Lateralised vestibular hypofunction: canal paresis and handedness.

In this retrospective study it was found that 549 out of 1175 patients seen for vestibular assessment within an 8-year period within a district hospital service showed lateralised canal paresis as determined by caloric testing. It was found that there was a tendency for canal paresis, indicative of vestibular hypofunction, to be on the side of handedness. This bias showed statistical significance, (chi-squared, p < .005), for the patients overall, as well as for the 65 left-handers considered separately, (p < .05). Surprisingly, this form of bias does not appear to have been reported previously. The bias was shown most clearly in the largest of the groups defined by sex and handedness, namely that of female right-handers. In this group the prevalence of associated hearing loss was similar for canal paresis on either side. This allowed speculation as to the particular type of disorder to which those cases of canal paresis that were associated with the bias might be due, from which it seemed that migraine, rather than Menière's disease or vestibular neuronitis, was likely.