%0 Journal Article %J J Alzheimers Dis %D 2021 %T Dementia and COVID-19, a Bidirectional Liaison: Risk Factors, Biomarkers, and Optimal Health Care. %A Toniolo, Sofia %A Scarioni, Marta %A Di Lorenzo, Francesco %A Hort, Jakub %A Georges, Jean %A Tomic, Svetlana %A Nobili, Flavio %A Frederiksen, Kristian Steen %K Alzheimer Disease %K Biomarkers %K Brain %K Cognitive Dysfunction %K Comorbidity %K COVID-19 %K Humans %K Neuroimaging %K Neuroimmunomodulation %K Patient Care %K SARS-CoV-2 %X

Cognitive impairment following SARS-CoV-2 infection is being increasingly recognized as an acute and possibly also long-term sequela of the disease. Direct viral entry as well as systemic mechanisms such as cytokine storm are thought to contribute to neuroinflammation in these patients. Biomarkers of COVID-19-induced cognitive impairment are currently lacking, but there is some limited evidence that SARS-CoV-2 could preferentially target the frontal lobes, as suggested by behavioral and dysexecutive symptoms, fronto-temporal hypoperfusion on MRI, EEG slowing in frontal regions, and frontal hypometabolism on 18F-FDG-PET. Possible confounders include cognitive impairment due to hypoxia and mechanical ventilation and post-traumatic stress disorder. Conversely, patients already suffering from dementia, as well as their caregivers, have been greatly impacted by the disruption of their care caused by COVID-19. Patients with dementia have experienced worsening of cognitive, behavioral, and psychological symptoms, and the rate of COVID-19-related deaths is disproportionately high among cognitively impaired people. Multiple factors, such as difficulties in remembering and executing safeguarding procedures, age, comorbidities, residing in care homes, and poorer access to hospital standard of care play a role in the increased morbidity and mortality. Non-pharmacological interventions and new technologies have shown a potential for the management of patients with dementia, and for the support of their caregivers.

%B J Alzheimers Dis %V 82 %P 883-898 %8 2021 %G eng %N 3 %1 https://www.ncbi.nlm.nih.gov/pubmed/34092646?dopt=Abstract %R 10.3233/JAD-210335 %0 Journal Article %J J Alzheimers Dis %D 2021 %T Is the Frontal Lobe the Primary Target of SARS-CoV-2? %A Toniolo, Sofia %A Di Lorenzo, Francesco %A Scarioni, Marta %A Frederiksen, Kristian Steen %A Nobili, Flavio %K Acute Febrile Encephalopathy %K Biomarkers %K COVID-19 %K Delirium %K Electroencephalography %K Frontal Lobe %K Humans %K Magnetic Resonance Imaging %K Nerve Net %K SARS-CoV-2 %K Virulence %X

Acute delirium and other neuropsychiatric symptoms have frequently been reported in COVID-19 patients and are variably referred to as acute encephalopathy, COVID-19 encephalopathy, SARS-CoV-2 encephalitis, or steroid-responsive encephalitis. COVID-19 specific biomarkers of cognitive impairment are currently lacking, but there is some evidence that SARS-CoV-2 could preferentially and directly target the frontal lobes, as suggested by behavioral and dysexecutive symptoms, fronto-temporal hypoperfusion on MRI, EEG slowing in frontal regions, and frontal hypometabolism on 18F-FDG-PET imaging. We suggest that an inflammatory parainfectious process targeting preferentially the frontal lobes (and/or frontal networks) could be the underlying cause of these shared clinical, neurophysiological, and imaging findings in COVID-19 patients. We explore the biological mechanisms and the clinical biomarkers that might underlie such disruption of frontal circuits and highlight the need of standardized diagnostic procedures to be applied when investigating patients with these clinical findings. We also suggest the use of a unique label, to increase comparability across studies.

%B J Alzheimers Dis %V 81 %P 75-81 %8 2021 %G eng %N 1 %1 https://www.ncbi.nlm.nih.gov/pubmed/33720900?dopt=Abstract %R 10.3233/JAD-210008 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Effects of Physical Exercise on Alzheimer's Disease Biomarkers: A Systematic Review of Intervention Studies. %A Frederiksen, Kristian Steen %A Gjerum, Le %A Waldemar, Gunhild %A Hasselbalch, Steen Gregers %K Alzheimer Disease %K Biomarkers %K Exercise %K Hippocampus %K Humans %K Outcome Assessment (Health Care) %K Physical Therapy Modalities %X

Physical exercise may be an important adjunct to pharmacological treatment of Alzheimer's disease (AD). Animal studies indicate that exercise may be disease modifying through several mechanisms including reduction of AD pathology. We carried out a systematic review of intervention studies of physical exercise with hippocampal volume (on MRI), amyloid-β, total tau, phosphorylated tau in cerebrospinal fluid (CSF), 18F-FDG-PET or amyloid PET as outcome measures in healthy subjects, patients with subjective memory complaints, mild cognitive impairment, or AD. We identified a total of 8 studies of which 6 investigated the effects of exercise on hippocampal volume in healthy subjects and 1 on CSF biomarkers and 1 on hippocampal volume in AD, and none investigating the remaining outcome measures or patient groups. Methodological quality of identified studies was generally low. One study found a detrimental effect on hippocampal volume and one found a positive effect, whereas the remaining studies did not find an effect of exercise on outcome measures. The present systematic study identified a relatively small number of studies, which did not support an effect of exercise on hippocampal volume. Methodological issues such small to moderate sample sizes and inadequate ramdomization procedures further limits conclusions. Our findings highlight the difficulties in conducting high quality studies of exercise and further studies are needed before definite conclusions may be reached.

%B J Alzheimers Dis %V 61 %P 359-372 %8 2018 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/29154278?dopt=Abstract %R 10.3233/JAD-170567