Atypical Presentation of Idiopathic Intracranial Hypertension: A Case Series and Literature Review

Abstract

Idiopathic intracranial hypertension (IIH) is a condition in which intracranial pressure (ICP) increases without an apparent cause. Typically, patients present with headaches, dizziness, pulsatile tinnitus, visual disturbances, blurred vision, diplopia, photophobia, visual field defects, and papilledema on fundoscopy. The association between IIH, spontaneous cerebrospinal fluid (CSF) rhinorrhea, and arachnoid cysts has been discussed in the literature; however, there is no clear explanation for this association. We aimed to present a series of four patients with a confirmed diagnosis of IIH with atypical presentations, discuss the management of each case, and provide an explanation for this association to alert clinicians to the atypical presentation of IIH and facilitate early diagnosis and proper treatment of this condition by CSF diversion. This was a retrospective case series of all patients who were diagnosed with IIH and showed improvement after ventriculoperitoneal shunt insertion after failure of at least one operative intervention resulting from primary radiological and clinical findings in 2001 to 2022. Data on demographics, clinical presentation, radiological findings, surgical management, and diagnostic criteria for IIH were recorded. We identified four patients with a confirmed diagnosis of IIH who presented with atypical presentations as follows: intracranial arachnoid cyst, cervical spine arachnoid cyst, giant Virchow perivascular space, and spontaneous CSF (CSF) rhinorrhea. All patients responded to CSF diversion after failure of surgical treatment targeting the primary pathology. IIH should be suspected after the failure of primary surgical treatment in cases of spontaneous CSF rhinorrhea, spinal and cranial arachnoid cysts, and symptomatic ventriculoperitoneal shunt. Treatment in such situations should be directed toward IIH with CSF diversion.

Keywords: Virchow perivascular space; arachnoid cyst; idiopathic intracranial hypertension; lumboperitoneal shunt; spontaneous CSF rhinorrhea.

Fig. 1

( A ) Preoperative axial computed tomography (CT) images showing the mass effect and midline shift (white arrows). ( B ) Axial T2-weighted magnetic resonance imaging showing the left temporal arachnoid cyst. ( C ) CT brain scan after craniotomy and microscopic fenestration of the cyst. Coronal and axial images showing the subgaleal cerebrospinal fluid collection (white arrows). ( D ) CT scan after insertion of a right frontal (red arrow) ventriculoperitoneal shunt.

Fig. 2

(A) T2-weighted magnetic resonance imaging (MRIs) showing the left side cervical arachnoid cyst at the intervertebral foramen. ( B ) T2-weighted MRIs showing regression of the cyst after ventriculoperitoneal shunt insertion.

Fig. 3

( A ) Axial computed tomography (CT) scan showing giant tumefactive perivascular space in the right-sided mesencephalon and thalamus (white arrow). ( B ) Axial T2-weighted magnetic resonance imaging showing the lesion the right aspect of the midbrain extending to the pons and thalamus on the ipsilateral side (white arrows). ( C ) Axial CT scan of the brain after insertion of the ventriculoperitoneal shunt.