1 Hz rTMS preconditioned by tDCS over the primary motor cortex in Parkinson’s disease: effects on bradykinesia of arm and hand

Abstract

To investigate whether a period of 1 Hz repetitive transcranial magnetic stimulation (rTMS) over M1 preconditioned by tDCS improves bradykinesia of the upper limb in Parkinson's disease (PD). Fifteen patients with PD performed index finger, hand tapping and horizontal pointing movements as well as reach-to-grasp movements with either hand before (baseline conditions) and after a period of 1 Hz rTMS preconditioned by (1) sham, (2) anodal or (3) cathodal tDCS over the primary motor cortex contralateral to the more affected body side. Movement kinematics was analysed using an ultrasound-based motion analyser at baseline, immediately after and 30 min after each stimulation session. Dopaminergic medication was continued. Compared to baseline, 1 Hz rTMS significantly increased the frequency of index finger and hand tapping as well as horizontal pointing movements performed with the contralateral hand. Movement frequency increased up to 40% over 30 min after cessation of the stimulation. Preconditioning with cathodal tDCS, but not with anodal tDCS, reduced the effectiveness of 1 Hz rTMS to improve tapping and pointing movements. There was no significant increase of movement frequencies of the ipsilateral hand induced by 1 Hz rTMS preconditioned by either tDCS session. Movement kinematics of reach-to-grasp movements were not significantly influenced by either stimulation session. In PD the beneficial effects of 1 Hz rTMS over the primary motor cortex on bradykinesia of simple finger, hand and pointing movements is reduced by preconditioning with cathodal tDCS, but not with anodal tDCS. Preconditioning with tDCS is a powerful tool to modulate the behavioural effect of 1 Hz rTMS over the primary motor cortex in PD.

Invasive and Non-Invasive Stimulation in Parkinson’s Disease

“…Boggio et al (2006) demonstrated that patients with PD performed better in a memory and alertness test during a left prefrontal tDCS than during sham-stimulation. In another study the technique of rTMS was combined with tDCS in order to improve bradykinesia in PD (Grüner et al, 2010). In this study low frequency rTMS over the primary motor cortex contralateral to the more effected upper extremity was preceded by either sham, cathodal or anodal tDCS.…”

Parkinson's disease treatments: focus on transcranial direct current stimulation (tDCS)

“…Similar to Lefaucheur's comprehensive review, 8 we chose to exclude three studies that used tDCS as a priming mechanism for testing an alternative intervention, namely rTMS. [9][10][11] tDCS tDCS involves the delivery of a low-intensity current (1-2 mA) using relatively large electrodes (~2-10 cm) generally placed on the scalp. Most studies of tDCS employ a " bipolar" montage consisting of one anode and one cathode to induce an electric field that passes across the various cranial structures (skin, bone, pia, and cerebrospinal fluid) to reach the brain parenchyma.…”

Non-invasive brain stimulation for Parkinson’s disease: Current concepts and outlook 2015

“…Cathodal tDCS interferes with beneficial effects of 1 Hz rTMS in finger tapping and pointing movements (Gruner et al, 2010), but anodal stimulation does not. Grasping cannot be modulated by tDCSprimed 1 Hz rTMS (Eggers, Gruner, Ameli, Sarfeld, & Nowak, 2012), and anodal tDCS, but not cathodal stimulation, with subsequent 1 Hz rTMS improves gait (von Papen, Fisse, Sarfeld, Fink, & Nowak, 2014).…”