Parkinson’s disease (PD) is one of the bedrock disorders of neurology. It is common, universal, well-defined, usually easily diagnosed, and eminently treatable, even if not curable. PD is so important that I have visited it so many times on this blog. My previous blog posts on this topic include:
PD is debilitating even when treated. This is because of the staggering number of motor and non-motor symptoms it provokes. And there is the long list of side effects the treatments induce, such as abnormal movements called dyskinesias. There is therefore a never-ending need for more effective and less agonising treatments for PD. And this blog has kept a keen eye on any advances that will make this disorder more bearable for the sufferers and their families, and less nerve-racking for the treating neurologist. It is therefore gratifying to know that there are many developments in the management of PD, and here I focus on 3 emerging interventional treatments.
Magnetic resonance-guided focused ultrasound (MRgFUS)
MRgFUS is a technique that uses thermal heat to create lesions in the brain. This is a much less invasive approach than the current interventional treatments for PD which are surgery and deep brain stimulation (DBS). Surgical interventions for PD work by making therapeutic lesions in the globus pallidus (pallidotomy). In a first of its kind, Young Cheol Na and colleagues used MRgFUS to create similar pallidal lesions. They published their finding in 2015 in the journal Neurology under the title Unilateral magnetic resonance-guided focused ultrasound pallidotomy for Parkinson disease. They reported improvement in the motor symptoms of PD, and in drug-induced dyskinesias. But before MRgFUS pallidotomy will take off, it has to be as good as surgical pallidotomy which reduces dyskinesias for as long as 12 years!
Repetitive transcranial magnetic stimulation (rTMS)
In a reasonably large randomized trial published in 2016 in the journal Neurology, Multifocal repetitive TMS for motor and mood symptoms of Parkinson disease, the study reports that the benefit was significant. Indeed a systematic review and meta-analysis by Ying-hui Chou and colleagues in the journal JAMA Neurology, published just the year before, had established the benefit of rTMS in PD. The review, titled Effects of repetitive transcranial magnetic stimulation on motor symptoms in Parkinson disease, concluded with the hope that their findings “may guide treatment decisions and inform future research“. Hopefully it has, because a 2018 paper, published in the Journal of Clinical Neuroscience, has gone on to establish that the best results for rTMS are obtained with stimulation of the primary and supplementary motor cortex. That’s scientific progress.
Spinal cord stimulation
It appears counterintuitive to think of the spinal cord in the context of PD, which is after all a disease of the brain. That is until you remember that walking impairment is a major problem in PD, and the spinal cord is the gateway for gait. Inspired by this insight, Carolina Pinto de Souza and colleagues stimulated the spinal cords of people with PD who have already undergone deep brain stimulation surgery. They published their findings in the journal Movement Disorders with the title Spinal cord stimulation improves gait in patients with Parkinson’s disease previously treated with deep brain stimulation. A clear title like this leaves little room for commentary. The authors however studied only four subjects, a number clearly missing from the paper’s title, but the benefit is an encouraging 50-65% improvement in gait. The omission is forgiven.
Taking things a step further, Reon Kobayashi and colleagues, writing in the journal Parkinsonism and Related Disorders, reported that a new mode of spinal cord stimulation called BurstDR, does a much better job than conventional stimulation. Again, the title of the paper is self-explanatory: New mode of burst spinal cord stimulation improved mental status as well as motor function in a patient with Parkinson’s disease.
Surely the future must be bright with all these developments in the field of PD.