Does transcranial direct current stimulation during writing alleviate upper limb freezing in people with Parkinson’s disease? A pilot study

Abstract

Transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) can boost motor performance in Parkinson's disease (PD) when it is applied at rest. However, the potential supplementary therapeutic effect of the concurrent application of tDCS during the training of motor tasks is largely unknown. The present study examined the effects of tDCS on upper limb motor blocks during a freezing-provoking writing task (the funnel task) requiring up- and down-stroke movements at alternating amplitudes. Ten PD patients and 10 age-matched controls underwent two sessions of writing combined with 20 min of anodal or sham tDCS on the left M1 in a randomized cross-over design. The primary outcome was the number of upper limb freezing episodes during five trials of the funnel task on a touch-sensitive tablet. PD patients showed a significant reduction in freezing episodes during tDCS compared to sham. No effects of tDCS were found for the amplitude, variability and speed of the strokes outside the freezing episodes. However, patients who reported freezing episodes in daily life (N = 6) showed a beneficial effect of tDCS on stroke characteristics. These results indicate a subgroup-dependent variability in response to non-invasive brain stimulation applied during the performance of motor tasks in PD. This warrants future studies to examine tDCS as an adjuvant tool for training programs aimed to reduce motor deficits related to freezing.

Transcranial direct current stimulation combined with physical or cognitive training in people with Parkinson’s disease: a systematic review

“…Seven studies had cross-over design [25,28,34,37,[39][40][41] and ten were controlled trials with parallel arms. Three studies did not mention information regarding how or if experiments were blinded [37,40,42], three studies consisted of single-blind experiments [28,34,36] and eleven studies consisted of double-blind experiments. It is worth mentioning that all the included studies randomly assigned participants into groups/conditions.…”

“…[25] and cognitive training [26,27]. The idea is that such combinations would promote greater, synergistic effects than the interventions applied separately [28,29]. In this context, tDCS can be applied concurrently or as a priming technique.…”

Can genetic polymorphisms predict response variability to anodal transcranial direct current stimulation of the primary motor cortex?

“…Nitsche & Paulus, 2000). This predictability has led to recent investigation into tDCS application in pathological population including Parkinson's disease (Broeder et al, 2019;Bueno et al, 2019), epilepsy (Lin et al, 2018;Tecchio et al, 2018) stroke rehabilitation (Biou et al, 2019;Solomons & Shanmugasundaram, 2019), cerebral palsy (Inguaggiato et al, 2019), chronic pain (Callai et al, 2019;Jafarzadeh et al, 2019), depression (Aparicio et al, 2019) and cognitive impairment (Emonson et al, 2019).…”

Non-invasive Transcranial Electrical Stimulation in Movement Disorders

“…Stimulation to SMA (2 mA, 13 min) (Costa-Ribeiro et al, 2016) or DLPFC (10 sessions, 2 mA, 20 min) (Doruk et al, 2014) revealed no significant benefit. Broeder et al (2019) noted an increase in writing amplitude with anodal tDCS to M1 (1 mA, 20 min). Fregni et al (2006) also noted some benefit in Purdue pegboard task with anodal tDCS to M1 (1 mA, 20 min), but other studies found no significant benefit in dexterity tasks with single-or multi-session tDCS to the fronto-polar area (five sessions, 1 mA, 15 min) (Ishikuro et al, 2018) or DLPFC (10 sessions, 2 mA, 20 min) (Doruk et al, 2014).…”

“…• Gait and balance (Benninger et al, 2010;Verheyden et al, 2013;Capecci et al, 2014;Kaski et al, 2014a;Mak and Yu, 2014;Manenti et al, 2014;Valentino et al, 2014;Costa-Ribeiro et al, 2016Schabrun et al, 2016;Swank et al, 2016;Fernandez-Lago et al, 2017;Lattari et al, 2017;Criminger et al, 2018;da Silva et al, 2018;Dagan et al, 2018;Harris et al, 2018;Yotnuengnit et al, 2018;Alizad et al, 2019;Putzolu et al, 2019) • Upper limb function (Fregni et al, 2006;Benninger et al, 2010;Doruk et al, 2014;Salimpour et al, 2015;Costa-Ribeiro et al, 2016;Ferrucci et al, 2016;Schabrun et al, 2016;Cosentino et al, 2017;Ishikuro et al, 2018;Broeder et al, 2019) • Cognition (Nitsche et al, 2005;Boggio et al, 2006;Biundo et al, 2015;Manenti et al, 2016;Elder et al, 2017;Lawrence et al, 2018;Adenzato et al, 2019) • Impulsive pathological gambling behavior (Benussi et al, 2017a) • Speech (Pereira et al, 2013) • Sleep (Hadoush et al, 2018) • Fatigue …”