The generation of action potentials in excitable cells requires selective ion channels that open and close upon changes in membrane potential. Initially, cell excitabil-ity was mainly studied in neuronal axons, and in this particular cell compartment, electrical excitability is almost exclusively governed by cation channels. For many years, voltage-dependent anion channels were thought to be of...

Schwartz-Jampel syndrome is a rare autosomal recessive disorder. Joint contractures, generalised myotonia, skeletal anomalies, and facial dysmorphism are common features; malignant hyperthermia is a potentially lethal complication during anaesthesia.

Atracurium was used to produce neuromuscular blockade in a patient with dystrophia myotonica. Operating conditions were excellent and myotonia was not seen. Sensitivity to atracurium was not seen and spontaneous recovery was not prolonged.

Muscle degeneration and myotonia are clinical hallmarks of myotonic dystrophy type 1 (DM1), a multisystemic disorder caused by a CTG repeat expansion in the 3' untranslated region of the myotonic dystrophy protein kinase (DMPK) gene. Transgenic mice engineered to express mRNA with expanded (CUG)(250) repeats (HSA(LR) mice) exhibit prominent myotonia and altered splicing of muscle chloride chann...

Although the sodium channel blocker, mexiletine, is the first choice drug in myotonia, some myotonic patients remain unsatisfied due to contraindications, lack of tolerability, or incomplete response. More therapeutic options are thus needed for myotonic patients, which require clinical trials based on solid preclinical data. In previous structure-activity relationship studies, we identified tw...

We describe five patients with Schwartz-Jampel syndrome (SJS) examined at the outpatient service for neuromuscular disorders at our Institution from 1996 to 1999 with the objective of emphasizing the characteristic dysmorphic phenotype of SJS and its different clinical forms. Two cases presented SJS-type 1A, two had SJS-type 1B and one manifested SJS-type 2. Two boys with 3 and 13 years of age ...

BACKGROUND Paramyotonia congenita (PMC) of von Eulenburg is an autosomal dominant muscular disease characterized by exercise- and cold-induced myotonia and weakness. To date, 18 missense mutations in the adult skeletal muscle sodium channel alpha-subunit (SCN4A) gene have been identified to cause a spectrum of muscular diseases, including PMC of von Eulenburg, PMC without cold paralysis, potass...

The myotonias are a group of uncommon disorders. All display a characteristic electromyographic picture and some of the disorders have systemic manifestations. They are important to the anaesthetist for several reasons. Anaesthetic and surgical interventions may induce myotonia which, when initiated, may complicate the course of anaesthesia and be difficult to abolish. Furthermore, patients oft...