Effect on electroencephalogram microstate in patients with post-stroke cognitive impairment: a comparative study of acupuncture with different stimulation methods at cognitive-emotional area

To observe the therapeutic effect on post-stroke cognitive impairment (PSCI) after acupuncture with different stimulation methods at cognitive-emotional area, and preliminarily explore its action mechanism using electroencephalogram (EEG) microstate parameters.

A total of 108 PSCI patients were randomized into a trial group No.1 (36 cases, 3 cases dropped out and 2 cases were eliminated), a trial group No.2 (36 cases, 3 cases dropped out and 3 cases were eliminated), and a control group (36 cases, 4 cases dropped out and 2 cases were eliminated). Besides the conventional acupuncture and basic treatment, acupuncture was operated at the cognitive-emotional area in each group. The repetitive transcranial acupuncture stimulation (rTAS) was adopted in the trial group No.1, electroacupuncture was adopted in the trial group No.2, and minimal manual twisting was adopted in the control group. The intervention was operated once daily for 6 days, followed by 1 day of interval. One course of treatment consisted of 4 weeks and 2 courses were required. Before and after treatment, the scores of the mini-mental state examination (MMSE), Montreal cognitive assessment (MoCA) and auditory verbal learning test (AVLT), and the completion time of shape trail test (STT) were compared in each group. EEG microstate parameters (duration [Dur], occurrence [Occ], coverage [Cov] and transition probability [TP]) were adopted and analyzed. After treatment, the clinical effect was compared among groups.

After treatment, MMSE scores increased when compared with the baseline in each group (P<0.05), and the scores in the trial groups No.1 and No.2 were higher than those in the control group (P<0.05). In each group, the total scores in MoCA and the scores on visuospatial function, language and orientation, as well as the scores on immediate recall and recognition of AVLT were higher (P<0.01), and the completion time of STT-A was reduced (P<0.05) when compared with the baseline. After treatment, in the trial groups No.1 and No.2, the scores on attention of MoCA and the scores on short-term delayed recall and long-term delayed recall of AVLT were elevated (P<0.01), and the completion time of STT-B was reduced (P<0.05) in comparison with the baseline. After treatment, the total scores in MoCA and the scores on each domain, as well as the scores on immediate recall, short-term delayed recall and long-term delayed recall of AVLT in the trial groups No.1 and No.2 were all higher than those of the control group (P<0.01), and the completion time of STT-A and STT-B was shorter (P<0.05); the score on language of MoCA in the trial group No.1 was lower than that in the trial group No.2 (P<0.01), and the score on attention of MoCA and the score on immediate recall of AVLT were higher and the completion time of STT-B was longer when compared with those in the trial group No.2 (P<0.01, P<0.05). After treatment, Dur, Occ and Cov in microstates C and D, as well as TP of microstates B→C, C→D and D→C in the trial groups No.1 and No.2 were superior to those in the control group (P<0.05), and Dur, Occ and Cov in microstates A and B, as well as TP of microstates C→B were inferior to those in the control group (P<0.05); Dur in microstate D in the trial group No.1 was longer than that in the trial group No.2 (P<0.05), and Dur in the microstate C was shorter (P<0.05). The total effective rate was 93.6% (29/31) in the trial group No.1 and was 93.3% (28/30) in the trial group No.2, higher than that (80.0%, 24/30) in the control group.

Acupuncture at the cognitive-emotional area with different stimulation methods improves the cognitive function in PSCI patients. The rTAS and electroacupuncture obtain the superior advantage on the therapeutic effect when compared with conventional acupuncture. The rTAS presents the best effect on ameliorating attention and memory, while electroacupuncture is more effective on improving lanague and executive function.