[A case of X-linked bulbar and spinal muscular atrophy with impaired neuromuscular transmission].
A 43-year-old man suffered from weakness of the upper limbs and easy fatigability. Low frequency (3 Hz) repetitive nerve stimulation (RNS) showed a marked waning with a maximum decrement of 20% of M wave amplitude. This remarkable waning was partially reduced by an administration of 60 mg bromopyridostigmine. High frequency RNS (30 Hz), however, did not induced waxing. Tensilon test and anti-AchR antibody were negative. The CAG repeat in androgen receptor gene was abnormally expanded ((CAG)n = 47), which confirmed a diagnosis of X-linked bulbar and spinal muscular atrophy. (BSMA). In some ALS patients, impaired neuromuscular transmission has been reported. The impaired neuromuscular transmission in ALS occurs in cases with rapidly progressive muscle wasting, suggesting that this abnormality is related to rapidly degenerating motor nerve endings. However, impaired neuromuscular transmission as seen in this patient has not been well documented in BSMA.
Kawakami
O
O
Department of Neurology, School of Medicine, Nagoya University.
Takano
A
A
Tanaka
A
A
Koike
Y
Y
Sobue
G
G
D000328:Adult; D006801:Humans; D008297:Male; D008526:Medulla Oblongata; D009134:Muscular Atrophy, Spinal / Q000235:genetics* / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000503:physiopathology*; D012730:Sex Chromosomes; D009435:Synaptic Transmission / Q000502:physiology