Brief Cognitive Exams Commonly Misdiagnose Dementia

By Kelly Young

Edited by Susan Sadoughi, MD, and Richard Saitz, MD, MPH, FACP, DFASAM

Brief cognitive assessments often don't accurately classify patients with dementia, according to a study in Neurology: Clinical Practice.

Researchers studied over 800 older adults who completed the Mini-Mental State Examination (MMSE), Memory Impairment Screen (MIS), and animal naming (AN) assessment. Just over a third of patients had a confirmed dementia diagnosis.

One third of patients' dementia status was misclassified (either false-positive or false-negative) by at least one assessment. Just one factor predicted misclassification in all three assessments — absence of poor memory as rated by the patient's informant. Additionally, years of education and heart problems predicted misclassification in the AN and MMSE.

Most patients without dementia who had a false-positive result still met the criteria for cognitive impairment.

Dr. Jennifer Rose V. Molano of NEJM Journal Watch Neurology comments: "Clinically, the resultsof this studysupport the importance of obtaining a comprehensive evaluation, including formal neuropsychological testing and information from a family member about functional status, to make the diagnosis."