Disparate Dementia Risk Factors Are Associated with Cognitive Impairment and Rates of Decline in African Americans.

OBJECTIVE: This study was undertaken to evaluate the frequency of modifiable dementia risk factors and their association with cognitive impairment and rate of decline in diverse participants engaged in studies of memory and aging. METHODS: Modifiable dementia risk factors and their associations with cognitive impairment and cognitive decline were determined in community-dwelling African American (AA; n = 261) and non-Hispanic White (nHW; n = 193) participants who completed ≥2 visits at the Mayo Clinic Alzheimer Disease Research Center in Jacksonville, Florida. Risk factors and their associations with cognitive impairment (global Clinical Dementia Rating [CDR] ≥ 0.5) and rates of decline (CDR Sum of Boxes) in impaired participants were compared in AA and nHW participants, controlling for demographics, APOE ɛ4 status, and Area Deprivation Index. RESULTS: Hypertension, hypercholesterolemia, obesity, and diabetes were overrepresented in AA participants, but were not associated with cognitive impairment. Depression was associated with increased odds of cognitive impairment in AA (odds ratio [OR] = 4.30, 95% confidence interval [CI] = 2.13-8.67) and nHW participants (OR = 2.79, 95% CI = 1.21-6.44) but uniquely associated with faster decline in AA participants (ß = 1.71, 95% CI = 0.69-2.73, p = 0.001). Fewer AA participants reported antidepressant use (9/49, 18%) than nHW counterparts (57/78, 73%, p < 0.001). Vitamin B12 deficiency was also associated with an increased rate of cognitive decline in AA participants (ß = 2.65, 95% CI = 0.38-4.91, p = 0.023). INTERPRETATION: Modifiable dementia risk factors are common in AA and nHW participants, representing important risk mitigation targets. Depression was associated with dementia in AA and nHW participants, and with accelerated declines in cognitive function in AA participants. Optimizing depression screening and treatment may improve cognitive trajectories and outcomes in AA participants. ANN NEUROL 2024;95:518-529.

Phosphorylated tau sites that are elevated in Alzheimer's disease fluid biomarkers are visualized in early neurofibrillary tangle maturity levels in the post mortem brain.

INTRODUCTION: Alzheimer's disease (AD) biomarkers are increasingly more reliable in predicting neuropathology. To facilitate interpretation of phosphorylated tau sites as an early fluid biomarker, we sought to characterize which neurofibrillary tangle maturity levels (pretangle, intermediary 1, mature tangle, intermediary 2, and ghost tangle) are recognized. METHODS: We queried the Florida Autopsied Multi-Ethnic (FLAME) cohort for cases ranging from Braak stages I through VI, excluding non-AD neuropathologies and tauopathies. Thioflavin-S staining was compared to immunohistochemical measures of phosphorylated threonine (pT) 181, pT205, pT217, and pT231 in two hippocampal subsectors across n = 24 cases. RESULTS: Each phosphorylated tau site immunohistochemically labeled early neurofibrillary tangle maturity levels compared to advanced levels recognized by thioflavin-S. Hippocampal burden generally increased with each Braak stage. DISCUSSION: These results provide neurobiologic evidence that these phosphorylated tau fluid biomarker sites are present during early neurofibrillary tangle maturity levels and may explain why these fluid biomarker measures are observed before symptom onset. HIGHLIGHTS: Immunohistochemical evaluation of four phosphorylated tau fluid biomarker sites. Earlier neurofibrillary tangle maturity levels recognized by phosphorylated tau in proline-rich region. Advanced tangle pathology is elevated in the subiculum compared to the cornu ammonis 1 of the hippocampus. Novel semi-quantitative frequency to calculate tangle maturity frequency.

The temporal onset of the core features in dementia with Lewy bodies.

INTRODUCTION: We examined the temporal sequence of the core features in probable dementia with Lewy bodies (DLB). METHODS: In 488 patients with probable DLB, the onset of each core feature and time to diagnosis was determined for men and women, and a pathologic subgroup (n = 209). RESULTS: REM sleep behavior disorder (RBD) developed before the other core features in men and women. Men were more likely to have RBD and were diagnosed with probable DLB earlier than women. Visual hallucinations developed after the other core features in men, but in women, they appeared earlier and concurrently with fluctuations and parkinsonism. Women were older and more cognitively impaired at first visit, were less likely to have RBD, more likely to be diagnosed with probable DLB later than men, and more likely to have neocortical tangles. DISCUSSION: An earlier latency to probable DLB was associated with men, RBD, and Lewy body disease without neocortical tangles.

