A pilot investigation of the safety and feasibility of the application of cathodal transcranial direct current stimulation to the contralesional primary motor cortex plus standard upper limb rehabilitation post-acute stroke

Jimena Garcia Vega

    Research output: ThesisMaster's Thesis

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    Abstract

    Title: A Pilot investigation of the safety and feasibility of the application of cathodal transcranial direct current stimulation to the contralesional primary motor cortex plus standard upper limb rehabilitation post-acute stroke.

    Purpose: The main aim of this study was to assess the feasibility and safety of the application of cathodal transcranial direct current stimulation (ctDCS) post-acute stroke (7-15 days); and to determine a minimal clinically important difference (MCID) using the Fugl Meyer upper extremity (FMUE) scale to assist with more accurately estimating sample size for a phase II trial in an acute stroke population. This pilot study also aimed to establish the feasibility of measuring motor recovery in the affected upper limb (UL) both clinically (FMUE scale) and using transcranial magnetic stimulation (TMS), commencing within the first two weeks post-stroke onset and continuing to at least four months post-stroke. It was hypothesised that individuals receiving ctDCS would show greater improvement in FMUE scores immediately post intervention, and improvements would be sustained at three months. A secondary aim was to define commonly reported physiotherapy (PT) and occupational therapy (OT) terminology extracted from medical documentation and to develop a consensus on therapy interventions for moderate to severe UL deficits in the acute and subacute phases of stroke recovery.

    Design: Qualitative and quantitative methodologies were used in the development of a consensus on UL therapy interventions in Stages I & II of this investigation, followed by a double-blind, sham-controlled, multisite, pilot study of the safety and feasibility of the application of ctDCS post-acute stroke (Stage III).Methods: Stage I Retrospective notes audit - A report of all first time ischaemic MCA strokes admitted to an acute stroke service between January – September 2011, was generated. An audit was conducted of UL therapy documentation at this service and two rehabilitation hospitals to which these cases were discharged. Stage II Qualitative and consensus on standard UL therapy focus groups - Twenty two therapists (9 PTs and 13 OTs) met to discuss and define the terminology identified from the notes audit.All definitions were collated and returned to the therapists for further comments or amendments, until agreement was reached that it was a true representation of therapy offered by their service. This document was then used to develop a template of interventions to be used in the management of individuals with moderate to severe UL impairment in the subsequent pilot trial. Stage III Safety and feasibility pilot randomised controlled trial of ctDCS and UL rehabilitation post-acute stroke – Over the 19 month recruitment period, 14 individuals within two weeks of stroke onset with moderate to severe UL impairment were randomised to receive 10 sessions of ctDCS (1mA) (n=7) or sham tDCS (n=7) to the contralesional primary motor cortex (M1) plus concurrent UL therapy for 30 minutes over a two-week period. The primary outcome was change from baseline in FMUE scores at 1 day, 2 weeks and 3 months post intervention. The secondary outcomes included: National Institute of Health Stroke Scale (NIHSS), Tardieu Spasticity Scale, Functional Independence Measure (FIM), and Post Stroke Depression Scale. TMS was used to assess cortical activity in the primary motor hand arm-area in a subset of cases.

    Results: With respect to common practices in UL rehabilitation in the acute and rehabilitation services studied, it was noted that terminology used was defined very similarly by both discipline groups, and differences in treatment focus amongst therapists appeared to be due to the amount of experience and training background of individual clinicians, both inter- and intra-professionally. Individualised goal based UL therapy, tailored according to impairment severity, was described in a standard therapy template, which was used to derive a ‘standard package of care’ during the safety and feasibility pilot trial of ctDCS and UL rehabilitation post-acute stroke. Twelve participants completed the pilot study. Groups were well matched at baseline. A variety of factors were identified which limited recruitment rates. No adverse events were associated with applying ctDCS to the contralesional MI as early as seven days post first ever ischaemic MCA stroke. It was feasible to assess an array of outcomes over a three month period post intervention, apart from TMS assessments which were limited by logistical issues. It was feasible to conduct a multisite rehabilitation trial involving acute stroke patients across at least five sites. Considerable improvement was seen over time in both groups, with no statistically significant difference between groups at any time point, consequently an MCID was unable to be established from the FMUE data.

    Conclusions: The application of ctDCS in an acute ischaemic stroke cohort is safe, and feasible in a multisite trial. Data from this pilot study were unable to be used to estimate a sample size for a phase II trial. Feasibility of a phase II trial would depend on adequate funding, the allocation of trained staff at all sites, and the addition of more recruitment sites with interest in participation on rehabilitation clinical trials. Previously established MCID from chronic stroke populations indicate that approximately 20 participants per group would be needed to examine the efficacy of the addition of ctDCS to usual UL therapy post-acute stroke, however the unexpected improvement seen in the sham tDCS group in the present study would indicate that this sample may be insufficient to establish the additional benefit of ctDCS to ten 30 minute sessions of structured UL therapy provided in the first month post-stroke.

    Original languageEnglish
    QualificationMasters
    Publication statusUnpublished - Aug 2015

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