AUTHOR=Shang Yajun , Chen Xinjie , Ai Mingda , Gao Xiaoran , Dai Shujuan , Zhao Mingjie , Yang Cen , Wang Liangfeng , Zhang Junyan , Zhong Lianmei , Bao Tianhao , Liu Xiaolei 

TITLE=Association of Essential Tremor With Dementia and Affective Disorders: A Meta-Analysis

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.842732

DOI=10.3389/fneur.2022.842732

ISSN=1664-2295

ABSTRACT=Background: The dementia and affective disorders are common non-motor features in patients with essential tremor (ET). However, the relationship of ET with cognitive impairments and affective disorders remains controversial. This meta-analysis aimed to analyze the association of ET with dementia and affective disorders.
Methods: Original studies published from Jan 1999 to Oct 2019 were systematically searched from the database of Medline (OvidSP), EMBASE(OvidSP) and the Cochrane Central Register of Controlled Trials. Pooled standard mean difference (SMD, random effect model), odds ratios (ORs), relative risk (RR), and 95% confidence interval (CI) were calculated.  
Results: Compared with non-ET group, ET patients had significantly lower Mini-Mental State (MMSE) score (SMD, −1.16; 95% CI, −1.75 to -0.58; P=0.0001), and had significantly higher depressive and anxiety symptoms scale score (SMD, 0.55; 95% CI, 0.22 to 0.87; P=0.0009). The OR for dementia and affective disorders in individuals with ET compared with individuals without ET was 2.49 (95% CI, 2.17 to 2.85, P＜0.00001). While there was no significance difference in Montreal Cognitive Assessment (MoCA) score between ET and Non-ET groups (SMD, −0.52; 95% CI, -0.16 to 0.13; P =0.23), there was significant difference in the risk of mortality between ET and Non-ET groups (RR=4.69, 95% CI, 2.18 to 10.07).
Conclusion: The non-motor symptoms should not be neglected among ET patients. However, the causal relationship between ET and dementia, depression, and anxiety is unclear.