EVENT-RELATED EVOKED-POTENTIAL RESPONSES (P-300) FOLLOWING EPIDURAL METHYLPREDNISOLONE THERAPY IN CHRONIC LOW-BACK-PAIN PATIENTS

P-300 event-related potentials were recorded in 12 patients with chron ic law back pain following epidural methylprednisolone administration. The values of absolute peak latencies and amplitudes of P-300 were re corded before (baseline) and on the 5th and 10th days following epidur al injection. Intensity of pain was also recorded using a 10-cm visual analogue scale score. The absolute peak latency of P-300 significantl y decreased on the 5th and 10th days following epidural methylpredniso lone (p<0.001) when compared with baseline value. Visual analogue scor es also decreased significantly (p < 0.001) after the 5th and 10th day s of epidural methylprednisolone. These observations suggest that foll owing epidural methylprednisolone administration in chronic low back p ain patients, significant improvement in cognitive functions and pain relief go hand in hand.