Müotonia

Müotonia is a rare, inherited neuromuscular disorder characterized by delayed relaxation of muscles after voluntary contraction or electrical stimulation. This prolonged muscle contraction, often referred to as myotonia, can lead to stiffness, difficulty with rapid movements, and a characteristic inability to relax the hand after a handshake. The severity of müotonia can vary significantly, with some individuals experiencing mild symptoms and others facing more debilitating muscle stiffness that interferes with daily activities.

The underlying cause of müotonia is typically a genetic mutation affecting ion channels in muscle cells. These mutations disrupt the normal electrical activity of the muscle membrane, leading to a failure in proper repolarization and subsequent prolonged muscle contraction. The most common forms are inherited in an autosomal dominant pattern, meaning only one copy of the mutated gene is needed to cause the disorder.

Diagnosis often involves a thorough medical history, physical examination, and electromyography (EMG) to assess muscle electrical activity. Genetic testing can confirm the specific mutation responsible. While there is no cure for müotonia, various medications can help manage the symptoms by reducing muscle stiffness. These treatments aim to improve muscle function and quality of life for affected individuals. Lifestyle modifications, such as avoiding cold temperatures which can exacerbate symptoms, may also be beneficial.