used pharmaceutical agents, were investigated in excised human external intercostal muscle. The effects of anthracene-9-carboxylic acid (9-AC), a well-known myotonia-producing chemical, were also tested for comparison. In the presence of these drugs the electrical threshold was lowered, and a constant current pulse produced multiple spiking. Short trains of direct stimuli were often followed by...

Paramyotonia congenita was first described by Eulenberg (1886). It is a rare, hereditary disorder of muscle in which severe loss of power is induced by degrees of cooling which are insufficient to affect normal muscle. Myotonia also appears on cooling. However, the paralysis produced by cooling distinguishes paramyotonia from Thomsen's disease. The weakness and myotonia can easily be produced u...

Myotonia congenita is a hereditary muscle disorder caused by mutations in the human voltage-gated chloride (Cl(-)) channel CLC-1. Myotonia congenita can be inherited in an autosomal recessive (Becker type) or dominant (Thomsen type) fashion. One hypothesis for myotonia congenita is that the inheritance pattern of the disease is determined by the functional consequence of the mutation on the gat...

BACKGROUND Muscle magnetic resonance imaging (MRI) is the most sensitive method in the detection of dystrophic and non-dystrophic abnormalities within striated muscles. We hypothesized that in severe myotonia congenita type Becker muscle stiffness, prolonged transient weakness and muscle hypertrophy might finally result in morphologic skeletal muscle alterations reflected by MRI signal changes....

Myotonia congenita is a rare muscular disorder with autosomal dominant or autosomal recessive inheritance, and is characterized by painless myotonia. A 44-year-old mother presented at our clinic with a son and a daughter, all sharing the same complaints of difficulty in relaxing their hands and beginning to walk, and spasms during chewing. The family had also another 16-year-old daughter, but s...