Spinal Cord Stimulation Fails to Improve Mobility in Advanced Parkinson’s Patients

Despite being safe, spinal cord stimulation does not lead to significant improvements in mobility in patients with advanced Parkinson’s disease, including those taking levodopa, a prospective trial has found.

The trial findings were reported in the study, “Spinal Cord Stimulation for Very Advanced Parkinson’s Disease: A 1-Year Prospective Trial,” published in the journal Movement Disorders.

Like deep brain stimulation (DBS), spinal cord stimulation (SCS) is a form of treatment that involves implanting a small device that sends electrical signals. In the case of SCS, these electrical signals go through nerves in a patient’s spinal cord, masking pain signals before they reach the brain. This form of therapy is approved in the U.S. for treating chronic pain.

Lately there has been increasing interest in SCS as a form of treatment for Parkinson’s, based on data from studies reporting that patients who underwent SCS experienced improvements in their gait and motor function.

To explore the therapeutic potential of SCS at alleviating Parkinson’s motor symptoms, researchers at the University of Toronto in Canada conducted a prospective, open-label trial in which they assessed the safety and effectiveness of the therapy in six pain-free patients with advanced disease.

Trial participants — three men and three women, ages 31–76, who had Parkinson’s for 12–18 years — underwent surgery to have two cylindrical electrodes implanted. After surgery, all patients were followed for a period of one year.

The Unified Parkinson’s Disease Rating Scale (UPDRS) and the freezing of gait (FOG) questionnaire were used to evaluate patients’ motor function and gait impairments, respectively. Assessment evaluations were performed in all patients before, one, three, six, and 12 months after surgery.

Apart from one patient who had a temporary delirium episode after surgery, none of the study participants experienced any adverse side effects.

However, SCS had no significant effects on patient’s motor function, balance, or gait, at any time-point. Additionally, investigators found no evidence suggesting that SCS could work together with levodopa at alleviating motor symptoms of the disease.

“Despite the (…) promising outcomes reported in short, small, and open-label PD [Parkinson’s disease] studies, our study confirms safety but shows no clinically meaningful effect on patients’ mobility, particularly while on L-dopa, thus failing to improve the motor signs resistant to dopaminergic treatment,” the researchers wrote.

“[W]e need further studies, enrolling larger samples and using a double-blind design, which will be possible thanks to more recent SCS modalities (e.g., burst stimulation), [to assess the therapeutic potential of SCS for Parkinson’s disease],” they added.