Albers J W, Zimnowodzki S, Lowrey C M, Miller B
Arch Neurol. 1983 Jun;40(6):351-3. doi: 10.1001/archneur.1983.04050060051008.
Differentiation of juvenile progressive bulbar palsy from bulbar myasthenia gravis is difficult. Characteristics of both may include ocular involvement, fluctuant course, abnormal fatigability, and normal acetylcholine receptor (AChR) antibody titers. Electrodiagnostic evaluation may demonstrate moment-to-moment variability in motor unit action potential amplitude, fibrillation potentials, and decremental motor evoked responses. Increased jitter with blocking may be the most prominent electrodiagnostic abnormality in either disorder, even in asymptomatic extremity muscles. Complete paralysis of facial muscles with electrical silence on needle electromyography, low-amplitude facial evoked responses without a decrement to repetitive stimulation, increased jitter and fiber density in asymptomatic extremity muscles, and normal AChR antibody levels suggested juvenile progressive bulbar palsy in two patients initially thought to have bulbar myasthenia. Early differentiation of these disorders is important because of therapeutic, genetic, and prognostic implications.
青少年进行性延髓麻痹与延髓型重症肌无力的鉴别诊断较为困难。两者的特征可能都包括眼部受累、病情波动、异常疲劳以及乙酰胆碱受体（AChR）抗体滴度正常。电诊断评估可能显示运动单位动作电位幅度、纤颤电位和递减性运动诱发电位存在逐时变化。即使在无症状的肢体肌肉中，增加的颤抖伴阻滞可能是这两种疾病中最突出的电诊断异常。两名最初被认为患有延髓型重症肌无力的患者，其面部肌肉完全麻痹，针极肌电图显示电静息，低幅度面部诱发电位对重复刺激无递减，无症状肢体肌肉的颤抖和纤维密度增加，且AChR抗体水平正常，提示为青少年进行性延髓麻痹。由于治疗、遗传和预后方面的影响，尽早鉴别这些疾病很重要。
