Transcranial Direct Current Stimulation in Patients With Disorders of Consciousness

To date, several studies have focused on the use of transcranial direct current stimulation(tDCS) in patients with impaired consciousness.However,its therapeutic effects have been variously documented.So,in this study ,investigators explore the effects of tDCS.

Background:tDCS was supposed as an experimental approach to disorders of consciousness treatment. Its therapeutic effects have been variously documented. Objective: The study aimed to investigate the reactivity of electroencephalography (EEG) and the clinical response of patients with disorders of consciousness and explore the neuromodulatory effects of highfrequency tDCS in DOC. Method:In this double-blind, randomized controlled trial,real or sham tDCS were applied to the left dorsolateral prefrontal (DLPF) cortex of participants with disorders of consciousness for two weeeks. Evaluations were blindly performed at baseline, immediately after the end of the 14-days treatment and 1 week later with the JFK Coma Recovery Scale-Revised (CRS-R) scale and EEG.

Using a sham-controlled randomized double-blind design, 20 patients were randomly assigned to either a real or sham stimulation group. Each intervention week included 10 daily sessions of 20-minute therapy with either anodal transcranial direct current stimulation (2 mA, 20 minutes; experimental group) or sham transcranial direct current stimulation (control group) over the left dorsolateral prefrontal cortex (DLPFC).

real tDCS:anodal transcranial direct current stimulation were delivered over the left DLPF cortex for 20 minutes in patients.

sham tDCS:sham transcranial direct current stimulation were delivered over the left DLPF cortex for 20 minutes in patients.

Direct current was applied by a battery-driven constant current stimulator using saline-soaked surface sponge electrodes (7 3 5 cm) with the anode positioned over the left dorsolateral prefrontal cortex (F3 according to the 10-20 international system for EEG placement) and the cathode placed over the right supraorbital region. During real tDCS, the current was increased to 2 mA from the onset of stimulation and applied for 20 minutes.

For the sham condition(sham tDCS), the same electrode placement was used as in the stimulation condition, but the current was applied for only 5 seconds, and was then ramped down.

The CRS-R is a tool used to characterise the level of consciousness.The CRS-R is a tool used to characterize the level of consciousness and to monitor neurobehavioural recovery in DOC. The scale consists of 23 hierarchically arranged items that comprise six subscales addressing the auditory, visual, motor, oromotor/verbal, communication and arousal processes. The lowest item on each subscale represents reflexive activity whereas the highest item represents cognitively mediated behaviors.

at baseline (T0), immediately after the end of the treatment (T1), 1 week later (T2).Investigators observed the changes from baseline to the end of stimulation.

delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz) and beta (12-30 Hz).an increase of delta and theta activity usually reflects encephalopathy and/or structural lesions, interpreted as poor outcome predictor of DOC .The power of α and β is related to the chance of recovery.

Inclusion Criteria: Clinical diagnosis of DOC Ages 14 to 65 years old No centrally acting drugs No neuromuscular function blockers and no sedation within the prior 24 hours; Exclusion Criteria: History with nervous or spirit disorders, or some other serious diseases A contraindication for tDCS

Wu M, Yu Y, Luo L, Wu Y, Gao J, Ye X, Luo B. Efficiency of Repetitive Transcranial Direct Current Stimulation of the Dorsolateral Prefrontal Cortex in Disorders of Consciousness: A Randomized Sham-Controlled Study. Neural Plast. 2019 Jun 11;2019:7089543. doi: 10.1155/2019/7089543. eCollection 2019.