Utility of surgical tumor resection for normal-pressure hydrocephalus associated with spinal schwannoma in the cauda equina: A case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Generally, schwannoma increases the concentration of protein in cerebrospinal fluid (CSF) and causes normal-pressure hydrocephalus (NPH) due to absorption disorders of CSF. Cases of NPH caused by spinal schwannoma in the cauda equina are very rare. Here, we report a case of spinal schwannoma-related NPH in the cauda equina successfully treated by surgical resection alone. CASE PRESENTATION: A 78-year-old man presented with a 3-month history of gradually worsening memory disturbance. Neurological examination on admission showed dementia, hemiparesis of the left lower limb and gait disturbance. Computed tomography (CT) of the head revealed ventricular dilatation. CSF pressure was 150 mmH2O. CSF analysis showed a normal cell count and a highly elevated protein level (3842 mg/dL). Magnetic resonance imaging (MRI) of the lumbar spine demonstrated an enhanced intradural extramedullary mass in the cauda equina at the L3-L4 level. We suspected schwannoma causing NPH and tumor resection with posterior L3-4 laminectomy was performed as a priority. Marked recovery of cognitive dysfunction and gait disturbance was evident postoperatively, and CT 4 months later showed narrowing of the ventricles. CLINICAL DISCUSSION: If NPH due to spinal schwannoma is suspected as a result of lumbar puncture in a patient with dementia, confirmation of spinal schwannoma by lumbar MRI is absolutely necessary, and tumor resection alone may avoid unnecessary shunt placement. CONCLUSION: These findings suggest that if a spinal schwannoma located in the cauda equina causes symptoms due to NPH, removal of the tumor should be considered a priority.

Relationship between Width and Height of π* Peak in C K-XANES of Graphitic Carbons.

The relationship between the width and height of the π* peak on X-ray absorption near edge structure (XANES) in the C K region of graphitic carbons is investigated from XANES measurements and theoretical analysis. This relationship is herein named the "characteristic diagram of π* peak profile". Mechanically ground (MG) graphite experimentally exhibits a linear correlation on the diagram. To understand the linear correlation, C K-XANES of the graphitic hexagonal carbon layers are calculated using first-principles calculations by focusing on the edge carbon atoms. The linear correlation is well explained by the ratio of the edge carbon atoms of the graphitic hexagonal carbon layers. The characteristic diagram of π* peak profile is applied to industrial carbon black (CB) for identification. CBs exhibit identical distributions on the diagram, which depend on their uses. It is therefore confirmed that the proposed characteristic diagram of π* peak profile can be a useful tool to identify graphitic carbons from the edge carbon atoms.

A rare case of neurosarcoidosis occurred only in the medulla oblongata mimicking malignant brain tumor.

BACKGROUND: Sarcoidosis is a multisystem disorder characterized by noncaseating epithelioid granulomas. However, neurosarcoidosis occurring only in the medulla oblongata is very rare and lacks specific imaging and clinical features. We report a rare case of neurosarcoidosis arising from the medulla oblongata alone, suggesting the significance of pathological findings for accurate diagnosis. CASE DESCRIPTION: A 78-year-old woman with a history of rheumatoid arthritis was admitted to our hospital with a 3-month history of progressive numbness in bilateral lower extremities and gait disturbance. Neurological examination on admission showed mild bilateral paired paralysis of the lower limbs (manual muscle test: right 2/V; left 4/V) and marked numbness in the right lower limb. Neuroimaging revealed a solid mass with clear boundaries in the dorsal medulla oblongata appearing hypointense on T1-weighted imaging (WI), hyperintense on T2-WI, and hypointense on diffusion WI (DWI), with strong enhancement on gadolinium-enhanced T1-WI. Cerebrospinal fluid analysis showed moderately elevated levels of protein and lymphocytic cells. Biopsy to determine the exact diagnosis revealed histological findings of noncaseating epithelioid granulomas and inflammatory infiltration, consistent with sarcoidosis. Postoperatively, corticosteroid therapy with prednisolone was initiated as soon as possible, resulting in marked reductions in lesion size. Follow-up neuroimaging after 12 months showed no signs of recurrence. CONCLUSION: Neurosarcoidosis is difficult to diagnose from routine neuroimaging and laboratory findings. Accurate diagnosis requires careful identification of clinical signs, hypointensity on DWI, and morphological findings from surgical biopsy.

Utility of targeted balloon protection of the venous sinus for endovascular treatment of dural arteriovenous fistula by transarterial embolization with Onyx: A case report and literature review.

BACKGROUND: Onyx has already been reported as an effective and safe agent in transarterial embolization of cranial dural arteriovenous fistula (d-AVF). However, successful treatment is related to not only complete shunt obliteration but also preservation of a normal route of venous drainage. Here, we present a case of transverse sigmoid d-AVF in which successful treatment was achieved by transarterial Onyx embolization with targeted balloon protection of the venous drainage. CASE DESCRIPTION: A 70-year-old man presented with a 3-month history of tinnitus in the left ear and mild headache. Magnetic resonance imaging (MRI) showed a cluster of abnormal blood vessels in the area of the left transverse sinus (TS)-sigmoid sinus (SS) junction. Cerebral angiography demonstrated a Cognard type IIa d-AVF at the left TS-SS junction, supplied mainly by vessels such as the left middle meningeal artery, left occipital artery, and left meningohypophyseal trunk. In the venous phase, the ipsilateral TS-SS was recognized as a functional sinus and the left vein of Labbe drained into the TS near the drainage channel. Based on these findings, we decided to perform endovascular treatment under a transarterial approach with Onyx using targeted balloon protection of the venous sinus to protect against Onyx migration and preserve antegrade sinus flow. The patient recovered well without sequelae, and follow-up MRI 12 months later showed complete disappearance of the d-AVF. CONCLUSION: This treatment strategy using targeted balloon protection may be very useful to preserve antegrade sinus flow in patients with Cognard type IIa d-AVF.