Pathophysiology of parkinsonian tremor: a focused narrative review

Tremor is one of the most common and most debilitating symptoms of Parkinson's disease (PD). Classic pill-rolling resting tremor is characteristic of PD and distinguishes it from other neurodegenerative disorders. Although it represents the most typical and most common form of tremor in PD, other tremor manifestations have also been reported to occur in PD. In this article, we review the current clinical classification of tremor with a focus on different types of parkinsonian tremor based on the consensus statement of the Movement Disorders Society. We also provide an overview of different hypotheses on the central mechanisms of the pathophysiology of parkinsonian tremor, and provide evidence for why peripheral mechanisms may play a role in the modulation of PD tremor.