Myotonia dystrophica(Synonym: Myotonia atrophica, Dystrophia myotonia, Steinert's disease) is a autosomal dominant hereditary multisystemic disorder involving several organs besides skeletal muscle, and commonly called with myotonia congenita, paramyotonia congenita as myotonia. Although most cases are of adult onset, where a mother has the disease, neonatal dystrophia myotonia can occur in her offspring. The main feature is a steadily progressive muscle dystrophy, complicated by myotonia, which is a failure of muscles to relax normally after a forceful contraction. Steinert in 1909 was the first to report the finding of atrophic testes and baldness in patients with myotonia dystrophica, and the other clinical feature of myotonia dystrophica were reported by many authors after that time. We are reporting a case of myotonia dystrophica, which showing familial history with brief review of literature.
Adult ; Alopecia ; Humans ; Mothers ; Muscle, Skeletal ; Muscles ; Myotonia Congenita ; Myotonia ; Myotonic Disorders ; Myotonic Dystrophy ; Testis

BACKGROUND AND PURPOSE: Mutations of the skeletal muscle sodium channel gene SCN4A, which is located on chromosome 17q23-25, are associated with various neuromuscular disorders that are labeled collectively as skeletal muscle sodium channelopathy. These disorders include hyperkalemic periodic paralysis (HYPP), hypokalemic periodic paralysis, paramyotonia congenita (PMC), potassium-aggravated myotonia, and congenital myasthenic syndrome. This study analyzed the clinical and mutational spectra of skeletal muscle sodium channelopathy in Korean subjects. METHODS: Six unrelated Korean patients with periodic paralysis or nondystrophic myotonia associated with SCN4A mutations were included in the study. For the mutational analysis of SCN4A, we performed a full sequence analysis of the gene using the patients' DNA. We also analyzed the patients' clinical history, physical findings, laboratory tests, and responses to treatment. RESULTS: We identified four different mutations (one of which was novel) in all of the patients examined. The novel heterozygous missense mutation, p.R225W, was found in one patient with mild nonpainful myotonia. Our patients exhibited various clinical phenotypes: pure myotonia in four, and PMC in one, and HYPP in one. The four patients with pure myotonia were initially diagnosed as having myotonia congenita (MC), but a previous analysis revealed no CLCN1 mutation. CONCLUSIONS: Clinical differentiating between sodium-channel myotonia (SCM) and MC is not easy, and it is suggested that a mutational analysis of both SCN4A and CLCN1 is essential for the differential diagnosis of SCM and MC.
Channelopathies ; Diagnosis, Differential ; DNA ; Humans ; Hypokalemic Periodic Paralysis ; Muscle, Skeletal ; Mutation, Missense ; Myasthenic Syndromes, Congenital ; Myotonia ; Myotonia Congenita ; Myotonic Disorders ; Paralyses, Familial Periodic ; Paralysis ; Paralysis, Hyperkalemic Periodic ; Sequence Analysis ; Sodium ; Sodium Channels

Congenital myotonia is a benign familial disorder, main problem is muscle stiffness, delayed relaxation of skeletal muscles after voluntary contraction or following mechanical or electrical stimulation. Although weakness is always present with progression of myotonic dystrophy, many patients with myotonia congenita never develop weakness. In the autosomal dominantly inherited form of congenital myotonia (Thomsen's disease), symptoms revolve around myotonia but weakness is not present. However, in the autosomal recessive (Becker's) type congenital myotonia, mild weakness and marked muscle hypertrophy is common. We report two cases of sporadic developing Becker's type congenital myotonia with electrophysiologic and muscle biopsy findings and review of literatures.
Biopsy ; Electric Stimulation ; Humans ; Hypertrophy ; Muscle, Skeletal ; Myotonia ; Myotonia Congenita* ; Myotonic Dystrophy ; Relaxation

