Repetitive transcranial magnetic stimulation of the prefrontal cortex for fibromyalgia syndrome: a randomised controlled trial with 6-months follow up

Abstract Objectives Fibromyalgia Syndrome (FMS), is a chronic pain disorder with poorly understood pathophysiology. In recent years, repetitive transcranial magnetic stimulation (rTMS) has been recommended for pain relief in various chronic pain disorders. The objective of the present research was to study the effect of low frequency rTMS over the right dorsolateral prefrontal cortex (DLPFC) on pain status in FMS. Methods Ninety diagnosed cases of FMS were randomized into Sham-rTMS and Real-rTMS groups. Real rTMS (1 Hz/1200 pulses/8 trains/90% resting motor threshold) was delivered over the right DLPFC for 5 consecutive days/week for 4 weeks. Pain was assessed by subjective and objective methods along with oxidative stress markers. Patients were followed up for 6 months (post-rTMS;15 days, 3 months and 6 months). Results In Real-rTMS group, average pain ratings and associated symptoms showed significant improvement post rTMS. The beneficial effects of rTMS lasted up to 6 months in the follow-up phase. In Sham-rTMS group, no significant change in pain ratings was observed. Conclusion Right DLPFC rTMS can significantly reduce pain and associated symptoms of FMS probably through targeting spinal pain circuits and top-down pain modulation . Trial registration: Ref No: CTRI/2013/12/004228.(AU)

Inhibitory control test, critical flicker frequency, and psychometric tests in the diagnosis of minimal hepatic encephalopathy in cirrhosis

Minimal hepatic encephalopathy [MHE] impairs health-related quality of life and driving ability of the patient. We assessed the utility of the inhibitory control test [ICT], critical flicker frequency [CFF], and psychometry in the diagnosis of MHE. Consecutive patients with cirrhosis underwent number connection tests A and B [NCT-A, B], digit symbol test [DST], line tracing test [LTT], serial dot test [SDT], CFF, and ICT at baseline and after four hours. Fifty healthy subjects served as controls for the ICT test. Fifty patients with cirrhosis [43.4 +/- 10.2 yrs, M: F 42:8] underwent psychometric tests [NCT-A [48.3 +/- 17.7 vs. 42.6 +/- 17.3 sec, P = 0.001], NCT-B [85.7 +/- 40.1 vs. 90.2 +/- 37.0 sec, P = 0.18], DST [23.5 +/- 9.3 vs. 23.0 +/- 8.7, P = 0.45], LTT [96.6 +/- 48.2 vs. 96.8 +/- 46.8 sec, P = 0.92], SDT [88.0 +/- 39.5 vs. 83.4 +/- 37.2 sec, P = 0.02]] at baseline and after four hours. Target accuracy of ICT was lower in patients with cirrhosis compared with controls [88.4 +/- 5.6 vs. 95.6 +/- 2.1, P = 0.01], whereas ICT lures were higher [18.3 +/- 4.2 vs. 10.2 +/- 2.8, P = 0.01]. Patients with cirrhosis showed a reduction in lures in the second evaluation compared with the first [18.3 +/- 4.2 vs. 17.1 +/- 4.3, P = 0.003] but no change in target accuracy [88.4 +/- 5.6 vs. 88.4 +/- 5.3, P = 0.97]. Control subjects did not show any change either in lures [10.2 +/- 2.8 vs. 10.3 +/- 2.1, P = 0.65] or target accuracy [95.6 +/- 2.1 vs. 95.5 +/- 2.2, P = 0.82]. The sensitivity and specificity of ICT test for the diagnosis of MHE at lure rate >16.5 was 88.5 and 56%, respectively. CFF in patients with MHE [38.4 +/- 1.8 vs. 38.6 +/- 1.5, P = 0.3] and non MHE [40.6 +/- 2.2 vs. 40.8 +/- 2.2, P = 0.6] did not show any difference after four hours as in controls [41.9 +/- 2.4 vs. 42.1 +/- 2.0, P = 0.3]. Thirty one [31%] patients preferred psychometric tests, 57 [57%] preferred CFF and only 12 [12%] preferred ICT [P = 0.001]. ICT, CFF, and psychometric tests are useful tools to assess MHE, and CFF was preferred by this study cohort