elevated cerebrospinal fluid (CSF) pressure, and increased CSF cell count with predominance of mononuclear cells. A repeat MRI scan on day 8 after the recurrent seizure showed cortical edema in the right cerebral hemisphere on fluid-attenuated inversion recovery (FLAIR), abnormal high signal on DWI, and decreased apparent diffusion coefficient. The patient was diagnosed with aseptic meningoencephalitis and treated with antiviral drugs and methylprednisolone pulse therapy. Serum anti-myelin oligodendrocyte glycoprotein (MOG) antibody was subsequently detected, and prednisolone was added to treat the FLAIR-hyperintense lesions in anti-MOG antibody associated encephalitis with seizures (FLAMES). It is important to identify the clinical picture and typical images of FLAMES to allow early treatment.

Bedside ocular ultrasonography for diagnosing increased intracranial pressure in patients with leptomeningeal metastases from non-small-cell lung cancer.

To explore the diagnostic accuracy of ultrasound measurement of optic nerve sheath diameter (ONSD) and optic disc height (ODH) in detecting intracranial hypertension in non-small-cell lung cancer (NSCLC) patients with leptomeningeal metastases (LM). Seventy-two patients with NSCLC-LM and 65 patients with NSCLC were enrolled. The ONSD, ODH, eyeball transverse diameter (ETD), and eyeball vertical diameter (EVD) were measured by ultrasound. Subsequently, lumbar puncture was performed in NSCLC-LM patients to measure cerebrospinal fluid pressure (CSFP), and intrathecal chemotherapy was regularly implemented. Pearson's correlation analysis was used to analyze the relationship between CSFP and ultrasound findings. The diagnostic accuracy of ONSD, ODH, and combined ONSD and ODH was evaluated by receiver operating characteristic (ROC) curve analysis and the corresponding area under the ROC curve (AUC). The ONSD, ODH, ONSD/ETD, and ONSD/EVD values were higher in the NSCLC-LM group (all p < 0.05). The ONSD, ODH, ONSD/ETD, and ONSD/EVD values were all elevated in the abnormally elevated CSFP group (all p < 0.05). ONSD, ODH, ONSD/ETD, and ONSD/EVD were positively correlated with CSFP (r=0.531, 0.383, 0.534, and 0.535, all p < 0.0001). The AUCs for ONSD, ODH, ONSD/ETD, and ONSD/EVD to detect CSFP >280 mmH2O were 0.787 (95% CI: 0.64-0.93, sensitivity 68.75%, specificity 91.07%), 0.885 (95% CI: 0.81-0.96, sensitivity 100%, specificity 69.64%), 0.765 (95% CI: 0.64-0.89, sensitivity 81.25%, specificity 64.29%), and 0.788 (95% CI: 0.64-0.93, sensitivity 56.25%, specificity 91.07%), respectively. When ONSD was combined with ODH, the AUC was 0.913 (95% CI: 0.83-0.99, sensitivity 87.85%, specificity 85.70%). Furthermore, intrathecal chemotherapy was associated with a downtrend in CSFP and ultrasound findings. There are important advantages of using bedside ultrasonography for detecting elevated CSFP in NSCLC-LM patients. Further research should be performed to evaluate the clinical significance of an enlarged ONSD and increased ODH in NSCLC-LM.

Intracranial pressure, lateral sinus patency, and jugular ultrasound hemodynamics in patients with venous pulsatile tinnitus.

