脂质沉积性肌病诊断及误诊分析

目的分析脂质沉积性肌病（LSM）的临床及病理特点，探讨脂质沉积性肌病被误诊的原因。方法分析8例确诊为脂质沉积性肌病患者的临床特点、实验室检查、神经电生理及病理学资料。结果LSM的临床特点是四肢近端肌无力和运动不耐受；肌酶谱轻中度甚至重度升高；肌电图表现肌源性损害、神经源性损害或混合性损害；肌肉病理学检查显示肌纤维中大小不等的空泡形成；7例0R0染色显示Ⅰ型肌纤维中大量脂质颗粒沉积，1例显示脂肪成分正常者电镜检查可见肌纤维内大量脂滴沉积，呈串珠状排列。2例进行神经活检，1例正常，1例光镜下部分髓鞘变薄，崩解脱失。电镜下髓鞘板层分离，雪旺氏细胞内出现脂滴沉积。确诊的LSM曾被误诊为多发性肌炎、肢带型肌营养不良、脊肌萎缩症、胶原血管病、慢性吉兰-巴雷综合征、病毒性心肌炎。结论LSM很易被误诊为其他肌病或神经源性肌病，肌肉活检及组化OR0染色可能染色不成功造成阴性结果，电镜检查是诊断LSM的主要依据。

Diagnosis and misdiagnosis analysis of Lipid Storage Myopathy

Objective Analyze the clinical and pathological feature of lipid storage myopathy（LSM）. Try to find out the reason of diagnosis error in this disease. Methods Analyze the clinical feature, lab exam, neuroelectricity and pathology of 8 patients with LSM. Results The clinical character of LSM is myasthenia with proxima of extremities as well as intolerance of exercises. From the auxiliary examination we can see creatase increase slightly and even severely. Electromyogram shows myogenic damage , neurogenic damage or mixed type of damage. The muscle pathology indicates different size of cavity in the muscle fibers. The ORO dyeing of 7 patients shows amounts of lipid granule deposit in muscle fiber type Ⅰ, Other patient with normal lipid ingredient displays lots of lipid droplet sediment in muscle by electron microscope, the shape of lipid droplet is like bead. After nerve biopsy of two patients, one is good. The other can see the attenuation and disintegration of myelin sheath partially by light microscope. With electron microscope we can see the segregation of myehn sheath , lipid droplet sediment in Schwann cell. I he LNM IS always be dlagosis as polymyositiss, limbgirdle type muscular dystrophy, spinal muscular atrophy, collagen vascular disease, chronic Guillain-Barre syndrome, viral myocarditis. Conclusions LSM is easily be diagnosis as other disease such as myopathy or neurogenic myopathy. Muscle biopsy, unsuccessful ORO dyeing will lead to negative results. Elctron microscope is the main method to diagnosis LSM.