Clinical，pathological and skeletal muscle magnetic resonance characteristics of tonic muscular dystrophy type1 / 中风与神经疾病杂志

@#To summarize characteristics of the clinical manifestation，pathology and lower limb muscle magnetic resonance imaging in 11 patients diagnosed as myotonic dystrophy 1.Methods Eleven patients with myotonic myopathy 1，who were admitted to Nanjing Drum Tower Hopsital from January 2012 to October 2020，were chosen in our study. All patients accepted clinical examination，skeletal muscle biopsy，and 5 of them received lower limb muscle magnetic resonance imaging （MRI）. Clinical data were collected for retrospective analysis.Results All 11 patients were observed muscle myotonia，weakness or amyotrophy to some extent and the latter two symptoms were more serious in distal limb than in proximal. Under the light microscopy，type I filber atrophy in ten cases，nucleus moving inward，nucleus gathering and sarcoplasmic masses in some cases were found.That fatty infiltration appears asymmetrical distribution and more serious in distal limb compared with the proximal limb in five cases was observed by MRI. Among lower limbs，vastus medialis，vastus lateralis，vastus intermedius，tibialis anterior，gastrocnemius，soleus muscles were the most severely affected.Conclusion Muscle magnetic resonance imaging examination is a trustworthy method for definite diagnosis of myotonic myopathies.

A Patient with Myotonic Dystrophy Type 1 Presenting as Parkinsonism

The current body of literature contains 5 reports of myotonic dystrophy (DM) with parkinsonism: 4 reports of DM type 2 and 1 report of clinically suspected DM type 1. To date, there have been no genetically proven cases of DM type 1 with parkinsonism. Here, we report the first case of genetically proven DM type 1 and parkinsonism that developed ahead of muscle symptoms with bilateral putaminal, presynaptic dopaminergic deficits on imaging. A 54-year-old female patient presented with bradykinesia, axial and bilateral limb rigidity, stooped posture, and hypomimia, which did not respond to levodopa. At age 56, she developed neck flexion weakness. Examination showed bilateral facial weakness, percussion and grip myotonia, and electromyography confirmed myotonic discharges. A genetic study of DM type 1 showed a DMPK mutation. At age 58, gait freezing, postural instability, and frequent falling developed and did not respond to increasing doses of levodopa. At age 59, the patient died from asphyxia.

Southern Analysis after Long-range PCR: Clinical Application in Korean Patients with Myotonic Dystrophy 1

PURPOSE: Myotonic dystrophy 1 (DM1, OMIM 160900) is an autosomal-dominant muscular disorder caused by an expansion of CTG repeats in the 3' UTR of the DMPK gene. Variable expansions of CTG repeats preclude the accurate determination of repeat size. We tried to show the clinical and analytical validity of the application of Southern blotting after long-range PCR was demonstrated in Korean DM1 patients. MATERIALS AND METHODS: The Southern blotting of long-range PCR was applied to 1,231 cases with clinical suspicion of DM1, between 2000 and 2011. PCR was performed using genomic DNA with forward 5'-CAGTTCACAACCGCTCCGAGC-3' and reverse 5'-CGTGGAGGATGGAACACGGAC-3' primers. Subsequently, the PCR fragments were subjected to gel electrophoresis, capillary transfer to a nylon membrane, hybridization with a labeled (CAG)10 probe. The correlation between clinical manifestations and the CTG repeat expansions were analyzed. RESULTS: Among a total of 1,231 tested cases, 642 individuals were diagnosed with DM1 and the range of the detected expansion was 50 to 2,500 repeats; fourteen cases with mild DM1 (75+/-14 repeats), 602 cases with classical DM1 (314+/-143 repeats), and 26 cases with congenital DM1 (1,219+/-402 repeats). The positive and negative predictive values were 100%. The age at test requested and the CTG repeat numbers were inversely correlated (R=-0.444, P<0.01). CONCLUSION: This study indicates that Southern blotting after long-range PCR is a reliable diagnostic method DM1.