Parkinsonism (also known as Parkinson's syndrome, atypical Parkinson's, or secondary Parkinson's) is a neurological
syndrome characterized by
tremor,
hypokinesia,
rigidity, and
postural instability.
[1] The underlying causes of parkinsonism are numerous, and diagnosis can be complex.
[2] While the
neurodegenerative condition
Parkinson's disease (PD) is the most common cause of parkinsonism, a wide-range of other
etiologies can lead to a similar set of symptoms, including some
toxins, a few
metabolic diseases, and a handful of non-PD neurological conditions.
[3] Its most common cause is as a side effect of medications, mainly neuroleptic antipsychotics especially the
phenothiazines (such as perphenazine and chlorpromazine),
thioxanthenes (such as flupenthixol and zuclopenthixol) and
butyrophenones (such as haloperidol (Haldol)),
piperazines (such as ziprasidone), and rarely, antidepressants.