Electrophysiological evidence of ?nerve entrapment syndromes? and subclinical peripheral neuropathy in progressive systemic sclerosis (scleroderma)

Abstract

We report the electrophysiological findings and the management of 5 subjects with progressive systemic sclerosis (PSS) and clinical evidence of nerve entrapment. Three had carpal tunnel syndrome (CTS), 1 bilateral CTS and right tarsal tunnel syndrome (TTS) and 1 Guyon's canal syndrome. Only 1 patient (with CTS) showed significant clinical improvement after surgical decompression; the other 4 demonstrated a slight recovery of conduction without lasting clinical relief after conventional treatment. To explain these failures we hypothesized that these entrapment syndromes were the clinical expression of underlying diffuse damage to the peripheral nervous system (PNS). The conduction values of nerves unaffected by entrapment syndromes were within normal limits, but almost all distal velocities were below the mean of controls. Such subclinical distal peripheral neuropathy was also verified in a selected sample of 17 patients with PSS, without clinical symptoms or signs of PNS involvement. In these 17 cases the mean distal sensory and motor conduction findings of the median, ulnar, sural and tibial nerves were significantly lower than those of a control group, while no significant differences were found in the more proximal tracts of the same nerves. Furthermore, 3 of the 17 patients showed classical electrophysiological evidence of TCS and TTS without any clinical symptoms. We conclude that the subjects with PSS had subclinical polyneuropathy which may become plain polyneuropathy or nerve entrapment syndromes perhaps induced by other risk factors.

Nerve conduction velocity study of the upper limb in Raynaud's phenomenon

“…This diuse damage is presumably related to distal peripheral neuropathy which may be subclinical, due to microangiopathy also aecting the vasa nervorum [1,10,12,14,15]. Similar subclinical neuropathy has also been encountered by us in nerves of the lower limbs [15], but no alterations in distal conduction have been demonstrated in subjects with only localized sclerosis (morphea) [16]. Peripheral nervous system involvement could play a role in the pathogenesis of RP in SS patients by altering vasomotor tonus [5].…”

“…Of the subjects, 13 had limited, and 5 diuse scleroderma. The clinical details and electrophysiological study of 14 of these 18 cases have already been published [15].…”

Peripheral neuropathy in CADASIL

“…Details of methods have been published elsewhere [6]. Skin temperature was kept between 32°C and 35°C.…”

Requests for electromyography from general practitioners and specialists: critical evaluation

“…In mononeuropathy, conduction study of the nerve and/or EMG of the respective muscles were performed and compared with lateral or contralateral muscles or nerves [ 17]. Analyses performed in cases of motomeuronal syndromes have been reported elsewhere [23].…”

“…Motor conduction velocity from elbow to wrist, distal motor latency (DML) and compound muscle action potential amplitude (CMAPa) were also measured in the ulnar and median nerves. The exams were performed as described by Cioni et al [15] and as reported in detail elsewhere [16,17].…”