Incidence of unilateral, high frequency, sensorineural hearing loss in shunt treated hydrocephalic children ipsilateral to shunt placement [electronic resource] / by Susan E. Spirakis.

by Spirakis, Susan E.

The purpose of this study was to investigate further the characteristics of hearing loss in ventriculoperitoneal (VP) shunted hydrocephalic children. Twelve VP shunt treated hydrocephalus children participated in this study. The etiology of the hydrocephalus was either intraventricular hemorrhage or spina bifida. A recent neurological examination reported the shunt to be patent in each child. Audiometric examination included pure tone air conduction thresholds, tympanometry, contralateral and ipsilateral acoustic reflex thresholds (ARTs), and distortion product otoacoustic emissions (DPOAE’s). A unilateral, high frequency, cochlear hearing loss was found in the ear ipsilateral to the shunt placement in 10 (83%) of the 12 shunt treated hydrocephalic children. No hearing loss was observed in the ear contralateral to shunt placement. Based on the pure tone findings coupled with the decrease in DPOAE amplitude in the shunt ear, the hearing loss appears to cochlear in nature. It is hypothesized that cochlear hydrodynamics are disrupted as the result of fluid pressure reduction within the perilymph being transmitted via a patent cochlear aqueduct as a reaction to the reduction of CSF via a patent shunt. In addition, a concomitant brain stem involvement is evidenced in the ART pattern possibly produced by the patent shunt draining the CSF from the subdural space resulting in cranial base hypoplasia. Susan E. Spirakis 3