Reversible Bilateral Vestibular Impairment Caused by Fourth Ventricle Epidermoid Tumor-Case Report-

Abstract

A 26-year-old man presented with an epidermoid tumor of the fourth ventricle manifesting as headache with nausea and vertigo. Neurological examination revealed no cerebellar signs, except nystagmus. Bilateral vestibular impairment was identified by the caloric test. The tumor was removed via the midline suboccipital approach. The bilateral peripheral vestibular function recovered remarkably postoperatively. This marked improvement suggests that the bilateral vestibular impairment was caused by compression of the vestibular nuclei by the tumor.

Clinical characteristics and diagnostic imaging of epidermoid tumors

“…19 Between 5% and 31% of all intracranial epidermoid tumors are also found in the 4th ventricle. 27 Intradiploic lesions account for 25% of epidermoids and 3% of these expand to include the subdural space. 28,29 Less common locations of development include the middle cranial fossa, thalamus, spinal canal, corpus callosum, lateral ventricles, parietal lobe and occipital lobe.…”

“…Although the tumor effects are dependent upon lesion location, tumor extension and mass effect on adjacent vital structures, their presentation ranges from mild headaches to seizures and rare fatal events. 14,18,19,22,27,32 However, acute onset of symptoms is atypical, with a median duration of two to four years prior to presentation. 22 Trigeminal neuralgia is reported to be a primary symptom in 40% of cerebellopontine angle epidermoid cysts, as the lesion extends into the surrounding cisterns which are rich in neurovascular structures.…”

“…Diplopia, dysphagia, and hoarseness may present at a later stage when the cranial nerves become involved. 27,44 Brainstem and pineal epidermoids are unique in that they tend to present in younger populations. Ten of twenty reported cases within the brainstem were fourteen months to ten years old, while eight others were in their twenties to thirties.…”

Epidermoid tumor of the fourth ventricle with accompanying congenital posterior arch defect of the atlas

“…Epidermoid tumors constitute approximately 1-2% of all intracranial tumors (5,10) . Most common site of their occurence is the cerebellopontine angle (CPA) followed by sellar and parasellar regions (1,5,9,10) . Fourth ventricle is a relatively rare location for epi-dermoid tumors with more than 100 reported cases (4,10) .…”

“…Fourth ventricle is a relatively rare location for epi-dermoid tumors with more than 100 reported cases (4,10) . Fourth ventricle epidermoid tumors account for 5-31.4% of all intracranial epidermoid tumors (5) . Herein we present a case of a fourth ventricle epidermoid tumor with accompanying congenital posterior arch defect of the atlas.…”