Although it has no specific characteristic to acoustic neuromas it is usually mild. The significance of this symptoms is that unilateral tinnitus should raise the suspicion of retrocochlear pathology and prompt an audiologic investigation. Vestibular symptoms in acoustic neuroma are surprisingly absent. This is due to the fact that since these are slow growing tumors central adaptation takes place while the vestibular function on the affected side is slowly lost. Other uncommon symptoms of acoustic neuromas are lower cranial nerve symptoms observed with very large tumors which are capable of encroaching upon the ninth, tenth and eleventh cranial nerves.
Facial paralysis is also an exceedingly uncommon symptom.
This is due to the resilience of motor nerves to slow pressure over prolonged time. Cerebellar signs and symptoms of ataxia, dysequilibrium and brainstem signs of long tract involvement by compression along with headaches from obstructing hydrocephalus are exceedingly rare signs at this day and age. However at the beginning of the century these were the most common presenting signs and symptoms of acoustic neuroma. The symptoms are usually slowly progressive, with a median duration of 2 years in one series. Asymmetric SNHL or impairment of speech discrimination disproportionate to the pure tone loss requires specific investigation for a retro-cochlear lesion.