A comparison of two different continuous theta burst stimulation paradigms applied to the human primary motor cortex.

Goldsworthy MR, Pitcher JB, Ridding MC

A comparison of two different continuous theta burst stimulation paradigms applied to the human primary motor cortex.

Clin Neurophysiol. 2012 May 25;

Authors: Goldsworthy MR, Pitcher JB, Ridding MC

Abstract
OBJECTIVE: The application of repetitive transcranial magnetic stimulation (rTMS) in bursts at theta frequencies (TBS) may produce lasting neuroplastic changes in the human cortex. However, there exists high variability in subjects' responses, possibly due to non-optimal stimulation characteristics. Here we compare the efficacy of two variations of continuous TBS (cTBS) for producing neuroplastic change in the human primary motor cortex (M1). METHODS: The two cTBS paradigms were: (1) standard cTBS (cTBS(std)) (three stimuli at 50Hz, repeated at 5Hz), and (2) modified cTBS (cTBS(mod)) (three stimuli at 30Hz, repeated at 6Hz with intensity). Motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous muscle before, as well as at 0, 5, 10, 20 and 30min following each paradigm. RESULTS: Both cTBS(std) (P=0.05) and cTBS(mod) (P<0.0001) induced a suppression of MEP amplitudes. However, MEP suppression following cTBS(mod) was greater (ANOVA(RM); P=0.02). Experiments using magnetic brainstem stimulation provided evidence that cTBS(mod) induced MEP suppression through cortical mechanisms. CONCLUSIONS: The neuroplastic response of the human M1 to cTBS is highly dependent on the stimulation parameters employed. SIGNIFICANCE: These findings may have significant implications for the clinical application of cTBS paradigms.

PMID: 22633917 [PubMed - as supplied by publisher]

Efficacy of Transcranial Direct Current Stimulation and Repetitive Transcranial Magnetic Stimulation for Treating Fibromyalgia Syndrome: A Systematic Review.

Marlow NM, Bonilha HS, Short EB

Efficacy of Transcranial Direct Current Stimulation and Repetitive Transcranial Magnetic Stimulation for Treating Fibromyalgia Syndrome: A Systematic Review.

Pain Pract. 2012 May 28;

Authors: Marlow NM, Bonilha HS, Short EB

Abstract
Objective: To systematically review the literature to date applying repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) for patients with fibromyalgia syndrome (FMS). Method: Electronic bibliography databases screened included PubMed, Ovid MEDLINE, PsychINFO, CINAHL, and Cochrane Library. The keyword "fibromyalgia" was combined with ("transcranial" and "stimulation") or "TMS" or "tDCS" or "transcranial magnetic stimulation" or "transcranial direct current stimulation". Results: Nine of 23 studies were included; brain stimulation sites comprised either the primary motor cortex (M1) or the dorsolateral prefrontal cortex (DLPFC). Five studies used rTMS (high-frequency-M1: 2, low-frequency-DLPFC: 2, high-frequency-DLPFC: 1), while 4 applied tDCS (anodal-M1: 1, anodal-M1/DLPFC: 3). Eight were double-blinded, randomized controlled trials. Most (80%) rTMS studies that measured pain reported significant decreases, while all (100%) tDCS studies with pain measures reported significant decreases. Greater longevity of significant pain reductions was observed for excitatory M1 rTMS/tDCS. Conclusion: Studies involving excitatory rTMS/tDCS at M1 showed analogous pain reductions as well as considerably fewer side effects compared to FDA approved FMS pharmaceuticals. The most commonly reported side effects were mild, including transient headaches and scalp discomforts at the stimulation site. Yearly use of rTMS/tDCS regimens appears costly ($11,740 to 14,507/year); however, analyses to appropriately weigh these costs against clinical and quality of life benefits for patients with FMS are lacking. Consequently, rTMS/tDCS should be considered when treating patients with FMS, particularly those who are unable to find adequate symptom relief with other therapies. Further work into optimal stimulation parameters and standardized outcome measures is needed to clarify associated efficacy and effectiveness.

PMID: 22631436 [PubMed - as supplied by publisher]

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A comparison of two different continuous theta burst stimulation paradigms applied to the human primary motor cortex.

Efficacy of Transcranial Direct Current Stimulation and Repetitive Transcranial Magnetic Stimulation for Treating Fibromyalgia Syndrome: A Systematic Review.