The Head Turning Sign in Dementia and Mild Cognitive Impairment: Its Relationship to Cognition, Behavior, and Cerebrospinal Fluid Biomarkers.

BACKGROUND/AIMS: The head turning sign (HTS) is frequently noticed in clinical practice, but few studies have investigated its etiological and neuropsychological correlates. METHODS: The presence and frequency of the HTS was operationalized and prospectively evaluated in patients with Alzheimer's disease (AD), amnestic mild cognitive impairment (MCI), and behavioral-variant frontotemporal dementia (bvFTD). Cerebrospinal fluid (CSF) samples for AD biomarkers were collected. Mini-Mental State Examination, Montreal Cognitive Assessment, Geriatric Depression Scale (GDS), and insight scale scores were ascertained. RESULTS: A total of 84 patients were included. The HTS was more prevalent in AD than in MCI or bvFTD. It correlated negatively with cognitive measures and depression. It also had a positive correlation with CSF total tau and hyperphosphorylated tau proteins. Total tau protein and GDS score were the only variables independently associated with the HTS. CONCLUSIONS: The presence of the HTS in a cognitively impaired individual suggests a diagnosis of AD. A higher HTS frequency correlates with higher CSF total tau levels, a smaller GDS score, and worse cognitive measures. In the MCI subgroup, the HTS may suggest a higher risk of progression.