Myotonic dystrophies (DM) are genetic neuromuscular diseases that have autosomal dominant inheritance and are characterized by progressive muscular weakness. Myotonic dystrophy type 1 (DM1) is caused by the expansion of an unstable CTG repeat in the DMPK (myotonic dystrophy protein kinase) gene on chromosome 19q13.3. Endocrine disorders associated with DM1 include primary hypogonadism with testicular atrophy and insulin resistance. However, DM1 accompanying hypogonodotropic hypogonadism has not previously been reported in Korea. A 56-year-old man who suffered from progressive weakness and walking disturbance for many years was hospitalized due to pneumonia. During his treatment for pneumonia, he received oral hypoglycemic agents because of hyperglycemia. He was diagnosed with DM1, based on the results of an EMG and genetic analyses. He also displayed anosmia and gynecomastia and was diagnosed with hypogonodotropic hypogonadism, based on the results of hormone tests.
Atrophy ; Gynecomastia ; Humans ; Hyperglycemia ; Hypoglycemic Agents ; Hypogonadism ; Insulin Resistance ; Korea ; Male ; Middle Aged ; Muscle Weakness ; Myotonic Dystrophy ; Neuromuscular Diseases ; Olfaction Disorders ; Pneumonia ; Walking ; Wills

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.
Accidental Falls ; Asphyxia ; Electromyography ; Extremities ; Female ; Freezing ; Gait ; Hand Strength ; Humans ; Hypokinesia ; Levodopa ; Middle Aged ; Myotonia ; Myotonic Dystrophy ; Neck ; Parkinsonian Disorders ; Percussion ; Posture

BACKGROUND: Myasthenia gravis (MG) and myotonic dystrophy type 2 (DM2) are rare disorders individually, and their coexistence in the same patient is very rare. We present a patient in which these two diseases coexisted. CASE REPORT: The patient complained of diplopia, fluctuating limb weakness, and difficulties in swallowing and speaking. A neurological examination revealed diplopia, facial, weakness of the neck and proximal limb muscles, dysphagia, dysphonia, and myotonia. The patient's mother had DM2 and her maternal grandfather had cataracts. MG was confirmed in our patient by positive results for neostigmine and a repetitive nerve stimulation test, and elevated serum anti-acetylcholine-receptor antibodies, while DM2 was confirmed by electromyography and genetic testing. The patient improved remarkably after treatment with anticholinesterases, corticosteroids, and azathioprine. CONCLUSIONS: This is the second reported case of the coexistence of DM2 and MG in the same patient. Since the symptoms of these two diseases overlap it is very important to keep in mind the possibility of their coexistence, so that MG is not overlooked in patients with a family history of myotonic dystrophy.
Adrenal Cortex Hormones ; Antibodies ; Cataract ; Cholinesterase Inhibitors ; Deglutition ; Deglutition Disorders ; Diplopia ; Dysphonia ; Electromyography ; Extremities ; Genetic Testing ; Humans ; Mothers ; Muscles ; Muscular Diseases ; Myasthenia Gravis ; Myotonia ; Myotonic Dystrophy ; Neck ; Neostigmine ; Neurologic Examination

The adult form of myotonic dystrophy type 1 is a neuromuscular disorder with multisystem involvement, including the central nervous system (CNS). The presenting clinical features of this condition include distal muscle weakness, myotonia, intellectual decline, cataract, frontal baldness and testicular atrophy. Magnetic resonance (MR) imaging shows characteristic white matter changes in the CNS. The clinical presentation, characteristic white matter changes in the brain on MR imaging and electromyographic findings aid in the diagnosis of this disorder.
Adult ; Atrophy ; complications ; Brain ; pathology ; Cataract ; complications ; Central Nervous System ; pathology ; Electromyography ; methods ; Hearing Disorders ; complications ; Humans ; Lactic Acid ; blood ; Magnetic Resonance Imaging ; methods ; Male ; Muscle Weakness ; complications ; Myotonic Dystrophy ; diagnosis ; pathology ; Neuromuscular Diseases ; diagnosis ; pathology

