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

Aging Heads of State: The Politics of Dementia and Geriatric Cognitive Disorders

BACKGROUND

Increasing life expectancy may explain why more elderly candidates appear to be running for office. This raises general questions regarding the specific risks of old age and frailty in demanding political positions. Therefore, I tried to give important contemporary examples of elderly leaders, study the mean age of leading political figures over the last 3 decades and present historical examples of heads of state with age-associated brain diseases and cognitive deficits. I reviewed the literature on mental illness and politics and analyzed the ages of international political leaders in 1990, 2000, 2010 and 2020.

SUMMARY

There are several impressive contemporary examples of elderly politicians. The mean age of political leaders has not increased significantly in most parts of the world over the last 3 decades with the exception of the Gulf States and sub-Saharan Africa. Health problems of heads of state in earlier centuries had not been primarily age associated. After 1900, dementia but also mild cognitive and mild behavioral impairment became important issues in politically critical situations, for example international peace negotiations, the rise of Nazi Germany, the breakup of communism, the Arab Spring and others. Key Messages: This paper collects anecdotal evidence of cognitive frailty in ageing politicians; it is not an in-depth analysis of political history. Observations confirm that a very long time in power may obviously increase the risk of age-associated problems; dynamic revolutionary or entrepreneurial idols may be misled to rely on their irreplaceable charisma for too long. However, caution must be exercised against ageism on one side versus silent acquiescence towards leaders with failing mental powers on the other, who may become victims of obscure parties and their decompensating personality disorders.

Diagnosis of Dementia and Cognitive Impairment

In this special issue of Diagnostics, expert contributors have produced up-to-date research studies and reviews on various topics related to the diagnosis of dementia and cognitive impairment. The methods of the assessments discussed extend from simple neurological signs, which may be elicited in the clinical encounter, through cognitive screening instruments, to sophisticated analyses of neuroimaging and cerebrospinal fluid biomarkers of disease. It is hoped that these various methods may facilitate earlier diagnosis of dementia and its subtypes, and provide differential diagnosis of depression and functional cognitive disorders, as a prelude to meaningful interventions.

Psychological and Cognitive Markers of Behavioral Variant Frontotemporal Dementia-A Clinical Neuropsychologist's View on Diagnostic Criteria and Beyond

Behavioral variant frontotemporal dementia (bvFTD) is the second leading cognitive disorder caused by neurodegeneration in patients under 65 years of age. Characterized by frontal, insular, and/or temporal brain atrophy, patients present with heterogeneous constellations of behavioral and psychological symptoms among which progressive changes in social conduct, lack of empathy, apathy, disinhibited behaviors, and cognitive impairments are frequently observed. Since the histopathology of the disease is heterogeneous and identified genetic mutations only account for ~30% of cases, there are no reliable biomarkers for the diagnosis of bvFTD available in clinical routine as yet. Early detection of bvFTD thus relies on correct application of clinical diagnostic criteria. Their evaluation however, requires expertise and in-depth assessments of cognitive functions, history taking, clinical observations as well as caregiver reports on behavioral and psychological symptoms and their respective changes. With this review, we aim for a critical appraisal of common methods to access the behavioral and psychological symptoms as well as the cognitive alterations presented in the diagnostic criteria for bvFTD. We highlight both, practical difficulties as well as current controversies regarding an overlap of symptoms and particularly cognitive impairments with other neurodegenerative and primary psychiatric diseases. We then review more recent developments and evidence on cognitive, behavioral and psychological symptoms of bvFTD beyond the diagnostic criteria which may prospectively enhance the early detection and differential diagnosis in clinical routine. In particular, evidence on specific impairments in social and emotional processing, praxis abilities as well as interoceptive processing in bvFTD is summarized and potential links with behavior and classic cognitive domains are discussed. We finally outline both, future opportunities and major challenges with regard to the role of clinical neuropsychology in detecting bvFTD and related neurocognitive disorders.

Number Needed to Diagnose, Predict, or Misdiagnose: Useful Metrics for Non-Canonical Signs of Cognitive Status?

Background/Aims

“Number needed to” metrics may hold more intuitive appeal for clinicians than standard diagnostic accuracy measures. The aim of this study was to calculate “number needed to diagnose” (NND), “number needed to predict” (NNP), and “number needed to misdiagnose” (NNM) for neurological signs of possible value in assessing cognitive status.

Methods

Data sets from pragmatic diagnostic accuracy studies examining easily observed and dichotomised neurological signs (“attended alone” sign, “attended with” sign, head turning sign, applause sign, la maladie du petit papier) were analysed to calculate the NND, NNP, and NNM.

Results

All measures of discrimination showed broad ranges. The range of NND and NNP suggested that these signs were, with a single exception, of value for correctly diagnosing or predicting cognitive status (presence or absence of cognitive impairment) when between 2 and 4 patients were examined. However, NNM showed similar values (range 1–5 patients) suggesting risk of misdiagnosis.

Conclusion

NND, NNP, and NNM may be useful, intuitive, metrics in assessing the utility of diagnostic tests in day-to-day clinical practice. A ratio of NNM to either NND or NNP, termed the likelihood to diagnose or misdiagnose, may clarify the utility or inutility of diagnostic tests.