Dystonia

When dystonia is a group of movement disorders, neurological origin lies in the motor centers in the brain. It is counted among the extrapyramidal hyperkinesis. In most cases, dystonia manifest itself in spasms, and poor posture, for example, the head ( torticollis ). For therapy, inter alia, botulinum toxin is applied.

Dystonia described here does not have anything to do with the autonomic dystonia.

Types of Dystonia

The dystonias include athetosis, tremor, and chorea ballism. Can also differ according to degree of spread between focal (only affected a region of the body ), segmental ( affects more than one region of the body ) and generalized ( whole body affected) dystonia. Furthermore, a distinction is made between primary dystonia without apparent cause (which includes all hereditary dystonia ) and secondary dystonias with identifiable cause (eg serious injury ).

Genetic causes

It has been described that the gene THAP1 (synonym DYT6, Dystonia 6) involved in hereditary movement disorders, including muscle contraction plays. THAP1 is Thanatos -associated [ THAP ] domain-containing apoptosis - associated protein 1 ( THAP1 ) and is a DNA binding protein that interacts with the protein PAWR/PAR-4 that plays a role in apoptosis.

Examples

• The cervical dystonia or spasmodic torticollis, which manifests itself in an abnormal posture of the head.
• The blepharospasm, eyelid spasm or blepharospasm also called, leading to uncontrollable blinking. In severe cases, sufferers are functionally blind.
• The oromandibular dystonia that affects the mouth area and the masticatory apparatus. Sufferers find it difficult to eat.
• The spasmodic dysphonia, also called vocal spasm. Affected talk fades away or pressed and are hardly understood.
• The limbs dystonia that may occur as writer's cramp, musician's cramp or Fußdystonie. In all cases, it leads to a spasm of the limbs, which makes it impossible for those affected to write, make music or to go.
• The Segawa syndrome, which is characterized by anomalies and the legs is caused by a genetic defect on chromosome 14.

Dystonias are not suppressed by the parties concerned. Often, however, there is the phenomenon of a gesture antagoniste in which, for example, touching the chin or touching the skin alleviates the symptoms.

The cause of dystonia is a disorder of regulation of unconscious motor activity in the basal ganglia in the brain. Especially the globus pallidus internus appears to play a role (see Parkinson's disease ). In most cases, no hereditary relationships are established. In hemifacial spasm of the facial nerve is concentrated within the skull by an arterial loop.

Diagnosis should include short duration dystonia often easily confused with tics. In the latter, those affected describe a kind of feeling of tension, which forces them to perform a movement that can be short-term but also suppressed.

Therapy

The sessions are held with a limited expansion of the dystonia often by local injections of botulinum toxin (usually serotype A). The effect starts after three to seven days, a slow and reached after three weeks its peak. The injections must each be repeated at intervals of weeks to months, with some patients decreases the effect. In this case, the dose can be increased up to a certain limit or changed to serotype 2. In advanced resistance or extended dystonias the maximum administrable dose of therapy sets a limit; a possible side effect, for example, dry mouth.

Other drugs that find therapeutic application here are anticholinergics. The exclusion of the affected muscles may also be operative, by the appropriate - but later renewable - nerves are severed. The Deep brain stimulation is a therapy approved for the treatment of dystonia and is usually applied when the therapy with botulinum toxin is no longer sufficient or effective. These regions of the brain are electrically stimulated by an implant, whereby the movement can improve.