Older adults on involuntary hold status in the emergency department.

BACKGROUND: As the United States' population ages, the health care system will experience overall change. This study aims to identify factors in the older adult that may contribute to involuntary hold status in the ED. METHODS: This study is a retrospective review conducted at a suburban acute-care hospital ED of adult patients evaluated while on involuntary hold from January 1, 2014, through November 30, 2015. Older adults (patients born on or before 06/31/1964) were compared to younger adults (born on or after 07/01/1964) according to demographic and clinical variables including medical comorbidity, ED length of stay, reason for involuntary hold, psychiatric disorder, suicide attempt, substance use disorder, serum alcohol level, urine drug testing, medical comorbidity, violence in the ED, 30-day ED readmission, and 30-day mortality. RESULTS: Of 251 patients, 90 (35.9%) were older adults. The most common reason for involuntary hold in both cohorts was suicidal ideation. Medical comorbidities were more prevalent in older adults [60 (66.7%) vs. 64 (39.8%), P ≤.0001]. Older adults were less likely to report current drug abuse [31 (34.4%) vs. 77 (47.8%), P = .04]. The most commonly misused substance in both groups was alcohol; however, despite similar rates, blood alcohol levels (BAC) and urine drug screen (UDS) were performed less often in older adults. Cohorts were not significantly different with respect to sex, race, violence in the ED, psychiatric diagnosis, and ED LOS. CONCLUSIONS: Involuntary older adult patients present with medical comorbidities that impact mental health. In the ED, they are less likely report substance use, and drug screening may be underutilized. Medical needs make their care unique and may present challenges in transfer of care to inpatient psychiatric facilities.

Involuntary patient length-of-stay at a suburban emergency department.

BACKGROUND: Patients who may be a danger to themselves or others often are placed on involuntary hold status in the Emergency Department (ED). Our primary objective was to determine if there are demographic and/or clinical variables of involuntary hold patients which were associated with an increased ED LOS. METHODS: Records of ED patients evaluated while on involuntary hold from January 1, 2014 through November 30, 2015 at a suburban acute-care hospital ED were reviewed. Data collected included demographics information, LOS, suicidal or homicidal ideation, suicide attempt, blood alcohol concentration (BAC), urine drug test (UDT), psychiatric disorder, substance use, medical illness, violence in the ED, and hospital admission. Linear regression based on the log of LOS was used to identify factors associated with increased LOS. RESULTS: Two-hundred and fifty-one patients were included in the study. ED LOS (median) was 6 h (1, 49). Linear regression analysis showed increased LOS was associated with BAC (p = 0.05), urine drug test (UDT) (p = 0.05) and UDT positive for barbiturates (p = 0.01). There was no significant difference in ED LOS with respect to age, gender, housing, psychiatric diagnosis, suicidal or homicidal ideation, suicide attempt, violence, medical diagnosis, or admission status. CONCLUSIONS: Involuntary hold patients had an increased ED LOS associated with alcohol use, urine drug test screening, and barbiturate use. Protocol development to help stream-line ED evaluation of alcohol and drug use may improve ED LOS in this patient population.

Patients Threatening Harm to Others Evaluated in the Emergency Department under the Florida Involuntary Hold Act (Baker Act).

