McKeon Andrew, Pittock Sean J, Glass Graham A, Josephs Keith A, Bower James H, Lennon Vanda A, Ahlskog J Eric
Department of Neurology, Gonda 8 South, Mayo Clinic, 200 First St SW, Rochester, MN 55902, USA.
Arch Neurol. 2007 Sep;64(9):1318-22. doi: 10.1001/archneur.64.9.1318.
Acquired generalized repetitive myoclonus may be mistaken for tremor. Distinguishing myoclonus has etiologic and therapeutic implications.
To describe isolated generalized polymyoclonus and the outcomes of etiologic evaluations at the time of diagnosis.
Computer search of the Mayo Movement Neurophysiology Laboratory database and medical records linkage system.
Department of Neurology, Mayo Clinic.
Nineteen adults with generalized repetitive myoclonus confirmed using surface electromyography (burst duration <50 milliseconds), and other neurologic features minimal or absent.
Treatment of myoclonus and underlying causes.
Clinical presentation and underlying etiologies.
We identified 19 patients with isolated generalized polymyoclonus resembling whole-body tremor. Onset was most often subacute (12 patients), mean symptom duration was 1.8 years, and mean age at onset was 55 years. Referral diagnoses or patient complaints were tremor, tremulousness, or shaking in all but 5 patients. All the patients had repetitive myoclonus of all limbs, impairing gait in 14 patients. Surface electromyography confirmed nonperiodic muscle burst durations of less than 50 milliseconds, typical of myoclonus. Clinical and serologic screening for cancer and autoimmunity revealed metastatic breast cancer in 2 patients (1 positive for ganglionic acetylcholine receptor antibody) and antibody profiles implicating neurologic autoimmunity in 3 patients (CRMP-5 IgG or neuronal voltage-gated potassium channel antibodies). Medications known to occasionally trigger myoclonus (opioids, selective serotonin reuptake inhibitors, and a serotonin-norepinephrine reuptake inhibitor) were being taken by 7 patients. Myoclonus resolved after discontinuation of selective serotonin reuptake inhibitor therapy in 1 patient; drug discontinuation was declined and follow-up was inadequate in the other 6.
Isolated whole-body tremulousness should raise the suspicion of generalized polymyoclonus, confirmed using routine surface electromyography. Recognition is important because the differential diagnosis includes autoimmunity and drug-induced myoclonus.
获得性全身性反复肌阵挛可能被误诊为震颤。鉴别肌阵挛具有病因学和治疗学意义。
描述孤立性全身性多肌阵挛及其诊断时病因评估的结果。
对梅奥运动神经生理学实验室数据库和病历链接系统进行计算机检索。
梅奥诊所神经内科。
19名成年人，经表面肌电图证实存在全身性反复肌阵挛（爆发持续时间<50毫秒），且其他神经学特征轻微或无。
治疗肌阵挛及其潜在病因。
临床表现和潜在病因。
我们确定了19例孤立性全身性多肌阵挛患者，其表现类似全身震颤。发病最常见为亚急性（12例患者），平均症状持续时间为1.8年，平均发病年龄为55岁。除5例患者外，所有患者的转诊诊断或患者主诉均为震颤、震颤样动作或抖动。所有患者四肢均有反复肌阵挛，14例患者步态受损。表面肌电图证实肌肉爆发持续时间非周期性且小于50毫秒，这是肌阵挛的典型表现。针对癌症和自身免疫的临床及血清学筛查发现，2例患者患有转移性乳腺癌（1例神经节乙酰胆碱受体抗体阳性），3例患者的抗体谱提示存在神经自身免疫（CRMP-5 IgG或神经元电压门控钾通道抗体）。7例患者正在服用已知偶尔会引发肌阵挛的药物（阿片类药物、选择性5-羟色胺再摄取抑制剂和5-羟色胺-去甲肾上腺素再摄取抑制剂）。1例患者停用选择性5-羟色胺再摄取抑制剂治疗后肌阵挛缓解；其他6例患者拒绝停药且随访不足。
孤立性全身震颤样动作应引起对全身性多肌阵挛的怀疑，可通过常规表面肌电图确诊。认识到这一点很重要，因为鉴别诊断包括自身免疫和药物性肌阵挛。
