Equilibrium Function Test Findings in Cases of Shy-Drager Syndrome

Equilibrium function tests were carried out in twelve cases of Shy-Drager syndrome. Orthostatic hypotension appeared in eleven and cerebellar ataxia was found in all.The results are summarized as follows : 1) Spontaneous nystagumus was found in six cases : gaze nystagumus in three, positional nystagumus of direction changing type in three, vestibular nystagmus in two.2) In the eye-tracking test, ETT, saccadic eye movement was provoked instead of smooth pursuit.3) In the optokinetic nystagumus pattern (OKP) test, all patients revealed abnormal patterns of OKN.4) In the pendular roatation test, PRT, normal rotatory nystagumus was induced in ten. However, abnormal following eye movements appeared in five patients who were asked to follow a standstill target during pendular rotation stimulation.5) As compared with so-called spino-cerebellar degeneration, slow eye speed in the slow phase of OKN and a fewer number of total beats were usually obtained in cases of Shy-Drager syndrome rather than in cases of spino-cerebellar degeneration.