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Identifying individuals with subtle cognitive decline

Dementia is a devastating neurological disease that may be better managed if diagnosed earlier when subclinical neurodegenerative changes are already present, including subtle cognitive decline and mild cognitive impairment. In a new study published in the journal Neuropsychology, researchers used item-level performance on the Montreal Cognitive Assessment (MoCA) to identify individuals with subtle cognitive decline. Method: Individual MoCA item data from the Alzheimer’s Disease Neuroimaging Initiative was grouped using k-modes cluster analysis. These clusters were validated and examined for association with convergent neuropsychological tests. The clusters were then compared and characterized using multinomial logistic regression. Results: A three-cluster solution had 77.3% precision, with Cluster 1 (high performing) displaying no deficits in performance, Cluster 2 (memory deficits) displaying lower memory performance, and Cluster 3 (compound deficits) displaying lower performance on memory and executive function. Age at MoCA (older in compound deficits), gender (more females in memory deficits), and marital status (fewer married in compound deficits) were significantly different among clusters. Age was not associated with increased odds of membership in the high-performing cluster compared to the others. Conclusions: We identified three clusters of individuals classified as cognitively unimpaired using cluster analysis. Individuals in the compound deficits cluster performed lower on the MoCA and were older and less often married than individuals in other clusters. Demographic analyses suggest that cluster identity was due to a combination of both cognitive and clinical factors. Identifying individuals at risk for future cognitive decline using the MoCA could help them receive earlier evidence-based interventions to slow further cognitive decline. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

For the abstract

Will Pellagra Make a Comeback?

Pellagra is a vitamin deficiency disease that is often reported in Africa, Central America, and South-east Asia. Caused by tryptophan and niacin-poor diets, it has also been identified in marginalized individuals in industrial societies (especially homeless, chronic alcoholic, and psychiatric patients who refuse food). Symptoms of pellagra include light sensitivity, dementia, diarrhea, and dermatitis. In advanced cases, pellagra can lead to psychotic delusions. Left untreated, pellagra cases die after several years without proper nutrition.

While first identified in Spain in the 18th century, it received its name from an epidemic in Italy ("pelle agra" means bitter skin in Italian). Pellagra was epidemic in parts of the US in the early 1900s before the nutritional basis for the disease was identified and niacin supplements made treatment possible. While easy to diagnose and treat, physicians often miss vital clues, especially in industrialized societies where pellagra is less likely to be encountered. Even in non-industrialized countries, improved standard of living and greater diversity in dietary sources have made pellagra less common.

But an article published a few years back in the American Journal of Therapeutics discussed the possible resurgence of pellagra in HIV patients and anorexia nervosa patients who neglect proper nutrition. The authors also reviewed a case f pellagra identified through the warning triad of "dermatosis, diarrhea, and dementia" and properly treated.   In the twelve years since that particular study was published,   there has been an upswing in new pellagra cases which have been largely linked to the popularity of certain restricted diets such as extreme veganism.   A 2021 article reviews a case of pellagra involving a strict vegan who was diagnosed and treated for pellagra and warns health professionals of the need to stay aware of how easily such a patient might be misdiagnosed.     

For all that it is considered extinct in affluent countries, pellagra has never completely gone away.    Something to think about if you are considering a new fad diet...

Infidelity and the Capgras Delusion

Remembering back to a fascinating case study described in the June 2008 issue of Clinical Neurophysiology.  The study concerns a patient who presented visual hallucinations and identification disorders associated with a Capgras syndrome. During his Capgras episodes, the patient not only misidentified his wife's face, but also perceived her as being an entirely different sexual partner. He then had sexual intercourse with his wife's "double" without having the slightest recollection of any familiarity with her and even changed his sexual habits. According to the authors, he is the only known neurological patient that made his wife a mistress. In discussing the case, the authors discuss the mechanism of Capgras delusion with reference to the processes involved in face recognition. The complete loss of familiarity not only with the face but also with all aspects of sexual intimacy suggests a specific disconnection between the neural pathways linked to face identification and the systems involved in emotional and episodic memory.

