Altered processing of otolithic information in isolated lateral medullary infarction.
Ocular and cervical vestibular-evoked myogenic potentials (VEMPs) evaluate the function of otolithic pathways in central as well as peripheral vestibular disorders. This study aimed to determine the associations and dissociations of otolithic dysfunction in lateral medullary infarction (LMI), the most well-known disorder of central vestibulopathy. At the Dizziness Clinic of a referral-based University Hospital, 45 patients with isolated LMI (28 men, mean age = 55.6 ± 12.5) had evaluation of the ocular tilt reaction (OTR), tilt of the subjective visual vertical (SVV), and ocular and cervical VEMPs from Janurary 2011 to August 2015 during the acute phase, 1-11 days from the symptom onset (median = 2 days). Almost all (42/45, 93 %) patients showed at least one component of the OTR or SVV tilt that was invariably ipsiversive. In contrast, oVEMPs were abnormal only in 12 (27 %) and cVEMPs in 13 (29 %) patients. Only three patients showed abnormal results in all the tests of the OTR, SVV tilt, and ocular and cervical VEMPs. Abnormal oVEMPs were more common in patients with the OTR than those without (38 vs 6 %, Pearson X2test, p = 0.021). In contrast, abnormality of cVEMPs showed no correlation with the presence of OTR (28 vs 31 %, Pearson X2test, p = 0.795). In patients with LMI, ipsiversive OTR is invariable, but abnormalities of oVEMPs and cVEMPs were much less common and mostly dissociated even in the patients with abnormal results. This discrepancy in otolithic dysfunction suggests different anatomical substrates and/or dissimilar reciprocal modulation for processing of each otolithic signal in central vestibular structures located in the dorsolateral medulla.
Department of Biomedical Laboratory Science, Kyungdong University, Goseong, Korea.
Hyo-Jung
HJ
Kim
Chung-Ang University School of Medicine, Seoul, Korea.
Seoyeon
S
Kim
Department of Neurology, School of Medicine, Catholic University of Daegu, Daegu, Korea.
Jae Han
JH
Park
Department of Neurology, Seoul National University College Medicine, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam, Gyeonggi, 463-707, Korea. jisookim@snu.ac.kr.
Ji-Soo
http://orcid.org/0000-0002-1508-2024
JS
Kim
D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001931:Brain Mapping; D004576:Electromyography; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D014854:Lateral Medullary Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010037:Otolithic Membrane / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012189:Retrospective Studies; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology*
Lateral medullary infarction; Ocular tilt reaction; Saccule; Subjective visual vertical; Utricle; Vestibular evoked myogenic potentials