Parkinson’s disease is a neurodegenerative disorder that can affect and deteriorate the motor function due to the loss of dopamine producing brain cells gradually and slowly. This is second most common movement disorder. Symptoms of parkinson’s disease are progressive loss of muscle control, trembling and stiffening of hands/limbs while at rest, slurred speech, and impaired balance. Parkinson’s disease can be trigged by the consistent exposure to certain toxins, advancing age and in rare cases, this disease can be genetically passed on to children from parents.
Doctors may review signs and symptoms of this disease and may suggest some imaging test such as MRI, PET Scans, blood tests, physical examination, and neurological assessment. Parkinson’s disease doesn’t have a proper treatment or cure presently and it can take time to diagnose it. Doctors may suggest lifestyle changes and certain physical therapies to manage some conditions of the disease. Surgical therapies like deep brain stimulation (DBS) cannot cure but can be used to treat the symptoms of parkinson’s disease like tremor, stiffness, dystonia that cannot be adequately controlled by medications.
Deep Brain Stimulation is a non- destructive type of surgery which involves implanting a device that sends high frequency electrical signals to the targeted area of the brain responsible for body movement. The electrodes are inserted on both the left and right sides of the brain through tiny holes made at the top of the skull. Electrodes are then connected by long thin wires passed under the skin to the stimulator (battery powered device) under the skin of collarbone near the chest. After turning the device on, electrical pulses will be passed to block the faulty nerve signals that cause tremors, stiffness and other symptoms. There are four parts of deep brain stimulator that are implanted inside the body:
1. Neurostimulator - battery operated pacemaker device which creates pulses and is placed under the chest skin below the collarbone or in the stomach.
2. Lead - a coated wire with a many electrodes at the tip is placed inside the brain and connects to the extended wire through tiny hole in the skull. These wires deliver electric pulses to the brain tissue.
3. Extension – an insulated wire that connects the lead to pulse generator and is placed near scalp, behind the ear, down from the neck to the chest.
4. A remote control to program the system.
Doctor will adjust the device program to give the best relief for parkinson’s disease symptoms after the device is turned on which can also be controlled by the patient itself.
Deep brain stimulation surgery is generally performed in one to three stages depending on the medical condition of the patient. During the first surgery, the electrodes are inserted into the brain but left unconnected. This is most essential step as electrodes have to be placed in a precise location to improve the conditions. Many ways can be used to introduce the electrodes into the precise targeted areas of the brain. CT or MRI scans can help in locating the targeted areas. In many cases, an electrode may be used to record from brain cells at the target to improve wire placement. This step can be done when the patient is awake during surgery. After locating the correct area, the permanent electrodes are implanted. This surgery can be performed under general anesthesia it may take a few weeks until the simulators and medications are adjusted before patients received relief from the symptoms.
Some of the advantages of deep brain stimulation are mentioned as below:
• DBS is reversible surgery and doesn’t damage other part of the brain. It has fewer complications than brain lesioning surgery.
• The electrical stimulation device is adjustable and can be changed as per the requirement and response to the medications change. No other surgery is needed to make the adjustments.
• If DBS is causing excessive side effects without any long-term consequences then the stimulator can also be turned off at any time.
Patient can be sent back to home with the instructions for adjusting the stimulation once the DBS has been programmed. The remote controller will allow the patient to turn the stimulator on and off, select programs and adjust it accordingly. Patient will need to use a charging unit if their DBS has a rechargeable battery. Patient can discuss whether he or she may want a primary cell battery or rechargeable unit prior to surgery.