Cranial Nerve Injuries, Vertigo and Headache

Abstract

The frequency with which persistent signs of cranial nerve injury were found amongst the consecutive series of patients is recorded in table 7.1. The main concern of this study has been the assessment of disability. In considering evidence of residual cranial nerve damage it seemed justifiable, therefore, to record differing degrees of impaired function of each nerve appropriate to the disability caused. A minor degree of impairment of the sense of smell was not only difficult to relate with certainty to the injury but also of negligible inconvenience compared with minor degrees of double vision due to residual external ocular muscle weakness. For these reasons only complete loss of the sense of smell, that is for gas, faeces and onions or, when tested, for asafoetida, and then only if the patient was certain that this had been present since the injury, was reckoned as ‘disability’ due to injury of the first cranial nerves. Similar considerations applied to the assessment of deafness. Only in cases where there was total or near total hearing loss on one side which had persisted since the accident has hearing loss been discussed. Disability due to traumatic vestibular dysfunction has been studied separately. Residual signs of other cranial nerve lesions have been recorded even when these were minimal.