Cognitive Impairment in Essential Tremor without Dementia

BACKGROUND AND PURPOSE: Several clinical studies have demonstrated that patients with essential tremor (ET) may have cognitive deficits; however, there are no published data regarding detailed neuropsychological assessments of ET without dementia. We therefore conducted a case-control study of cognitive function in patients with ET. METHODS: The cohort for this study comprised 34 consecutive patients with ET without dementia and 33 age-matched controls, all of who completed a dementia-screening questionnaire and underwent a detailed neuropsychological investigation. RESULTS: Severe impairments were observed in most domains for the ET group compared to the controls, including attention, part of language function, verbal memory, and frontal executive functions. CONCLUSIONS: Our results support the finding that the subclinical cognitive deficits characterized by attention, verbal memory impairments, and executive dysfunction are a clinical feature of ET. In addition, our results also support the finding that age at examination and educational status are the most important risk factors associated with cognitive deficits in patients with ET.