RESUMEN
Brain-computer interfaces (BCI) are used in stroke rehabilitation to translate brain signals into intended movements of the paralyzed limb. However, the efficacy and mechanisms of BCI-based therapies remain unclear. Here we show that BCI coupled to functional electrical stimulation (FES) elicits significant, clinically relevant, and lasting motor recovery in chronic stroke survivors more effectively than sham FES. Such recovery is associated to quantitative signatures of functional neuroplasticity. BCI patients exhibit a significant functional recovery after the intervention, which remains 6-12 months after the end of therapy. Electroencephalography analysis pinpoints significant differences in favor of the BCI group, mainly consisting in an increase in functional connectivity between motor areas in the affected hemisphere. This increase is significantly correlated with functional improvement. Results illustrate how a BCI-FES therapy can drive significant functional recovery and purposeful plasticity thanks to contingent activation of body natural efferent and afferent pathways.
Asunto(s)
Interfaces Cerebro-Computador , Terapia por Estimulación Eléctrica/métodos , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/fisiopatología , Brazo/inervación , Brazo/fisiopatología , Encéfalo/fisiopatología , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Movimiento , Vías Nerviosas/fisiopatología , Plasticidad Neuronal/fisiología , Recuperación de la Función , Técnicas Estereotáxicas , Accidente Cerebrovascular/diagnóstico , Resultado del TratamientoRESUMEN
The usefulness of cognitive rehabilitative treatment in the acute stages after brain injury seems questionable because patients in severe acute confusional state early after coma clinically seem unable to learn and store new information. Therefore, the capability of patients in acute confusional state to learn and retain associative information was assessed. On two occasions pairs of simple nouns were presented to six patients in severe acute confusional state. Stimuli were presented repeatedly either in written form only or with additional pictorial representations. Immediate and 20 minutes delayed recall was measured. Patients in acute confusional state were able to learn progressively more word pairs across several presentations. They retained some information over an interval of 20 minutes. In addition, they learned and remembered pictorially supported associations better than pure verbal associations. Patients in severe acute confusional state may retain some explicit information and may profit from an imagery mnemonic aid. These results were not expected on the basis of clinical findings alone and they have potential implications for the care of patients in acute confusional state.