Cognitive dysfunction in NIDDM: P3 event related evoked potential study.

P3 component of the endogenous cerebral evoked response is a sophisticated, objective and quantitative approach to assess higher functions of the brain. This test was employed using auditory 'odd ball' paradigm to assess cognitive functions in thirty non insulin dependent diabetic patients (NIDDM) aged 43.6 +/- 9 yrs with poor blood glucose control. (HbAlc. 9.9 +/- 1.0%). The peak latencies of N2, P3 components of event related evoked potentials obtained in these patients were compared with 30 age and sex matched non diabetic healthy controls. Latencies of these potentials were: N2 = 248.0 +/- 36.3, P3 = 391.6 +/- 49.9 msec in NIDDM as compared to 220.6 +/- 26.4, 326.2 +/- 26.8 msec in controls and were highly significant (P < 0.001). The duration of disease, blood glucose level or the physical parameters of height, weight and blood pressure did not show any correlation with N2 or P3 latencies or amplitude. These findings provide an electrophysiological evidence of delayed cognition in poorly controlled NIDDM cases.