Sensory gating in chronic posttraumatic stress disorder: reduced auditory p50 suppression in combat veterans

• Published in: Biological psychiatry (1969) Vol. 46; no. 12; pp. 1656 - 1664
• Main Authors: Neylan, Thomas C, Fletcher, Daniel J, Lenoci, Maryann, McCallin, Keith, Weiss, Daniel S, Schoenfeld, Frank B, Marmar, Charles R, Fein, George
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 15.12.1999; Elsevier Science
• Subjects: Adult and adolescent clinical studies; Anxiety disorders. Neuroses; Auditory Threshold; Biological and medical sciences; Brain - physiopathology; Case-Control Studies; Electroencephalography; evoked potentials; Evoked Potentials, Auditory; habituation; Habituation, Psychophysiologic; hippocampus; Humans; Male; Medical sciences; Middle Aged; Neural Inhibition; Post-traumatic stress disorder; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Stress disorders; Stress Disorders, Post-Traumatic - physiopathology; United States; Veterans - statistics & numerical data; Vietnam; Warfare; United States; Vietnam; Stress disorders; electroencephalography; neural inhibition; hippocampus; habituation; evoked potentials; Human; Posttraumatic syndrome; Acoustic stimulus; Anxiety disorder; Information processing; Electrophysiology; Electroencephalography; Veteran; Gating; Event evoked potential; Stress
• ISSN: 0006-3223; 1873-2402
• DOI: 10.1016/S0006-3223(99)00047-5

Background: Posttraumatic stress disorder (PTSD) may be associated with a general impairment of cognitive function that extends beyond the processing of trauma-specific stimuli. Suppression of the auditory P50 response to repeated stimuli occurs in normal subjects and reflects the central nervous system’s ability to screen out repetitive stimuli, a phenomenon referred to as sensory gating. This study examines P50 sensory gating to nonstartle auditory stimuli in PTSD subjects and normal controls. Methods: P50 generation and gating were studied using a conditioning/testing paradigm in 15 male subjects with PTSD and 12 male controls. P50 test/conditioning (T/C) ratios were estimated using the Singular Value Decomposition method. Results: The amplitude of the P50 response to the conditioning stimulus did not differ in subjects with PTSD compared to normal controls. The P50 T/C ratio is increased in PTSD subjects (mean = .408, SD = .275) as compared to the controls (mean = .213, SD = .126, two tailed t, p = .024). Conclusions: This study provides evidence that PTSD is associated with impaired gating to nonstartle trauma-neutral auditory stimuli. Biol Psychiatry 1999;46:1656–1664