AIMS: To assess the significance of combined neurophysiological and neurourological examinations for diagnosis of neurogenic male sexual dysfunction.
METHODS: This is a prospective study of 32 spinal cord injured men. Each underwent clinical and neurophysiological examinations (sympathetic skin responses (SSR), pudendal somato-sensory evoked potentials (P-SSEP), bulbocavernosus reflex (BCR)) and neuro-urological measurements (urodynamic examination (UE), reflex erections (RE), psychogenic erections (PE) and nocturnal penile tumescence recordings (NPTR)).
RESULTS: Erectile dysfunction due to impairment of RE was associated with loss of BCR and detrusor areflexia (P > 0.001), whereas that due to impairment of PE was associated with loss of perineal SSR (P < 0.001). P-SSEP corresponded in 94% with impairment of penile sensibility and duration of erections in NPTR. The NPTRs were less related to functional sexual impairment. NPTRs in complete and incomplete suprasacral (level > T10) spinal lesion showed sufficient erections despite strongly disturbed PE. NPTRs in lumbosacral lesion revealed significant reduction in or absent erections and underestimated the presence of well excitable PE.
CONCLUSIONS: Combined neurophysiologic and neurourologic testing provides highly relevant diagnostic informations about sexual dysfunction in men with spinal cord injury. Loss of the BCR and detrusor areflexia imply loss of somatic and parasympathetic reflex activity and correlate with loss of RE. Loss of PE correlates with loss of perineal SSR (sympathetic denervation).