Glossary of Parkinson's Disease Terms
Thalamus: A large group of brain cells centrally placed deep in the brain near its base and serving as a major relay station for impulses traveling from the spinal cord and cerebellum to the cerebral cortex.
Toxin: A poisonous substance.
Tremor: Rhythmic shaking and involuntary movement of part(s) of the body due to muscle contractions.
Unilateral: Occurring on one side of the body. Parkinson's disease symptoms usually begin unilaterally.
Wearing-off effect: The tendency, following long-term levodopa treatment, for each dose of the drug to be effective for shorter periods of time.