Reversible bilateral vestibular impairment caused by fourth ventricle epidermoid tumor.

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.