OBJECTIVES: This study describes the specific threats of harm to others that led to the use of the Baker Act, the Florida involuntary hold act for emergency department (ED) evaluations. The study also summarizes patient demographics, concomitant psychiatric diagnoses, and emergent medical problems. METHODS: This is a retrospective review of 251 patients evaluated while on involuntary hold from January 1, 2014 through November 30, 2015 at a suburban acute care hospital ED. The data that were collected included demographic information, length of stay, reason for the involuntary hold, psychiatric disorder, substance use, medical illness, and violence in the ED. The context of the homicidal threat also was collected. RESULTS: We found that 13 patients (5.2%) were homicidal. Three patients had homicidal ideations alone, whereas 10 made homicidal threats toward others. Of the 10 making homicidal threats, 7 named a specific person to harm. Ten of the 13 homicidal patients (76.9%) also were suicidal. Eleven patients (84.6%) had a psychiatric disorder: 9 patients (69.2%) had a depressive disorder and 8 patients (61.5%) had a substance use disorder. Eight patients had active medical problems that required intervention in the ED. CONCLUSIONS: We found that three-fourths of patients expressing homicidal threats also were suicidal. The majority of patients making threats of harm had a specific plan of action to carry out the threat. It is important to screen any patient making homicidal threats for suicidal ideation. If present, there is a need to implement immediate management appropriate to the level of the suicidal threat, for the safety of the patient. Eighty-five percent of patients making a homicidal threat had a previously documented psychiatric disorder, the most common being a depressive disorder. This finding differs from previous studies in which psychosis predominated. More than 60% of homicidal patients had an unrelated medical disorder requiring intervention. It is important not to overlook these medical disorders while focusing on the psychiatric needs of the patient; most of our homicidal patients proved to be cooperative in the ED setting.

Patients on Involuntary Hold Status in the Emergency Department.

OBJECTIVES: Patients requiring involuntary holds are frequently seen in the emergency department (ED). Much of what is known comes from studies of patients at urban academic centers. Our aim was to describe the demographic and clinical characteristics of patients who were evaluated while on involuntary status at a suburban ED. METHODS: The medical records of patients seen in the ED requiring involuntary hold status between January 1, 2014 and November 30, 2015 were reviewed. Demographic and clinical variables including medical and psychiatric comorbidity were collected. A subanalysis was performed comparing patients who attempted suicide with all other involuntary patients. RESULTS: Two hundred fifty-one patient records were reviewed; 215 patients (85.3%) had psychiatric disorders-depression was the most common (57%)-and 108 patients (43%) had substance use disorders. Only 13 patients (5.2%) had neither a psychiatric disorder nor a history of substance use. Twenty-two patients (8.8%) were violent in the ED. Thirteen patients (5.2%) were readmitted, and 1 patient died within 30 days of discharge from the ED. One hundred twenty-four patients (49.4%) had medical disorders. Suicidal ideation was the most common reason for involuntary hold (n = 185, 73.7%); 63 patients (25.1%) attempted suicide. Compared with other involuntary patients, the patients who attempted suicide were less likely to use opiates (odds ratio 0.27, 95% confidence interval 0.08-0.94, P = 0.04) and to have medical disorders (odds ratio 0.52, 95% confidence interval 0.28-0.98, P = 0.04). CONCLUSIONS: Patients in this study differed from those in urban centers with respect to sex and psychiatric disorder; however, substance misuse was common in both settings. Suicidal ideation including suicide attempt was the most common reason for involuntary status. Patients who attempted suicide were similar to other patients on involuntary hold with respect to demographic and clinical variables.

Substance use disorders and their effect on the psychiatric and justice systems.

BACKGROUND AND OBJECTIVES: A high proportion of persons in institutionalized settings such as the criminal justice system and psychiatric hospitals have substance use disorders (SUDs). We explored the association between substance use, demographics, and criminal justice involvement in a population of patients placed on involuntary 72-h holds in a psychiatric facility. METHODS: We retrospectively identified patients aged 18 through 57 years who had been placed on 72-h holds during an acute psychiatric hospitalization during a 1-year period. Data were analyzed with standard descriptive statistics, and data collection was reviewed by 2 randomly assigned psychiatrists. RESULTS: We identified 336 patients placed on 72-h holds during an acute psychiatric stay. Of these, more than two-thirds (68.5%; n = 230) had an SUD. Compared with patients not using substances, those with SUDs were significantly more likely to be younger (p = .003), male (p = .005), and unmarried (p < .001) and to have criminal justice involvement before (p < .001) and after hospitalization (p < .001). The rate of unemployment was similarly high in both users (67.4%) and nonusers (69.2%). DISCUSSION AND CONCLUSIONS: Most patients on involuntary psychiatric holds have comorbid SUDs. These patients are more likely to have interacted with the criminal justice system and less likely to have social support in the form of marriage. Unemployment was common among all patients. SCIENTIFIC SIGNIFICANCE: When SUDs are not treated by the criminal justice or mental health system, rehospitalization and criminal recidivism may result. (Am J Addict 2018;27:574-577).

