What is parkinsonism?

Parkinsonism refers to a collection of symptoms, including slow movement, tremor, stiffness and difficulty walking. This set of symptoms is present in several disorders, including Parkinson’s disease (PD), which are known as ‘parkinsonian’ conditions. Making a specific and definite diagnosis of PD is sometimes difficult, since various parkinsonian conditions produce similar symptoms, at least at the beginning of the illness.

Diseases that may be confused with PD include:

• essential tremor – produces a tremor of the limbs. There is usually only a tremor of the arms and head, typically present on both sides of the body, and becoming worse during activity. In contrast, the tremor in PD may affect only one side of the body, and is present at rest
• drug-induced parkinsonism – condition in which the symptoms of PD are mimicked by the use of a medication. The symptoms may disappear completely when the medication causing the problem is withdrawn
• vascular parkinsonism – condition in which individuals suffering from cerebrovascular disease (i.e., disease affecting blood vessels supplying the brain) have features that resemble PD but which do not respond well to treatment with the medication levodopa
• rare parkinsonisms – collection of uncommon disorders that appear similar to PD at the start, but often develop differently. These disorders include multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD)