The Analysis Of Clinical And Muscle Pathological Characteristics Of Myotonic Dystrophy

Background:Myotonic dystrophy is an autosomal dominant genetic disease. It’s the second largedisease in muscular dystrophy incidence. The global incidence is approximately1/20000,has obvious geographical and ethnic differences. MD can involve multiple-system symptoms,with myotonia, muscle atrophy, insulin resistance, cardiac conduction disorders, cataract asthe main clinical manifestations, but also with the performance of a cognitive impairmentand mental retardation and other symptoms. The disease is caused by the abnormalamplification of the pathogenic genes’s specific nucleotide sequence. Two genes wererespectively identified and were named DM1and DM2in1992and1998:on chromosome19: q13.2-13.3DMPK gene and chromosome21:3q ZNF9. The two genes’ abnormalamplification caused the symptoms. At present the diagnosis is according to the clinicalfeatures, laboratory examinations, electrophysiological examination, muscle biopsy and genequantitative.Objectives:In order to facilitate early diagnosis, disease classification and treatment, Analysis thecharacteristics of myotonic dystrophy patients, include the most common initial symptomssigns, clinical features, its muscle enzymes and electrophysiological examination, thedisease of other systemic involvement, and the muscle biopsy pathologic features.Materials and Methods:In this study, data from September2006to September2011, Department of Neurology,First Hospital of Jilin University, in and out-patients, a total of22cases. Collected theclinical data, including: gender, age, medical history, symptoms, serum enzymology check,nerve electrophysiological examination and ECG. All the patients were performed musclebiopsy. We analyze the the patients’ clinical and muscle pathological features, and analyzemorphometric characteristics of the muscle biopsy pathology, and taking comparison withnormal muscle pathology.Results:1.Both men and women can have Myotonic dystrophy, but the prevalence of male washigher than female, male: female equal to3.4:1. The disease can be occur on ever age, the mean age of onset was31.1years old, concentrated between10to40years old group. Thedisease progresses slowly, and have varying severity. Making a fist with both hands can notimmediately release (54.55%) is the mainly first symptom, followed by the limbs startingdifficulty (9.09%) and weakness (9.09%).2.Making a fist with both hands can not immediately release(54.55%) and" muscle theball" syndrome(54.55%) are the most common symptoms. And the limb muscle strengthdecline (40.91%) and muscle atrophy (36.36%) can be seen.Only2cases of patients withvisible characteristic " axes". Muscle atrophy in sternocleidomastoid muscle is the mostcommon (22.72%) in the atrophy of muscles. Non-specific muscle tonus and tendon reflexeschanges can be seen also.3. In the22patients group,6cases other system diseases. The most is cardiovascularsystem disease, including atrial septal defect (3cases), atrioventricular block (3cases) andright bundle branch block (1cases).4.10cases (45.5%)of this group have a family history.5. The patients’ muscle enzymes is elevated or normal. The analysis the relationshipbetween muscle enzymes and course, we find there is no correlation between then. In22cases patients’ electromyography have myotonia potential distribution.6. The results of the22patients with DM muscular pathology histochemical staining:on HE staining tablets we can see atrophy, normal and hypertrophic muscle fiber. Atrophicmuscle fibers were round or angular. The fibers with normal mosaic distribution. There aresarcoplasmic block, annular fibers, opaque fibers and muscle fiber fiber tearing, necrosis andregeneration of muscle fibers, part of muscle membrane have nuclear number increasing.There are nuclear transfer, nuclear clusterin. Muscle membrane nuclear number can increasemild. In GT staining there are a few RRF.In NADH-TR and COX staining, type I and IImuscle fiber distribution in normal. We can see type I muscle fiber atrophy, and type IImuscle fiber is dominant. Some necrosis muscle fibers have lobulated or worm-eaten shape.Acid histochemical staining some muscle fibers’ enzyme activity increased. PAS and OROstaining showed no obvious abnormality. There is no vascular inflammation cell infiltration.Immunohistochemical staining: Anti Dystrophin-N, C, R, Dysferlin, Sarcoglycan alpha,Larmin A/C and MHC-I monoclonal antibody staining were no abnormal change.7. Morphometric analysis: the group of22patients and a control group of9cases ofmuscle tissue pathology in CCO staining of type I and type II fibres were compareddistinctively,as well as type I and type II fibers were compared with a control group of type I and type II distinctively. We compared the area, perimeter, equivalent circle diameter,maximum diameter and minimum diameter. The results showed: the DM patients of type Iand type II fibers are differences (P <0.05), in which the minimum diameter of thedifference between type I and type II fibers (P <0.01) in DM patients; between type I fibersand a control group of type I fibers, the maximum diameter and minimum diameter have asignificantly different (P <0.01); The area， perimeter, diameter of equivalent round of DMpatients’ II fiber with a control group, there are significant differences between the maximumdiameter (P <0.01).Conclusion:1.DM is an autosomal dominant disease, and has a higher heritability. The prevalence ofmale is higher than female. Making a fist with both hands can not immediately release and"muscle the ball" syndrome are the most common symptoms. Can be associated with muscleatrophy, with sternocleidomastoid muscle atrophy are the most common. DM can becomplicated with multiple system changes, to the circulatory system and endocrine systemare the most common.2.Electromyography is the auxiliary examination for DM patients, but muscle enzymeshas no specificity for diagnosis of DM.3.Muscle histochemistry staining showed myogenic lesion.Morphometric analysis ofmuscle prompt the type Ⅰ muscle fiber has the most presence of atrophy, and type II musclefiber performances hypertrophy most.DM patients have the previous nuclear shift fiber thanLGMD patients.