Violent behavior by emergency department patients with an involuntary hold status.

BACKGROUND: Violence against health care workers has been increasing. Health care workers in emergency departments (EDs) are highly vulnerable because they provide care for patients who may have mental illness, behavioral problems, or substance use disorders (alone or in combination) and who are often evaluated during an involuntary hold. Our objective was to identify factors that may be associated with violent behavior in ED patients during involuntary holds. METHODS: Retrospective review of patients evaluated during an involuntary hold at a suburban acute care hospital ED from January 2014 through November 2015. RESULTS: Of 251 patients, 22 (9%) had violent incidents in the ED. Violent patients were more likely to have a urine drug screen positive for tricyclic antidepressants (18.2% vs 4.8%, P=0.03) and to present with substance misuse (68.2% vs 39.7%, P=0.01), specifically with marijuana (22.7% vs 9.6%, P=0.06) and alcohol (54.5% vs 24.9%, P=0.003). ED readmission rates were higher for violent patients (18.2% vs 3.9%, P=0.02). No significant difference was found between violent patients and nonviolent patients for sex, race, marital status, insurance status, medical or psychiatric condition, reason for involuntary hold, or length of stay. CONCLUSION: Violent behavior by patients evaluated during an involuntary hold in a suburban acute care hospital ED was associated with tricyclic antidepressant use, substance misuse, and higher ED readmission rates.

Discordance Between Physician Assessment and Patient-Reported Depressive Symptoms in Parkinson Disease.

OBJECTIVE: To assess concordance between physician assessment and patient-reported symptoms when screening for depression in Parkinson disease (dPD). BACKGROUND: Depression in Parkinson disease is highly prevalent (∼40%) and has a significant impact on quality of life and disability, yet physician recognition and treatment remain inadequate. METHODS: One thousand seventy-six patients with PD completed the Brief Symptom Inventory-18 (BSI-18), a screening questionnaire for psychiatric symptoms, which was compared to item #3 (depression) on the Unified Parkinson's Disease Rating Scale (UPDRS). RESULTS: The mean BSI-18 depression score was 51.4 (9.7). Of the 170 (16%) patients screening positive for dPD on the BSI-18, 104 (61%) were not recognized as depressed by neurologists on the UPDRS. Factors associated with lower neurologist recognition included male gender, better mental health quality of life, and lack of antidepressant use. CONCLUSION: More than 60% of patients screening positive for depression on self-report were not recognized by neurologists on the UPDRS. A patient-reported screening tool for depression may improve recognition and management of dPD.

Electroconvulsive therapy in N-methyl-d-aspartate receptor encephalitis: A retrospective cohort and scoping review of literature.

Neuropsychiatric symptoms in N-methyl-d-aspartate receptor encephalitis (NMDARE) have led some to pursue empiric trials of electroconvulsive therapy (ECT). A scoping review identified 39 patients diagnosed with NMDARE undergoing ECT. Separately, a retrospective cohort was reviewed to characterize 21 patients. Clinical improvement was attributed to ECT in 49% of patients in the scoping review and 19% of patients in the retrospective cohort; timing of immunotherapies was a confounding factor. Worsening of clinical course following ECT was reported in 28% of patients in the scoping review and 38% of patient in the retrospective review. There is currently insufficient data supporting a beneficial effect of ECT in NMDARE.

Best Practices for Communicating a Diagnosis of Dementia: Results of a Multi-Stakeholder Modified Delphi Consensus Process.

