進行性筋ジストロフィーおよび運動ニューロン疾患の横隔膜誘発電位の検討

Abstract

The diaphragmatic evoked potentials (DEP) by phrenic nerve stimulation were recorded in 77 cases of neuromuscular diseases : 55 patients with Duchenne muscular dystrophy (DMD), 8 with Becker muscular dystrophy (BMD), 9 with myotonic dystrophy (MyD), 2 with facioscapulohumeral (FSH) muscular dystrophy, 2 with limb-girdle (LG) muscular dystrophy, 2 with Fukuyama type congenital muscular dystrophy (FCMD), 5 with chronic Werdnig-Hoffmann (CWH) disease and 19 with amyotrophic lateral sclerosis (ALS). At the same time, spirogram, arterial blood gas analysis, serum CK and clinical severity of limbs' disability were checked in these patients. Amplitude and latency of DEP were analyzed in comparison with these parameters. Sixty-three normal persons were used as controls. In control subjects, mean amplitudes were 813±210 μV (right) and 872±208 μV (left). Mean latencies were 6.83±0.36 msec (right) and 6.73±0.41 msec (left). Mean latecies were 6.83±0.36 msec (right) and 6.73±0.41 msec (left). A high correlation was recognized between latency and height. Amplitudes were smaller than mean-2SD of controls in 30 cases of DMD, 3 cases of BMD, 4 cases of MyD, 1 case of LG and 10 cases of ALS, but larger than mean+2SD in 3 cases of CWH. Latencies adjusted for influence of height were longer than mean+2SD of controls in 4 cases of DMD, 4 cases of BMD, 5 cases of MyD, 1 case of LG, 1 case of FCMD and 15 cases of ALS. Significant correlation of amplitude of DEP was observed to %VC, Pa＿＜o_2＞, Pa＿＜co_2＞, clinical severity and creatine kinase (CK) in DMD, %VC and Pa＿＜co_2＞ in BMD, clinical severity in MyD and CWH, %VC and Pa＿＜o_2＞ in ALS. Latency of DEP had a high correlation to %VC, Pa＿＜co＿2＞, clinical severity and CK in DMD, Pa＿＜o＿2＞, and CK in MyD, Pa＿＜co＿2＞, and clinical severity in CWH and Pa＿＜co＿2＞, in ALS. Amplitude and latency of DEP would be considered to denote diaphragmatic function and could be utilized as valuable indeces for evaluation of chronic ventilatory impairment in neuromuscular diseases.