Parkinson's disease describes a condition that occurs when nerve cells found in the base of the brain, which function to produce dopamine---a chemical in the brain that helps effectively transmit nerve signals to the body, become destroyed. Four main symptoms characterize Parkinson's disease including bradykinesia, which is slowness of movement, tremor, rigidity and balance problems. Many conditions that affect the nerves in the brain produce these same symptoms, prompting doctors to use the phrase "parkinsonism," which describes a syndrome characterized by these symptoms. Treatments for Parkinson's disease and parkinsonism syndrome includes medications and surgical procedures.
Dopamine Precursors
Dopamine binds to dopamine receptors in the brain to help control movements. A decreased level of dopamine, which occurs in Parkinson's disease and parkinsonism syndromes, contributes to the onset of the motor symptoms such as tremors, rigidity and bradykinesia. Taking dopamine should, therefore, help to relieve these symptoms; however, dopamine medications cannot cross the blood-brain barrier. Dopamine precursor medications, such as levodopa, can cross the blood-brain barrier, and once in the brain, the nerve cells transform it into dopamine. Levodopa remains the most effective medication for Parkinson's symptoms, according to the Parkinson's Disease Foundation, but its effectiveness may diminish over time.
Dopamine Agonists
Dopamine agonist medications, pramipexole and ropinirole, do not convert into dopamine in the brain, but rather mimic the effects of dopamine, as described by MayoClinic.com. Although less effective in relieving motor symptoms such as bradykinesia and rigidity, doctors often prescribe dopamine agonists along with levodopa to enhance its effectiveness, according to the National Institute of Neurologic Disorders and Stroke.
MAO-B Inhibitors
MAO-B Inhibitors, such as selegiline and rasagiline, inhibit the activity of the enzyme known as monoamine oxidase B (MAO-B), which functions to break down dopamine in the brain. By decreasing the effects of MAO-B, the level of dopamine in the brain increases, therefore, helping to relieve Parkinson's syndrome symptoms. MAO-B inhibitors cannot be taken with some antidepressant medications, but when MAO-B inhibitors are taken in conjunction with levodopa they can help to enhance and prolong its effectiveness.
Anticholinergics
A decrease in the level of dopamine allows another neurotransmitter in the brain known as acetylcholine to affect nerve signaling contributing to tremors and rigidity. Mild Parkinson syndrome symptoms can often be controlled with medications known as anticholinergic agents that inhibit the effects of acetylcholine, therefore, relieving tremors and rigidity.
Surgical Procedures
When medications fail to provide relief, doctors may recommend one of several surgical procedures. Pallidotomy destroys a section of the brain known as globus pallidus. This procedure can improve tremors, rigidity and bradykinesia, according to the National Institute of Neurologic Disorders and Stroke. Another procedure, known as thalamotomy, destroys the thalamus in the brain, helping to reduce tremors. Deep brain stimulation describes a procedure that utilizes a surgically implanted electrode to deliver electrical pulses to various regions of the brain. Stimulating the thalamus can reduce the occurrence of tremors, while stimulating the globus pallidus or the subthalamic nucleus can reduce tremor, bradykinesia and rigidity, as described by the National Institute of Neurologic Disorders and Stroke.
