Box 2:

Differential diagnosis of idiopathic Parkinson's disease

Degenerative disorders

  • Multiple system atrophy parkinsonian type

  • Progressive supranuclear palsy

  • Corticobasal degeneration

  • Dementia with Lewy bodies.

Nondegenerative disorders

  • Essential tremor

  • Dystonic tremor

  • Vascular parkinsonism

  • Drug-induced parkinsonism

  • Tremor related to metabolic (eg hyperthyroidism) or functional causes.