背景:脊髓和延髓性肌萎缩症(SBMA)是一种X连锁的隐性遗传性神经肌肉疾病,由雄激素受体基因中三核苷酸重复序列扩大引起。SBMA的主要临床表现包括球和四肢肌肉无力,束感,震颤,抽筋,感觉障碍,和男性乳房发育症。然而,非典型SBMA病例可能导致误诊。肌肉疲劳和对重复神经刺激(RNS)的递减反应,尽管在一些SBMA患者中观察到,通常发生在MG患者中,很少报道有咀嚼疲劳症状的患者。此外,已经对SBMA患者进行了心脏检查,发现了一些ECG改变.在这里,我们报告了一名SBMA患者,表现为咀嚼疲劳的罕见发作症状,在血清中检测到肌动蛋白抗体阳性,并显示WPW模式心电图。
方法:患者在3年的咀嚼肌肉中表现出轻度进行性疲劳。神经系统检查显示面部肌肉无力和舌头萎缩,但是弱点,浪费,或四肢肌束震颤不明显。3HzRNS在双侧眼轮匝肌中显示出下降的反应。血清肌动蛋白抗体检测呈阳性,心电图显示为WPW型心电图。遗传分析显示AR基因中串联CAG重复的数量(39个重复)增加,这证实了SBMA的诊断。口服溴吡啶斯的明治疗后,疲劳症状明显改善。
结论:这个病例需要更多关注肌肉疲劳作为肯尼迪病的发病症状。心电图筛查在SBMA患者中很重要,需要进一步的研究来研究SBMA患者以及其他神经源性疾病中的肌动蛋白抗体。
BACKGROUND: Spinal and bulbar muscular atrophy (
SBMA) is an X-linked recessive hereditary neuromuscular disorder caused by the expanded trinucleotide repeat in the androgen receptors gene. The major clinical manifestations of
SBMA consist of weakness in the bulbar and limb muscles, fasciculations, tremors, cramps, sensory impairment, and gynecomastia. However, atypical
SBMA cases may lead to misdiagnosis. Muscular fatigue and decremental responses to repetitive nerve stimulation (RNS), despite being observed in some SBMA patients, are usually occurred in MG patients, and patient with the symptom of mastication fatigue was rarely reported. In addition, cardiological investigations have been performed in SBMA patients and several ECG alterations were identified. Here we report an
SBMA patient presenting with a rare onset symptom of mastication fatigue, who has been detected with a positive titin antibody in the serum and showed a WPW pattern electrocardiogram.
METHODS: The patient showed mildly progressive fatigue in the muscles of mastication over 3 years. Neurological examination showed facial muscle weakness and a wasting tongue with fasciculations, but the weakness, wasting, or fasciculations were not obvious in the limbs. 3-Hz RNS showed a decremental response in bilateral orbicularis oculi. The test of titin antibody was positive in the serum, and the electrocardiogram showed a WPW pattern ECG. Genetic analysis revealed an increased number (39 repeats) of tandem CAG repeats in the AR gene, which confirmed the diagnosis of SBMA. The fatigue symptom was significantly improved after oral pyridostigmine bromide treatment.
CONCLUSIONS: This case calls for more attention to muscular fatigue as the onset symptoms of Kennedy\'s disease. ECG screening is of importance in SBMA patients and further studies are needed to investigate the titin antibody in
SBMA patients as well as other neurogenic disorders.