Memory impairment in Amyloidß-status Alzheimer's disease is associated with a reduction in CA1 and dentate gyrus volume: In vivo MRI at 7T.

INTRODUCTION: In Alzheimer's disease (AD), early diagnosis facilitates treatment options and leads to beneficial outcomes for patients, their carers and the healthcare system. The neuropsychological battery of the Uniform Data Set (UDSNB3.0) assesses cognition in ageing and dementia, by measuring scores across different cognitive domains such as attention, memory, processing speed, executive function and language. However, its neuroanatomical correlates have not been investigated using 7 Tesla MRI (7T MRI). METHODS: We used 7T MRI to investigate the correlations between hippocampal subfield volumes and the UDSNB3.0 in 24 individuals with Amyloidß-status AD and 18 age-matched controls, with respective age ranges of 60 (42-76) and 62 (52-79) years. AD participants with a Medial Temporal Atrophy scale of higher than 2 on 3T MRI were excluded from the study. RESULTS: A significant difference in the entire hippocampal volume was observed in the AD group compared to healthy controls (HC), primarily influenced by CA1, the largest hippocampal subfield. Notably, no significant difference in whole brain volume between the groups implied that hippocampal volume loss was not merely reflective of overall brain atrophy. UDSNB3.0 cognitive scores showed significant differences between AD and HC, particularly in Memory, Language, and Visuospatial domains. The volume of the Dentate Gyrus (DG) showed a significant association with the Memory and Executive domain scores in AD patients as assessed by the UDSNB3.0.. The data also suggested a non-significant trend for CA1 volume associated with UDSNB3.0 Memory, Executive, and Language domain scores in AD. In a reassessment focusing on hippocampal subfields and MoCA memory subdomains in AD, associations were observed between the DG and Cued, Uncued, and Recognition Memory subscores, whereas CA1 and Tail showed associations only with Cued memory. DISCUSSION: This study reveals differences in the hippocampal volumes measured using 7T MRI, between individuals with early symptomatic AD compared with healthy controls. This highlights the potential of 7T MRI as a valuable tool for early AD diagnosis and the real-time monitoring of AD progression and treatment efficacy. CLINICALTRIALS: GOV: ID NCT04992975 (Clinicaltrial.gov 2023).

The psychosocial outcomes of anoxic brain injury following cardiac arrest.

AIM OF THE STUDY: This exploratory study aimed to investigate the psychosocial outcomes for cardiac arrest survivors and explore if there is a greater impact on psychosocial outcome for individuals experiencing anoxic brain injury as a result of the cardiac arrest. METHODS: Self-report measures were used to compare the quality of life, social functioning and symptoms of anxiety, depression and post-traumatic stress of individuals with and without anoxic brain injury. Secondary measures of subjective memory and executive difficulties were also used. Fifty-six participants (27 with anoxia, 29 without anoxia) took part in the study between six months and four years after experiencing cardiac arrest. RESULTS: A MANOVA identified a significant difference between the two groups, with the anoxia group reporting more psychosocial difficulties. They reported more social functioning difficulties and more anxiety, depression and post-traumatic stress symptoms. There was, however, no significant difference in self-reported quality of life between the two groups. CONCLUSION: As the first known study to compare psychosocial outcomes for cardiac arrest survivors experiencing anoxic brain injury with those without anoxia, the current results suggest that cardiac arrest survivors with subsequent acquired brain injury experience more psychosocial difficulties. This could be due to a combination of neuropsychological, social and psychological factors.

Factors associated with strain in carers of people with traumatic brain injury.

OBJECTIVE: To explore factors associated with strain in carers of patients with traumatic brain injury. DESIGN: Cross-sectional cohort study. PARTICIPANTS: Forty-eight carers of patients with traumatic brain injury admitted to a neurosurgical unit over a 9-year period were assessed an average of 9.3 years after injury. MEASURES: Caregiver Strain Index (CSI), Neurobehavioral Functioning Inventory (NFI), Glasgow Outcome Scale (GOS), Virginia Prediction Tree Score, and carer and patient demographics. PROCEDURE: Carers were assessed via postal survey for levels of strain using the CSI and for their perception of the patients' disabilities using the NFI. RESULTS: Elevated levels of strain were found in 42% of carers. Using logistic regression, outcome as rated by the patients' general practitioner on the GOS and all subscales of the NFI (except Somatic) explained 41% to 57% of the variance in strain and predicted group membership correctly in 72.9% of cases. No individual variable contributed significantly to the explained variance in the model. CONCLUSION: A number of factors appear to combine to result in feelings of strain, but the GOS could be used as a crude screening tool. Interventions for cognitive, behavioral, and emotional difficulties may be most useful for carers.