Non-motor phenotype of dopa-responsive dystonia and quality of life assessment.

BACKGROUND: Dopa-responsive dystonia (DRD) is a young-onset neurometabolic disorder often presenting with a combination of parkinsonism and dystonia. The pathophysiology includes an impairment of dopaminergic and serotonergic neurotransmission. Uncontrolled reports suggest an increased frequency of neuropsychiatric abnormalities and sleep impairment. METHODS: In 23 GCH1 mutation-positive DRD patients and 26 healthy controls, non-motor features and their effect on the quality of life (QoL) were assessed. Six patients underwent polysomnography (PSG). RESULTS: Depressive and anxiety symptoms were not more common among DRD patients. Average sleep quality was similar across groups. This was also true for self-reported mean sleep onset (27.5 vs. 27.1 min) and total sleep time (6.5 vs. 6.6 h). Upon PSG, the number of spontaneous arousals was increased in four patients. QoL was impaired with respect to physical health. Sleep impairment and depressive but not anxiety symptoms were associated with lower QoL. CONCLUSION: The present results do not confirm the clinical impression and biologically plausible assumption of an increased frequency of non-motor symptoms in DRD. The impairment of QoL is associated with a decline of the physical condition only but not with other factors.

Clinical neuroimaging and electrophysiological assessment of three DYT6 dystonia families.

The purpose of the study was to delineate clinical and electrophysiological characteristics as well as laryngoscopical and transcranial ultrasound (TCS) findings in THAP1 mutation carriers (MutC). According to recent genetic studies, DYT6 (THAP1) gene mutations are an important cause of primary early-onset dystonia. In contrast to DYT1 mutations, THAP1 mutations are associated with primary early-onset segmental or generalised dystonia frequently involving the craniocervical region and the larynx. Blood samples from twelve individuals of three German families with DYT6 positive index cases were obtained to test for THAP1 mutations. Eight THAP1 MutC were identified. Of these, six (three symptomatic and three asymptomatic) THAP1 MutC could be clinically evaluated. Laryngoscopy was performed to evaluate laryngeal dysfunction in patients. Brainstem echogenicity was investigated in all MutC using TCS. Two of the patients had undergone bilateral pallidal DBS. In all three symptomatic MutC, early-onset laryngeal dystonia was a prominent feature. Laryngeal assessment demonstrated adductor-type dystonia in all of them. On clinical examination, the three asymptomatic MutC also showed subtle signs of focal or segmental dystonia. TCS revealed increased substantia nigra (SN) hyperechogenicity in all MutC. Intraoperative microelectrode recordings under general anesthesia in two of the patients showed no difference between THAP1 and previously operated DYT1 MutC. The presence of spasmodic dysphonia in patients with young-onset segmental or generalised dystonia is a hallmark of DYT6 dystonia. SN hyperechogenicity on TCS may represent an endophenotype in these patients. Pallidal DBS in two patients was unsatisfactory.