Pre-op Deaf Post-op Dumb: A Case Report of a Tectal Plate Glioma and a Brief Literature Review

Any disorder of the brain stem that involves the auditory pathways and/or centers may produce hearing abnormalities. Auditory pathways are tonotopically organized, and they cross the midline at several points both below and at the level of the inferior colliculus but the central nucleus of the inferior colliculus and higher centers have a clear contralateral dominance. Ipsilateral auditory abnormalities are caused by lesions below or within the cochlear nuclei; bilateral auditory abnormalities are caused by lesions rostral to cochlear nuclei or they may be silent. A patient with a tectal plate glioma can present with bilateral hearing impairment due to the involvement of both inferior colliculi. Our case is a 28-year-old male who presented with progressive bilateral hearing impairment and a generalized headache despite normal pure-tone audiometry. Computed tomography (CT) of the brain revealed a tectal plate glioma (TPG) extending into the right thalamus, and an obstructive hydrocephalus. Following a ventriculoperitoneal shunt for cerebrospinal fluid (CSF) diversion, navigation-guided tumour excision was performed via a supracerebellar infratentorial approach. Postoperatively he developed unexpected aphasia probably due to ischemic changes in the cerebellar vermis and a focus of the adjacent right cerebellar hemisphere. This case highlights the rarity of bilateral auditory impairment in a TPG, surgical challenges posed by the tumour’s location, and potentially rare post-op complication of cerebellar mutism syndrome.