Action tremor: Rhythmic, involuntary movement of a limb when movement is initiated (for example, when writing or lifting a cup). Not usually seen in the earlier stages of Parkinson's disease.
Agonist: A chemical or drug that turns on or activates a particular part of a cell that regulates disease activity (receptor). For example, dopamine agonists used in the treatment of Parkinson's disease activate the dopamine receptors in the brain, resulting in improvement in symptoms.
Akinesia: Absence or difficulty in producing movements.
Alpha-Tocopherol: A biologically active form of vitamin E.
Amantadine (Gocovri, Osmolex, Symmetrel): A drug that improves the symptoms of Parkinson's by increasing the amount of a brain chemical called dopamine. Amantadine can reduce the involuntary movements of Parkinson's disease by acting on other brain chemicals as well.
Anticholinergic: A substance, usually a medication that halts the actions of a chemical that transmits signals between nerves called acetylcholine. The side effects include blurred vision and dry mouth.
Anticholinergic drugs (such as Artane and Cogentin): This group of drugs decreases the action of the nerve chemical acetylcholine. These drugs may help reduce rigidity, tremor, and drooling in Parkinson's.
Apomorphine: A drug used to treat severe Parkinson's. It is a form of morphine that can increase the amount of dopamine available in the brain, thereby decreasing symptoms of Parkinson's.
Ataxia: Loss of balance.
Athetosis: Abnormal involuntary movements that are slow, repetitive, and sinuous.
Autonomic nervous system: The part of the body's complex system of nerves that controls the involuntary activity of some of the internal organs, such as breathing or heartbeat.
Basal ganglia or nuclei: These are structures located deep in the brain that are responsible for normal movement such as walking. The basal ganglia are made up of three main parts, the caudate nucleus, the putamen, and the globus pallidus.
Benign essential tremor: A condition characterized by tremor of the hands, head, voice, and 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.
Beta-blockers: Drugs that block the action of the hormone epinephrine. Usually used to treat high blood pressure and heart disease, they may be effective in the treatment of benign essential tremor (see above).
Bilateral: Occurring on both sides of the body.
Blepharospasm: Spasms of the eyelid, spasmodic blinking, or involuntary closing of the eyelids.
Bradykinesia: Slowing down of movement. It is a major symptom of Parkinson's.
Carbidopa (Lodosyn): A drug that is usually given in combination with a Parkinson's drug called levodopa; the combination drug's brand name is Sinemet. Carbidopa improves the effectiveness of levodopa and can be used to reduce the side effects of levodopa.
Central nervous system (CNS): The brain and spinal cord.
Cerebellum: Part of the brain that is involved in coordination of movements.
Cerebral cortex: The largest part of the brain, responsible for thought, reasoning, memory, sensation, and voluntary movement.
Chorea: A type of abnormal movement or dyskinesia, characterized by continuing, rapid, dance-like movements. May result from high doses of levodopa and/or long-term levodopa treatment.
Choreoathetosis: A type of abnormal movement or dyskinesia characterized by involuntary jerky snake-like movements usually of the arms.
Cogwheel rigidity: Stiffness in the muscles, with a jerky quality when arms and legs are repeatedly moved.
Constipation: Decreased ability of intestinal muscles to move stool through the bowels, often resulting in difficulty moving the bowels or in very hard stools.
Cryothalamotomy: A surgical procedure where a "super-cooled" probe is inserted deep into the part of the brain called the thalamus in an effort to stop the tremors of Parkinson's. This type of surgery is rarely recommended and has been replaced by deep brain stimulation (DBS).
Deep brain stimulation (DBS): A new surgical procedure that is very effective in treating Parkinson's disease. The surgery includes the implantation of permanent electrodes in various parts of the brain through which continuous pulses of electricity are given to control the symptoms of Parkinson's.
Dementia: The loss of some intellectual abilities, characterized by loss of awareness and confusion.
Selegiline: (Deprenyl, Eldepryl, Emsam, Zelapar): A drug that slows the breakdown of important brain chemicals like dopamine. This medication may help slow the progression of Parkinson's disease early in the course of the illness.
Dopamine: A chemical produced by the brain; it assists in the effective transmission of messages from one nerve cell to the next. People with Parkinson's have decreased amounts of the chemical in the basal ganglia and substantia nigra, two structures located deep in the brain. Dopamine coordinates the actions of movement, balance, and walking.
Dopamine agonist: Drugs that copy the effects of the brain chemical dopamine and increase the amount of dopamine that is available to the brain for use.
