Association of Cognitive Impairment with Essential Tremor Patients

Abstract

Background: Tremor is the most common involuntary movement disorder. Among all causes, Essential tremor (ET) is the most common action tremor. It is a monosymptomatic disease. However, many studies in different countries have shown that ET is associated with cognitive deficits, mainly in attention, memory, and visuospatial processes. So, exploration of all cognitive impairments of ET may help in setting the management plan.

Methodology: This cross-sectional observational study was conducted in the Department of Neurology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from November 2021 to August 2022. All patients aged more than 18 years who were diagnosed with essential tremors by a movement disorder specialist, fulfilling the inclusion and exclusion criteria, were taken as the study population. The same number of age and sex-matched healthy subjects were enrolled as controls in this study. Then the cognitive function of essential tremor patients and healthy controls was evaluated by the Montreal Cognitive Assessment (MoCA) scale.

Result: A total number of 120 subjects were recruited for this study, of which 60 patients were in the case group presenting with essential tremor and the rest of 60 subjects were healthy controls. The mean visuospatial score with SD among the case and control groups was 2.98±1.228 and 3.43±0.647, respectively (p value=0.014). The mean naming score with SD among the case and control groups was 2.78±0.415 and 2.90±0.303, respectively (p value=0.082). The mean score of attention variables of the MoCA scale with SD among the case and control groups was 3.33±1.100 and 3.72±0.691, respectively (p value=0.024). The mean score of language variables of the MoCA scale with SD among the case and control groups was 2.05±0.910 and 2.48±0.504, respectively (p value=0.002). The mean score of abstraction variables of the MoCA scale with SD among the case and control groups was 1.45±0.622 and 1.48±0.504, respectively (p value=0.748). The mean score of delayed recall variables of the MoCA scale with SD among the case and control groups was 1.76±0.817 and 2.97±0.663, respectively (p value=0.000). The mean score of orientation variables of the MoCA scale with SD among the case and control groups was 5.17±0.847 and 5.68±0.469, respectively (p value=0). The mean score of the total MoCA score with SD among the case and control groups was 20.18±3.301 and 22.67±2.137, respectively (p value=0.000).

Conclusion: In conclusion, cognitive impairment, including visuospatial function, attention, language, delayed recall, orientation variable as well as total MoCA score are significantly associated with essential tremor patients.