Head turning sign.

The head turning sign was first described as such more than 20 years ago but only recently have empirical studies of the sign in large cohorts of patients being assessed for cognitive disorders been reported. Although precise operationalisation of the sign has differed between studies, nevertheless it appears to be frequently observed in cognitive clinic patient cohorts, more so in Alzheimer's disease than in other dementias and with an intermediate frequency in mild cognitive impairment. Head turning is an easily observed and categorised sign and may raise suspicion of the presence of a cognitive disorder. The exact neuropsychological, psychiatric and neurobiological correlates of the sign remain to be determined.