Abstract
BACKGROUND: Parkinson's disease (PD) is characterized by various motor symptoms, with tremors being the most common symptom. This case series reports two sporadic cases of re-emergent tremors involving the tongue in patients with PD, and discusses their clinical significance. CASES: The first case involved a 74-year-old man with a 7-year history of parkinsonism who developed a re-emergent tongue tremor at 4-5 Hz, emerging approximately 3 seconds after tongue protrusion. The second case describes a 65-year-old woman with a 25-year history of PD who exhibited a similar re-emergent tongue and jaw tremor with 3-s latency. LITERATURE REVIEW: A literature review identified five previous case reports of re-emergent tremors of the tongue and jaw lip in patients with PD. The tongue appears to be the most commonly involved site among the facial regions affected by re-emergent tremors. The frequency and latency of tongue and jaw re-emergent tremors were similar to those observed in upper limb tremors, suggesting a shared underlying mechanism. CONCLUSION: This case series highlights the recognition of re-emergent tremors in the facial regions as potential manifestations of PD, and emphasizes the need for more comprehensive and standardized assessment protocols for neurological examinations.