A 33 year old patient has sensorineural hearing loss and loss of corneal reflex on the left side. He is noted to have reduced facial sensation on that same side. He also complains of tinnitus and vertigo. What is the SINGLE most definitive investigation?
A. Computed tomography of internal auditory meatus B. Nuclear imaging of brain C. Magnetic resonance imaging of internal auditory meatus D. Radioisotope scan E. X-ray skull
Hearing loss, tinnitus, vertigo points towards an affected vestibulocochlear nerve. Absent corneal reflex and reduced facial sensation is due to the trigeminal nerve being affected.
Acoustic neuroma could account for these set of symptoms in which case MRI would be the investigation of choice.
Acoustic neuroma Acoustic neuromas (more correctly called vestibular schwannomas) account for approximately five percent of intracranial tumours and 90 percent of cerebellopontine angle. It causes problems by having local pressure and behaving as a space-occupying lesion.
Features can be predicted by the affected cranial nerves • Cranial nerve VIII: hearing loss (sensorineural deafness), vertigo, tinnitus • Cranial nerve V: absent corneal reflex • Cranial nerve VII: facial palsy
Bilateral acoustic neuromas are seen in neurofibromatosis type 2
Investigation • MRI of the cerebellopontine angle is the investigation of choice