Neuromuscular transmission abnormalities in myotonic dystrophy type 1: A neurophysiological study.
OBJECTIVE
Weakness and fatigue are frequent symptoms in myotonic dystrophy type 1 (DM1), mainly as a result of muscle impairment. However, neuromuscular junction (NMJ) abnormalities could play an additional role in determining these manifestations. We aimed to document the possible NMJ involvement in DM1.


METHODS
In order to substantiate this hypothesis we performed low rate repetitive nerve stimulation (RNS) and single fiber electromyography (SFEMG), in 14 DM1 subjects.


RESULTS
RNS resulted abnormal in four patients while SFEMG revealed a pathological jitter in ten. A significative correlation was found between jitter values and decrementing response (p<0.000311; r=0.822).


CONCLUSIONS
These results suggest a possible involvement of NMJ in DM1.
Neuromuscular and Neurological Rare Diseases Centre, Neurology and Neurophysiology Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy.
Francesco
F
Bombelli
Neuromuscular and Neurological Rare Diseases Centre, Neurology and Neurophysiology Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy.
Ludovico
L
Lispi
Medical Genetics Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy.
Sandro Costanzi
SC
Porrini
Neuromuscular and Neurological Rare Diseases Centre, Neurology and Neurophysiology Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy.
Manlio
M
Giacanelli
Neuromuscular Centre, Neuroscience, Department of Systems Medicine, University of Rome Tor Vergata, V.le Oxford, 81-00133, Rome, Italy.
Chiara
C
Terracciano
Neuromuscular Centre, Neuroscience, Department of Systems Medicine, University of Rome Tor Vergata, V.le Oxford, 81-00133, Rome, Italy.
Roberto
R
Massa
Neuromuscular and Neurological Rare Diseases Centre, Neurology and Neurophysiology Unit, S. Camillo Forlanini Hospital, C. Gianicolense, 87-00152, Rome, Italy. Electronic address: anpetrucci@scamilloforlanini.rm.it.
Antonio
A
Petrucci
D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D004576:Electromyography; D005221:Fatigue / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology*; D009223:Myotonic Dystrophy / Q000150:complications / Q000503:physiopathology*; D009469:Neuromuscular Junction / Q000503:physiopathology*
Fatigue; Myotonic dystrophy type 1; Neuromuscular transmission abnormalities; Repetitive nerve stimulation; Single fiber electromyography; Weakness