Association of motor subtype and tremor type with Parkinson's disease progression: An exploratory longitudinal analysis

BackgroundParkinson's disease (PD) is a neurodegenerative disorder with heterogenous symptoms and progression rates. Some studies have classifying PD into tremor-dominant and non-tremor-dominant PD (TD-PD and Non-TD-PD), finding that TD-PD tend to have a better prognosis, slower disease progression, and lower pathological burden compared to Non-TD-PD. However, this classification does not consider the specific types of tremors, even though recent studies have shown that different types of tremors in PD might have distinct underlying mechanism.ObjectiveData from 517 de novo drug-naïve PD patients was analyzed.MethodsSurvival analysis was carried out including motor subtypes, rest tremor presence, kinetic tremor presence, postural tremor presence, as well as the instability of tremor presence or motor subtypes as predictors. Occurrence of 6 outcomes, including motor and non-motor milestones at follow-up, were used as the time-to-event.ResultsBoth TD-PD subtype and rest tremor presence was associated with slower PD progression, while kinetic tremor presence and postural tremor presence, especially kinetic tremor presence, was associated with a faster one.ConclusionsOur study suggests different types of tremors are associated with distinct PD prognoses, indicating potential differences in underlying mechanisms. Further investigation is warranted to elucidate the specific mechanisms underlying different types of tremors in PD and to explain their relationship to disease prognosis.