Peripheral neuropathy: an underdiagnosed cause of erectile dysfunction

OBJECTIVES

? To assess the prevalence of peripheral neuropathy in patients with erectile dysfunction (ED). ? To evaluate the reliability of clinical tests such as the five‐item version of the International Index of Erectile Function (IIEF‐5) and the Neuropathy Symptom Score (NSS) classification system in predicting the concurrence of peripheral neuropathy.

PATIENTS AND METHODS

? We studied 90 patients who were consecutively recruited from the Department of Andrology of the Central Hospital of Asturias. ? Anamnesis included questions about risk factors related to ED. ? The severity of ED was classified according to IIEF‐5 scores and symptoms of peripheral neuropathy were assessed using the NSS. ? Neurophysiological tests included electromyography, nerve conduction studies, evoked potentials from pudendal and tibial nerves as well as bulbocavernosus reflex. ? Small fibre function was assessed using quantitative sensory tests and sympathetic skin response. Statistical analysis was performed using the SPSS‐11 program.

RESULTS

? Patients with more severe symptoms of peripheral neuropathy showed lower (worse) IIEF‐5 scores (P= 0.015) and required more aggressive therapies (P < 0.001). ? Neurophysiological exploration confirmed neurological pathology in 68.9% of patients, of whom 7.8% had myelopathy and 61.1% peripheral neuropathy. ? Polyneuropathy was found in 37.8% of the patients, of whom 8.9% had pure small fibre polyneuropathy, and pudendal neuropathy was diagnosed in 14.4%. ? No association between neurophysiological diagnosis and IIEF‐5 score was detected, but a statistical association was found between neuropathy and NSS scores.

CONCLUSIONS

? Up to now, the impact of peripheral neuropathy in the pathogenesis of ED has been underestimated. The combination of anamnesis and an ad hoc neurophysiological protocol showed its high prevalence and provided a more accurate prognosis. ? In future, clinical practice should optimize the assessment of pelvic small fibre function.