Functional and anatomical correlates of impaired velocity storage.
Velocity storage (VS), a brainstem function, extends the low-frequency response of the vestibular system. To better understand VS mechanisms and characteristics in humans, we analyzed retrospectively functional measures of gait, electrophysiological measures of vestibular function, and imaging studies in an attempt to determine clinical, electrophysiological, and anatomical correlates of abnormalities in VS. Two cohorts of patients referred to our Risk of Falls Assessment Clinic participated in this investigation. Group 1 (control) patients demonstrated normal caloric and rotary chair tests. Group 2 patients with impaired velocity storage (experimentals) differed clinically from Group 1 only by demonstrating abnormal multifrequency vestibulocular reflex phase measures on rotational testing. Results showed that Group 2 patients had greater impairments in postural stability and gait than Group 1 patients. Additionally, 80% of patients in Group 2 and none in Group 1 showed pontine hyperintense lesions on MRI.
Jacobson
Gary P
GP
Division of Audiology, Henry Ford Hospital, Detroit, MI, USA. gary.jacobson@vanderbilt.edu
McCaslin
Devin L
DL
Patel
Suresh
S
Barin
Kamrin
K
Ramadan
Nabih M
NM
D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology; D001933:Brain Stem / Q000033:anatomy & histology / Q000098:blood supply / Q000473:pathology*; D016022:Case-Control Studies; D015331:Cohort Studies; D004244:Dizziness / Q000503:physiopathology; D004584:Electronystagmography; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D012189:Retrospective Studies; D015837:Vestibular Diseases / Q000503:physiopathology*; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000033:anatomy & histology / Q000502:physiology*; D000159:Vestibulocochlear Nerve / Q000502:physiology