Learn About Parkinson’s Disease

Normally, dopamine works in a delicate balance with other neurotransmitters to help coordinate the millions of nerve and muscle cells involved in movement. Therefore, dopamine is essential for smooth body movement. Without enough dopamine, this balance is disrupted, leading to tremors (shaking of the hands, arms, legs, and jaw), stiff limbs, slowness of movement, and poor balance and coordination—the hallmark symptoms of Parkinson's disease.

The disease is named after the English physician James Parkinson, who described the disease in a medical journal in 1817.

While the condition usually develops after the age of 55, it can affect people in their 30s and 40s.

Parkinson's disease results from a loss of dopamine in the nerves of the basal ganglia in the brain, which controls the regulation of the motor system and other systems.

• Involuntary tremors in certain parts of the body: hands, arms, legs, and jaw.

• Muscle stiffness and lack of flexibility, most common in the arms, shoulders, or neck.

• Decreased mental skill, delayed reaction time, changes in voice, decreased facial expressions, etc.

• Gradual loss of spontaneous movement, which may lead to decreased blinking, difficulty swallowing, and drooling.

• Bent spine syndrome with bent elbows, knees, and hips.

• Balance problems.

• Slow thinking.

• Reduced sense of smell.

Currently, the diagnosis of Parkinson's disease is based primarily on the common symptoms described above. There is no X-ray or blood test that can confirm the disease. However, non-invasive diagnostic imaging, such as positron emission tomography (PET), can support a doctor's diagnosis. Typical diagnostic criteria include:

• The presence of at least two basic symptoms.

• No other neurological signs on examination.

• No history of other possible causes of tremor, such as the use of sedative medications, head injury, or stroke.

• Response to Parkinson's disease medications, such as levodopa.

Most Parkinson's patients are treated with medications to relieve the symptoms. These medications work by stimulating the remaining cells to produce more dopamine (levodopa medications) or by inhibiting some of the acetylcholine activity (anticholinergic medications), thus restoring the balance of brain chemicals. Treatment plans must be tailored to each patient, as side effects and effectiveness vary. Over time, some medications may lose effectiveness even at higher doses.

Dr. Zeiad Yossry, Professor of Neurosurgery and Parkinson's Disease, offers deep brain stimulation (DBS) for such conditions. This procedure involves implanting small electrodes to deliver electrical impulses to deep parts of the brain involved in motor function. Electrode implantation is guided by magnetic resonance imaging (MRI) and neurophysiological mapping to determine the correct location. The electrodes are connected to wires leading to a pulse generator placed under the chest skin. Patients have a control device that allows them to turn the device on and off. Electrodes are typically placed on one side of the brain. An electrode implanted on the left side of the brain controls symptoms on the right side of the body, and vice versa. 

This form of stimulation helps rebalance the brain's motor signals, thereby suppressing tremors. Deep brain stimulation may be effective in treating all the core motor features of Parkinson's disease and may allow for a significant reduction in medication dosages.