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. The underlying causes of parkinsonism are numerous, and diagnosis can be complex. 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.
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.
If PD has been excluded, the differential diagnosis
or list of potential causes for this syndrome includes:
- AIDS can sometimes lead to the symptoms of Parkinson's disease, due to commonly causing dopaminergic dysfunction.
- Corticobasal degeneration
- Creutzfeldt-Jakob disease
- Diffuse Lewy body disease
- Drug-induced parkinsonism (due to drugs such as antipsychotics, metoclopramide, MPTP)
- Encephalitis lethargica
- Multiple system atrophy
- Pantothenate kinase-associated neurodegeneration (Hallervorden-Spatz syndrome)
- Progressive supranuclear palsy
- Toxicity due to substances such as carbon monoxide, carbon disulfide, manganese, paraquat, hexane, rotenone, and toluene.
- Vascular parkinsonism
- Wilson's disease is a genetic disorder in which there is an abnormal accumulation of copper. The excess copper can lead to the formation of a copper-dopamine complex, which leads to the oxidation of dopamine to aminochrome.
- Paraneoplastic syndrome. Neurological symptoms caused by antibodies associated with various cancers.