Dopaminergic: An adjective used to describe a chemical, a drug, or a drug effect related to dopamine.
Drug-induced Parkinsonism: Parkinson's symptoms, which have been caused by drugs used to treat other conditions, (for example, Reglan, a drug used to treat stomach problems, and certain antidepressants).
Dysarthria: Speech difficulties due to impairment of the muscles associated with speech.
Dyskinesia: Abnormal muscle movements. May appear as a side effect of long-term drug treatment in Parkinson's and may worsen in response to stress. (See also Levodopa Induced Dyskinesia)
Dysphasia: Difficulty speaking.
Epinephrine (adrenaline): A hormone secreted from the adrenal glands (which sit atop the kidneys) 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. Epinephrine also acts as a chemical messenger in the brain to transmit signals between nerve cells.
Ethopropazine (Parsidol/Parsitan): A drug sometimes used in the past to treat Parkinson's disease.
Extrapyramidal nervous system: Refers to the basal ganglia and its connections, Mainly concerned with the regulation of automatic movements.
Festination: Walking in rapid, short, shuffling steps.
Flexion: A bent or curved posture.
Glaucoma: A sustained increase of pressure within the eyeball, which can injure the optic nerve and cause impaired vision or blindness. Although rare, treatment with anticholinergic drugs (see anticholinergic) may exacerbate glaucoma.
Globus pallidus: A structure located deep in the brain in the inner part of the basal ganglia.
Hypokinesia: Decreased motor activity.
Idiopathic: An adjective meaning "of unknown cause." The usual form of Parkinson's is idiopathic Parkinson's.
Intention tremor: Tremor occurring when the person attempts voluntary movement.
Lenticular nucleus: A group of nerve cells located in the basal ganglia, a structure deep within the brain. The lenticular nucleus contains the cells of the putamen and globus pallidus.
Levodopa: A drug, containing a form of the important brain chemical dopamine, commonly used to treat symptoms of Parkinson's disease. In combination with carbidopa, it is called Sinemet; combined with benserazide, it is called Prolopa.
Levodopa-induced dyskinesias: A side effect of taking levodopa that may occur with prolonged use and is marked by abnormal, involuntary movements. Reducing the amount of levodopa may alleviate the side effect.
Lewy body: Brain cells that have abnormal pigmented spheres inside them. They are found in the damaged parts of the brain in people with Parkinson's disease.
Livido reticularis: A purplish or bluish coloration of the skin seen usually below the knee and on the forearm in persons treated with amantadine (such as Symmetrel). This is usually a benign condition.
Micrographia: The tendency to have very small handwriting due to difficulty with fine motor movements in Parkinson's disease.
MPTP: A toxic chemical, exposure to which causes Parkinson's disease symptoms in some intravenous drug users. It is now used to produce Parkinson's symptoms in laboratory animals in order to study the disease.
Myoclonus: Jerking, involuntary movement of arms and legs, usually occurring during sleep.
Neostriatum: A vital part of the brain made up of caudate nucleus and putamen. These are part of the basal ganglia.
Neuroleptic drugs: (Also called major tranquilizers.) A group of drugs which block dopamine. These medications are used in the treatment of serious psychiatric conditions, but can produce or aggravate symptoms of Parkinson's disease. These drugs are sold under the brand names Haldol, Compazine, Stelazine, and Thorazine.
Neuron: A nerve cell
Neurotransmitter: A specialized chemical produced in nerve cells that permits the transmission of information between nerve cells. Dopamine is one example.
Nigrostriatal degeneration: Degeneration or destruction of the nerve pathways from the part of the brain called the substantia nigra to the basal ganglia or striatum. These pathways are normally rich in dopamine and are affected in Parkinson's disease.
Norepinephrine (Noradrenalin): Chemical transmitter found in the brain.
On-off effect: Fluctuations that occur in response to levodopa treatment in which the person's mobility changes suddenly and unpredictably from a good response (on) to a poor response (off).
Palilalia: A symptom of Parkinson's disease, in which a word or syllable is repeated and the flow of speech is interrupted.
Pallidectomy: A surgical procedure where the globus pallidus, a structure deep in the brain that is affected by Parkinson's disease, is removed to improve tremors, rigidity, and bradykinesia. This type of surgery is rarely recommended and has been replaced by deep brain stimulation (DBS).
Paraesthesia: Sensations, usually unpleasant, arising spontaneously in a limb or other part of the body, experienced as "pins and needles" or fluctuations of warmth or coldness.