The clinical and hemodynamic characteristics of venous pulsatile tinnitus (PT) patients with normal or elevated cerebrospinal fluid pressure (CSFP) have not been clearly differentiated. This study aimed to explore CSFP among patients with PT as the solitary symptom, as well as quantitatively and qualitatively assess the role of the degree of transverse sinus (TS) stenosis and jugular hemodynamics in venous PT patients. A total of 50 subjects with venous PT with or without sigmoid sinus wall anomalies (SSWAs) were enrolled in this study. In addition to radiologic assessments for TS stenosis and invagination of arachnoid granulation (AG) in TS, CSFP and jugular hemodynamics were measured via cerebrospinal fluid (CSF) manometry and Doppler ultrasound. Apart from group comparisons and correlation analyses, multivariate linear regression, and receiver operating characteristic (ROC) models were used to identify the sensitivity and specificity of the index of transverse sinus stenosis (ITSS) and hemodynamic variables with inferential significance. The mean CSFP of all cases was 199.5 ± 52.7 mmH2O, with no statistical difference in CSFP between the diverticulum and dehiscence groups. Multivariate linear regression analysis demonstrated that CSFP was linearly correlated with ITSS and pulsatility index (PI). ROC analysis showed that the area under the ROC curve of PI was 0.693 at 200 mmH2O threshold, and the best PI cut-off value was 0.467, with a sensitivity of 65.7% and specificity of 81.8%. For 250 mmH2O threshold, the area under the ROC curve of PI was 0.718, and the best PI cut-off value was 0.467 with a sensitivity of 68.4% and specificity of 75.0%. Additionally, the area under the ROC curve of ITSS was 0.757, and the best ITSS cutoff value was 8.5 (p = 0.002, 95% CI = 0.616–0.898) with a sensitivity of 72.4% and specificity of 75.0% at 200 mmH2O threshold. In conclusion, patients with venous PT as the only presenting symptom should be suspected of having borderline or increased CSFP when they present with high ITSS, BMI and low PI. Further, AG in TS without encephalocele and empty sellae are not limiting findings for differentiating the level of CSFP in patients with venous PT.

Elevated perioptic lipocalin-type prostaglandin D synthase concentration in patients with idiopathic intracranial hypertension.

The pathophysiology of vision loss and loss of visual field in patients with idiopathic intracranial hypertension with papilloedema is not fully understood. Although elevated CSF pressure induces damage to the optic nerve due to stasis of axoplasmic flow, there is no clear relationship between the severity of papilloedema and CSF pressure. Furthermore, there are cases of purely unilateral papilloedema and cases without papilloedema despite significantly elevated intracranial pressure as well as papilloedema that can persist despite a successfully lowered intracranial pressure. We hypothesize that at least in some of such cases, in addition to purely pressure-induced damage to the optic nerve, the biochemical composition of the CSF in the subarachnoid space surrounding the orbital optic nerve may play a role in the pathogenesis of vision loss. In this retrospective study, we report on lipocalin-type prostaglandin D synthase concentrations in the CSF within the perioptic and lumbar subarachnoid space in 14 patients with idiopathic intracranial hypertension (13 females, mean age 45 ± 13 years) with chronic persistent papilloedema resistant to maximum-tolerated medical therapy and visual impairment. CSF was collected from the subarachnoid space of the optic nerve during optic nerve sheath fenestration and from the lumbar subarachnoid space at the time of lumbar puncture. CSF was analysed for lipocalin-type prostaglandin D synthase and the concentrations compared between the two sites using nephelometry. The mean lipocalin-type prostaglandin D synthase concentration in the perioptic subarachnoid space was significantly higher compared with the concentration in the lumbar subarachnoid space (69 ± 51 mg/l without correction of serum contamination and 89 ± 67 mg/l after correction of serum contamination versus 23 ± 8 mg/l; P < 0.0001, Mann–Whitney U-test). These measurements demonstrate a change and imbalance in the biochemical environment of the optic nerve. Its possible effect is discussed.

Myelin oligodendrocyte glycoprotein antibody-associated aseptic meningitis without neurological parenchymal lesions: A novel phenotype

BackgroundMyelin oligodendrocyte glycoprotein (MOG) antibodies mediate inflammatory demyelinating diseases of the central nervous system. This study aimed to understand the clinical characteristics of MOG antibody-associated aseptic meningitis (MOGAM). MethodsHere, we report the cases of two children with MOGAM. A systematic literature review was conducted and included patients who had MOGAM only, without neurological parenchymal lesions. The clinical characteristics that may have affected the outcome were statistically analyzed. ResultsWe reviewed 12 cases of MOGAM; male: female = 9: 3. Prolonged fever lasting over 7 days (11/12) was the most frequent symptom, followed by headache (10/12), vomiting (5/12), and seizures (4/12). None of the patients had focal neurological manifestations or parenchymal lesions on imaging. Cerebrospinal fluid (CSF) leukocytosis was observed in all patients (12/12), and blood leukocytosis and elevated CSF pressure was observed in all patients who had corresponding results (9/9 and 4/4, respectively). Seizures occurrence was lower than that of MOG antibody-associated cortical encephalitis. Seven cases progressed to other MOG antibody-associated diseases (MOGADs) in the later phase of MOGAM. Patients who did not progress to other MOGADs had a shorter disease duration from onset to the initiation of intravenous methylprednisolone than those who did. All the patients achieved full recovery after steroid treatment. One patient had relapses. ConclusionsMOGAM without inflammatory demyelination is a rare but distinct phenotype of MOGAD, with fewer clinical manifestations mimicking bacterial or viral meningitis/encephalomeningitis. Delayed diagnosis and treatment may induce the progression to other severe MOGADs. Early recognition of this unique autoimmune aseptic meningitis may contribute to early diagnosis, treatment, and better outcomes.

Popping the balloon: Abrupt onset of a spinal CSF leak and spontaneous intracranial hypotension in idiopathic intracranial hypertension, a case report.

Spontaneous intracranial hypotension (SIH) is a debilitating neurologic condition that is often thought of as separate from idiopathic intracranial hypertension (IIH). The unique case presented here details a spontaneous spinal cerebrospinal fluid (CSF) leak that developed abruptly following a CSF pressure elevating maneuver in a patient with pre-existing intracranial hypertension, raising the possibility of a causative link between the two conditions. A 40-year-old woman with symptomatic IIH developed a dural tear of a thoracic spinal nerve root sleeve during an episode of Valsalva maneuver leading to a CSF leak and development of symptomatic SIH. This was successfully treated with epidural blood and fibrin glue patch and the patient is now symptom-free. The implication of a possible causative link between elevated CSF pressure and subsequent development of dural rupture and SIH raises important questions regarding the pathophysiology of SIH in some cases. Furthermore, it suggests that there could be a potential prophylactic benefit of CSF pressure lowering medications in preventing the development of SIH in patients with IIH.

Persistent headache in a young kidney transplant recipient caused by tacrolimus associated pseudotumor cerebri - A case report

Pseudotumor cerebri (PC) is characterized by chronic elevation of intracranial pressure with normal cerebrospinal fluid (CSF) examination and normal neuro-imaging. We report a case of a 22-year-old female with renal allograft and for the past 4 years on immunosuppressant including prednisolone, tacrolimus, and mycophenolate mofetil. The patient presented with persistent headache for 2 months along with nausea and vomiting. Fundoscopic examination revealed bilateral papilledema. Magnetic resonance imaging-brain with venogram was normal and cytochemical examination of CSF was also normal. Ocular coherence tomography revealed increased retinal nerve fiber layer thickness. A diagnosis of PC was made based on an elevated CSF pressure (35 cm H20). We reduced the dose of tacrolimus and added acetazolamide but the dose of prednisolone and mycophenolate mofetil was not modified. There was the gradual improvement of symptoms. On follow-up visits, papilledema disappeared and the patient is now asymptomatic with normal allograft function.

Large- and Small-Fiber Neuropathy in Patients with Tarlov Cysts.

PurposeTarlov cysts (TCs) are dilated nerve root sheaths originating from increased cerebrospinal pressure. Patients with TCs often complain of neuropathic pain and paresthesia. The aim of this study was to retrospectively review intraepidermal nerve fiber density (IENFD) and electrodiagnostic (EDX) data from TC patients.Patients and MethodsLower leg skin biopsy results and EDX data from the L2–S4 myotomes of patients with lumbar or sacral TCs ≥8 mm were retrieved from a database of a physical medicine clinic. Patients with compressive pathology, diabetes mellitus and chemotherapy were excluded.ResultsIENFD data from 17 patients and EDX data from 24 patients with TCs ≥8 mm were available. The mean age was 47 ± 10y, and 83% were women. In 82% of patients, the IENFD was below the 5th percentile by age and sex. EDX showed increased Hoffmann reflex latencies in 25%, increased anal reflex latencies in 95%, and a patchy distribution of neurogenic motor unit potentials in 100%. More than 50% of needle EMG abnormalities appeared in myotomes unrelated to the location of the TCs.ConclusionSmall- and/or large-fiber neuropathy was documented in a significant proportion of patients with TCs. The novel findings may add to the understanding of the mechanisms involved in symptomatic TCs. We propose that pathologically elevated cerebrospinal fluid pressure not only dilates some of the nerve root sheaths to form TCs but also potentially damages axons in nondilated nerve root sheaths and neurons in the dorsal root ganglia.