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Charting Cognitive Functioning in Seniors Across Europe

With ageing mental health issues, as age-related cognitive decline, increase. A study recently published in the journal Aging, Neuropsychology, and Cognition aims to evaluate the prevalence of cognitive impairment among older European adults and to evaluate its association with clinical and sociodemographic variables, using SHARE. Numeracy, temporal orientation, verbal fluency, and memory were the measures used to evaluate cognitive performance. From 44 963 individuals included, mean age was 70.0 ± 9.0 years old and 56.3% were female. Overall prevalence of impairment was of 13.0% (temporal orientation), 24.8% (numeracy), 27.6% (verbal fluency) and 50.5% (memory). Men showed higher impairment prevalence in temporal orientation and memory and lower in numeracy and verbal fluency. Age, fewer years of education, difficulties performing iADLs, physical inactivity, and poor self-perceived health were independently associated with impairment in all cognitive abilities. These results showed the burden of cognitive impairment across Europe. Factors identified as associated should be taken in consideration to develop effective interventions to prevent cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

 

For the abstract

 

 

Seeing the Little People

Lilliputian hallucinations concern hallucinated human, animal or fantasy entities of minute size. Having been famously described by the French psychiatrist Raoul Leroy in 1909, who wrote from personal experience, to date they are mentioned almost routinely in textbooks of psychiatry, albeit with little in-depth knowledge. A paper recently published in the journal Neuroscience and Biobehavioral Reviews systematically reviewed 145 case reports and case series comprising 226 case descriptions, concluding that lilliputian hallucinations are visual (61 %) or multimodal (39 %) in nature. In 97 % of the cases, they are perceived as grounded in the actual environment, thus indicating involvement of higher-level regions of the perceptual network subserving the fusion of sensory and hallucinatory content. Perceptual release and deafferentiation are the most likely underlying mechanisms. Etiology is extremely diverse, with schizophrenia spectrum disorder, alcohol use disorder and loss of vision accounting for 50 % of the cases and neurological disease for 36 %. Recovery was obtained in 62 % of the cases, whereas 18 % of the cases ended in chronicity and 8 % in death. Recommendations are made for clinical practice and future research. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

 

For the abstract

Is Brain Resilience Heritable?

Resilience is the capacity of complex systems to persist in the face of external perturbations and retain their functional properties and performance. In a new study published in the journal Neuroimage, researchers investigated how individual variations in brain resilience, which might influence response to stress, aging and disease, are influenced by genetics and/or the environment, with potential implications for the implementation of resilience-boosting interventions. Resilience estimates were derived from in silico lesioning of either brain regions or functional connections constituting the connectome of healthy individuals belonging to two different large and unique datasets of twins, specifically: 463 individual twins from the Human Connectome Project and 453 individual twins from the Colorado Longitudinal Twin Study. As has been reported previously, moderate heritability was found for several topological indexes of brain efficiency and modularity. Importantly, evidence of heritability was found for resilience measures based on removal of brain connections rather than specific single regions, suggesting that genetic influences on resilience are preferentially directed toward region-to-region communication rather than local brain activity. Specifically, the strongest genetic influence was observed for moderately weak, long-range connections between a specific subset of functional brain networks: the Default Mode, Visual and Sensorimotor networks. These findings may help identify a link between brain resilience and network-level alterations observed in neurological and psychiatric diseases, as well as inform future studies investigating brain shielding interventions against physiological and pathological perturbations. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

For the abstract

Hazy memories in the courtroom: A review of alcohol and other drug effects on false memory and suggestibility.

Alcohol and other psychoactive drugs are oftentimes implicated in legal cases. A pertinent question herein is whether such substances might adversely affect testimonies of victims, eyewitnesses, or suspects by propelling the formation of false memory and increasing susceptibility to suggestion. In a new review published in Neuroscience and Biobehavioral Reviews, researchers amassed all available evidence on the effects of intoxication on false memory formation and suggestibility, including the substances alcohol, benzodiazepines, cannabis, stimulants, hallucinogens, and antipsychotics. The review indicated that alcohol and cannabis under certain conditions increased the susceptibility to false memories and/or suggestion with effect sizes ranging from medium to large. When intoxicated during an event, alcohol is most likely to increase this susceptibility at high intoxication levels or after a delay, whereas cannabis exerts detrimental effects during acute intoxication but not necessarily once sober. For other substances, ecologically valid research separating different memory phases is needed. Overall, differences between substances regarding false memory effects exist, suggesting that a nuanced approach is needed when dealing with intoxicated individuals in a legal context. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

For the abstract

How Does Being Premature Affect Social Cognition?

