Involvement of peripheral sensory fibers in amyotrophic lateral sclerosis: Electro‐physiological study of 64 cases

Abstract

We report electrophysiological findings of conduction along peripheral sensory fibers in 64 patients with amyotrophic lateral sclerosis. Distribution of the values of action potential amplitudes and conduction velocities of peripheral afferent fibers were significantly lower than in normal age-matched controls. Sensory action potential amplitudes (SAPas) were more affected than sensory conduction velocities (SCVs). When single patients were considered, SAPas were slightly but significantly reduced in 22% of the cases (median nerve 17%, ulnar nerve 11%, and sural nerve 22%). A parallel decrease in SCVs and MCVs in 14 patients in whom the study was repeated over a period of time was also found. All these electrophysiological findings are due to progressive neuronopathy of peripheral sensory fibers. A pathogenetic mechanism is proposed.

Nerve conduction studies in amyotrophic lateral sclerosis

“…2 Thus, the pathophysiological basis for these changes can be independent. Sensory potentials showed no abnormality, even in very weak muscles, 21,37 reflecting the general concept that sensory potentials are normal in ALS.…”

“…31,32 Certain motor conduction abnormalities, nevertheless, are well recognized in ALS. The distal motor latency may be increased, 3,36 a feature that has been correlated with the degree of atrophy, 17,23,37,49 but which may also occur in muscles that are only mildly affected. 36 Increased distal motor latencies have been related to slowly conducting, thin, distal, regenerated motor axons, and perhaps also to a defect in neuromuscular transmission.…”

“…16 However, mild abnormalities have been detected either using near-nerve needle electrodes 48 or in the later phases of the disease. 21, 37 Mills and Nithi attempted to correlate the clinical and neurophysiological findings in ALS 36 but utilized relatively few variables. The objectives of our study were to study motor and sensory conduction parameters of the ulnar nerve in patients with ALS and to evaluate the results in relation both to target muscle strength as assessed by the MRC scale and to clinical signs of upper motor neuron lesion in the studied limb.…”

Multisystem neuronal involvement and sicca complex: broadening the spectrum of complications

“…27 Sensory involvement can be demonstrated in advanced ALS but is never a prominent feature of the condition as it was in our patient. 2,9,18,20 Motor involvement as an important feature of sicca complex has rarely been reported. Yamashita and colleagues 30 described a man with progressive bulbar atrophy and Sjögren's syndrome.…”

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].…”