Clinical Arterial Spin-Labeling MR Imaging to Screen for Typical and Atypical Neurodegenerative Disease in the New Era of Alzheimer Treatment.

The clinical standard of care in the diagnosis of neurodegenerative diseases relies on [18F] FDG-PET/CT or PET MR imaging. Limitations of FDG-PET include cost, the need for IV access, radiation exposure, and availability. Arterial spin-labeling MR imaging has been shown in research settings to be useful as a proxy for FDG-PET in differentiating Alzheimer disease from frontotemporal dementia. However, it is not yet widely used in clinical practice, except in cerebrovascular disease. Here, we present 7 patients, imaged with our routine clinical protocol with diverse presentations of Alzheimer disease and other neurodegenerative diseases, in whom arterial spin-labeling-derived reduced CBF correlated with hypometabolism or amyloid/tau deposition on PET. Our case series illustrates the clinical diagnostic utility of arterial spin-labeling MR imaging as a fast, accessible, and noncontrast screening tool for neurodegenerative disease. Arterial spin-labeling MR imaging can guide patient selection for subsequent PET or fluid biomarker work-up, as well as for possible therapy with antiamyloid monoclonal antibodies.

Brain fog in long COVID limits function and health status, independently of hospital severity and preexisting conditions.

Importance: The U.S. government has named post-acute sequelae of COVID-19 (longCOVID) as influential on disability rates. We previously showed that COVID-19 carries a medical/functional burden at 1 year, and that age and other risk factors of severe COVID-19 were not associated with increased longCOVID risk. Long-term longCOVID brain fog (BF) prevalence, risk factors and associated medical/functional factors are poorly understood, especially after mild SARS-CoV-2 infection. Methods: A retrospective observational cohort study was conducted at an urban tertiary-care hospital. Of 1,032 acute COVID-19 survivors from March 3-May 15, 2020, 633 were called, 530 responded (59.2 ± 16.3 years, 44.5% female, 51.5% non-White) about BF prevalence, other longCOVID, post-acute ED/hospital utilization, perceived health/social network, effort tolerance, disability. Results: At approximately 1-year, 31.9% (n = 169) experienced BF. Acute COVID-19 severity, age, and premorbid cardiopulmonary comorbidities did not differ between those with/without BF at 1 year. Patients with respiratory longCOVID had 54% higher risk of BF than those without respiratory longCOVID. BF associated with sleep disturbance (63% with BF vs.29% without BF, p < 0.0001), shortness of breath (46% vs.18%, p < 0.0001), weakness (49% vs.22%, p < 0.0001), dysosmia/dysgeusia (12% vs.5%, p < 0.004), activity limitations (p < 0.001), disability/leave (11% vs.3%, p < 0.0001), worsened perceived health since acute COVID-19 (66% vs.30%, p < 0.001) and social isolation (40% vs.29%, p < 0.02), despite no differences in premorbid comorbidities and age. Conclusions and relevance: A year after COVID-19 infection, BF persists in a third of patients. COVID-19 severity is not a predictive risk factor. BF associates with other longCOVID and independently associates with persistent debility.