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Lowenthal-Raz J1,2, Soroker N3,4, Libermann D1, Friedman J1
1Tel Aviv University, Physiotherapy, Tel Aviv, Israel, 2Loewenstein Rehabilitation Hospital, Physiotherapy, Ra'anana, Israel, 3Loewenstein Rehabilitation Hospital, Neurological Rehabilitation, Ra'anana, Israel, 4Tel Aviv University, Medical School, Tel Aviv, Israel
Background: Significant upper limb (UL) paresis, post stroke, is associated with poor chances for recovery of functional motor activity. Recent research suggests that application of transcranial direct current stimulation (tDCS) induces modulatory effects on intra- and inter-hemispheric dynamics by inducing focal excitatory/inhibitory activity that presumably enhance neural plasticity. Combined with conventional upper limb (UL) training, tDCS may enhance motor recovery after a stroke. Important theoretical questions have to be answered before tDCS can become part of the standard clinical practice in stroke rehabilitation, one of them being what is the most efficient stimulation mode for a patient with a given severity of motor impairment.
Purpose: We aimed to assess the likelihood of obtaining improvements in reaching in terms of endpoint kinematic descriptors of the paretic upper limb using different stimulation modes, in stroke patients with variant residual motor functioning.
Methods: 31 subacute stroke patients performed planar point-to-point reaching movements with the paretic upper limb, before and after anodal-tDCS (excitatory), cathodal-tDCS (inhibitory), and sham-tDCS, in a randomized order. tDCS electrodes were placed over the left and right M1 hand area (C3, C4). Spatio-temporal kinematic variables derived from the minimum-jerk model were analyzed before and after training, comparing the 3 stimulation modes one with each other.
Results: a-tDCS had a greater effect when applied on the lesioned hemisphere. Number of peaks, straight line deviation and movement time improved (only the former two reached statistical significance). The Fugl Meyer (FM) score at baseline correlated negatively with the magnitude of improvement post-anodal stimulation of the contralesional hemisphere. This was reflected in number of peaks and in movement time.
Conclusion(s): a-tDCS applied on the lesioned hemisphere combined with motor training shows immediate positive effects on path smoothness (less fragmented paths) and path straightness (shorter paths). Higher FM scores at baseline likely imply smaller corticospinal damage in the affected hemisphere, and thus, greater likelihood that perilesional re-mapping will be the dominant mechanism underlying recovery. In the presence of higher corticospinal reserve one would expect anodal (excitatory) stimulation of the contralesional hemisphere to exert a detrimental effect on function. It remains to be shown whether such stimulation is beneficial in the absence of corticospinal reserve.
Implications: tDCS can be implemented in the clinical setting as an adjuvant to traditional Physical Therapy treatments. It still remains to be determined which factors contribute to positive effects of tDCS
Keywords: Stroke, Transcranial direct current stimulation, kinematics
Funding acknowledgements: Loewenstein Rehabilitation Hospital Research Foundation
Elsa and Leo Abramson Foundation, Tel Aviv University
Purpose: We aimed to assess the likelihood of obtaining improvements in reaching in terms of endpoint kinematic descriptors of the paretic upper limb using different stimulation modes, in stroke patients with variant residual motor functioning.
Methods: 31 subacute stroke patients performed planar point-to-point reaching movements with the paretic upper limb, before and after anodal-tDCS (excitatory), cathodal-tDCS (inhibitory), and sham-tDCS, in a randomized order. tDCS electrodes were placed over the left and right M1 hand area (C3, C4). Spatio-temporal kinematic variables derived from the minimum-jerk model were analyzed before and after training, comparing the 3 stimulation modes one with each other.
Results: a-tDCS had a greater effect when applied on the lesioned hemisphere. Number of peaks, straight line deviation and movement time improved (only the former two reached statistical significance). The Fugl Meyer (FM) score at baseline correlated negatively with the magnitude of improvement post-anodal stimulation of the contralesional hemisphere. This was reflected in number of peaks and in movement time.
Conclusion(s): a-tDCS applied on the lesioned hemisphere combined with motor training shows immediate positive effects on path smoothness (less fragmented paths) and path straightness (shorter paths). Higher FM scores at baseline likely imply smaller corticospinal damage in the affected hemisphere, and thus, greater likelihood that perilesional re-mapping will be the dominant mechanism underlying recovery. In the presence of higher corticospinal reserve one would expect anodal (excitatory) stimulation of the contralesional hemisphere to exert a detrimental effect on function. It remains to be shown whether such stimulation is beneficial in the absence of corticospinal reserve.
Implications: tDCS can be implemented in the clinical setting as an adjuvant to traditional Physical Therapy treatments. It still remains to be determined which factors contribute to positive effects of tDCS
Keywords: Stroke, Transcranial direct current stimulation, kinematics
Funding acknowledgements: Loewenstein Rehabilitation Hospital Research Foundation
Elsa and Leo Abramson Foundation, Tel Aviv University
Topic: Neurology: stroke
Ethics approval required: Yes
Institution: Loewenstien Rehabilitation hospital
Ethics committee: Loewenstien Rehabilitation hospital committee and Tel Aviv ethics committee
Ethics number: 123444
All authors, affiliations and abstracts have been published as submitted.
