A team of researchers in the US and Japan reports that spinal cord stimulation (SCS) measurably decreased pain and reduced motor symptoms of Parkinson’s disease, both as a singular therapy and as a “salvage therapy” after deep brain stimulation (DBS) therapies were ineffective.
First author Dr Krishnan Chakravarthy, assistant professor of anaesthesiology at University of California San Diego School of Medicine, and colleagues at the Tokyo Metropolitan Neurological Hospital; Juntendo University, Tokyo; and National Centre Hospital of Neurology and Psychiatry-Tokyo, recruited 15 patients with Parkinson’s disease, a neurodegenerative disorder that is commonly characterised by physical symptoms, such as tremors and progressive difficulty walking and talking, and non-motor symptoms, such as pain and mental or behavioural changes.
The mean age of the patients was 74, with an average disease duration of 17 years. All of the patients were experiencing pain not alleviated by previous treatments. Eight had undergone earlier DBS, a non-invasive, pain therapy in which electrical currents are used to stimulate specific parts of the brain. Seven patients had received only drug treatments previously.
Researchers implanted percutaneous (through the skin) electrodes near the patients’ spines, who then chose one of three types of electrical stimulation: continuous, on-off bursts or continuous bursts of varying intensity.
Following continuous programmed treatment post-implantation, the researchers said all patients reported significant improvement, based on the Visual Analogue Scale, a measurement of pain intensity, with a mean reduction of 59% across all patients and stimulation modes.
73% of patients showed improvement in the 10-meter walk, a test that measures walking speed to assess functional mobility and gait, with an average improvement of 12%. And 64% of patients experienced improvements in the Timed Up and Go (TUG) test, which measures how long it takes a person to rise from a chair, walk three meters, turn around, walk back to the chair and sit down. TUG assesses physical balance and stability, both standing and in motion. Average TUG improvement was 21%.
The authors said the findings suggest SCS may have therapeutic benefit for patients with Parkinson’s in terms of treatment for pain and motor symptoms, though they noted further studies are needed to determine whether improved motor function is due to neurological changes caused by SCS or simply decreased pain.
“We are seeing growing data on novel uses of spinal cord stimulation and specific waveforms on applications outside of chronic pain management, specifically Parkinson’s disease,” said Chakravarthy, pain management specialist at UC San Diego Health. “The potential ease of access and implantation of stimulators in the spinal cord compared to the brain suggests that this is a very exciting area for future exploration.”
Background: In this study we analyze new clinical data in the use of spinal cord stimulation (SCS) for the treatment of pain and motor symptoms in patients with Parkinson’s Disease (PD), as both a singular bioelectric therapy and as a salvage therapy after deep brain stimulation (DBS). Methods: Fifteen patients were recruited and had percutaneous electrodes implanted at the level of the thoracic or cervical spine. Participants were set to one of three stimulation modes: continuous tonic stimulation, continuous Burst stimulation (40 Hz, 500 Hz, 1000 μs), or cycle mode (on time of 10–15 s, off time of 15–30 s) with Burst (40 Hz, 500 Hz, 1000 μs). Patients completed the Visual Analogue Scale (VAS), Unified Parkinson’s Disease Rating Scale, SelfRating Depression Scale, Hamilton Depression Rating Scale, Profile of Mood State, 10-meter walking test, and the Timed Up and Go (TUG). Results: All patients experienced significant improvement in VAS scores with a mean reduction of 59% across all patients. Patients who chose the cycling burst stimulation parameter had an average 67% reduction in VAS scores, as compared to the continuous burst parameter group, which had an average 48% reduction in VAS scores. Seventy-three percent of patients experienced improvement in the 10-meter walk, with an average improvement of 12%. Sixty-four percent of patients experienced clinically relevant improvements in the TUG, with an average improvement of 21%. Conclusions: This study points to the potential utility of SCS to address both pain and certain aspects of motor symptoms in PD patients who have and have not received DBS therapy.
Krishnan Chakravarthy, Rahul Chaturvedi, Rajiv Reddy, Takashi Agari, Hirokazu Iwamuro, Ayano Matsui
University of California San Diego School of Medicine material
Bioelectronic Medicine abstract