Abstract
The head-shaking test (HST) was used in the examination of 338 patients who complained of virtigo or dizziness in our clinic. Head-shaking nystagmus (HSN) was observed in 131 patients (38.8%) -a higher incidence than that of other types of nystagmus. Nystagmus was monophasic in 107 patients (81.7%) and biphasic in 24 (18.3%). HSN was usually horizontal or had a rotatory component. Vertical or oblique nystagmus was observed in only ten patients. An abnormal righting reflex and an abnormal deviation reaction were more frequently observed in HSN-positive patients. The first phase of nystagmus was directed to the opposite to the deviation side of deviation reaction, opposite to the side of hearing loss and to that of CP in the caloric test. HSN is very common and is useful in determining the location of a lesion. Therefore HST is a very important aid in equilibrium examinations.