Background and Objectives: Many individuals with dementia and their families report not receiving a dementia diagnosis. Previously published standards for delivering a dementia diagnosis are now more than 10 years old and were developed without patient and caregiver input. The objective of this study was to identify best practices for delivering a diagnosis of dementia using existing literature, involvement of diverse stakeholders, and consensus building through a formal modified Delphi approach. Methods: We convened a multi-stakeholder working group including a patient, caregivers, Alzheimer's Association staff, and clinicians from diverse backgrounds. The panel used the American Academy of Neurology process for recommendation development, consisting of a half-day workshop and 3 rounds of anonymous modified Delphi voting to achieve consensus. Results: The working group convened from May 2022 through January 2023. The group chose to focus statements on a limited number of best practices that can be applied across clinic types. Seven best practice statements achieved consensus after a maximum of 3 rounds of voting. These included the following: (1) Clinicians must show compassion and empathy when delivering a diagnosis of dementia (level A). During dementia diagnosis disclosure, clinicians should (2) ask regarding diagnosis preferences, (3) instill realistic hope, (4) provide practical strategies, (5) provide education and connections to high-quality resources, (6) connect caregivers to support resources, and (7) provide written summaries of the diagnoses, plan, and relevant resources (each level B). Discussion: Clinicians need to customize discussion of a dementia diagnosis for individual patients and their caregivers. These 7 best practices provide a diagnosis communication framework that can be implemented across varied clinical settings. Additional strategies, such as using optimal general communication approaches, are also important for dementia diagnosis discussions. Thoughtful application of these best practices is particularly important when caring for individuals from underrepresented communities. Further improving communication regarding dementia diagnoses will require health system changes (e.g., for sufficient time), improved access to specialty dementia care, and clinician training for delivering difficult diagnoses. More research is needed to identify culturally sensitive approaches to discussing dementia diagnoses.

Alzheimer Disease Cerebrospinal Fluid Biomarkers in a Tertiary Neurology Practice.

OBJECTIVE: To evaluate the performance of Alzheimer disease (AD) cerebrospinal fluid (CSF) biomarkers in a tertiary neurology clinic setting with high frequency of non-AD cases, including normal pressure hydrocephalus (NPH). METHODS: There were 534 patients who underwent AD CSF biomarkers (Roche Elecsys Aß42, p-Tau181, total-Tau) from April 1, 2020, through April 23, 2021. A behavioral neurologist blinded to CSF results assigned a clinical diagnosis retrospectively on the basis of consensus criteria, and a neuroradiologist blinded to the diagnosis and CSF studies graded brain magnetic resonance images for indicators of CSF dynamics disorders. Associations between biomarkers, diagnoses, and imaging were assessed by χ2, analysis of covariance, and linear regression methods. RESULTS: Median age at time of testing was 67 years (range, 19 to 96 years), median symptom duration was 2 years (range, 0.4 to 28 years), and median Short Test of Mental Status score was 30 (range, 0 to 38). Clinical diagnoses significantly correlated with different CSF biomarker values (χ2=208.3; P=10e-4). p-Tau181/Aß42 ratios above 0.023 positively correlated with Alzheimer dementia (more than individual measures). This ratio also had the best performance for differentiating Alzheimer dementia from NPH (area under the curve, 0.869). Imaging markers supportive of CSF dynamics disorders correlated with low Aß42, p-Tau181, and total-Tau. CONCLUSION: In a heterogeneous clinical population, abnormal p-Tau181/Aß42 ratios (>0.023) have the strongest association with Alzheimer dementia and probably represent a comorbid AD pathologic component in persons clearly matching non-AD neurodegenerative syndromes. Altered CSF dynamics were associated with lower concentrations of AD CSF biomarkers regardless of clinical diagnosis, but the ratio compensates for these changes. In the appropriate clinical setting, an isolated abnormal Aß42 should prompt consideration of NPH.

Clinicopathologic Heterogeneity and Glial Activation Patterns in Alzheimer Disease.

