The relationship between leukocyte-based inflammation indices and essential tremor

Abstract

Aim: Previous limited studies have indicated that pro-inflammatory cytokines are elevated in patients with essential tremor (ET). This elevation could lead to a more pronounced inflammatory response in these patients. Thus, this study aimed to investigate the relationship between leukocyte-based inflammatory indices and ET. Material and Methods: In this retrospective study, 103 patients diagnosed with ET between January 2021 and December 2023 were included, along with 103 healthy individuals who were matched by age and gender, participated in check-up programs, and had no other comorbidities. To evaluate tremor severity, the Fahn-Tolosa-Marin (FTM) tremor rating scale was utilized. The leukocyte-based inflammatory indices were calculated as follows: NLR= neutrophils / lymphocytes, PLR = platelets / lymphocytes, systemic immune-inflammation index (SII) = platelets × neutrophils / lymphocytes, and systemic inflammatory response index (SIRI) = neutrophils × monocytes / lymphocytes. Results: The ET group exhibited higher levels of leukocytes, their subtypes, CRP and leukocyte-based inflammatory indices compared to the control group. Increased CRP (OR= 3.71, p < 0.001) and SIRI (OR= 11.73, p < 0.001) levels were independent predictors of ET. In predicting ET. SIRI exhibited superior diagnostic performance compared to other inflammatory parameters. The threshold for SIRI levels was set at 7 and above, with a sensitivity of 85.4% and a specificity of 82.5%. There was a positive correlation between SIRI and FTM scores. Conclusion: Among the leukocyte-based inflammation indices, SIRI demonstrated superior diagnostic performance in predicting ET and was associated with higher tremor severity. This suggests that inflammation may play a potential role in the pathophysiology of ET.