THE CLINICAL-APPLICATION OF DORSAL PENILE NERVE CEREBRAL-EVOKED RESPONSE RECORDING IN THE INVESTIGATION OF IMPOTENCE

Objective To determine whether recording of penile cerebral-evoked res ponse (CER) is useful in the assessment of men with impotence. Patient s and methods A total of 280 impotent men underwent CER recording as p art of an assessment for a complaint of impotence. They were categoriz ed from findings in the history and examination as having non-neurogen ic impotence (n=106), impotence related to existing neurological distu rbance (n=67), type I diabetes (n=49) or type II diabetes (n=58). Incr eased period of latency or absence of first positive peak (P1) on CER were used as the criteria for an abnormal response with reference to a n age-matched control group of potent men (n = 34). Results Overall, i mpotent men with diabetes or a history of neurological disturbance had significantly longer P1 latencies and lower response amplitudes compa red with the control group. In contrast the CER recorded from men with non-neurogenic impotence was similar to the control group. Individual results showed an increased period of latency or absence of P1 in 100 (36%) impotent men, 72 (72%) of whom were diabetic or had a history o f neurological dysfunction. CER abnormalities were associated with neu rological signs on physical or cystometrographic examination in 40 (40 %) individuals. Conclusion Although technically satisfactory, the clin ical usefulness of CER recording is limited by the poor discriminatory value of response latencies. Most abnormal results could be predicted by the presence of diabetes or pre-existing neurological dysfunction, or by evidence of neurological deficit on physical examination. The t est is not therefore suitable for routine clinical assessment of impot ence but may be worthwhile if objective evidence of penile sensory dys function is required.