title: Analysis of stapedial reflex in neuromuscular diseases.
abstract: An impedance audiometric analysis of the stapedial reflex was carried out in 17 patients with motor neuron disease (MND), 11 with myasthenia gravis (MG), and 3 myotonic dystrophy (MD). The features examined were the threshold and latency parameters and the response pattern of the reflex. All groups had mean reflex thresholds within normal limits (80-90 dB hearing level). The MND group showed a lengthened mean reflex latency (L1). The MG group showed an unstable response pattern to 10-second tone stimuli and a lengthened L1. Half the group demonstrated abnormal decay of the reflex. The MD group showed a reduction in the growth of averaged reflex in response to stimuli with short interstimulus intervals (2.6 s) and the L1 and C50 were lengthened.
mesh_terms: D000158:Acoustic Impedance Tests; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons; D009157:Myasthenia Gravis / Q000175:diagnosis; D009223:Myotonic Dystrophy / Q000175:diagnosis; D009468:Neuromuscular Diseases / Q000175:diagnosis*; D012022:Reflex, Acoustic