Importance: Factors associated with clinical heterogeneity in Alzheimer disease (AD) lay along a continuum hypothesized to associate with tangle distribution and are relevant for understanding glial activation considerations in therapeutic advancement. Objectives: To examine clinicopathologic and neuroimaging characteristics of disease heterogeneity in AD along a quantitative continuum using the corticolimbic index (CLix) to account for individuality of spatially distributed tangles found at autopsy. Design, Setting, and Participants: This cross-sectional study was a retrospective medical record review performed on the Florida Autopsied Multiethnic (FLAME) cohort accessioned from 1991 to 2020. Data were analyzed from December 2022 to December 2023. Structural magnetic resonance imaging (MRI) and tau positron emission tomography (PET) were evaluated in an independent neuroimaging group. The FLAME cohort includes 2809 autopsied individuals; included in this study were neuropathologically diagnosed AD cases (FLAME-AD). A digital pathology subgroup of FLAME-AD cases was derived for glial activation analyses. Main Outcomes and Measures: Clinicopathologic factors of heterogeneity that inform patient history and neuropathologic evaluation of AD; CLix score (lower, relative cortical predominance/hippocampal sparing vs higher, relative cortical sparing/limbic predominant cases); neuroimaging measures (ie, structural MRI and tau-PET). Results: Of the 2809 autopsied individuals in the FLAME cohort, 1361 neuropathologically diagnosed AD cases were evaluated. A digital pathology subgroup included 60 FLAME-AD cases. The independent neuroimaging group included 93 cases. Among the 1361 FLAME-AD cases, 633 were male (47%; median [range] age at death, 81 [54-96] years) and 728 were female (53%; median [range] age at death, 81 [53-102] years). A younger symptomatic onset (Spearman ρ = 0.39, P < .001) and faster decline on the Mini-Mental State Examination (Spearman ρ = 0.27; P < .001) correlated with a lower CLix score in FLAME-AD series. Cases with a nonamnestic syndrome had lower CLix scores (median [IQR], 13 [9-18]) vs not (median [IQR], 21 [15-27]; P < .001). Hippocampal MRI volume (Spearman ρ = -0.45; P < .001) and flortaucipir tau-PET uptake in posterior cingulate and precuneus cortex (Spearman ρ = -0.74; P < .001) inversely correlated with CLix score. Although AD cases with a CLix score less than 10 had higher cortical tangle count, we found lower percentage of CD68-activated microglia/macrophage burden (median [IQR], 0.46% [0.32%-0.75%]) compared with cases with a CLix score of 10 to 30 (median [IQR], 0.75% [0.51%-0.98%]) and on par with a CLix score of 30 or greater (median [IQR], 0.40% [0.32%-0.57%]; P = .02). Conclusions and Relevance: Findings show that AD heterogeneity exists along a continuum of corticolimbic tangle distribution. Reduced CD68 burden may signify an underappreciated association between tau accumulation and microglia/macrophages activation that should be considered in personalized therapy for immune dysregulation.

Age-Specific Barriers and Facilitators to Research Participation Amongst African Americans in Observational Studies of Memory and Aging.

BACKGROUND: Black/African Americans experience a high burden of Alzheimer disease and related dementias yet are critically underrepresented in corresponding research. Understanding barriers and facilitators to research participation among younger and older African Americans is necessary to inform age-specific strategies to promote equity in studies of early- and late-onset neurodegenerative diseases. STUDY DESIGN: Survey respondents (n = 240) rated barriers and facilitators of research participation. Age-specific differences were evaluated using nonparametric Kruskal-Wallis tests across respondents aged 18-44 years (n = 76), 45-64 years (n = 83), and ≥ 65 years (n = 81). Strategies to mitigate barriers and promote facilitators were further explored via community-based focus groups. Pooled frequency of common themes discussed in focus groups were evaluated and compared across different ages including ≥ 45 years, ≥ 65 years, and mixed ages ≥ 45 years. RESULTS: Younger respondents (aged 18-44 and 45-64 years) expressed a greater need for flexibility in when, where, and how research testing takes place versus adults ≥ 65 years. Focus groups emphasized long-lasting consequences of systemic racism and the need to build and foster trust to resolve barriers and promote research engagement amongst African Americans. DISCUSSION: Age-specific strategies are needed to increase engagement, address recruitment disparities, and promote retention of African American participants in memory and aging studies across the lifespan.

Retrospective Evaluation of Neuropathologic Proxies of the Minimal Atrophy Subtype Compared With Corticolimbic Alzheimer Disease Subtypes.

