Brain stimulation helps with Parkinson's disease-related walking problems

Delivering electrical stimulation over the cerebellum appears to improve gait disturbances in patients with Parkinson’s disease (PD) and help them walk better, as reported in a study from Japan.

“We ... developed a novel neuromodulation approach using gait-combined closed-loop transcranial electrical stimulation and demonstrated promising gait improvements in [stroke survivors]. [W]e tested the efficacy of this intervention in 23 patients with Parkinsonian gait disturbances,” said lead study author Ippei Nojima from Shinshu University in Nagano and Nagoya City University in Nagoya, Japan.

Treatment involved externally placing an electrode that carried a low current (up to 2 mA) to the occipital region of the patient’s head. A reference electrode was then placed in the neck region to establish a stable electrical reference point and to complete the electrical circuit. The brain side showing severe impact was specifically targeted during the electrical stimulation therapy.

Over the course of 10 treatment sessions, patients who underwent gait-combined closed-loop transcranial electrical stimulation showed significantly increased gait speed (p=0.002) and stride length (p=0.007). These improvements did not occur for those who received sham stimulation. [J Neurol Neurosurg Psychiatry 2023;doi:10.1136/jnnp-2022-329966]

Electrical stimulation also improved walking symmetry measured by swing phase time (p=0.002) and reduced the amount of time the patients spent freezing (characterized as a sudden inability to start or to continue walking; p=0.001).

None of the patients dropped out from the study. More importantly, patients from both the electrical stimulation and sham groups showed good and comparable compliance to the intervention. Side effects such as skin irritation, vertigo, or odd sensations/perceptions were not documented in any of the patients during the study.

The role of cerebellum

The cerebellum is mainly responsible for motor movement regulation and balance control. Therefore, Nojima and colleagues hypothesized that the electrical stimulation of this region would likely exert therapeutic benefits. [https://my.clevelandclinic.org/health/body/23418-cerebellum]

Indeed, the researchers found encouraging results after just several treatment sessions.

“Gait-combined closed-loop transcranial electrical stimulation over the cerebellum improved Parkinsonian gait disturbances, possibly through the modulation of brain networks generating gait rhythms,” Nojima explained.

He stressed out that the findings have important implications, given that gait disturbance negatively affects the ability of the affected patients to carry out activities of daily living and that Japan is witnessing a sharp rise in its elderly population.

Also, pharmacological, surgical, and rehabilitative treatments have limited effectiveness on gait disturbance.

As a noninvasive intervention, gait-combined closed-loop transcranial electrical stimulation “could be a breakthrough in restoring gait function in patients with Parkinson’s disease and related disorders,” according to Nojima.