Neural hearing loss in a child with poliomyelitis: a histopathological study

The temporal bones of a 26-month-old white female with a paralytic syndrome clinically and pathologically identical to poliomyelitis were examined. Th e aetiological agent was unknown although a non-poliomyelitis enterovirus i nfection seemed likely. There was a complete absence of the cochlear neurons and substantially redu ced peripheral and central axons with loss of some inner hair cells but pre servation of outer hair cells. Scarpa's ganglion, and the geniculate gangli on were partially atrophied. The saccule and utricle were mildely dilated a nd Reissner's membrane of the apical turn was bulging. In two previous audiulogical studies a 10-20 dB bilateral sensorineural hea ring loss was found in poliomyelitis patients and a neuronal lesion was pos tulated which is now supported by bur findings. This is a rare example of a n almost pure neural hearing loss.