PURPOSE: The purpose of this study is to make a diagnostic classification and discuss a diagnostic strategy of floppy infants by investigating clinical, neurological, electrophysiological, and genetic analysis of infants admitted to intensive care units with the complaint of hypotonia. METHODS: A retrospective study was performed from Jan. 1993 to Dec. 2005 in neonatal and pediatric intensive care units of Seoul National University Children's Hospital. Clinical features and all tests related to hypotonia were investigated. RESULTS: There were 21 cases of floppy infants admitted to intensive care units. Final diagnosis was classified as centra (7 cases[33.3 percent]), peripheral (11 cases [52.4 percent]), and unspecified (3 cases [14.3 percent]). Among the central group, three patients were diagnosed as hypoxic ischemic encephalopathy, two patients as Prader-Willi syndrome, one patient as chromosomal disorder, and one patient as transient hypotonia. Among the peripheral group, four patients were diagnosed as myotubular myopathy, three patients as SMA type 1, two patients as congenital myotonic dystrophy, one patient as congenital muscular dystrophy, and one as unspecified motor-neuron disease. Motor power was above grade 3 on average, and deep tendon reflex was brisk in the central group. Among investigations, electromyography showed 66 percent sensitivity in the peripheral group, and muscle biopsy was all diagnostic in the peripheral group. Brain image was diagnostic in the central group, and Prader-Willi FISH or karyotyping was helpful in diagnosis in central group. Morbidity and mortality was more severe in the peripheral group CONCLUSION: Classification of diagnosis by clinical characteristics in this study, and application of investigations step by step, may provide an effective diagnostic strategy.
Biopsy ; Brain ; Chromosome Disorders ; Classification* ; Diagnosis ; Electromyography ; Humans ; Hypoxia-Ischemia, Brain ; Infant* ; Intensive Care Units ; Intensive Care Units, Pediatric* ; Karyotyping ; Mortality ; Muscle Hypotonia ; Muscular Dystrophies ; Myopathies, Structural, Congenital ; Myotonic Dystrophy ; Prader-Willi Syndrome ; Reflex, Stretch ; Retrospective Studies ; Seoul

PURPOSE: Myotonic dystrophy, also known as dystrophia myotonica (DM), is an autosomal dominant disorder with 2 genetically distinct forms. DM type 1 (DM1) is the more common form and is caused by abnormal expansion of cytosine/thymine/guanine (CTG) repeats in the DM protein kinase (DMPK) gene. Our study aimed to determine whether the age of onset is correlated with CTG repeat length in a population of pediatric patients with DM1. METHODS: We retrospectively identified 30 pediatric patients with DM1 that underwent DMPK testing, of which the clinical data of 17 was sufficient. The cohort was divided into 2 subgroups based on the clinical phenotype (congenital-onset vs. late-onset) and number of CTG repeats ( < 1,000 vs. ≥1,000). RESULTS: We found no significant difference between the age of onset and CTG repeat length in our pediatric patient population. Based on clinical subgrouping, we found that the congenital-onset subgroup was statistically different with respect to several variables, including prematurity, rate of admission to neonatal intensive care unit, need for respiratory support at birth, hypotonia, dysphagia, ventilator dependence, and functional status on last visit, compared to the late-onset subgroup. Based on genetic subgrouping, we found a single variable (poor feeding in neonate) that was significantly different in the large CTG subgroup than that in the small CTG subgroup. CONCLUSION: Clinical variables exhibiting statistically significant differences between the subgroups should be focused on prognosis and designing tailored management approaches for the patients; our findings will contribute to achieve this important goal for treating patients with DM1.
Age of Onset ; Cohort Studies ; Deglutition Disorders ; Genetic Association Studies ; Genotype ; Humans ; Infant, Newborn ; Intensive Care, Neonatal ; Muscle Hypotonia ; Myotonic Dystrophy ; Myotonin-Protein Kinase ; Parturition ; Phenotype ; Prognosis ; Retrospective Studies ; Ventilators, Mechanical

The phenomenon of Myotonia consist in a failure of voluntary muscles to relax immediately when voluntary innervation ceases. The stiffness is accentuated by cold and relieved by exercise, while generalized muscle weakness and atrophy (or not commonly hypertrophy of muscle) is common. Myotonia is a feature of four principal clinical syndromes which have been classified myotonia congenita (Thomsens disease), myotonia atrophica (Steinerts disease), paramyotonia and myotonia and myotonia acquisita by Walton et al. We report here a forty six years old male of myotonia atrophica (Dystrophia myotonia, Steinerts disease) who presents bilateral cataracts, frontal baldness, gonadal atrophy, facial myopathy, sterno-cleidomastoid muscle atrophy and a progressive generalized myopathy of peripheral distribution in the limbs.
Alopecia ; Atrophy ; Cataract ; Extremities ; Gonads ; Humans ; Hypertrophy ; Male ; Muscle Weakness ; Muscle, Skeletal ; Muscular Atrophy ; Muscular Diseases ; Myotonia Congenita ; Myotonia ; Myotonic Dystrophy