Ablative Surgery

Also called destructive surgery — involves locating, targeting, then ablating (destroying) a specific brain region that has been altered or changed by Parkinson's disease.

Adjunct Therapy

Use of therapies in addition to the primary mode of treatment, i.e., the addition of a second Parkinson's disease therapy to either carbidopa/levodopa or another Parkinson's disease drug therapy.

Akinesia [A kih NEE zee uh]

Lack of or loss of the ability to initiate movement.

Bradykinesia [bray dee kih NEE zee uh]

Slowness of movement.

Bradyphrenia [bray dee fre NEE uh]

Slowness of thinking.

Deep Brain Stimulation (DBS)

Brain surgery in which an electrical stimulator is implanted into the patient’s chest under the skin with wires that run up through the neck to the brain where they can “turn-off” brain regions that can cause Parkinson's disease symptoms.

Dopamine

A neurotransmitter (chemical messenger) that transports signals to the parts of the brain that control movement.  

Dyskinesia [dis kih NEEZ ee uh]

Abnormal, random, involuntary movement.  

Dysphagia [dis FAY gee uh]

Difficulty swallowing.

Dystonia [dis TOH nee uh]

Sustained involuntary muscle contraction.

Freezing or Freezing of Gait (FoG)

The sudden but temporary inability to move the legs and feet when walking — the feeling of feet being glued to the floor.  

Hallucinations

Perception of objects, sounds, or sensations with no reality. 

Hoehn & Yahr Scale [HAY N and YAR]

A five-stage scale used by physicians and researchers to rate the level of disability and the severity of the symptoms caused by Parkinson's disease.

Hypokinetic Dysarthria [hy PO ki net ik dis ARTH ree uh]

Reduced speed and clarity of speech.

Hypophonia [hy PO fo nee uh]

Reduced speech volume.

Micrographia [my KRO graf ee uh]

Small, cramped handwriting.

Monotherapy

The use of a single therapy in the treatment of a condition, such as Parkinson's disease.

Motor Symptoms

Symptoms of Parkinson's disease affecting movement.

Neuron

A cell that conducts impulses and carries information from one part of the brain to another.

Non-motor Symptoms

Parkinson's disease symptoms unrelated to movement, such as depression, sleep disturbances, loss of energy and pain.

"Off" Time

Time when Parkinson's disease medications fail to control symptoms. Commonly experienced before a dose of medication has “kicked in,” or when an earlier dose has worn off.

"On" Time

Time when Parkinson's disease medications successfully control symptoms.  

On-Off Phenomenon

Unpredictable responses to a dose of levodopa, in which rapid switches are made between adequate symptom control (“on” time) and inadequate symptom control (“off” time).

Pallidotomy

One of the older surgical options used to limit Parkinson's disease symptoms, in which permanent lesions are made in the globus pallidus (a part of the brain) to “turn-off” symptoms.

Resting Tremor

A tremor that is more obviously seen when the affected body part is at rest.

Rigidity

Stiffness in the muscles or resistance to movement.  

Substantia Nigra [sub STAN shuh NIGH gruh]

One of the movement control centers in the brain where loss of dopamine-producing cells trigger Parkinson's disease symptoms.

Thalamotomy [THAL um ot o mee]

An older surgical option in which lesions are made in the thalamus to block tremor impulses.  

Thalamus [THAL uh mus]

A section of the brain where the loss of dopamine signals may produce tremor.  

Unified Parkinson’s Disease Rating Scale (UPDRS)

A scale used by physicians to assign a numerical rating to the various symptoms of Parkinson's disease and to determine the severity of the disease. In clinical trials, the UPDRS is often used to gauge the effectiveness of a treatment by measuring UPDRS scores at the initiation of a trial and again after the administration of a new treatment.