Ocular motor dysmetria1 and skew deviation2,3 are characteristic manifestations of disease in the posterior cranial fossa. However, no attempt has been made previously to assess the localizing value of dysmetria as to sidedness and recent observations on skew deviation4 have suggested findings at variance with those previously reported.5-7 Clarification of these uncertainties is clearly indicated.
To determine whether or not these signs had lateralizing value, 51 cases were selected in which surgical exploration or clinical signs indicated convincingly whether the lesion was unilateral or bilateral. The dysmetria and skew deviation were not necessarily present in the same patient and 10 of the patients have been previously included in a report on internuclear ophthalmoplegia.4
Dysmetria was manifest by an overshoot of the eyes when fixation was alternately directed from an eccentrically placed object on either side to a midline point. In instances in which the dysmetria