The head turning sign “outside the clinic walls” in patients with mild cognitive impairment and dementia

Background In clinical settings, the head turning sign (HTS) occurs when patients with cognitive complaints turn their head toward the accompanying person seeking assistance. Due to its nature, and unlike other non-canonical neurological signs of cognitive impairment, the HTS is likely to occur in ecological, daily-life scenarios too. However, this hypothesis has not been tested yet. Objective To assess the prevalence and clinical correlates of the “ecological HTS” (eHTS) in MCI and dementia due to chronic-degenerative etiologies. Methods This retrospective cohort included 112 patients with MCI/dementia due to Alzheimer's disease (AD; N = 71), frontotemporal lobar degeneration ( N = 6), Lewy body disease ( N = 6), chronic cerebrovascular diseases (CVD; N = 11), mixed (i.e., AD + CVD; N = 15) unspecified non-AD neurodegenerative etiologies ( N = 3). We recorded the number of HTSs displayed by patients during the MMSE and inquired accompanying persons whether the HTS occurred in daily life too. Results The overall prevalence of the eHTS in the cohort was 50%; its distribution was independent of demographics, disease severity (i.e., MCI versus dementia), and etiology. Within multiple logistic models, the presence of the eHTS + proved to be predicted both by lower scores on the Spatial Orientation subtest of the MMSE and by a higher number of HTSs during the execution of the MMSE. Moreover, a trend towards longer disease duration and the occurrence of the eHTS was found. Conclusions In MCI and dementia, the HTS is an ecologically valid non-canonical sign, frequently occurs in daily life too, associated with longer disease duration and spatial disorientation.