Parkinson’s disease is a chronic, progressive neurodegenerative movement disorder. Tremors, rigidity, slow movement (bradykinesia), poor balance, and difficulty walking (called parkinsonian gait) are characteristic primary symptoms of Parkinson’s disease.
Idiopathic Parkinson’s disease is the most common form of parkinsonism, a group of movement disorders that have similar features and symptoms. Parkinson’s disease is called idiopathic Parkinson’s because the cause is unknown. In the other forms of parkinsonism, a cause is known or suspected.
Parkinson’s results from the degeneration of dopamine-producing nerve cells in the brain, specifically in the substantia nigra and the locus coeruleus. Dopamine is a neurotransmitter that stimulates motor neurons, those nerve cells that control the muscles. When dopamine production is depleted, the motor system nerves are unable to control movement and coordination. Parkinson’s disease patients have lost 80% or more of their dopamine-producing cells by the time symptoms appear.
The cause of Parkinson’s disease is unknown. Many researchers believe that several factors combined are involved: free radicals, accelerated aging, environmental toxins, and genetic predisposition.
Diagnosis is based on symptoms and ruling out other disorders that produce similar symptoms.
Treatment centers on the administration of medication to relieve symptoms. Medication selection and dosage is tailored to the individual. Some of the medications used to treat PD include: Levodopa and carbidopa combined (Sinemet®), Bromocriptine (Parlodel®), Pramipexole (Mirapex®), Ropinirole (Requip®), Rotigotine (Neupro®), Amantadine (Symmetryl®)
Surgery is another method of controlling symptoms and improving quality of life when medication ceases to be effective or when medication side effects, such as jerking and dyskinesias, become intolerable. Not everyone is a good candidate for surgery. For example, if a patient never responded to, or responded poorly to levodopa/carbidopa, surgery may not be of any help. Only about 10% of Parkinson’s patients are estimated to be suitable candidates.