Nerve conduction studies, skeletal muscle EMG, and sphincter EMG in multiple system atrophy.

Abstract

Although autonomic failure, parkinsonism, and cerebellar and pyramidal signs are well documented in multiple system atrophy, much less is known about the frequency and severity of involvement of the peripheral nervous system. The frequency and nature of peripheral nerve involvement has therefore been determined in 74 patients with multiple system atrophy using nerve conduction studies and skeletal muscle EMG. These findings were compared with those on sphincter EMG. Ninety per cent of the patients had an abnormal sphincter EMG, indicating denervation and reinnervation consistent with anterior horn cell loss in Onuf's nucleus, but only 40% PATIENTSSeventy four patients with clinically probable multiple system atrophy (pathologically established in 11) underwent peripheral electrophysiological studies (n = 40) or sphincter EMG (n = 71), or both. All patients undergoing peripheral electrophysiological studies had both nerve conduction studies and skeletal muscle EMG. In 35 patients both peripheral electrophysiological studies and sphincter EMG were performed. Fifty one of the patients were men (68%) and 23 were women (32%). Their mean age at the time of sphincter electromyography was 52-8 (range 33-67) years, and at the time of peripheral electrophysiological studies (nerve conduction studies and skeletal muscle EMG) it was 55-1 (41-67) years.Patients were diagnosed according to published clinical criteria.'0 There were 56 (76%) patients with multiple system atrophy of striatonigral degeneration (SND) type, either with (24) or without (32) cerebellar signs. Eighteen (24%) patients were classified as having multiple system atrophy of olivopontocerebellar atrophy (OPCA) type, either without ("pure" OPCA type, eight) or with ("predominant" OPCA type, 10) extrapyramidal features.The mean age at onset of the first symptoms was 50 3 (range 33-71) years.Symptoms at onset were autonomic dysfunction in 28 (38%), parkinsonism in 25 (34%), cerebellar dysfunction in seven (9%), and mixed in the remaining 18% of these patients. The most common initial diagnosis was Parkinson's disease, then cerebellar syndrome, and then multiple system atrophy. At

Nerve Conduction Studies in Multiple System Atrophy

“…This result is in good agreement with findings of earlier investigators [6, 7]. According to electrophysiological criteria, peripheral neuropathy in MSA is most frequently of a motor axonal type with features of mild axonal loss.…”

Peripheral nerve involvement and severity of motor disorder in Parkinson\'s disease: a correlational study

“…Surprisingly, the proportion was higher than that in the study by Pramstaller et al focused on MSA patients. 14 This probably means that, similar to the authors of previous studies who considered the underlying pathological process in MSA to be the cause of polyneuropathy as well, neurodegenerative processes (in a broad sense) may be considered the cause of polyneuropathy in our group of Parkinson's patients. The mechanism of peripheral neurodegeneration has not been explicitly described as yet which is understandable given the fact that neurodegeneration of the CNS is also far from being completely explained.…”

Erectile and urinary dysfunction may be the presenting features in patients with multiple system atrophy: a retrospective study

“…Although reports from these laboratories have shown electromyographic changes of chronic reinnervation in the motor units of the striated muscle of the sphincter in 75-100% of MSA patients compared to only 0-17% of IPD patients, [14][15][16][17][18] other studies have disputed this finding, and the test is not universally accepted. 19 However, SpEMG has been found to be clinically useful in identifying abnormalities found in patients subsequently diagnosed as having MSA, differentiating them from patients with IPD and coincidental urogenital symptoms.…”