Cotton rats (Sigmodon hispidus) with a high prevalence of hydrocephalus without clinical symptoms.

Normal-pressure hydrocephalus (NPH) is a condition in which the ventricle is enlarged without elevated cerebrospinal fluid pressure, and it generally develops in later life and progresses slowly. A complete animal model that mimics human idiopathic NPH has not yet been established, and the onset mechanisms and detailed pathomechanisms of NPH are not fully understood. Here, we demonstrate a high spontaneous prevalence (34.6%) of hydrocephalus without clinical symptoms in inbred cotton rats (Sigmodon hispidus). In all 46 hydrocephalic cotton rats, the severity was mild or moderate and not severe. The dilation was limited to the lateral ventricles, and none of the hemorrhage, ventriculitis, meningitis, or tumor formation was found in hydrocephalic cotton rats. These findings indicate that the type of hydrocephalus in cotton rats is similar to that of communicating idiopathic NPH. Histopathological examinations revealed that the inner granular and pyramidal layers (layers IV and V) of the neocortex became thinner in hydrocephalic brains. A small number of pyramidal cells were positive for Fluoro-Jade C (a degenerating neuron marker) and ionized calcium-binding adaptor molecule 1 (Iba1)-immunoreactive microglia were in contact with the degenerating neurons in the hydrocephalic neocortex, suggesting that hydrocephalic cotton rats are more or less impaired projections from the neocortex. This study highlights cotton rats as a candidate for novel models to elucidate the pathomechanism of idiopathic NPH. Additionally, cotton rats have some noticeable systemic pathological phenotypes, such as chronic kidney disease and metabolic disorders. Thus, this model might also be useful for researching the comorbidities of NPH to other diseases.

Empty Sella and Unilateral Sixth Nerve Palsy in a Pediatric Patient with Idiopathic Intracranial Hypertension

Purpose: We report the case of a child with idiopathic intracranial hypertension who presented with binocular papillary edema and monocular sixth cranial nerve palsy accompanied by empty sella syndrome evident on brain magnetic resonance imaging.Case summary: A 9-year-old, normal-weight male patient visited the emergency room complaining of headache and diplopia 4 days in duration. The alternative prism cover test revealed esotropia of 16 prism diopters and a -1 right lateral gaze limitation. A fundus examination revealed papilledema and peripapillary hemorrhages in both eyes, and a visual field examination an enlarged, physiological blind spot in the right eye. Brain magnetic resonance imaging revealed elevated cerebrospinal fluid pressure, an empty sella, and posterior scleral flattening. We diagnosed and treated idiopathic intracranial hypertension. After 4 months, the papilledema and peripapillary hemorrhages of both eyes resolved, and the right lateral gaze limitation improved. The empty sella improved on brain magnetic resonance imaging, and we noted no recurrence 8 months after treatment.Conclusions: If a child with suspected idiopathic intracranial hypertension visits a hospital, but it is difficult to perform a lumbar puncture, brain magnetic resonance imaging should be scheduled. If abnormalities are found, these help to determine the course of disease.

Monocular Diplopia in Idiopathic Intracranial Hypertension: A Case Report and Literature Review.