BACKGROUND AND OBJECTIVES: Alzheimer disease (AD) is neuropathologically classified into 3 corticolimbic subtypes based on the neurofibrillary tangle distribution throughout the hippocampus and association cortices: limbic predominant, typical, and hippocampal sparing. In vivo, a fourth subtype, dubbed "minimal atrophy," was identified using structural MRI. The objective of this study was to identify a neuropathologic proxy for the neuroimaging-defined minimal atrophy subtype. METHODS: We applied 2 strategies in the Florida Autopsied Multi-Ethnic (FLAME) cohort to evaluate a neuropathologic proxy for the minimal atrophy subtype. In the first strategy, we selected AD cases with a Braak tangle stage IV (Braak IV) because of the relative paucity of neocortical tangle involvement compared with Braak >IV. Braak IV cases were compared with the 3 AD subtypes. In the alternative strategy, typical AD was stratified by brain weight and cases having a relatively high brain weight (>75th percentile) were defined as minimal atrophy. RESULTS: Braak IV cases (n = 37) differed from AD subtypes (limbic predominant [n = 174], typical [n = 986], and hippocampal sparing [n = 187] AD) in having the least years of education (median 12 years, group-wise p < 0.001) and the highest brain weight (median 1,140 g, p = 0.002). Braak IV cases most resembled the limbic predominant cases owing to their high proportion of APOE ε4 carriers (75%, p < 0.001), an amnestic syndrome (100%, p < 0.001), as well as older age of cognitive symptom onset and death (median 79 and 85 years, respectively, p < 0.001). Only 5% of Braak IV cases had amygdala-predominant Lewy bodies (the lowest frequency observed, p = 0.017), whereas 32% had coexisting pathology of Lewy body disease, which was greater than the other subtypes (p = 0.005). Nearly half (47%) of the Braak IV samples had coexisting limbic predominant age-related TAR DNA-binding protein 43 encephalopathy neuropathologic change. Cases with a high brain weight (n = 201) were less likely to have amygdala-predominant Lewy bodies (14%, p = 0.006) and most likely to have Lewy body disease (31%, p = 0.042) compared with those with middle (n = 455) and low (n = 203) brain weight. DISCUSSION: The frequency of Lewy body disease was increased in both neuropathologic proxies of the minimal atrophy subtype. We hypothesize that Lewy body disease may underlie cognitive decline observed in minimal atrophy cases.

Association of Plasma Biomarkers of Alzheimer Disease With Cognition and Medical Comorbidities in a Biracial Cohort.

BACKGROUND AND OBJECTIVES: Recent advances in blood-based biomarkers offer the potential to revolutionize the diagnosis and management of Alzheimer disease (AD), but additional research in diverse populations is critical. We assessed the profiles of blood-based AD biomarkers and their relationships to cognition and common medical comorbidities in a biracial cohort. METHODS: Participants were evaluated through the Mayo Clinic Jacksonville Alzheimer Disease Research Center and matched on age, sex, and cognitive status. Plasma AD biomarkers (ß-amyloid peptide 1-42 [Aß42/40], plasma tau phosphorylated at position 181 [p-tau181], glial fibrillary acidic protein [GFAP], and neurofilament light) were measured using the Quanterix SiMoA HD-X analyzer. Cognition was assessed with the Mini-Mental State Examination. Wilcoxon rank sum tests were used to assess for differences in plasma biomarker levels by sex. Linear models tested for associations of self-reported race, chronic kidney disease (CKD), and vascular risk factors with plasma AD biomarker levels. Additional models assessed for interactions between race and plasma biomarkers in predicting cognition. RESULTS: The sample comprised African American (AA; N = 267) and non-Hispanic White (NHW; N = 268) participants, including 69% female participants and age range 43-100 (median 80.2) years. Education was higher in NHW participants (median 16 vs 12 years, p < 0.001) while APOE ε4 positivity was higher in AA participants (43% vs 34%; p = 0.04). We observed no differences in plasma AD biomarker levels between AA and NHW participants. These results were unchanged after stratifying by cognitive status (unimpaired vs impaired). Although the p-tau181-cognition association seemed stronger in NHW participants while the Aß42/40-cognition association seemed stronger in AA participants, these findings did not survive after excluding individuals with CKD. Female participants displayed higher GFAP (177.5 pg/mL vs 157.73 pg/mL; p = 0.002) and lower p-tau181 (2.62 pg/mL vs 3.28 pg/mL; p = 0.001) levels than male participants. Diabetes was inversely associated with GFAP levels (ß = -0.01; p < 0.001). DISCUSSION: In a biracial community-based sample of adults, we observed that sex differences, CKD, and vascular risk factors, but not self-reported race, contributed to variation in plasma AD biomarkers. Although some prior studies have reported primary effects of race/ethnicity, our results reinforce the need to account for broad-based medical and social determinants of health (including sex, systemic comorbidities, and other factors) in effectively and equitably deploying plasma AD biomarkers in the general population.

