Parkinsonism

Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia, rigidity, and postural instability.^[1][2] Parkinsonism shares symptoms found in Parkinson's disease, from which it is named; but parkinsonism is a symptom complex, and differs from Parkinson disease which is a progressive neurodegenerative illness. The underlying causes of parkinsonism are numerous, and diagnosis can be complex.^[3][4] The neurodegenerative condition Parkinson's disease (PD) is the most common cause of parkinsonism. However, a wide range of other etiologies may lead to a similar set of symptoms, including some toxins, a few metabolic diseases, and a handful of neurological conditions other than Parkinson's.^[5]

About 7% of people with parkinsonism have developed their symptoms following treatment with particular medications. 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. The incidence of drug-induced parkinsonism increases with age. Drug induced parkinsonism tends to remain at its presenting level, i.e. does not progress like the parkinson disease.^[6]

Differential diagnoses

Before Parkinson's disease is diagnosed the differential diagnoses include:

• AIDS can sometimes lead to the symptoms of secondary parkinsonism, due to commonly causing dopaminergic dysfunction. Indeed, parkinsonism can be a presenting feature of HIV infection.^[7]
• Corticobasal degeneration^[1]
• Creutzfeldt-Jakob disease^[8]
• Dementia pugilistica or "boxer's dementia" is a condition that occurs in boxers due to chronic brain trauma
• Diffuse Lewy body disease^[1]
• Drug-induced parkinsonism ("pseudoparkinsonism") due to drugs such as antipsychotics, metoclopramide, MPTP^[1][9]
• Encephalitis lethargica^[1]
• Essential tremor, an illness which has some diagnostic overlap with Parkinson's disease.^[10]
• Multiple system atrophy^[11]
• Pantothenate kinase-associated neurodegeneration, also known as Neurodegeneration with brain iron accumulation (NBIA) or Hallervorden-Spatz syndrome^[12][13]
• Parkinson plus syndrome
• Progressive supranuclear palsy^[1]
• Toxicity due to substances such as carbon monoxide,^[14] carbon disulfide,^[14] manganese,^[14] paraquat,^[15] mercury,^[16] hexane, rotenone, and toluene^[17] (inhalant abuse: "huffing")^[18]
• Vascular parkinsonism, associated with underlying cerebrovascular disease^[19][20]
• 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.^[21] The most common manifestations include bradykinesia, cogwheel rigidity^[22] and a lack of balance.^[23]
• Paraneoplastic syndrome: neurological symptoms caused by antibodies associated with cancers
• Genetic
  • Rapid onset dystonia parkinsonism (DYT12)
  • Parkin mutation
  • X-linked dystonia parkinsonism (DYT3)
  • Autosomal recessive juvenile parkinsonism (ARJP)

References

External links

• GeneReviews/NIH/NCBI/UW entry on Perry syndrome
• GeneReviews/NCBI/NIH/UW entry on X-Linked Dystonia-Parkinsonism