Idiopathic torsion dystonia (ITD)
Which are the symptoms?
Dystonia can affect only one area of the body and is called focal, if the muscles of two or more adjacent parts of the body are affected, then segmental; multifocal, when several non-contiguous areas are affected; generalized, when the lower limbs plus another part of the body are involved. It also differs in infantile or juvenile-onset forms and variations typical of adults. In the first case, symptoms appear before the age of 20 and more often affect the lower limb, but gradually spread to many parts of the body (generalized forms); in adults, they are very often focal and usually affect the neck (cervical dystonia), face (blepharospasm). Another typical adult dystonia is action dystonia (see Seizures of a scribe, musician). There are familiar shapes; the type of inheritance is autosomal dominant with reduced penetrance (not all people carrying the mutated gene develop the disease clinically). The mutation is in the DYT1 gene, located on chromosome 9, in most cases of primary juvenile-onset dystonia (before age 25), although other chromosomes have been found.
How is it diagnosed?
Dystonia is recognized primarily from a clinical point of view; Once a diagnostic suspicion is formulated, instrumental tests such as EMG and MRI, as well as genetic tests, assist in diagnostic confirmation.
How is it treated?
Two types of approaches can be used in the treatment of dystonia:
- pharmacological: drugs of first choice are represented by dopaminergic agonists (L-dopa, bromocriptine) and anticholinergics (trihexyphenidyl), to which, at least partially, about 40-50 percent of patients respond. The second choice is baclofen. Other drugs that, when used alone or in combination, can reduce symptoms in the early stages are benzodiazepines and antipsychotics. Local injections of botulinum toxin are preferred for cases beginning in adulthood.
- surgical: the use of stereotaxic methods that stimulate some areas of the brain with high-frequency current, in particular the pallidum.