Impotence Associated with Charcot-Marie-Tooth Syndrome
by T.D. Bird and H.P. Lipe, Department of Medicine (Neurology and Medical
Genetics), University of Washington VA Medical Center, Seattle, Wash.,
USA, and L.D. Crabtree, CMT International, St. Catharines, Ont., Canada
published in Euro Neurol 1994;34:155-157
Key Words
Charcot-Marie-Tooth syndrome; Impotence; Papaverine; Penile implants</p>
Abstract
We report 7 men (ages 45-61 years) with impotence associated with the
Charcot-Marie-Tooth syndrome (CMT). The range of onset of erectile dysfunction
varied from 38 to 55 years of age. One patient had classic CMT 1A with
autosomal dominant inheritance, slow motor nerve conduction velocities
and the 17pDNA duplication. One had probable type-II hereditary motor
and sensory neuropathy. None of the patients had diabetes. There was some
benefit from papaverine injection therapy or penile implants. The association
of impotence with CMT is likely to be more common than previously recognized.
Introduction
Impotence is a fairly common complication of numerous polyneuropathies.
The best example is diabetes mellitus. Surprisingly, there has not been
a formal report of impotence associated with the Charcot-Marie-Tooth syndrome
(CMT; hereditary motor and sensory neuropathy, HMSN), even in extensive
reviews of the disorder [1]. We report here 7 instances of this association
and suggest that it is more common than previously recognized.
Patient Report
Case 1 is a 45-year-old man with classic CMT 1A. He is a member of a 4-generation
autosomal dominant pedigree (No. 1549) that is part of a larger genetic
study of CMT [2]. The neuropathy in this family has been documented to
be associated with the 17p DNA duplication. Motor nerve conduction velocities
in family members have ranged from 10 to 35 m/s with a mean of 20 m/s.
This particular individual had served in the Navy and was married with
2 children. At age 36, following an injury to his elbow, a physical examination
revealed signs of long-standing neuropathy and motor nerve conduction
velocities were slow (median motor nerve conduction - 20 m/s). He had
bilateral pes cavus foot deformity with moderate foot-drop. There was
atrophy of the interossei muscles of both hands. Tendon reflexes were
entirely absent and plantar reflexes were down. Sensation was decreased
to vibration and pinprick in both feet. Ulnar and posterior auricular
nerves were palpably enlarged. He had no tremor, no nystagmus and normal
bulk and strength of proximal limb muscles. At approximately age 38, he
noted the onset of impotence. This was evaluated by an internist, a neurologist
and a urologist. No cause for the erectile dysfunction could be found
other than his inherited neuropathy. Fasting blood sugar and glucose tolerance
tests were normal. Prostate evaluation was unremarkable. At age 41, detailed
electrophysiologic studies revealed a prolonged bulbocavernosus reflex
latency ranging from 64 to 94 ms (normal &lt; 42 ms). Pudendal somatosensory
evoked potential primary cortical components were well formed but significantly
delayed: P1 = 52.4 ms (normal &lt; 48 ms), and N1 62.8 ms (normal &lt;
60.4 ms). Testosterone injections provided no benefits. 0.2 cm3 of locally
injected papaverine sometimes produced an erection. The patient noted
that his impotence significantly impaired his self-confidence and self-esteem.