Yawning-related tremor in patients with Parkinson's disease: prevalence and clinical associations

This cross-sectional study of 119 Parkinson's disease patients found yawning-triggered tremor (YRT) significantly more prevalent in PD (18.5%) than controls (2.7%), with notably higher rates in patients with concurrent essential tremor (41.2%) or REM sleep behavior disorder (68.2%). In approximately one-third of cases, YRT preceded motor symptom onset by ~21 months, suggesting it may serve as an early neurodegeneration marker reflecting shared brainstem pathophysiology.