Head Turning Sign May Help Identify Alzheimer's
COPENHAGEN — A simple, rapid test called the Head Turning Sign (HTS) may help to assess the presence of Alzheimer's disease (AD) dementia.
Patients who turn their head toward their caregiver for assistance or cues to help them answer simple questions are more likely to have AD dementia than mild cognitive impairment (MCI) or frontotemporal dementia (FTD), a new study shows.
"Turning one's head should be regarded as a warning sign, although a nonspecific warning sign, for AD, especially if it's repeated throughout a consultation," said lead study author Miguel Tábuas Pereira, Neurology Department, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal. "The more frequent the sign, the more specific it is."
They also found that presence of the sign correlated with AD biomarkers, including tau and phosphorylated tau, in cerebrospinal fluid (CSF).
Dr Pereira presented the study here at the Congress of the European Academy of Neurology (EAN) 2016.
Although the HTS was first described more than 20 years ago and was once considered common in AD, there's "a surprising shortage of papers" on the diagnostic utility of this test, said Dr Pereira.
The current study included 78 patients with amnestic MCI (aMCI), AD, or FTD who had had a full neuropsychiatric evaluation and CSF biomarkers, including amyloid β, tau, and phosphorylated tau. They also had to have a trusted caregiver accompany them to assessments.
Researchers excluded patients with severe dementia or aphasic dementia and those who would be unable to cooperate for the tests.
Study participants completed the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment, and the Geriatric Depression Scale. Researchers also assessed the participants' insight into their cognitive deficits.
Researchers defined HTS as a voluntary head movement toward a caregiver seated at a 45-degree angle about a meter behind the patient when responding to five consecutive predetermined questions posed by a clinician. The questions included "When was your last meal?" and "What is the date?"0 HTS was graded on a 0-to-5 scale, with scores depending on how many times the participant turned for assistance.
HTS was present in 30 of 36 (83.3%) patients with AD and 12 of 27(44.4%) of those with aMCI. The intensity of the sign was higher in AD (P = .015). The median value was 0.0 in MCI and 1.0 in AD.
The study showed a statistically significant difference in severity of HTS between patients with MCI and those with MCI and between the AD group and the FTD group.
"We found that this sign is statistically significantly more frequent in AD than in MCI and FTD," said Dr Pereira.
"If you consider the presence of at least one time of the head turning sign for AD, it has a sensitivity of about 80% and specificity of 53%. It also has a positive predictive value of 60% and a negative predictive value of 75%."
The researchers also found a positive correlation between HTS and tau protein (P = .002) and phosphorylated tau (P = .002) in CSF and MMSE scores (P = .021).
There was no significant association with "insight" or depression.
Session co-chair, Theodor Landis, MD, honorary professor of neurology, University of Geneva, Switzerland, and former chair of that university's Department of Clinical Neurosciences, described the study as "original."
"It's unusual to find this kind of very clinically oriented signs" being used, he said.
Dr Landis asked whether the researchers checked for unilateral hearing impairment. "If patients don't hear well, they have a tendency to turn their head."
The researchers didn't objectively test for this, Dr Pereira responded, but noted they had excluded patients who were considered to be deaf.
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