ABSTRACT
Parkinson’s disease (PD) is primarily a clinical diagnosis with a phenotype characterized by bradykinesia, rigidity, tremor and postural instability. Non-motor manifestations, such as anosmia and autonomic dysfunction, are also common in PD. Another clinical feature used by some investigators to confirm the diagnosis of PD is sustained clinical response to dopamine replacement therapy.1 While the usual pathological substrate of PD is Lewy body disease (LBD), other pathological entities such as progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) less often clinically resemble PD.2 The latter disorders usually have other features that are not common in PD such as eye movement abnormalities and cerebellar signs.
