Characteristics of cognitive dysfunction in essential tremor patients

Objective: To explore the characteristics and influencing factors of cognitive dysfunction in patients with essential tremor (ET). Methods: We recruited ET patients diagnosed by the Department of Neurology of the First Affiliated Hospital of Xi'an Jiaotong University and healthy volunteers who matched the ET patients in age, gender and education level for the study. We recorded all the patients' demographic information, tremor degree, and family history based on the family tree. All the participants were tested by MMSE, MoCA, ADL, HAMD and HAMA. Results: There were 88 ET patients and 63 normal subjects included in the study. According to MMSE, 31.82% of the patients had cognitive dysfunctions, with orientation, short-term memory, calculation ability, language skills, retelling, reading comprehension, three-level command and drawing being significantly lower than those of the healthy volunteers (P<0.01); orientation was the most serious damage in cognitive function domain (K=0.624, S=0.726); three-level command was the least serious damage (K=0.274, S=0.319). According to MoCA, 86.36% of the ET patients had cognitive dysfunction higher than normal people (P<0.05); visual space and execution, clock drawing task, naming, attention, “100-7”, language skills, abstract thinking and orientation were significantly lower than normal people (P<0.01); the most serious damage in cognitive function domain was visual space and execution (K=0.651, S=0.786); the least serious damage cognitive function domain was “100-7” (K=0.406, S=0.484). Education level and age affected cognitive dysfunction (P<0.05). ADL scores showed negative correlation with cognitive function (correlation =-0.375 and -0.383, respectively; P<0.001). After the effects of anxiety and depression were excluded, onset age and tremor grading were correlated with cognitive dysfunction (P<0.05). When the above factors were put into binary Logistic regression model, education level was found to be contributed to the model (P<0.05). Conclusion: Patients with ET widely suffer from cognitive impairment. Age, education level, daily life disability, age of onset, and tremor degree classification can affect cognitive dysfunction.