Franklin O. Black

Spatial Distribution of Vestibular Nerve in Internal Auditory Canal

Although neuroanatomical pathways of the vestibular system have recently become more clarified, detailed anatomical information regarding the innervation of smaller areas of the vestibular end-organs has been incomplete. It is important to determine the precise relationships of the vestibular nerve fibers in the internal auditory canal for correlation with neurophysiological studics. The present study was designed to plot the course of vestibular nerve fibers by mapping out the spatial distribution of the afferent vestibular nerves in the internal auditory canal from each of the vestibular end-organs.

Acrocephalosyndactyly (Apert's Syndrome): Temporal Bone Findings

The otologic manifestation of acrocephalosyndactyly (Aperts syndrome) has usually consisted of bilateral conductive hearing impairment. Invariably, fixation of the stapes footplate has been found at tympanotomy. Manipulation or removal of the stapes has resulted in a copious flow of fluid from the vestibule, suggesting an unusually patent cochlear aqueduct with escape of cerebrospinal fluid. Histologic examination of a temporal bone from an infant with acrocephalosyndactyly showed cartilaginous fixation of the stapes footplate. The lumen of the cochlear aqueduct was not unusually large or widely patent in this case.

The Sequential Bithermal Binaural Caloric Test: I. A Statistical Analysis of Normal Subject Responses

Statistical analysis of bithermal binaural caloric test results gave a statistically significant response difference between ears for right-handed normal subjects. There were no significant response differences due to temperature of stimulation or due to the interaction between temperature of stimulation and ear stimulated. Of the four different orders of stimulation tested, all were statistically equivalent. Because intrasubject variance from a statistical analysis of normal subject responses was evidently much smaller than percentage based variance, the use of absolute differences or confidence intervals for determination of normal limits should yield more precise normal criteria than percentage based comparisons allow.

The Sequential Bithermal Binaural Caloric Test: II. Clinical Application of New Statistical Methods for Interpretation

Three tests for the determination of caloric nystagmus response abnormalities have been developed, based upon analysis of intrasubject normal responses, obtained by using a statistical model that provided an exact fit with clinical procedures. Normal limits derived from interaural, stimulus temperature, and nystagmus direction responses should provide a more sensitive index of abnormality than limits based on percentage based response criteria. A retrospective examination of caloric responses from Ménières disease patients provided preliminary support for clinical feasibility and increased sensitivity of the statistical methods advocated for clinical usage.