To investigate the analgesic effect of transcranial direct current stimulation (tDCS) over the primary motor (M1), dorsolateral prefrontal cortex (DLPFC), and sham tDCS in patients with painful diabetic polyneuropathy (PDPN).
Patients with PDPN (n=60) were divided randomly into the three groups (n=20 per group). Each group received anodal tDCS with the anode centered over the left M1, DLPFC, or sham stimulation for 20 minutes at intensity of 2 mA for 5 consecutive days. A blinded physician rated the patients' pain using a visual analog scale (VAS), Clinical Global Impression (CGI) score, anxiety score, sleep quality, Beck Depression Inventory (BDI), and the pain threshold (PT) to pressure.
After the tDCS sessions, the M1 group showed a significantly greater reduction in VAS for pain and PT versus the sham and DLPFC groups (p<0.001). The reduction in VAS for pain was sustained after 2 and 4 weeks of follow-up in the M1 group compared with the sham group (p<0.001, p=0.007). Significant differences were observed among the three groups over time in VAS for pain (p<0.001), CGI score (p=0.01), and PT (p<0.001). No significant difference was observed among the groups in sleep quality, anxiety score, or BDI score immediately after tDCS.
Five daily sessions of tDCS over the M1 can produce immediate pain relief, and relief 2- and 4-week in duration in patients with PDPN. Our findings provide the first evidence of a beneficial effect of tDCS on PDPN.
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To develop and evaluate the psychometric properties of a modified Naturalistic Action Test (m-NAT) for Korean patients with impaired cognition. The NAT was originally designed to assess everyday action impairment associated with higher cortical dysfunction.
We developed the m-NAT by adapting the NAT for the Korean cultural background. The m-NAT was modeled as closely as possible on the original version in terms of rules and scoring. Thirty patients receiving neurorehabilitation (twenty-three stroke patients, five traumatic brain injury patients, and two dementia patients) and twenty healthy matched controls were included. Inter-rater reliability was assessed between two raters. Validity was evaluated by comparing the m-NAT score with various measures of attention, executive functions, and daily life.
Performance on the m-NAT in terms of the total score was significantly different between patients and controls (p<0.01). Patients made significantly more total errors than controls (p<0.01). Omissions error was the most frequent type of error in patient group. Intraclass correlation coefficients for total m-NAT score was 0.95 (95% confidence interval [CI], 0.92 to 0.97; p<0.001); total error was 0.91 (95% CI, 0.89 to 0.92; p<0.001). Total m-NAT score showed moderate to strong correlations with Stroop test interference score & index, Trail Making Test parts A and B, Sustained Attention to Response Task commission error, Functional Independence Measure, Korean instrumental activities of daily living, Korean version of the Cognitive Failures Questionnaire, and Executive Behavior Scale (p<0.05).
The m-NAT showed very good inter-rater reliability and adequate validity. The m-NAT adjusted to Korean cultural background can be useful in performance-based assessment of naturalistic action for clinical and research purposes.
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