Social cognitive abilities are affected by preterm birth, but pathways to, and risk factors for this outcome are not well mapped.   A new study published in the journal Neuroscience and Biobehavioral Reviewse examines direct assessment tasks including objective coding of parent-child play to chart social development in infancy and pre-school years. A systematic search and data-extraction procedure yielded seventy-nine studies (4930 preterm and 2109 term children, aged birth - five years), for inclusion. The authors detected a pattern of reduced social attention in the first 12 months of life with evidence of reduced performance in social cognitive tasks later in the preschool years. However, they did not identify a consistent, distinctive preterm social phenotype in early life. Instead, the interactive behaviour of preterm infants reflects factors from outside the social cognitive domain, such as attention, language, and socioeconomic status. By combining data across samples and measures we revealed the role of domain-general skills, which may in future prove fruitful intervention targets. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

For the abstract

When The Brain is Under Stress

Psychosocial stress is an omnipresent phenomenon whose neural correlates in humans are still poorly understood. Several paradigms have been developed to induce acute stress in fMRI settings, but it is unclear whether there is a global brain activation pattern related to psychosocial stress. In a recent paper published in the journal Neuroscience and Biobehavioral Reviews, researchers  examined different neuronal activation patterns through an activation likelihood estimation analysis on 31 studies totaling 1279 participants. Studies used the ScanSTRESS, Montreal Imaging Stress Test, aversive viewing paradigm (AVP), Social-Evaluative Threat or Cyberball. The analysis revealed bilateral activation clusters comprising the claustrum, insula and inferior frontal gyrus. This indicates that exposure to psychosocial stress leads to activations in brain areas involved in affective processing and the endocrine stress response. Furthermore, in a systematic review, Cyberball and AVP presented themselves as outliers due to increased activation in motor areas and lack of induction of stress related activity changes, respectively. As different paradigms emphasize different dimensions of psychosocial stress such as social evaluation or performance pressure, future research is needed to identify differences between the paradigms. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

For the abstract.

Can Brain Imaging Measure Disgust?

In recent years, more and more studies on disgust have shown the association between disgust and various psychopathologies. Revealing the spontaneous brain activity patterns associated with disgust sensitivity from the perspective of individual differences will give us an insight into the neurologic nature of disgust and its psychopathological vulnerability.  New research published in the journal Behavioural Brain Research examined two modal brain imaging techniques (resting fMRI and resting EEG) to reveal spontaneous brain activity patterns closely related to disgust sensitivity. The amplitude of low-frequency fluctuation results showed that disgust sensitivity is negatively correlated with the spontaneous activity of the right cerebellum crus II and positively correlated with the spontaneous activity of the right superior frontal cortex, which are inhibition-related brain regions. Furthermore, the microstate results of rest EEG indicated that the corrected duration, occurrence rate, and contribution of Class C, which is related to the anterior default mode network and is considered to be related to subjective representation of one’ own body by combining interoceptive information with affective salience, were significantly positively correlated with the disgust sensitivity level. This data-driven approach provides the first evidence on the intrinsic brain features of disgust sensitivity based on two resting-state brain modalities. The results represent an initial effort to uncover the neurological basis of disgust sensitivity and its connection to psychopathology. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

For the abstract

German Police Shoot Turkish Man with Alzheimer's Disease

A 63-year-old Turkish man  was left critically injured after being shot by a police officer in the German province of Bavaria according to reports dated April 1, 2021.  The man, identified as Habeş Temiz, had confronted police after refusing to leave  the premises of his neighbor’s property.    Temiz, who is reportedly suffering from Alzheimer's disease had become confrontational and was swinging a toy truck when police first used tear gas and, when that failed, followed with a round of warning shots and then three shots targeting the man.   Temiz was then hospitalized and his condition remains guarded.  

While the shooting is currently under investigation, German police have been repeatedly of harassing many of the the country's three million Turkish immigrants.    With a population of 81 million people, Germany has the second-largest Muslim population in Western Europe after France and anti-Muslim hate crimes have been frequently reported.  In 2018 alone,  there were 910 known incidents, including 48 attacks on mosques alone though this represents a slight decline from previous years.

According to one recent report by professor Tobias Singelnstein of Ruhr-University Bochum, institutionalized racism remains of  a structural problem among the German police, with reports of racist, Islamophobic and anti-Semitic insults, confirmed by police officers and victim testimonies.   Witnesses interviewed for the report have also accused some officers of going on deliberate "Turk hunts" in which they target Turkish immigrants and provoke them into verbal or physical reactions to which the officers respond with deadly force.   While it remains unclear whether this latest incident will reflect that trend, critics are already calling for better police training for dealing with people suffering from mental health issues that might lead to confrontations.