Parkinson's facies: A stoic, mask-like facial expression, with infrequent blinking; it is characteristic of Parkinson's disease.
Parkinsonism: A group of symptoms that include tremor, rigidity, bradykinesia, stooped posture, and shuffling gait. The more common causes of Parkinsonism are Parkinson's disease, striatonigral degeneration, and a reversible condition induced by certain drugs.
Paralysis agitans: The Latin form of the older, popular term "shaking palsy," which was used to designate early Parkinson's diagnosis.
Postural instability: Difficulty with balance.
Postural tremor: Tremor that increases when hands are stretched out in front.
Pramipexole (Mirapex): A newer dopamine agonist that is tolerated well and is more effective than its predecessors.
Precursor: Something that precedes, (for example, Levodopa is a precursor to dopamine in that levodopa is converted to dopamine in the brain).
Progressive supranuclear palsy (PSP): A degenerative brain condition sometimes difficult to distinguish from Parkinson's disease especially in the early stages. PSP symptoms are rigidity and akinesia (loss of muscle movement), difficulty looking up and down, and speech and balance problems. Those with PSP often have poor response to Parkinson's disease medications.
Prolopa: A drug used to treat Parkinson's. It is composed of levodopa and benserazide.
Propulsive gait: Disturbance of gait typical of people with symptoms of Parkinson's in which, during walking, steps become faster and faster with progressively shorter steps that passes from a walking to a running pace and may precipitate falling forward.
Range of motion: The extent that a joint will move from being fully straightened to completely bent.
Rasagiline (Azilect): A once-daily drug that can be taken alone in early Parkinson's disease or with other medications as the disease progresses. Azilect slows the breakdown of the brain chemical dopamine. Early animal studies suggest Azilect may also slow progression of Parkinson's. Side effects include headache, joint pain, indigestion, and depression.
Receptor: A structure located on the nerve cell that receives the chemical messenger (neurotransmitter, such as dopamine) sent from an adjacent nerve cell. This is how nerve cells communicate. Most of the drugs used to treat Parkinson's disease are designed to interact with nerve cell receptors and improve nerve cell communication.
Resting tremor: Shaking that occurs in a relaxed and supported limb.
Retropulsive gait: Walking that is propelled backwards.
Rigidity: Muscular stiffness that is common in people with Parkinson's disease. It is characterized by a resistance to movement in the limbs.
Ropinirole (Requip): A new drug used to treat Parkinson's. It works by increasing the amount of dopamine available in the brain.
Rotigotine (Neupro): A dopamine agonist, this drug is approved for those with Parkinson's disease and restless legs syndrome. It comes in the form of a skin patch.
Seborrhoea: Increased oily secretions from the sweat glands of the skin; occurs often in those with Parkinson's disease.
Shaking palsy: Old term used for what we now call Parkinson's disease.
Shy-Drager syndrome/MSA: A rare condition where there is failure of the autonomic nervous system and abnormalities in muscle function. A person with Shy-Drager syndrome has symptoms of Parkinson's (Parkinsonism), extremely low blood pressure that worsens upon standing, bladder problems, severe constipation, and decreased sweating.
Sinemet: Trade name for the Parkinson's disease drug that is a mixture of levodopa and carbidopa.
Sinemet CR: A version of Sinemet that works for a longer period of time as it releases the drug more slowly into the body.
Stereotactic surgery: Surgical technique that involves placing a small electrode in an area of the brain to destroy a tiny amount of brain tissue (see deep brain stimulation).
Striatonigral degeneration: This is a condition where certain nerve pathways in the brain are destroyed. People with this condition also have Parkinsonism.
Striatum: The part of the basal ganglia (a structure located deep in the brain) controlling movement, balance, and walking.
Sustention or postural tremor: Tremor that increases when hands are stretched out in front.
Symmetrel (amantadine): A drug that releases the nerve chemical messenger dopamine and is useful in treating Parkinson's.
Tardive dyskinesia: This condition is a common side effect of long-term use of medications such as chlorpromazine, Haldol, and Loxapine. People with this condition have the characteristic abnormal, involuntary movements of the face and mouth or arms.
Thalamotomy: Operation in which a small region of the thalamus (a structure deep in the brain) is destroyed. Tremor and rigidity in Parkinsonism and other conditions may be relieved by thalamotomy. This surgery is rarely recommended and has been replaced by deep brain stimulation.
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.