Purpose: To our knowledge no direct measurement of autonomic failure in the penis is currently available. Indirect techniques in clinical use, such as bulbocavernosus reflex, genital somatosensory evoked potentials and biothesiometry, all rely on large nerve fiber function. Since micturition and potency depend on small fibers of the peripheral system, tests of these fibers might be more relevant in the clinical diagnostic evaluation. We provide upper normal limits and demonstrate repeatability of small fiber mediated sensations of warm and cold sensory thresholds on penile skin.
Materials and methods: Penile warm and cold sensory thresholds were measured in 35 healthy volunteers (at 2 sessions in 27) via 2 methods.
Results: Upper normal values, expressed as 95% confidence limits for warm and cold thresholds, through methods of limits and levels as well as inter-session repeatability are given.
Conclusions: Penile thermal thresholds are repeatable and can be used as a valid diagnostic tool to assess somatic small fiber function in patients with lower urinary tract disorders.