Acetylcholine: a chemical messenger (neurotransmitter) released by cholinergic nerves in the striatum area of the brain. It is involved in many brain functions, such as memory and control of motor activity. There appears to be an interplay between the actions of acetylcholine and dopamine.
Action tremor: a tremor that occurs or increases when the hand is moving voluntarily
Adjunctive: supplemental or secondary (but not essential) to the primary agent; sometimes used to describe medications to enhance levodopa therapy
Agonist: a chemical or drug that enhances the activity of a neurotransmitter such as dopamine
Akinesia: delay in initiating movement; inability to move; “freezing”
Ancillary: auxiliary; serving as an aid
Antioxidant: an agent that prevents the loss of oxygen in chemical reactions
Anxiolytic: an agent or a class of medications that reduce anxiety
Apoptosis: a form of cell death in which cells shrink and disappear; sometimes referred to as “cell suicide”. In Parkinson’s disease, some scientists believe that the nerve cells in the substantia nigra portion of the brain die by apoptosis.
Ataxia: loss of balance
Athetosis: slow, involuntary movements of the hands and feet (see Dyskinesia)
Autonomic nervous system: the system that controls involuntary body functions
Blepharospasm: involuntary clinching of the eyelid
Blood-brain barrier: the protective membrane that separates the bloodstream from brain tissue
Bradykinesia: slowness of movement
Bradyphrenia: slowness in thought processing
Chorea: excessive involuntary movements, ranging from twisting or writhing to flailing movements of the extremities (see Dyskinesia)
Cogwheeling: a ratchet-like movement in the joints, characteristic of Parkinson’s disease
CT Scan: Computerized Tomography; a type of x-ray; also known as a CAT Scan
Delusion: false, fixed belief, not substantiated by sensory or objective evidence
Dementia: a range of symptoms such as disorientation, confusion, memory loss, impaired judgment, and alterations in mood and personality — symptoms can arise from a variety of causes
DNA (deoxyribonucleic acid) : the basic chemical substance that makes up the gene
Dopamine: achemical messenger (neurotransmitter) in the brain that controls movement
Dysarthria: low voice volume or muffled speech
Dyskinesia: abnormal, involuntary, purposeless body movements that can appear as jerking, fidgeting, twisting, and turning movements; frequently induced by Parkinson medications. They may be mild (slight ankle twisting) or severe (uncontrollable writhing movements). Dyskinesias are usually felt during the time you are on when you have taken your medication; this is also called “peak dose dyskinesias”. Dystonia, athetosis, and chorea are forms of dyskinesias.
Dysphagia: difficulty in swallowing
Dystonia: involuntary spasms of muscle contraction which cause abnormal movements and postures (see Dyskinesia)
Endogenous: originating internally; developing from within, rather than caused by external factors; the opposite of exogenous
Essential tremor (ET): a condition more common than Parkinson’s disease, which often includes shaking of the hands or head, and an unsteady quality of the voice
Etiology: the causes or origins of a disease. The etiology of Parkinson’s disease is not known.
Exogenous: originating externally; arising from external rather than internal factors; the opposite of endogenous
Festination: short, shuffling steps
Free radicals: toxic substances that are continuously produced by all cells of the human body
Freezing: temporary, involuntary inability to take a step or initiate movement
Half life: the time taken for the concentration of a drug in the bloodstream to decrease by one-half. Drugs with a shorter half life must be taken more frequently.
Hallucinations: hearing sounds or seeing animals, objects or people that are not real
Hypomimia: decreased facial expression due to rigidity of facial muscles
Idiopathic: of unknown origin or without apparent cause (Idiopathic Parkinson’s disease)
Lewy bodies: pink-staining spheres found in nerve cells, considered to be a pathological marker for Parkinson’s disease
Livido reticularis: purplish or bluish mottling of the skin caused by certain Parkinson medications
Micrographia: small, cramped handwriting
MPTP: a chemical produced during an attempt to make a synthetic narcotic. MPTP produces a condition that mimics Parkinson’s disease
Myoclonus: abrupt, jerking movements of the arms or legs, usually occurring during sleep
MRI (Magnetic Resonance Imaging) : computerized images based on nuclear magnetic resonance of atoms within the body induced by radio waves
Neuroleptics: drugs that block dopamine receptors, usually prescribed to treat psychiatric symptoms
Neuron: a cell that generates or conducts electrical impulses to carry information from one part of the brain to another
Neurotransmitter: a chemical substance (such as dopamine, acetylcholine, or norepinephrine) that carries impulses from one nerve cell to another
Neurotrophic factors: substances that prevent nerve cells from dying
Norepinephrine: chemical transmitter involved in regulating the involuntary nervous system
Off-On phenomenon: sudden, unpredictable changes in motor performance by people on levodopa therapy; When medications such as levodopa relieve symptoms, you are in your “on” state. This means you can do your daily activities. When the medication does not work and the symptoms return, you are in your “off” state. This means you may not be able to do the things you want or need to do.
Orthostatic hypotension: a drop in blood pressure upon standing; can cause fainting
Palsy: paralysis of a muscle group
Pathogenesis: the production or development of a disease
PET (positron emission tomography) : an imaging method that allows one to see brain dopamine systems using an injection of a radioactive substance
Postural tremor: the rhythmic shaking of the hands with arms outstretched
Resting tremor: one of the primary symptoms of Parkinson’s disease; typically present in arm, leg, lips, chin or tongue; tremor occurs or worsens when at rest; decreases with active motions.
Rigidity: increased resistance to the passive movement of a limb
Striatum: the area of the brain that controls movement, balance, and walking
Substantia nigra: area of the brain where cells produce dopamine
Wearing-off phenomenon: reduced effectiveness of levodopa prior to the scheduled time for the next dose, resulting in decreased motor performance; If your symptoms return before your next dose of medication, it means you are in a “wearing off” state.
Sources: National Parkinson Foundation (US), www.parkinson.org, November 2007.
Young Onset Parkinson’s Association, www.yopa.org, 2007.
PEP: Parkinson Education Program for Community Caregivers , Parkinson Canada Southwestern Ontario Region, 2007.