EXAGGERATED ACOUSTIC STARTLE REFLEX IN GULF-WAR VETERANS WITH POSTTRAUMATIC-STRESS-DISORDER

Objective: Exaggerated startle reflex is reputed to be one of the card inal symptoms of-post-traumatic stress disorder (PTSD). The goal of th is study was to assess the magnitude of the acoustic startle reflex in Gulf War veterans with PTSD. Method: The eye-blink component of the s tartle reflex was measured in response to six blocks of pseudorandomiz ed 40-msec white noise bursts of varying intensities (90, 96, 102, 108 , and 114 dB) in 10 Gulf War veterans with PTSD, seven Gulf War vetera ns without PTSD, and 15 civilian subjects without. PTSD. Results: The magnitude of the first startle response, as well as the magnitude of s tartle response averaged across blocks of testing, was significantly g reater in Gulf-War veterans with PTSD than in veteran and civilian com parison groups. Conclusions: Consistent with some clinical studies inv estigating the startle response in Vietnam veterans with PTSD, this in vestigation provides Evidence for exaggerated startle response in this disorder. Preclinical studies of shock sensitization of the startle r esponse suggest that the higher levels of startle response seen in the PTSD subjects may reflect a sensitization of the fear/alarm response created by the stress of combat trauma.