The neuropsychiatry of vitamin B12 deficiency in elderly patients.

Vitamin B12 deficiency is a common cause of neuropsychiatric symptoms in elderly persons. Malabsorption accounts for the majority of cases. Vitamin B12 deficiency has been associated with neurologic, cognitive, psychotic, and mood symptoms, as well as treatment-resistance. Clinician awareness should be raised to accurately diagnose and treat early deficiencies to prevent irreversible structural brain damage, because current practice can be ineffective at identifying cases leading to neuropsychiatric sequelae. This clinical review focuses on important aspects of the recognition and treatment of vitamin B12 deficiency and neuropsychiatric manifestations of this preventable illness in elderly patients.

Intensive care unit delirium in patients with severe COVID-19: A prospective observational cohort study.

Background: Delirium is common in patients with severe coronavirus disease-19 (COVID-19). The purpose of our study was to determine whether severe COVID-19 is an independent risk factor for the development of delirium in patients treated in the intensive care unit (ICU). Methods: This prospective observational cohort study involved 162 critically ill patients admitted to a multidisciplinary ICU during 2019 and 2020. A validated screening tool was used to diagnose delirium. Multiple delirium risk factors were collected daily including clinical characteristics, hospital course, lab values, vital signs, surgical exposure, drug exposure, and COVID-19 characteristics. After univariate analysis, a multivariate logistic regression analysis was performed to determine independent risk factors associated with the development of delirium. Results: In our study population, 50 (31%) patients developed delirium. A total of 39 (24.1%) tested positive for COVID-19. Initial analysis showed COVID-19 to be more prevalent in those patients that developed delirium (40% vs. 17%; P = 0.003). Multivariate analysis showed opioid use (odds ratio [OR]: 24 [95% confidence intervals (CI): 16-27]; P ≤ 0.001), benzodiazepine use (OR: 23 [95% CI: 16-63] P = 0.001), and estimated mortality based on acute physiology and chronic health evaluation IV score (OR: 1.04 [95% CI: 1.01-1.07] P = 0.002) to be independently associated with delirium development. COVID-19 (OR: 1.44 [95% CI: 0.13-10.6]; P = 0.7) was not found to be associated with delirium. Conclusion: Delirium is prevalent in critically ill patients admitted to the ICU, including those with COVID-19. However, after adjustment for important covariates, we found in this cohort that COVID-19 was not an independent risk factor for delirium.

Cytokine profiles in intensive care unit delirium.

BACKGROUND: Neuroinflammation causing disruption of the blood-brain barrier and immune cell extravasation into the brain parenchyma may cause delirium; however, knowledge of the exact pathophysiologic mechanism remains incomplete. The purpose of our study was to determine whether cytokine profiles differ depending on whether delirium occurs in the setting of sepsis, coronavirus disease 2019 (COVID-19), or recent surgery. METHODS: This prospective observational cohort study involved 119 critically ill patients admitted to a multidisciplinary intensive care unit (ICU) during 2019 and 2020. Delirium was identified using the validated confusion assessment method for the ICU. Multiple delirium risk factors were collected daily including clinical characteristics, hospital course, lab values, vital signs, surgical exposure, drug exposure, and COVID-19 characteristics. Serums samples were collected within 12 hours of ICU admission and cytokine levels were measured. RESULTS: The following proinflammatory cytokines were elevated in our delirium population: tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-18, C-C motif ligand (CCL) 2, CCL3, C-X-C motif chemokine ligand (CXCL)1, CXCL10, IL-8, IL-1 receptor antagonist, and IL-10. Analysis of relative cytokine levels in those patients that developed delirium in the setting of sepsis, COVID-19, and recent surgery showed elevations of CCL2, CXCL10, and TNF-α in both the sepsis and COVID-19 group in comparison to the postsurgical population. In the postsurgical group, granulocyte colony-stimulating factor was elevated and CXCL10 was decreased relative to the opposing groups. CONCLUSIONS: We identify several cytokines and precipitating factors known to be associated with delirium. However, our study suggests that the cytokine profile associated with delirium is variable and contingent upon delirium precipitating factors.