Peripheral neuropathy: an underdiagnosed cause of erectile dysfunction

Abstract

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.

The vascular and neurogenic factors associated with erectile dysfunction in patients after pelvic fractures

“…The latency of cortical P40>45ms or left–right difference >2.5ms were considered abnormal in PTSSEPs test. P40 latency>44.1 ms was considered pathological in PDEPs test ( 20 ). BCR test was performed by applying electrical pulses on the penis and the responses were recorded from both bulbocavernosus muscles with concentric needle electrodes ( 20 , 21 ).…”

“…P40 latency>44.1 ms was considered pathological in PDEPs test ( 20 ). BCR test was performed by applying electrical pulses on the penis and the responses were recorded from both bulbocavernosus muscles with concentric needle electrodes ( 20 , 21 ). Abnormal results include absent responses, response latency >37ms and interside differences >1.5ms.…”

Small fibre pathology is associated with erectile dysfunction in men with type 2 diabetes

“…Organic, relational, and psychological factors contribute to ED and include neurogenic, vasculogenic, iatrogenic, and endocrine pathways, which mediate penile endothelial dysfunction and defective noradrenergic and cholinergic nerve signalling with increased cavernosal contractile sensitivity and impaired dilatory function . Vascular abnormalities including penile smooth muscle and endothelial dysfunction and altered cavernosal haemodynamics have been considered to play a major role in diabetes related ED, whilst the impact of neuropathy has been underestimated . Indeed, some studies have identified an association between cardiac autonomic and somatic neuropathy and ED and attributed failure of phosphodiesterase type‐5 (PDE5) inhibitor therapy in patients with ED to the presence of small fibre and autonomic neuropathy …”

“…10 Vascular abnormalities including penile smooth muscle and endothelial dysfunction and altered cavernosal haemodynamics have been considered to play a major role in diabetes related ED, 11 whilst the impact of neuropathy has been underestimated. 12 Indeed, some studies have identified an association between cardiac autonomic and somatic neuropathy and ED and attributed failure of phosphodiesterase type-5 (PDE5) inhibitor therapy in patients with ED to the presence of small fibre and autonomic neuropathy. [13][14][15] The contribution of neuropathy to ED has been assessed using symptoms, vibration perception and reflexes, 16 neurophysiology, 17,18 quantitative sensory testing (QST), and the sympathetic skin response (SSR).…”

Small-fibre neuropathy in men with type 1 diabetes and erectile dysfunction: a cross-sectional study

“…Recent studies in participants with type 1 diabetes from the DCCT and EDIC cohorts have also shown that cardiovascular autonomic neuropathy and peripheral neuropathy are major risk factors for erectile dysfunction [8, 9]. Furthermore, failure of erectile dysfunction therapy has been attributed to severe erectile dysfunction at presentation, worsening of endothelial dysfunction and the presence of a significant neuropathy [10, 11]. …”