Diplopia is the double vision of a single object, and can be binocular or monocular. Binocular diplopia is caused by the misalignment of the visual axes, with images falling on the fovea of the fixating eye and on the extra-foveal retina of the non-fixating eye, as a consequence of both neurological (i.e., oculomotor nerve palsies, ocular myopathies, neuromuscular junction disorders) and ophthalmic disorders (i.e., decompensation of a pre-existing strabismus). In contrast, monocular diplopia is generally explained by intraocular pathology (i.e., refractive errors, ocular media abnormalities, dry eyes), causing the image of a single object to fall, at the same time, on the fovea and on the extra-foveal retina of the same eye. We report the case of a 22-year-old woman presenting with acute-onset monocular diplopia. The diagnosis of idiopathic intracranial hypertension (IIH) was based on the presence of papilloedema and elevated cerebrospinal fluid (CSF) pressure. Monocular diplopia resolved after CSF subtraction. We describe a case of monocular diplopia as a presenting symptom of IIH, and discuss diagnostic issues of this possibly underestimated symptom in neurology clinical practice. Careful ophthalmic and neuro-ophthalmic examination can identify clinical features of diplopia, and drive diagnosis and treatment. Monocular diplopia is mostly an ophthalmological condition but can occur in a number of neurological diseases.Idiopathic intracranial hypertension can present with monocular diplopia.Differential diagnoses of diplopia in neurology and ophthalmology settings need to account for headache disorders.

Effect of cerebrospinal fluid pressure elevation on spinal cord perfusion during aortic cross-clamping with distal aortic perfusion.

Distal aortic perfusion (DaP) is a widely accepted protective adjunct facilitating early reinstitution of visceral perfusion during extended thoracic and thoraco-abdominal aortic repair. DaP has also been suggested to secure distal inflow to the paraspinal collateral network via the hypogastric arteries and thereby reduce the risk of spinal cord ischaemia. However, an increase in cerebrospinal fluid (CSF) pressure is frequently observed during thoracoabdominal aortic aneurysm repair. The aim of this study was to evaluate the effects of DaP on regional spinal cord blood flow (SCBF) during descending aortic cross-clamping and iatrogenic elevation of cerebrospinal fluid pressure. Eight juvenile pigs underwent central cannulation for cardiopulmonary bypass according to our established experimental protocol followed by aortic cross-clamping of the descending thoracic and abdominal aorta-mimicking sequential aortic clamping-with the initiation of DaP. Thereafter, CSF pressure elevation was induced by the infusion of blood plasma until baseline CSF pressure was tripled. At each time-point, microspheres of different colours were injected allowing for regional SCBF analysis. DaP led to a pronounced hyperperfusion of the distal spinal cord [SCBF up to 480%, standard deviation (SD): 313%, compared to baseline]. However, DaP provided no or only limited additional flow to the upper and middle segments of the spinal cord (C1-Th7: 5% of baseline, SD: 5%; Th8-L2: 24%, SD: 39%), which was compensated by proximal flow only at C1-Th7 level. Furthermore, DaP could not counteract an experimental CSF pressure elevation, which led to a further decrease in regional SCBF most pronounced in the mid-thoracic spinal cord segment. Protective DaP during thoraco-abdominal aortic repair may be associated with inadequate spinal protection particularly at the mid-thoracic spinal cord level ('watershed area') and result in the adverse effect of a potentially dangerous hyperperfusion of the distal spinal cord segments.

Leptomeningeal Carcinomatosis From Gallbladder Cancer After Curative Resection: A Case Report and Review of Literature

Introduction Only 12 cases of gallbladder (GB) cancer associated with leptomeningeal carcinomatosis (LMC) have been reported so far. Herein, we report the first known case of LMC originating from GB cancer after curative resection and discuss the risk factors of LMC associated with GB cancer. Case Presentation An 85-year-old Japanese woman presented with vomiting and impaired awareness 2 years after curative extended cholecystectomy for GB cancer. Computed tomography showed hydronephrosis of the right kidney and ureteral thickening. Magnetic resonance imaging revealed areas of hyperintense reflecting lesions along the cerebral sulci, suggesting meningitis. A spinal tap showed an elevated cerebrospinal fluid pressure of &amp;gt;270 mmH2O and cytologic examination of the spinal fluid revealed the presence of adenocarcinoma cells. The patient was diagnosed with retroperitoneal metastasis and LMC originating from GB cancer. The patient was given palliative care and died 4 weeks after the onset of symptoms. Conclusion The findings of this study show that LMC could occur even after curative resection of GB cancer and should be considered when patients present with neurologic symptoms. Retroperitoneal metastases and poorly differentiated tumors are possible risk factors of LMC originating from GB cancer.