Motor symptoms – resting tremor

Tremors are a common and highly-visible symptom of PD, typically present when the patient is fully at rest.⁵ The shaking action tends to be a rhythmic, medium-frequency oscillation.¹ It starts when the particular body part is relaxed and supported by a surface, disappears with active movement, and then returns again once movement has ceased (re-emergent tremor).¹ Whilst this pattern is normally a tell-tale symptom of parkinsonism, it is not unknown for some patients with PD to present with tremors during active movement (action tremor).⁵

Tremor occurs mostly in the upper and lower limbs, as well as the tongue and jaw, while head tremor is less common.¹ The classic form of resting tremor in patients with PD is the so-called ‘pill-rolling’ action, during which the thumb repeatedly rubs against the index finger.¹ Fingers may also repeatedly flex and extend in a tapping-like movement.¹

References:
1.Massano J, Bhatia KP. Clinical approach to Parkinson’s disease: features, diagnosis, and principles of management. Cold Spring Harb Perspect Med 2012; 2 (6): a008870.

2.Pfeiffer RF, Wszolek ZK, Ebadi M. Parkinson’s Disease, 2nd edition. Boca Raton: CRC Press, 2012.

3.Belvisi D, Conte A, Bologna M, et al. Re-emergent tremor in Parkinson’s disease. Parkinsonism Relat Disord 2017; 36: 41–46.

4.Lenka A, Jankovic J. Tremor syndromes: an updated review. Front Neurol 2021; 12: 684835.

5.DeMaagd G, Philip A. Parkinson’s disease and its management. Pharmacol Therapeut 2015; 40 (8): 504–510.