Parkinson’s disease and brain stimulation – not a cure but a hope

Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease. Early symptoms of PD include tremor, rigidity, and difficulty walking. The underlying pathology of PD is selective death of dopamine-generating cells in the substantia nigra, a part of the brain involved in movement, reward, and addiction.

Treatment of PD with Levodopa temporarily controls motor symptoms but does not slow disease progression. Like other common diseases, PD is thought to arise from complex interactions between genetic and environmental factors, which remain mostly unknown.

It is possible to have a good to great quality of life with PD. Working with your doctor and following recommended therapies are essential in successfully treating symptoms by using dopaminergic medications. People with PD need this medication because they have low levels or are missing dopamine in the brain, mainly due to impairment of neurons in the substantia nigra.

It is important to understand that people with PD first start experiencing symptoms later in the course of the disease because a significant amount of the substantia nigra neurons have already been lost or impaired.

Scientists are exploring ways to identify biomarkers for PD that can lead to earlier diagnosis and more tailored treatments to slow down the disease process. Currently, all therapies used for PD improve symptoms without slowing or halting the disease progression.

In addition to movement-related signals, Parkinson’s symptoms may be unrelated to movement; PD are often more impacted by their non-motor symptoms than motor symptoms. Examples: apathy, depression, constipation, sleep behaviour disorders, loss of sense of smell and cognitive impairment.

Deep Brain Stimulation (DBS) surgery was first approved in 1997 to treat PD tremor, then in 2002 for the treatment of advanced Parkinson’s symptoms. More recently, in 2016, DBS surgery was approved for the earlier stages of PD (people who have had PD for at least four years and have motor symptoms not adequately controlled with medication).

In DBS surgery, electrodes are inserted into a targeted area of the brain (using MRI) and recordings of brain cell activity during the procedure. A second procedure is performed to implant an impulse generator battery (like a pacemaker), placed under the collarbone or in the abdomen, that produces an electrical impulse to a part of the brain involved in motor function. Those who undergo DBS surgery are given a controller to turn the device on or off.

DBS is certainly the most important therapeutic advancement since the development of Levodopa. It is most effective for people who experience disabling tremors, wearing-off spells and medication-induced dyskinesias, with studies showing benefits lasting at least five years. That said, it is not a cure and it does not slow PD progression. It is also not right for every person with PD. It is not thought to improve speech or swallowing issues, thinking problems or gait freezing.

Like all brain surgeries, DBS carries a small risk of infection, stroke, bleeding or seizures and may be associated with reduced clarity of speech.

It is important that a person with PD considering DBS surgery be informed about the procedure and be realistic in his or her expectations.

Article submitted by the HPA Health Group