Myotonic dystrophy

Synonyms

Dystrophia myotonica, Curschmann disease, Curschmann-Steinert disease : Myotonic (muscular) Dystrophy.

Introduction

Myotonic dystrophy is one of the most common muscular dystrophies. It is accompanied by muscle weakness and atrophy, especially in the face, neck, forearms, hands, lower legs and feet. Characteristic here is the combination of the symptoms muscle weakness and delayed muscle relaxation after contraction.

This is accompanied by disorders of other body systems to varying degrees: Testicular atrophy and hormonal disorders, cardiac dysrhythmia, cataract, swallowing and speaking disorders, occasionally intellectual performance is impaired during the course of the disease. Myotonic dystrophy is a hereditary disease that shows a tendency to appear earlier from generation to generation. The cause of the disease was found to be a characteristic change in the genetic material on chromosome 19, which leads to a reduced production of a protein that ensures the integrity of the muscle fiber membrane.

Overall, the severity of the disease and the infestation of various organs varies from patient to patient, and the life expectancy of patients is determined primarily by the infestation of the heart. There is no causal therapy for the disease, the disease-related symptoms of the affected organs can be treated symptomatically by medication. There is an increased risk of anaesthesia during operations, which can be reduced by using certain drugs.

Definition

Dystrophic myotonia is the most common muscular dystrophy in adulthood and is associated with muscle weakness, atrophy and delayed muscle relaxation after activity. The disease can also affect various other organ systems. Clinically, 3 forms of myotonic dystrophy are distinguished

  • A congenital (congenital) one with onset of symptoms in infancy
  • An adult (most common form) with onset in the second and third decade of life and
  • A late form with beginning only in higher age.

Epidemiology

The frequency of myotonic dystrophy is given as 1/8000 – 1/20000. The disease is autosomal-dominantly hereditary, which means that the children of affected individuals have a 50% risk of developing the disease themselves, regardless of gender. The tendency is that the onset of the disease is earlier from generation to generation and the disease is more pronounced (“anticipation”).