Parieto-motor Cortical Dysfunction in Primary Cervical Dystonia

Background: Dystonia is considered as a motor network disorder involving the dysfunction of the posterior parietal cortex, a region involved in preparing and executing reaching movements. Objective/hypothesis: We used transcranial magnetic stimulation to test the hypothesis that cervical dystonic pa...

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Detalles Bibliográficos
Autores: Porcacchia, Paolo, Palomar, Francisco J., Cáceres-Redondo, María Teresa, Huertas Fernández, Ismael, Martín Rodríguez, Juan Francisco, Carrillo, Fátima, Koch, Giacomo, Mir Rivera, Pablo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/107977
Acceso en línea:https://hdl.handle.net/11441/107977
https://doi.org/10.1016/j.brs.2014.06.007
Access Level:acceso abierto
Palabra clave:Dystonia
Hypokinesia
Parietal lobe
Transcranial magnetic stimulation
Descripción
Sumario:Background: Dystonia is considered as a motor network disorder involving the dysfunction of the posterior parietal cortex, a region involved in preparing and executing reaching movements. Objective/hypothesis: We used transcranial magnetic stimulation to test the hypothesis that cervical dystonic patients may have a disrupted parieto-motor connectivity. Methods: We enrolled 14 patients with primary cervical dystonia and 14 controls. A paired-pulse transcranial magnetic stimulation protocol was applied over the right posterior parietal cortex and the right primary motor area. Changes in the amplitudes of motor evoked potential were analyzed as an index of parieto-motor effective connectivity. Patients and healthy subjects were also evaluated with a reaching task. Reaction and movement times were measured. Results: In healthy subjects, but not in dystonic patients, there was a facilitation of motor evoked potential amplitudes when the conditioning parietal stimulus preceded the test stimulus applied over the primary motor area by 4 ms. Reaction and movement times were significantly slower in patients than in controls. In dystonic patients, the relative strength of parieto-motor connectivity correlated with movement times. Conclusions: Parieto-motor cortical connectivity is impaired in cervical dystonic patients. This neurophysiological trait is associated with slower reaching movements.