Combined study of transcranial direct current stimulation and electroencephalography for the analysis on upper limb function: a systematic review

Neurological disorders can directly affect basic functions of the upper limbs, leading to an alteration in or the loss of motor capacity and hindering the performance of activities of daily living. Transcranial direct current stimulation (tDCS) is a noninvasive technique capable of modulating cortical excitability, favoring both brain activity and neuroplasticity. The objective was to systematize and discuss the effects of transcranial direct current stimulation combined with electroencephalogram for the analysis of upper limb movements in individuals with neurological impairment. For such, the following research question was used: Is the combined use of tDCS and EEG effective for the analysis of upper limb movements? A systematic review was performed in the international network of databanks using the following criteria: (1) design: randomized controlled clinical trial; (2) population: healthy individuals or individuals with neurological impairment; (3) intervention: tDCS combined with EEG; (4) control group with different intervention or no intervention; (5) outcome: analysis of upper limb movement and function. Eight arti-cles were selected, revealing no consensus on the parameters to use. Few studies have evaluated the use of tDCS, physical therapy and electroencephalogram. The small number of studies and methodological variation hinder the determination of the combined effects of tDCS and EEG. Further studies are needed to define the ideal quantity of session, intervals between sessions and the administration of physical therapy concomitant to the use of tDCS.