Imaging and interventions in idiopathic intracranial hypertension: A pictorial essay

Rapidly progressive medulloblastoma initially mimicking idiopathic intracranial hypertension and Chiari I malformation: A case report

Introduction

Medulloblastoma (MDB) often causes signs and symptoms of elevated intracranial pressure (ICP) with imaging findings of mass lesion. Here, we report a case of MDB who initially presented with clinical features imitating idiopathic intracranial hypertension (IIH) and Chiari I malformation (CIM).

Case presentation

A 19-year-old man had clinical symptoms of elevated ICP without mass lesion on imaging. He was initially diagnosed with IIH and CIM, which underwent shunt surgery and posterior fossa decompression. Later on, he had recurrent symptoms, and the new imaging revealed the development of MDB in the right cerebellar hemisphere. After tumor resection, the patient rapidly deteriorated with spinal metastases.

Discussion and conclusion

Management of the coexistence between IIH and CIM in patients with rising ICP is complicated. MDB is one of the aggressive malignant brain tumors showing a wide range of imaging features, including non-enhancing mass. Therefore, recognizing the possibility of brain tumors mimicking IIH or CIM is crucial.

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The coexistence of idiopathic intracranial hypertension (IIH) and Chiari I malformation (CIM) is complicated.

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Medulloblastoma (MDB) can present with a wide range of imaging features, including non-enhancing mass.

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Exclusion of the secondary cause of rising intracranial pressure is necessary before making the diagnosis of IIH or CIM

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Early diagnosis, including subtype of MDB, and urgent treatment are crucial for better outcome.

Dural Venous Sinus Stenosis: Why Distinguishing Intrinsic-versus-Extrinsic Stenosis Matters

BACKGROUND AND PURPOSE

Dural venous sinus stenosis has been associated with idiopathic intracranial hypertension and isolated venous pulsatile tinnitus. However, the utility of characterizing stenosis as intrinsic or extrinsic remains indeterminate. The aim of this retrospective study was to review preprocedural imaging of patients with symptomatic idiopathic intracranial hypertension and pulsatile tinnitus, classify the stenosis, and assess a trend between stenosis type and clinical presentation while reviewing the frequencies of other frequently seen imaging findings in these conditions.

MATERIALS AND METHODS

MRVs of 115 patients with idiopathic intracranial hypertension and 43 patients with pulsatile tinnitus before venous sinus stent placement were reviewed. Parameters recorded included the following: intrinsic or extrinsic stenosis, prominent emissary veins, optic nerve tortuosity, cephalocele, sella appearance, poststenotic fusiform enlargement versus saccular venous aneurysm, and internal jugular bulb diverticula. χ² cross-tabulation statistics were calculated and recorded for all data.

RESULTS

Most patients with idiopathic intracranial hypertension (75 of 115 sinuses, 65%) had extrinsic stenosis, and most patients with pulsatile tinnitus (37 of 45 sinuses, 82%) had intrinsic stenosis. Marked optic nerve tortuosity was more common in idiopathic intracranial hypertension. Cephaloceles were rare in both cohorts, with an increased trend toward the presence in idiopathic intracranial hypertension. Empty sellas were more common in idiopathic intracranial hypertension. Cerebellar tonsils were similarly located at the foramen magnum level in both cohorts. Saccular venous aneurysms were more common in pulsatile tinnitus. Internal jugular bulb diverticula were similarly common in both cohorts.

CONCLUSIONS

In this cohort, most patients with idiopathic intracranial hypertension had extrinsic stenosis, and most patients with pulsatile tinnitus had intrinsic stenosis. Awareness and reporting of these subtypes may reduce the underrecognition of potential contributory stenoses in a given patient's idiopathic intracranial hypertension or pulsatile tinnitus.

Is Magnetic Resonance Imaging Diffusion Restriction of the Optic Disc Head a New Marker for Idiopathic Intracranial Hypertension?

Background Idiopathic intracranial hypertension (IIH) is a headache syndrome due to raised intracranial pressure of unknown etiology. Before making the diagnosis of IIH, secondary causes of raised intracranial pressure must be ruled out. The radiological features associated with this condition have variable sensitivity and specificity. In this case series, we aim to describe a potential new radiological marker of IIH, that is, diffusion restriction, in the optic disc head and propose that this can be a specific finding in the appropriate clinical picture. Importance IIH causes vision loss and disabling daily headaches. The diagnosis of this condition is based on history and physical examination findings. Magnetic resonance imaging (MRI) is used to exclude other causes, but specific radiological markers for the diagnosis of IIH are lacking. Observations Five patients presented with the main complaint of headache, which was associated with blurry vision. All of our patients had a formal neuro-ophthalmological evaluation that confirmed the presence of optic disc edema in both eyes. They also underwent an MRI of the brain that showed diffusion restriction in the optic nerve head in either eye or both eyes. Patients underwent lumbar puncture in the lateral decubitus position, which revealed cerebrospinal fluid opening pressures > 25 cm H ₂ O. They all responded well to standard treatments, with the resolution of symptoms in their follow-up appointments. Conclusion and Relevance The MRI diffusion restriction in the optic nerve head may be a reliable noninvasive marker for the diagnosis of IIH in the appropriate clinical picture.

Management of Spontaneous CSF Rhinorrhea: An Institutional Experience

Introduction  Cerebrospinal fluid (CSF) rhinorrhea is the leakage of CSF through nasal cavity, due to abnormal communication between the arachnoid membrane and nasal mucosa. Middle-age (fourth to fifth decade) group, female gender, and obesity (body mass index > 40) are the most commonly reported risk-factors for this rare entity. In this study, we present our single center experience of spontaneous CSF rhinorrhea discussing important clinicoradiological aspects in preoperative evaluation and nuances in the endoscopic repair technique. Material and Methods  A retrospective study conducted for 43 spontaneous CSF rhinorrhea patients admitted between Jan 2011 to Jan 2018 at our tertiary care center. All patients underwent endoscopic repair of the defect depending upon their site of leak. Results  Mean age in our study was 36.7 ± 12.3 years (range: 9-62 years). Average BMI in males was found lower (28.7) as compared with females (32). Most common site of CSF leak was cribriform plate ( n  = 32, 74.4%) and Planum was found to be the least common site ( n  = 1, 2.3%) of CSF leak. Intraoperatively, 23 (53.5%) patients showed high-flow leak. Intrathecal injection of fluorescein dye was used to identify the site of CSF leakage in 15 cases (34.8%). The overall success rate of primary endoscopic repair in our study was 95.3%. Conclusion  Spontaneous CSF rhinorrhea occurs secondary to elevated intracranial pressure, with a predilection for obese females in fourth to fifth decade. Individualized tailored surgical approach depending upon the site, size, and flow-variety of the defect forms the cornerstone of management.