The two most common forms of non-dystrophic myotonia (NDM) are congenita (Thomsen disease or Becker-type) and paramyotonia congenita. Symptoms, including muscle stiffness, cramps, transient weakness, can affect a person’s quality life. An unmet need for validated tool to assess symptom severity frequency, as well disability caused by myotonia, led the development Clinical Myotonia Rating Scale ...

characterized by muscle stiffness and an inability of the muscle to quickly relax after voluntary contraction. although myotonia can affect any skeletal muscles, including muscles of the face and tongue, it occurs most often in the legs. myotonia causes muscle stiffness (a myotonic disorder should be considered in the differential diagnosis of a patient complaining of muscle stiffness) that can...

We describe the case of a girl with a probable autosomal recessive form of nondystrophic hereditary myotonia whose clinical findings are more compatible with the dominant ones mainly myotonia congenita of Thomsen or myotonia fluctuans. Besides the clinical aspects of the atypical form presented by our patient, the efficacy of the more available drugs employed for the treatment of myotonia conge...

the myotonic disorders are a heterogeneous group of genetically determined diseases that are unified by the presence of myotonia, which is defined as failure of muscle relaxation after activation. the presentation of these disorders can range from asymptomatic electrical myotonia, as seen in some forms of myotonia congenita (mc), to severe disability with muscle weakness, cardiac conduction def...

Abstract Background Congenital myotonia is a congenital disorder that affects skeletal muscles with myotonia. Affected show stiffness and pain sometimes. The two major types of congenita are known as Thomsen disease Becker disease. These conditions distinguished by the severity their symptoms patterns inheritance. causative factor mutations in CLCN1 gene. Myotonia rarely reported black especial...

Clinical, electrophysiological, and molecular findings are reported for a family with dominant myotonia congenita in which all affected members have experienced long-term fluctuations of the symptom of myotonia. In some patients myotonia is combined with myalgia. The myotonia-causing mutation in this family is in the gene encoding the muscular chloride channel, hCIC-1, predicting the amino acid...

1. The objective of the study was to determine the effect of temperature reduction on the response of rat skeletal muscles to myotonia-inducing agents. 2. A model myotonia was induced in the muscles in vitro, using either the chloride channel blocker anthracene-9-carboxylic acid or chloride-free Krebs solution. This model is similar in its characteristics to the myotonia which occurs in autosom...

Advances in molecular genetics are allowing better phenotype to genotype correlation of the non-dystrophic myotonic disorders. We report a 32-year-old woman, who first noted myotonia that was associated with weakness during her first pregnancy. The work-up disclosed that she had Thomsen's disease which is not known to be associated with weakness. In addition, her myotonia was of the fluctuating...

OBJECTIVE Patients with myotonia congenita have muscle hyperexcitability due to loss-of-function mutations in the ClC-1 chloride channel in skeletal muscle, which causes involuntary firing of muscle action potentials (myotonia), producing muscle stiffness. The excitatory events that trigger myotonic action potentials in the absence of stabilizing ClC-1 current are not fully understood. Our goal...

Myotonia congenita is a hereditary chloride channel disorder characterized by delayed relaxation of skeletal muscle (myotonia). It is caused by mutations in the skeletal muscle chloride channel gene CLCN1 on chromosome 7. The phenotypic spectrum of myotonia congenita ranges from mild myotonia disclosed only by clinical examination to severe and disabling myotonia with transient weakness and myo...