What is Parkinson's Disease?
Parkinson’s disease is a progressive nervous system disease that affects your ability to control movement. The disease usually starts out slowly (e.g. a barely noticeable tremor in just one hand) and worsens over time.
In the early stages of Parkinson's disease, your face ma
y show little or no expression, you may shake, have muscle stiffness, have trouble walking and maintaining your balance and coordination and you
r speech may become soft or slurred.
As the disease worsens, you may have trouble talking, sleeping, have mental and memory problems, experience behavioural changes and have other symptoms.
Although Parkinson's disease can't be cured, medications might significantly improve your symptoms. Occasionally, your doctor may suggest surgery to regulate certain regions of your brain and improve your symptoms.
What is Deep Brain Stimulation?
Deep Brain Stimulation (DBS) is a surgical procedure that involves implanting electrodes into certain areas of the brain. These electrodes produce electrical impulses that regulate and control abnormal impulses in the brain. The electrical impulses can also affect certain cells and can adjust the chemical imbalances within the brain that cause various conditions.
DBS is used to treat a variety of conditions such as:
Parkinson's disease
Essential tremor
Dystonia
Epilepsy
Obsessive-compulsive disorder
DBS is surgical intervention used to treat patients suffering with movement disorders however is not limited to only those disorders as OCD and epilepsy can be treated using DBS. This treatment is reserved for people whose medication is no longer effective in controlling their symptoms so they cannot maintain a good quality of life.
How does it work?
The DBS system involves three distinct components:
The electrode is a thin, insulated wire inserted through a small opening in the skull and implanted into a specific brain area.
The extension wire is also insulated and passed under the skin of the head, neck and shoulder, connecting the electrode to the internal pulse generator (IPG).
The IPG (a pacemaker-like device) is the third piece of the system and is usually implanted under the skin in the upper chest. This controls the amount of stimulation received.
The patient uses a handheld controller to turn the DBS system on and off via the generator. The doctor programs the stimulator settings with a wireless device. The stimulation settings can be adjusted as a patient's condition changes over time. Unlike other surgeries DBS does not damage the brain tissue.
The generator is programmed to send continuous electrical pulses to your
brain. The patient controls the generator, and can turn it on or off using a special remote control. DBS is very effective at reducing dyskinesias, the uncontrolled wiggling movements caused by high doses of levodopa medication. Typically, DBS will help make
your symptoms less severe so that lower medication doses may be used.
In Parkinson’s, parts of the basal ganglia are either under- or over-stimulated therefore normal movement is replaced by tremors, rigidity and stiffness. DBS of specific ganglia alters the abnormal electrical circuits and helps stabilise the feedback loops therefore reducing symptoms.
Electrodes can be placed in the following brain areas :
Subthalamic nucleus (STN) – effective for tremor, slowness, rigidity, dystonia and dyskinesia. Most commonly used to treat Parkinson's disease.
Thalamus (VIM) – effective for tremor. It is often used to treat essential tremor and tremors related to Parkinson’s
Globus pallidus (GPi) – effective for tremor, slowness, rigidity, dystonia and dyskinesia. It is used to treat dystonia and Parkinson's disease.
How can DBS help manage Parkisons?
DBS can help treat many of the symptoms caused by Parkinson's disease: tremor, rigidity, and slowness of movement caused by the death of dopamine-producing nerve cells responsible for relaying messages that control body movement.
DBS Risks:
Similar to all treatments there are a few risks in undergoing DBS. The procedure involves creating small holes in the skull to implant the electrodes into the brain tissue as well as performing surgery to implant the device that contains the batteries under the skin in the chest.
Complications of surgery may include:
Misplacement of leads
Bleeding in the brain
Infection
Nausea and breathing difficulties
Heart problems
Seizure and stroke
Additionally after the procedure the patient may experience side effects such as:
Seizures and headaches
Infections and pain or swelling
Confusion and difficulty concentrating
Stroke
Hardware complications, such as an eroded lead wire
Results from studies:
A study by the Mayo Clinic in 2011 showed:
DBS patients often saw positive results which included regaining significant mobility.
Patients with Parkinsons had significantly improved symptoms of bradykinesia, tremor, gait disturbance, and rigidity.
DBS of the STN improves the symptoms of slowness, tremor, and rigidity in about 70% of patients.
Most people are able to reduce their medications and lessen their side effects, including dyskinesias.
DBS of the VIM of the thalamus has shown to improve tremor control in patients with Parkinson disease.
Patients report other benefits of DBS e.g better sleep, more involvement in physical activity, and improved quality of life. The procedure has shown to decrease the use of medications and managing symptoms in the long term.
According to a 2019 study published in the Journal of Neurosurgery that addressed long-term outcomes for DBS patients:
72.5% of patients improved symptoms of tremors
Other motor symptoms remained stable.
Ability to conduct activities of daily living remained stable
Patient satisfaction, however, remained high:
92.5% happy with DBS
95% would recommend DBS
75% felt it provided symptom control
Can it cure Parkinson’s Disease?
DBS unfortunately cannot cure Parkinson’s so Parkinson’s to this day has no cure. However DBS will significantly improve the quality of life for those who undergo the surgery and will reduce their symptoms but in some cases medication will still be necessary. However for some the treatment will not be successful and other procedures may be more successful. Additionally there are many risks associated with DBS and treatment is only available for those who have severe symptoms so not everyone can gain the results of DBS.
Research: