Muscle diseases are referred to as myopathies ( Gr. "Muscle ailments"). As a rule, with the exception of cardiomyopathy , the striated skeletal muscles are meant. The main symptom of all myopathies is a weakness of the muscles . In pure myopathies, sensitivity is never affected. Other clinical pictures that are also associated with weakness of the muscles are to be distinguished from myopathies. These include diseases of the motor neuron (such as amyotrophic lateral sclerosis and spinal muscular atrophy ) and diseases of the neuromuscular junction (such as myasthenia and the Lambert-Eaton syndrome ).
The medical history and distribution pattern are important for the diagnosis. The clinical suspicion of the presence of myopathy can be confirmed by electromyography and confirmed in a muscle biopsy . Molecular genetic investigations are becoming increasingly important in primary diagnostics . According to the ICD-10, the group of myopathies is divided into primary myopathies, myopathies in other underlying diseases and other myopathies. Another important group are the inflammatory myopathies.
Primary myopathies are diseases that are primarily based on a disease of the muscles.
- The muscular dystrophies are a group of primary degenerative muscle diseases. The two most common forms are dystrophinopathies of the Duchenne type and the Becker-Kiener type. Other muscular dystrophies are the limb-girdle muscular dystrophy which facioscapulohumeral muscular dystrophy , the oculopharyngeal muscular dystrophy and the heterogeneous group of congenital muscular dystrophies .
- Myotonic syndromes are diseases that are characterized by a pathologically prolonged, tonic muscle tension. This group includes myotonic dystrophy type 1 , myotonic dystrophy type 2 , myotonia congenita Thomsen , myotonia congenita Becker and the paramyotonia congenita Eulenburg .
- Congenital myopathies are muscle diseases that become noticeable in newborns. These include clinical pictures such as Brody's disease , central core myopathy , multicore myopathy , myotubular myopathy , nemalin myopathy , fingerprint body myopathy and myopathy with congenital fiber type disproportion .
- Mitochondrial myopathies is a mitochondrial disease , that is a failure of the energy metabolism of mitochondria , is based. Mutations in the mitochondrial DNA have changed the mitochondria functionally, structurally or numerically.
- Myofibrillar myopathies are a group of congenital muscle diseases that usually only become noticeable in middle adulthood. With them, a structural defect in certain proteins of the muscle cell leads to the clumping of these proteins and thus ultimately to the destruction of the muscle cell.
Myopathies in other underlying diseases
Myopathies can appear as a symptom of a variety of other underlying diseases , in particular:
- Vitamin D deficiency myopathy
- Myopathies that occur in endocrine diseases (such as hyperthyroidism or hypothyroidism , Cushing's disease or hyper- or hypoparathyroidism ) are called endocrine myopathies.
- Myopathies can occur with metabolic diseases. In particular, disorders of the energy metabolism are often noticeable in the muscles due to the high energy requirements. Important diseases are glycogen storage diseases and the group of lipid storage diseases .
This group includes other myopathies triggered by exogenous substances.
- Alcohol Myopathy in Alcohol Disease .
- Toxic myopathies are myopathies that are triggered by damage from exogenous toxins.
Inflammatory myopathies can occur as part of autoimmune diseases or be caused by pathogens.
- Autoimmune diseases with involvement of the muscles are polymyositis , dermatomyositis, and inclusion body myositis .
- An example of a pathogen-related inflammatory myositis is trichinosis .
- Helga Kessler: Strong Lives - How Muscle Sick People Cope with Everyday Life. rüffer & rub, Zurich 2009. ISBN 978-3-907625-46-0
- L. Ceglia: Vitamin D and skeletal muscle tissue and function. In: Molecular Aspects of Medicine . Volume 29, Number 6, December 2008, pp. 407-414, . doi: 10.1016 / j.mam.2008.07.002 . PMID 18727936 (Review).
- Neuromuscular Desease Center - excellent Washington University (USA) website, especially the Myopathy & Neuromuscular Junction Disorders: Differential Diagnosis section