One-Year Vestibular and Balance Outcomes of Oklahoma City Bombing Survivors

Abstract

AbstractThis multisite investigation assessed subjective, behavioral, and objective balance function in 30 blast survivors. Subjects with vertigo, dizziness, or imbalance were screened (n = 6) or evaluated (n = 27) during 1 year. Tests included a questionnaire, electronystagmography (ENG), and computerized dynamic posturography (CDP). Ninety-seven percent of subjects were located inside a building during the blast, and 63 percent of subjects experienced dys-equilibrium within 48 hours. Forty-three percent of symptoms could not be attributed to head injury. Sixty percent of subjects had abnormal ENG and/or CDP; ENG abnormalities mostly were peripheral or nonlocalizing, whereas CDP patterns were “vestibular,” “surface dependent,” and “physiologically inconsistent.” At 1-year postblast, 55 percent of initially abnormal CDP results were normal, and 72 percent of subjects said symptoms were unchanged or occurred intermittently. A serial, test battery approach is recommended to assess symptoms. Blast-related dysequilibrium had clinically significant manifestations and should be considered a valid component of aural blast injury. Abbreviations: BPPV = benign paroxysmal positioning vertigo, CDP = computerized dynamic posturography, dB pSPL = decibel re: peak sound pressure level, ENG = electronystagmography, MCT = motor control test, psi = air pressure measured in pounds per square inch, Q = quarterly evaluations, SHA = smooth harmonic acceleration, SOT = sensory organization test, TNT = trinitrotoluene