Vestibular evoked myogenic potentials (VEMP) have been known to useful in documenting abnormality in patients with various vestibular disorders but the studies of VEMP in stroke patients are rare. We recorded VEMP in 17 consecutive patients with acute ischemic stroke in the brainstem lesions. All patients underwent magnetic resonance imaging and we compare VEMP results with the lesion documented by brain imaging. VEMP were defined to be abnormal when they were very asymmetrical (one is 2 times of more as large as the other), or absent in one side. VEMP abnormalities were found in 71%(12/17) of acute infarction patients with brainstem lesions. Most abnormalities found in the ipsilateral side of the lesion(9/12) but abnormalities in contralateral side of lesion were found in 25%(3/12) of patients.VEMP would be considered a useful complementary neurophysiological tool for the evaluation of brainstem dysfunction in acute stroke patients

Background
Idiopathic Parkinson's disease (IPD) is closely related to Lewy body pathology. Pathological changes in medullar oblongata and pontine tegmentum have been reported in patients with subclinical motor symptom. Vestibular evoked myogenic potential (VEMP) is mediated by vestibular nuclei in lower brainstem and reflects the function of lower brainstem. The purpose of our study is to estimate the lower brainstem function in IPD patients.M e t h o d s: Ten patients with idiopathic Parkinson's disease underwent VEMP test. The patients were divided into Hohn-Yahr (H-Y) stage I (unilateral motor involvement) group and H-Y stage II or more severe (bilateral motor involvement) group. VEMP results were compared between groups using Mann-Whitney U test.R e s u l t s: Among patients, 6 patients showed abnormal VEMP (unilateral abnormality 2, bilateral abnormalities 4). Between H-Y stage I group and H-Y II,III group, there was no statistical difference in the results of VEMP.Conclusions: We concluded that the lower brainstem dysfunction reflected in VEMP could occur in IPD regardless of the progression of the disease.