Parkinsonism is a term used to describe the collection of signs and symptoms found in Parkinson’s disease (PD). These include slowness (bradykinesia), stiffness (rigidity), tremor and imbalance (postural instability). Conditions other than PD may have one or more of these symptoms, mimicking Parkinson’s.

Idiopathic Parkinson’s is the most common form of Parkinsonism. However, about 15 percent of those with symptoms suggesting PD have one of several diseases termed, atypical parkinsonism disorders. These conditions are typically more difficult to treat than PD and include:

Multiple System Atrophy (MSA)

• MSA is a term encompassing several neurodegenerative disorders in which one or more systems in the body deteriorates.
• Similar syndromes include: Shy-Drager syndrome, striatonigral degeneration and olivopontocerebellar atrophy.
• Average age of onset is in the mid-50’s.

1. In 2007, a new classification was proposed with two major subtypes:
2. MSA-P (similar to SND) in which parkinsonism dominates.

• MSA-C in which cerebellar ataxia, (incoordination), dominates.
• MSA symptoms include: incoordination (ataxia), dysfunction in the autonomic nervous system that automatically controls things such as blood pressure and bladder function. These are in addition to variable degrees of parkinsonism including symptoms such as slowness, stiffness and imbalance.
• Initially, it may be difficult to distinguish MSA from Parkinson’s. More rapid progression, poor response to common PD medications and development of other symptoms in addition to parkinsonism may be clues.
• The diagnosis of MSA is made based on clinical features. There is no specific test that provides a definitive diagnosis.
• There is no specific treatment for MSA. Treatment focuses on alleviating symptoms.
• People with MSA usually respond poorly to PD medications and may require higher doses than the typical person with PD, often with only modest benefit.

Progressive Supranuclear Palsy (PSP)

• Most common degenerative type of atypical parkinsonism.
• Average age of onset is in the mid-60’s.
• Symptoms tend to progress more rapidly than PD. People with PSP may fall frequently early in the course of disease. Later symptoms include limitations in eye movements, particularly looking up and down, which also contributes to falls.
• Those with PSP also often have problems with swallowing (dysphagia), difficulty in producing speech (dysarthria), sleep problems, memory and thinking problems (dementia).
• The diagnosis of PSP is made based on clinical features. There is no specific test that provides a definitive diagnosis.
• There is no specific treatment for PSP. Treatment focuses on alleviating symptoms.

Corticobasal Syndrome (CBS)

• CBS is the least common of the atypical causes of Parkinsonism.
• Usually begins with symptoms affecting one limb. In addition to parkinsonism, other symptoms can include abnormal posturing of the affected limb (dystonia), fast, jerky movements ( myoclonus), difficulty with some motor tasks despite normal muscle strength (apraxia), difficulty with language (aphasia) among others.
• Typically begins after age 60.
• Progresses more rapidly than PD.
• No specific test for CBS. Treatment focuses on symptoms.
• Supportive treatment such as botulinum toxin (Botox®) for dystonia, antidepressants, speech and physical therapy may be helpful. Levodopa and dopamine agonists (common PD medications) seldom help.

Dementia with Lewy bodies (DLB)

• Dementia with Lewy bodies (DLB) is a progressive, neurodegenerative disorder in which abnormal deposits of a protein called alpha-synuclein build up in multiple areas of the brain.
• Dementia with Lewy bodies is second to Alzheimer’s as the most common cause of degenerative dementia that first causes progressive problems with memory and fluctuations in thinking, as well as hallucinations. These symptoms are joined later in the course of the disease by parkinsonism with slowness, stiffness and other symptoms similar to PD.
• While the same abnormal protein (alpha synuclein) is found in the brains of those with PD, when individuals with PD develop memory and thinking problems it tends to occur later in the course of the disease.
• There are no specific treatments for DLB. Treatment focuses on symptoms.

Drug-induced Parkinsonism

• This is the most common form of what is known as secondary parkinsonism.
• Side effects of some drugs, especially those affecting brain dopamine levels (anti-psychotic or anti-depressant medication), can cause parkinsonism.
• Although tremor and postural instability may be less severe, this condition may be difficult to distinguish from Parkinson’s.
• Medications that can cause the development of Parkinsonism include:

1. Antipsychotics
2. Certain antiemetics (anti-nausea medications)
3. Some antidepressants
4. Reserpine
5. Tetrabenazine
6. Some calcium channel blockers
7. Usually after stopping those medications parkinsonism gradually disappears over weeks to months, though symptoms may last for up to a year.

Vascular Parkinsonism (VP)

• There is some evidence to suggest that multiple small strokes in key areas of the brain may cause Parkinsonism.
• No specific clinical features or diagnostic tests reliably differentiate PD and vascular parkinsonism, though some features may suggest VP.
• A severe onset of parkinsonism immediately following (or progressively occurring within a year of) a stroke may indicate VP.
• Other signs that can indicate VP include: evidence of vascular disease on an MRI (magnetic resonance imaging) of the brain in combination with varying levels of deterioration, prominent early cognitive problems and lower body issues, such as early gait and balance problems.
• Dopaminergic medications (like levodopa) may possibly have modest benefit, depending on the location of vascular disease in the brain.