TY - JOUR
T1 - Function and ultrastructure of the neuromuscular junction in post-polio syndrome
AU - Maselli, Ricardo A
AU - Wollmann, R.
AU - Roos, R.
PY - 1995
Y1 - 1995
N2 - We performed a detailed morphological and electrophysiological analysis of the neuromuscular junction in muscle biopsies from 10 patients with post-polio syndrome (PPS). This was done to clarify the basis for the apparent neuromuscular transmission impairment in PPS. In six patients, intracellular microelectrode recordings demonstrated either reduction of amplitudes of miniature end-plate potentials (MEPPs) or decreased quantal content or both. In one patient, reduction of quantal content was only present with prolonged or high-frequency nerve stimulation. In three patients no significant abnormalities were found by the intracellular microelectrode studies. Histologically, atrophy of individual muscle fibers were present in 6 out of the 10 biopsies, but grouped atrophy was not seen. Fiber type grouping suggesting reinnervation was seen in 8 out of the 10 muscle biopsies. Fragmentation and dispersion of the end plate was present in three patients. In two of these patients dispersion of the end plate was associated with an apparent increase of the quantal content. Electron microscopy revealed either normal neuromuscular junctions or small axon termini apposed to normal postsynaptic folds. In summary, variable degrees and different types of failure of neuromuscular transmission were seen in association with histological signs of reinnervation in the muscle biopsies of affected patients. Functional and structural abnormalities of the neuromuscular junction, although very common, were not invariably present and, therefore, they do not appear to be a necessary condition to define the post-poliomyelitic syndrome.
AB - We performed a detailed morphological and electrophysiological analysis of the neuromuscular junction in muscle biopsies from 10 patients with post-polio syndrome (PPS). This was done to clarify the basis for the apparent neuromuscular transmission impairment in PPS. In six patients, intracellular microelectrode recordings demonstrated either reduction of amplitudes of miniature end-plate potentials (MEPPs) or decreased quantal content or both. In one patient, reduction of quantal content was only present with prolonged or high-frequency nerve stimulation. In three patients no significant abnormalities were found by the intracellular microelectrode studies. Histologically, atrophy of individual muscle fibers were present in 6 out of the 10 biopsies, but grouped atrophy was not seen. Fiber type grouping suggesting reinnervation was seen in 8 out of the 10 muscle biopsies. Fragmentation and dispersion of the end plate was present in three patients. In two of these patients dispersion of the end plate was associated with an apparent increase of the quantal content. Electron microscopy revealed either normal neuromuscular junctions or small axon termini apposed to normal postsynaptic folds. In summary, variable degrees and different types of failure of neuromuscular transmission were seen in association with histological signs of reinnervation in the muscle biopsies of affected patients. Functional and structural abnormalities of the neuromuscular junction, although very common, were not invariably present and, therefore, they do not appear to be a necessary condition to define the post-poliomyelitic syndrome.
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U2 - 10.1111/j.1749-6632.1995.tb27539.x
DO - 10.1111/j.1749-6632.1995.tb27539.x
M3 - Article
C2 - 7611622
AN - SCOPUS:0029051042
VL - 753
SP - 129
EP - 137
JO - Annals of the New York Academy of Sciences
JF - Annals of the New York Academy of Sciences
SN - 0077-8923
ER -