Affiliation:
1. From the Department of Otolaryngology, University of Texas Southwestern Medical Center, Dallas, Texas
2. and the Epidemiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
Abstract
METHODS Vestibular complaints of Gulf War veterans were characterized by a nested case-control study of 23 veterans with 3 different Gulf War syndromes and 20 matched control subjects. All subjects completed a standardized symptom questionnaire and underwent standard audiovestibular tests administered by audiologists blinded to group identities. RESULTS The prevalence of reported dizzy spells was higher in veterans with Gulf War syndromes 1 (100%), 2 (85%), and 3 (100%) than in controls (25%, P < 0.0001). Dizzy spells were more frequent, lasted longer, and involved a wider variety of accompanying symptoms in veterans with syndrome 2 than in those with syndromes 1 and 3. Audiovestibular testing showed greater interocular asymmetry of nystagmic velocity on sinusoidal harmonic acceleration in syndromes 1 ( P = 0.015) and 2 ( P = 0.002), greater asymmetry of saccadic velocity in syndrome 2 ( P = 0.4), diminished nystagmic velocity after caloric stimulation bilaterally in syndrome 3 ( P = 0.02 to 0.04), more subjects with pathologic nystagmus ( P = 0.09), and greater interside asymmetry of wave I to III interpeak latency on auditory brain stem response in syndromes 1 ( P = 0.005) and 2 ( P = 0.07). Asymmetry of gain on sinusoidal harmonic acceleration and pathologic nystagmus were most strongly associated with symptoms of paroxysmal vertigo ( P = 0.002 and 0.07, respectively); asymmetry of saccadic velocity, with the severity of vertigo ( P = 0.004); and abnormal caloric response, with chronic dysequilibrium ( P = 0.006). CONCLUSIONS The findings are compatible with a subtle neurologic injury from organophosphate-induced delayed neurotoxicity.
Subject
Otorhinolaryngology,Surgery