Treating Parkinson's Disease

Parkinson's Disease (PD), of unknown cause, is the most common type (approximately 80%) of Parkinsonism, a condition characterized by changes in the brain's motor control areas (basal ganglia).(1) First described by James Parkinson in 1817, it is the name given to a whole group of conditions in which disruptions of motor and nerve function occur.(2) PD usually occurs between the ages of 40 and 70 years, with peak age of onset in the sixth decade, and it is rare before the age of 30. The symptom first noticed by a patient is a tremor at rest, often in the hand, which appears early in the disease and may remain throughout. Other secondary factors can cause the remaining 20% of Parkinsonism:

• Methanol (rubbing alcohol)
• Carbon monoxide intoxication
• Cyanide
• Carbon disulfide intoxication
• Manganese intoxication

• Creutzfeldt-Jakob disease
• AIDS
• Fungal infections

• Multi-strokes

• Chronic hepatocerebral (liver-brain) degeneration
• Hypocalcemia

• Lithium
• Dopamine receptor blockers (neuroleptics)
• Dopamine depleters (tetrabenazine, reserpine)

Parkinson's Disease is progressive, the symptoms worsening over the years. The main symptoms can be remembered with mnemonic PART:

• Postural reflex impairment (stooped posture)
• Akinesia/Bradykinesia (loss of voluntary movement)
• Rigidity (cogwheel) (stiff movements)
• Tremor (resting)

Initiation of treatment (especially drug therapy) is a very important decision in the management of PD and is highly individualized.(3) If the symptoms of disease do not affect the patient's life, treatment is usually not helpful. It is recommended that the disease be left untreated until it limits motor functions.

When treatment becomes necessary, physical therapy, with emphasis on posture and gait, should be the first component. Visualization techniques to improve gait can be particularly useful. Next, drugs and surgical techniques will need to be considered.

Many drugs are available. They are divided into four major categories:

Levodopa

• Carbidopa/Levodopa
• Carbidopa/Levodopa (controlled-release)

• Pramipexole (Mirapex®)
• Ropinirole (Requip®
• Pergolide (Permax®)
• Bromocriptine (Parlodel®)

• Tolcapone (Tasmar®)
• Entacapone (Comtan®) Investigational drug.

• Procyclidine (Kemadrin®)
• Trihexyphenidyl (Artane®)
• Benztropine (Cogentin®)

• Selegiline (Eldepryl®) (MAO-B inhibitor)
• Amantadine (Symmetrel®) (antiviral agent)
• Vitamin E
• Hormone Replacement Therapy (HRT)