Does Multisession Cathodal Transcranial Direct Current Stimulation of the Left Dorsolateral Prefrontal Cortex Prime the Effects of Cognitive Behavioral Therapy on Fear of Pain, Fear of Movement, and Disability in Patients with Nonspecific Low Back Pain? A Randomized Clinical Trial Study

Abstract

Many studies have shown that low back pain (LBP) is associated with psychosomatic symptoms which may lead to brain changes. This study aimed to investigate the effect of the concurrent application of cognitive behavioral therapy (CBT) and transcranial direct electrical stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) on fear of pain, fear of movement, and disability in patients with nonspecific LBP. This study was performed on 45 LBP patients (23 women, 22 men; mean age 33.00 ± 1.77 years) in three groups: experimental (2 mA cathodal tDCS (c-tDCS)), sham (c-tDCS turned off after 30 s), and control (only received CBT). In all groups, CBT was conducted for 20 min per session, with two sessions per week for four weeks. Fear of pain, fear of movement, and disability were evaluated using questionnaires at baseline, immediately after, and one month after completion of interventions. Results indicated that all three different types of intervention could significantly reduce fear and disability immediately after intervention (p > 0.05). However, improvement in the experimental group was significantly higher than in the other groups immediately after and at the one-month follow-up after interventions (p < 0.05). DLPFC c-tDCS can prime the immediate effects of CBT and also the lasting effects on the reduction in the fear of pain, fear of movement, and disability in LBP patients.

Keywords: cognition; disability; fear; left dorsolateral prefrontal cortex; low back pain; transcranial direct electrical stimulation.

Figure 1

Flow diagram of participants’ eligibility assessment.

Figure 2

Experimental design: 8 sessions of interventions in three groups. PASS, TSK, and RMDQ questionnaires were used for assessment before, immediately after, and 1 month after intervention.

Figure 3

(A) The comparison of the Pain Anxiety Symptoms Scale (PASS) scores (mean ± SEM) before, immediately after, and one month after the intervention in DLPFC c-tDCS concurrent with CBT, sham DLPFC c-tDCS concurrent with CBT, and CBT alone groups; * indicates the significant differences in PASS score after intervention between groups. (B) The comparison of the Pain Anxiety Symptoms Scale (PASS) scores (mean ± SEM) before, immediately after, and one month after the intervention in each group; * indicates the significant differences in PASS score after intervention rather than baseline in each group.

Figure 4

(A) The comparison of the Roland–Morris Scale (RMS) scores (mean ± SEM) before, immediately after, and one month after the intervention in DLPFC c-tDCS concurrent with CBT, sham DLPFC c-tDCS concurrent with CBT, and CBT alone groups; * indicates the significant differences in RMS score after intervention between groups. (B) The comparison of the Roland–Morris Scale (RMS) scores (mean ± SEM) before, immediately after, and one month after the intervention in each group; * indicates the significant differences in RMS score after intervention rather than baseline in each group.

Figure 5

(A) The comparison of the Tampa Scale for Kinesiophobia (TSK) scores (mean ± SEM) before, immediately after, and one month after the intervention in DLPFC c-tDCS concurrent with CBT, sham DLPFC c-tDCS concurrent with CBT, and CBT alone groups; * indicates the significant differences in TSK score after intervention between groups. (B) The comparison of the Tampa Scale for Kinesiophobia (TSK) scores (mean ± SEM) before, immediately after, and one month after the intervention in each group; * indicates the significant differences in TSK score after intervention rather than baseline in each group.