The vestibulo-ocular reflex in pupils at a Dutch school for the hearing impaired; findings relating to acquired causes.

The vestibulo-ocular reflex was evaluated with caloric tests and velocity step (VS) tests in 121 pupils at a school for the hearing-impaired. Vestibular impairment was found in a total of 50 pupils (41%). It was found in 17 out of the 33 (52%) pupils with acquired causes of hearing impairment and significantly more often in pupils with a pure tone hearing threshold of more than 90 dB than in those with a lower threshold. In the group with prenatal causes, 5 out of 8 rubella cases showed vestibular impairment. Four of these cases had impaired VS responses and normal caloric responses. The high proportion of vestibular impairment in the group with postnatal causes was due to 5 cases with meningitis, all of whom showed caloric weakness. Kernicterus was significantly associated with vestibular hyperreactivity (5 cases out of 7), presumably due to a central dysfunction.