Inherited disorders of amine biosynthesis

The genetics of dystonias

Dystonia has been defined as a syndrome of involuntary, sustained muscle contractions affecting one or more sites of the body, frequently causing twisting and repetitive movements or abnormal postures. Dystonia is also a clinical sign that can be the presenting or prominent manifestation of many neurodegenerative and neurometabolic disorders. Etiological categories include primary dystonia, secondary dystonia, heredodegenerative diseases with dystonia, and dystonia plus. Primary dystonia includes syndromes in which dystonia is the sole phenotypic manifestation with the exception that tremor can be present as well. Most primary dystonia begins in adults, and approximately 10% of probands report one or more affected family members. Many cases of childhood- and adolescent-onset dystonia are due to mutations in TOR1A and THAP1. Mutations in THAP1 and CIZ1 have been associated with sporadic and familial adult-onset dystonia. Although significant recent progress had been made in defining the genetic basis for most of the dystonia-plus and heredodegenerative diseases with dystonia, a major gap remains in understanding the genetic etiologies for most cases of adult-onset primary dystonia. Common themes in the cellular biology of dystonia include G1/S cell cycle control, monoaminergic neurotransmission, mitochondrial dysfunction, and the neuronal stress response.

Uneventful electroconvulsive therapy in a patient with dopa-responsive dystonia (Segawa syndrome)

BACKGROUND

The Segawa syndrome is an autosomal dominant form of guanosine triphosphate cyclohydrolase deficiency, resulting in decreased dopamine and serotonin levels, typically presenting as a dopa-responsive dystonia.

METHOD

Case presentation of a 56-year-old man with dopa-responsive dystonia, treated with electroconvulsive therapy for a psychotic depression.

RESULTS

Scores on the Inventory of Depressive Symptomatology dropped from 35 before treatment to 3 after the eighth treatment session. Etomidate and succinylcholine were used as anesthetics. Apart from 2 sessions with postictal agitation, the course of electroconvulsive therapy was finished uneventfully. Electroconvulsive therapy and anesthesia had no untoward effects on motor function.

CONCLUSIONS

Electroconvulsive therapy can be administered safely and effectively in a patient with dopa-responsive dystonia (Segawa syndrome).