Olfaction impairment in Parkinson's disease patients with tremor dominant subtype compared to those with akinetic rigid dominant subtype

Parkinson's disease (PD) may present with different motor subtypes depending on the predominant symptoms (tremor or rigidity/bradykinesia). Slower disease progression and cognitive decline have been observed in tremor-dominant (TD) patients compared to those with akinetic-rigid dominant (ARD) subtype. Olfactory disorders have been described in parkinsonian patients, although the definite correlations with different subtypes of PD are not clear. Thus, we investigated the possible olfactory impairment in PD patients with TD subtype in comparison to ARD subtype.