RESUMO
PURPOSE: To assess clinical efficacy of deep brain stimulation (DBS) of the pallidum in Myoclonus-Dystonia (M-D) patients, and to compare pre- and post-operative striatal dopamine D2 receptor availability. METHODS: Clinical parameters were scored using validated rating scales for myoclonus and dystonia. Dopamine D2 receptor binding of three patients was studied before surgery and approximately 2 years post-operatively using 123-I-iodobenzamide Single Photon Emission Computed Tomography. Two patients who did not undergo surgery served as controls. RESULTS: Clinically, the three M-D patients improved 83, 17, and 100%, respectively on the myoclonus rating scale and 78, 23, and 65% on the dystonia rating scale after DBS. Dopamine D2 receptor binding did not change after surgery. In the two control subjects, binding has lowered further. CONCLUSION: These findings confirm that DBS of the pallidum has beneficial effects on motor symptoms in M-D and suggest this procedure might stabilize dopamine D2 receptor binding.
RESUMO
BACKGROUND: Myoclonus-dystonia (M-D) is an autosomal dominantly inherited movement disorder characterized by myoclonic jerks and dystonic postures or movements. Morphometric studies have been performed in other, mainly heterogenous, types of dystonia producing conflicting results. However, all these studies agree on abnormalities in sensorimotor structures, mainly in the basal ganglia. We aimed to study gray matter (GM) volumes in sensorimotor brain structures with magnetic resonance imaging (MRI) in a genetically homogeneous form of dystonia, M-D. METHODS: Twenty-five clinically affected DYT11 mutation carriers (MC) and 25 matched control subjects were studied using T1-weighted 3D anatomical images of the entire brain, obtained with a 3.0 Tesla MRI. MC were clinically scored using the Burke Fahn Marsden dsytonia rating scale (BFMDRS) and the unified myoclonus rating scale (UMRS). GM volumes in sensorimotor cortices and basal ganglia of patients and controls were compared, and multiple regression analyses were used to correlate the GM volumes of patients with the clinical rating scales BFMDRS and UMRS. RESULTS: No significant differences were found between groups, but dystonia severity in MC was strongly correlated with increased GM volume in bilateral putamina. CONCLUSIONS: This study provides further evidence for the involvement of putamina as important motor structures in the pathophysiology of (myoclonus-) dystonia. Changes in these structures are associated with the severity of dystonia.
Assuntos
Distúrbios Distônicos/diagnóstico , Distúrbios Distônicos/fisiopatologia , Putamen/patologia , Índice de Gravidade de Doença , Adolescente , Adulto , Idoso , Distúrbios Distônicos/genética , Feminino , Lateralidade Funcional/genética , Lateralidade Funcional/fisiologia , Predisposição Genética para Doença/genética , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares/genética , Mutação , Putamen/fisiopatologia , Córtex Somatossensorial/patologia , Córtex Somatossensorial/fisiopatologia , Adulto JovemRESUMO
PURPOSE: To study striatal dopamine D(2) receptor availability in DYT11 mutation carriers of the autosomal dominantly inherited disorder myoclonus-dystonia (M-D). METHODS: Fifteen DYT11 mutation carriers (11 clinically affected) and 15 age- and sex-matched controls were studied using (123)I-IBZM SPECT. Specific striatal binding ratios were calculated using standard templates for striatum and occipital areas. RESULTS: Multivariate analysis with corrections for ageing and smoking showed significantly lower specific striatal to occipital IBZM uptake ratios (SORs) both in the left and right striatum in clinically affected patients and also in all DYT11 mutation carriers compared to control subjects. CONCLUSIONS: Our findings are consistent with the theory of reduced dopamine D(2) receptor (D2R) availability in dystonia, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out.
