Evaluation of olfactory functions in essential tremor

Objective: Recently, non-motor symptoms are increasingly recognized in patients with essential tremors. This study evaluates essential tremor (ET) patients' olfactory dysfunction, a notable non-motor symptom.Method: This study included 34 patients with ET and 25 healthy controls. Participants underwent nasal examinations and the Connecticut Chemosensory Clinical Research Center (CCCRC) odor test.Results: The ET patients had significantly lower CCCRC odor total scores (p=0.044) and odor threshold scores than the control group (p=0.007). However, both groups had similar CCCRC odor discrimination scores (p>0.05). While not statistically significant, a positive correlation was observed between the tremor duration and odor scores (p>0.05).Conclusion: Our study demonstrates the impairment of olfactory functions in ET patients, reinforcing the notion of a neurodegenerative process. Further large-scale studies examining additional non-motor symptoms could provide deeper insights into the disease's pathogenesis.