Test time affects the detection of cognitive dysfunction by Montreal Cognitive Assessment in elderly patients after stroke

Abstract

Objective To compare if the Montreal cognitive assessment (MoCA) performed in the morning or afternoon would affect abnormal rate of cognitive function in the elderly with stroke. Methods A total of 378 senile patients (≥ 65 years) with acute ischemic stroke and low NIHSS score (≤ 3) were enrolled in the prospective study, which was held in the Department of Neurology at Cangzhou Hospital of Integrated Traditional Chinese Medicine.MoCA was assessed after one month of hospitalization.Based on the time of MoCA assessment, all patients were randomly divided into the group A (assessed in the morning, 9 am-12 am) and the group B (assessed in the afternoon, 12 am to 5 pm). Clinical data were collected, and RANKIN scale (mRS) examination was performed.Moreover, patients were further divided into severe cognitive impairment (SCI) subgroup (score 26) according to the MoCA score. Results There were 189 patients in the group A (50%), and 189 cases in the group B (50%). There was no significant difference in age, gender, education level, disability (mRS score < 1), history of hypertension, diabetes, hyperlipidemia, smoking and atrial fibrillation between the two groups.Based on the MoCA score, 211 cases had NCI, 142 had MCI, and 25 had SCI.Compared with patients in group B, patients in group A was associated with significantly higher positive rate of SCI[12.2% (23/189)vs.1.1% (2/189), P=0.000], MCI[40.2% (76/189)vs.34.9% (66/189), P=0.013]and slightly higher positive rate of NCI[56.6% (107/189)vs.55.0% (104/189), P=0.214]. Conclusions The test time of MoCA may have an effect on the cognitive function detection rate in elderly patients with stroke, and the time of MoCA examination should be considered in clinical examination. Key words: Cognition Disorders; Stroke; Time