Follow-up Study On Sensory Evoked Potentials In Panic Disorder

Background: Panic disorder(PD) is a common and disabling psychiatric disorder. The etiology and pathogenesis of PD is still not clear. Studies have suggested that there are some disturbances in information processing in patients with PD. Brain evoked potentials as one of neuroelectrophysiological technics which can reflect the status of cortex simultaneously and have been used a lot in spiritual psychological field. Auditory, visual and somatosensory evoked potentials are three common and matural sensory evoked potentials. The late components(50⁵00ms) of these evoked potentials are known as reflecting psychological status of subjects and have shown their values in studying spiritual psychological diseases. Objective: 1.To study the characteristics of late components of three sensory evoked potentials in patients with PD. 2.To determine the different changes of these sensory evoked potentials in comparing PD with GAD. 3.To study the changes of three sensory evoked potentials in PD patients under SSRIs treatment over one month and three months and try to find out neuroelectrophysiological indexes in supervising clinical response to drugs. Method: 1.We used Hamilton Rating Scales of Axiety(HAMA) to assess the severity of anxiety state. 2.Long latency sensory evoked potentials were recorded from every subject, using a Keypoint instrument. Results: 1.PD patients showed no significant differences than GAD patients in HAMA. The HAMA of PD patients continuously decreased under treatment and were no differences in one and three months study than NC. 2.Compared with NC, before treatment PD patients have shown: AEP/N₁P₂ and P₂N₂ amplitudes decreased; VEP/N₁ latency were porlonged and VEP/N₁P₂, P₂N₂ amplitudes decreased; SEP/N₁, P₂, N₂ latencies were prolonged. 3.Compared with NC, GAD patients have shown similar changes with PD patients besides VEP/P₂ latency were prolonged. 4.Compared with PD, GAD patients have shown VEP/N₁, P₂ latencies prolonged and VEP/P₂N₂ amplitude decreased. 5 . Follow-up study of PD patients has shown: AEP,VEP/N₁P-2 amplitudes continuously increased, and VEP/N-1, SEP/N-2 latencies continuously shortened which were no statistical differences comparing with NC. AEP,VEP/P₂N₂ amplitudes and SEP/P-2 latency have no significant improvement. SEP/N₁ latency was continuously prolonged and had shown significant longer than NC. Conclusion: 1.PD and GAD patients have shown the same changes in three sensory evoked potentials: latency prolonged and amplitude decreased. These changes suggest a disturbance in auditory, visual and somatosensory information processing of PD and GAD. This suggests a decreased ability of patients'brain integration. 2 .PD has significant differences in VEP/N₁, P-2 latencies andVEP/P₂N-2 amplitude with GAD patients. 3.AEP, VEP/N₁P-2 amplitudes and VEP/N1, SEP/N2 latencies may be state markers of PD patients and are hopeful to be neuroelectrophysiological indexes in supervising clinical response to SSRIs treatment.