Word	Description
	AA Test Glossary	AA Test Glossary AA Test Glossary AA Test Glossary
	Acetylcholine	A chemical that acts as a neurotransmitter. An imbalance between dopamine and acetylcholine results in some Parkinson’s disease symptoms.
	Action Tremor	Rhythmic, involuntary movement of a limb when movement is initiated, e.g., when writing or lifting a cup. Not usually seen in the earlier stages of Parkinson’s.
	Activities of Daily Living (ADL)	Activities of Daily Living that people with Parkinson’s disease may have difficulty with, including: dressing, cooking, house cleaning, child rearing, walking. There is a sub-scale within the United Parkinson’s Disease Rating Scale that formally measures ADL.
	Adrenaline (epinephrine)	The neurotransmitter of the adrenal gland which is secreted in moments of crisis. It stimulates the heart to beat faster and work harder, increases the flow of blood to the muscles, causes an increased alertness of mind, and produces other changes to prepare the body to meet an emergency.
	Agonist	A chemical or drug, which increases neurotransmitter activity by stimulating the dopamine receptors directly.
	Akinesia	Difficulty initiating body movement; it could also describe marked slowness or complete absence of movement.
	Allograft	Transplant cells taken from a different member of the same species (such as using a human fetus for human brain cell transplantation).
	Alpha-Tocopherol	Chemical name for biologically active form of Vitamin E.
	Amantadine	A drug, which stimulates the release of available dopamine in the brain.
	Amino Acid Decarboxylase (AADC)	On of the two main enzymes (the other one being catechol-O-methyltransferase or COMT) that is responsible for the breakdown of levodopa in the bloodstream before it reaches the brain. AADC breaks down levodopa into dopamine before it can cross the blood brain barrier.
	Anticholinergic	Anti-Parkinson drugs that block the action of acetylcholine, thereby rebalancing it in relation to dopamine and reducing rigidity and tremor; e.g. Artane, Cogentin. The specified drugs may help reduce rigidity, tremor and drooling in Parkinson’s.
	Antihistamines	Drugs that are often used to relieve cold or allergy symptoms (i.e., Benadryl) but may also be effective in reducing tremor.
	Apnea	Cessation of breathing.
	Apomorphine	A dopamine agonist given as a continuous subcutaneous infusion or as a subcutaneous injection. Apomorphine is used to alleviate the symptoms of severe PD that is responding poorly to levodopa. It is of particular benefit in patients with PD that experience “off” times that last more than 30 minutes as it reverses symptoms within 10-15 minutes.
	Ataxia	Loss of balance
	Athetosis	Dyskinesias in which there are slow, repetitive, sinuous involuntary movements.
	Auditory hallucinations	State of hearing voices or sounds that are not real.
	Autonomic Nervous System	That part of the nervous system that is responsible for automatic functions, such as the heartbeat, digestion and salivation.
	Axon	The long, hair-like extension of a nerve cell that carries a message to the next nerve cell.
	Basal Ganglia or Nuclei	Deeper structures in the brain, concerned with normal movement and walking. The caudate nucleus, putamen and substantia nigra are basal ganglia affected in Parkinson’s.
	Benign Essential Tremor	A condition characterized by tremor of the hands, head, voice, and sometimes other parts of the body. Essential tremor often runs in families and is sometimes called familial tremor. It is sometimes mistaken for a symptom of Parkinson’s . However, this is an action tremor and there is no rigidity or bradykinesia.
	Benzodiazepines	A class of anti-anxiety medications
	Beta-Blockers	Drugs which block the action of epinephrine at certain sites. Usually used to treat hypertension and heart disease, they may be effective in the treatment of benign essential tremor.
	Bilateral	Occurring on both sides of the body.
	Blepharospasm	Spasmodic blinking or involuntary closing of the eyelids; a type of dystonia.
	Blink rate	The number of times per minute that the eyelid automatically closes. A normal rate may be 10 to 30 times per minute; for the parkinsonian it may be 0 to 5 times per minute.
	Blood-brain barrier	The protective membrane that separates circulating blood from brain cells. Many drugs pass less readily into the brain than into the other tissues. This difference in permeability is known as the blood-brain barrier.
	Bradykinesia	Deeper structures in the brain, concerned with normal movement and walking. The caudate nucleus, putamen and substantia nigra are basal ganglia affected in Parkinson’s.
	Carbidopa	A drug that inhibits the action of amino acid Decarboxylase (AADC), an enzyme responsible for the breakdown of levodopa in the blood before it reaches the brain. Carbidopa allows more levodopa to cross the blood-brain barrier to be converted into dopamine. Virtually all levodopa therapy today is administered in a combination pill with Carbidopa (Sinemet).
	Cardinal symptom	A principal or essential symptom of a disease or syndrome
	Cataplexy	Sudden attacks of muscle weakness triggered by laughter or other emotions
	Central Nervous System (CNS)	Consists of the brain and spinal cord.
	Cerebellum	Part of the brain that is involved in coordination.
	Cerebral Cortex	The largest part of the brain; responsible for thought, reasoning, memory, sensation and voluntary movement.
	Chorea	A type of dyskinesia (abnormal movement), characterized by continuing, rapid, dance-like movements. May result from high doses of levodopa and/or long term levodopa therapy.
	Choreoathetosis	A dyskinesia characterized by choreic and athetoid movements.
	Circadian dysrhythmias	A sleep disorder in which an individual’s biologic clock has shifted.
	COMT	Otherwise known as catechol-O-methyltransferase, it is one of the two main enzymes (the other one being amino acid Decarboxylase – AADC) responsible for the breakdown of levodopa before it reaches the brain. COMT breaks down levodopa into 30-O-methyldopa before it can be converted to dopamine in the brain.
	COMT inhibitor	Inhibits the action of catechol-O-methyltransferase (COMT), a key enzyme responsible for the breakdown of levodopa in the bloodstream before it reaches the brain. COMT inhibitors improve delivery of levodopa to the brain.
	Constipation	Diminished ability of intestinal muscles to move feces (stool), often resulting in very hard stool. A common problem in Parkinson’s patients.
	Corpus straitum	Also known as the striatum, it is the largest part of the basal ganglia. This area receives information about the position and movement of the body form several different parts of the brain and transmits it to the substantia nigra. The globus pallidus forms part of the corpus striatum.
	Cowheel rigidity	A ratchet-like movement in the joints, characteristic of PD.