Detection of mild cognitive impairment in middle-aged and older adults with obstructive sleep apnoea

Obstructive sleep apnoea increases the risk for mild cognitiveimpairment and dementia. The present study aimed to characterise the ability of two cognitive screening tests, the Mini-Mental State Examinationand the Montreal Cognitive Assessment, to detect mild cognitiveimpairment in adults aged 55–85 years with and without obstructive sleep apnoea. We included 42 subjects with mild and 67 subjects with moderate-to-severe obstructive sleep apnoea. We compared them to 22 control subjects. Mild cognitiveimpairment was diagnosed by a comprehensive neuropsychological assessment. We used receiver operating characteristic curves to assess the ability of the two screening teststo detect mild cognitiveimpairment. The two screening testsshowed similar discriminative ability in control subjects. However, among the mild and the moderate-to-severe obstructive sleep apnoea groups, the Mini-Mental State Examinationwas not able to correctly identify subjects with mild cognitiveimpairment. The Montreal CognitiveAssessment9s discriminant ability was acceptable in both sleep apnoea groups and was comparable to what was observed in controls. The Mini-Mental State Examinationshould not be used to screen for cognitiveimpairment in patients with obstructive sleep apnoea. The Montreal Cognitive Assessmentcould be used in clinical settings. However, clinicians should refer patients for neuropsychological assessmentwhen neurodegenerative processes are suspected.