Non-invasive brain stimulation for the lower limb after stroke: what do we know so far and what should we be doing next?

Abstract

Background: Non-invasive brain stimulation (NIBS) is promising as an adjuvant to rehabilitation of motor function after stroke. Despite numerous studies and reviews for the upper limb, NIBS targeting the lower limb and gait recovery after stroke is a newly emerging field of research. Purpose: To summarize findings from studies using NIBS to target the lower limb in stroke survivors. Methods: This narrative review describes studies of repetitive transcranial magnetic stimulation, paired associative stimulation and transcranial direct current stimulation with survivors of stroke. Results: NIBS appears capable of inducing changes in cortical excitability and lower limb function, but stimulation parameters and study designs vary considerably making it difficult to determine effectiveness. Conclusions: Future research should systematically assess differences in response with different stimulation parameters, test measures for determining who would be most likely to benefit and assess effectiveness with large samples before NIBS can be considered for use in clinical practice.

Implications for Rehabilitation

• Stroke is a leading cause of disability, often resulting in dependency in activities of daily living and reduced quality of life.

• Non-invasive brain stimulation has received considerable interest as a potential adjuvant to rehabilitation after stroke and this review summarizes studies targeting the lower limb and gait recovery.

• Non-invasive brain stimulation can be used to modulate excitability of lower limb muscle representations and can lead to improvements in motor performance in stroke survivors.

• Non-invasive brain stimulation for gait recovery needs further investigation before translation to clinical practice is possible.

Keywords:

• Gait
• stroke
• transcranial direct current stimulation
• transcranial magnetic stimulation

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Funding information

MKF is funded by a King’s College London doctoral studentship and a project grant awarded to DJN from The Stroke Association [TSA 2013-09].