PREFRONTAL CORTEX GLUCOSE-METABOLISM AND STARTLE EYEBLINK MODIFICATION ABNORMALITIES IN UNMEDICATED SCHIZOPHRENIA-PATIENTS

Attentional modulation of the startle reflex was studied in 16 unmedic ated schizophrenia patients and 15 control individuals during the F-18 -2-deoxyglucose uptake period for positron emission tomography. in a t ask involving attended, ignored, and novel tones that served as prepul ses, control individuals showed greater prepulse inhibition (PPI) at 1 20 ms and greater prepulse facilitation at 4,500 ms during attended th an during ignored prepulses; the amount of PPI and facilitation during novel prepulses was intermediate. In contrast, patients failed to sho w differential PPI at 120 ms and tended to show greater facilitation a t 4,500 ms during novel prepulses. For control individuals, greater PP I was associated with higher relative metabolic activity rates in pref rontal (Brodmann Areas 8, 9, and 10 bilaterally) and lower in visual c ortex. Patients showed this relationship only for Area 10 on the left. Patients also had low metabolism in superior, middle, and inferior pr efrontal cortex. Consistent with animal models, our results demonstrat e the importance of the functional integrity of prefrontal cortex to P PI modulation.