APOE ε2 is associated with increased tau pathology in primary tauopathy.

Apolipoprotein E (APOE) ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease mainly by modulating amyloid-ß pathology. APOE ε4 is also shown to exacerbate neurodegeneration and neuroinflammation in a tau transgenic mouse model. To further evaluate the association of APOE genotype with the presence and severity of tau pathology, we express human tau via an adeno-associated virus gene delivery approach in human APOE targeted replacement mice. We find increased hyperphosphorylated tau species, tau aggregates, and behavioral abnormalities in mice expressing APOE ε2/ε2. We also show that in humans, the APOE ε2 allele is associated with increased tau pathology in the brains of progressive supranuclear palsy (PSP) cases. Finally, we identify an association between the APOE ε2/ε2 genotype and risk of tauopathies using two series of pathologically-confirmed cases of PSP and corticobasal degeneration. Our data together suggest APOE ε2 status may influence the risk and progression of tauopathy.

At the Intersection of Patient Experience Data, Outcomes Research, and Practice: Analysis of HCAHPS Scores in Neurology Patients.

OBJECTIVE: To assess variation in patient-reported experience in inpatient neurology patients. PATIENTS AND METHODS: We retrospectively identified 1045 patients 18 years and older admitted to a neurology service and discharged from January 1, 2013, through September 30, 2016, who completed Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) surveys. Multivariable logistic regression evaluated the associations of patient factors with HCAHPS measures. Key driver analysis identified associations between HCAHPS measures and the Global score (combination of 0-10 hospital rating and likelihood to recommend). Multivariable logistic regression compared HCAHPS scores between neurology patients and those admitted to a neurosurgery (n=2190) or internal medicine (n=3401) service during the same period. RESULTS: Among patients admitted to a neurology service, overall (summary) scores did not vary significantly by diagnosis after adjustment for age, education, and overall health, but patients with neurologic diagnoses other than stroke, epilepsy, and neurodegenerative disease were more likely to report lower Pain Management scores compared with patients with cancer. Key driver analysis showed Care Transition scores as drivers of the Global score. After adjustment, general internal medicine service patients were more likely to report low Summary scores and neurosurgery service patients were significantly less likely to report low Summary scores compared with neurology service patients. CONCLUSION: Efforts to improve how neurology patients experience their care should be aimed at targeting patients' perceptions of pain management, and improving care transitions is an important first-priority target for improvement. This analysis may help other institutions improve hospital rating, value-based payments, and patient-centered outcomes.

Replication of progressive supranuclear palsy genome-wide association study identifies SLCO1A2 and DUSP10 as new susceptibility loci.

BACKGROUND: Progressive supranuclear palsy (PSP) is a parkinsonian neurodegenerative tauopathy affecting brain regions involved in motor function, including the basal ganglia, diencephalon and brainstem. While PSP is largely considered to be a sporadic disorder, cases with suspected familial inheritance have been identified and the common MAPT H1haplotype is a major genetic risk factor. Due to the relatively low prevalence of PSP, large sample sizes can be difficult to achieve, and this has limited the ability to detect true genetic risk factors at the genome-wide statistical threshold for significance in GWAS data. With this in mind, in this study we genotyped the genetic variants that displayed the strongest degree of association with PSP (P<1E-4) in the previous GWAS in a new cohort of 533 pathologically-confirmed PSP cases and 1172 controls, and performed a combined analysis with the previous GWAS data. RESULTS: Our findings validate the known association of loci at MAPT, MOBP, EIF2AK3 and STX6 with risk of PSP, and uncover novel associations with SLCO1A2 (rs11568563) and DUSP10 (rs6687758) variants, both of which were classified as non-significant in the original GWAS. CONCLUSIONS: Resolving the genetic architecture of PSP will provide mechanistic insights and nominate candidate genes and pathways for future therapeutic intervention strategies.

TIA1 Mutations in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Promote Phase Separation and Alter Stress Granule Dynamics.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are age-related neurodegenerative disorders with shared genetic etiologies and overlapping clinical and pathological features. Here we studied a novel ALS/FTD family and identified the P362L mutation in the low-complexity domain (LCD) of T cell-restricted intracellular antigen-1 (TIA1). Subsequent genetic association analyses showed an increased burden of TIA1 LCD mutations in ALS patients compared to controls (p = 8.7 × 10-6). Postmortem neuropathology of five TIA1 mutations carriers showed a consistent pathological signature with numerous round, hyaline, TAR DNA-binding protein 43 (TDP-43)-positive inclusions. TIA1 mutations significantly increased the propensity of TIA1 protein to undergo phase transition. In live cells, TIA1 mutations delayed stress granule (SG) disassembly and promoted the accumulation of non-dynamic SGs that harbored TDP-43. Moreover, TDP-43 in SGs became less mobile and insoluble. The identification of TIA1 mutations in ALS/FTD reinforces the importance of RNA metabolism and SG dynamics in ALS/FTD pathogenesis.

Characterizing Apolipoprotein E ε4 Carriers and Noncarriers With the Clinical Diagnosis of Mild to Moderate Alzheimer Dementia and Minimal ß-Amyloid Peptide Plaques.

IMPORTANCE: ß-Amyloid peptide (Aß) plaques are a cardinal neuropathologic feature of Alzheimer disease (AD), yet more than one-third of apolipoprotein E ε4 (APOE4) noncarriers with the clinical diagnosis of mild to moderate Alzheimer dementia may not meet positron emission tomographic criteria for significant cerebral amyloidosis. OBJECTIVES: To clarify the percentage of APOE4 carriers and noncarriers with the primary clinical diagnosis of mild to moderate Alzheimer dementia near the end of life and minimal Aß plaques noted at autopsy and the extent to which these cases are associated with appreciable neurofibrillary degeneration or a primary neuropathologic diagnosis other than AD. DESIGN, SETTING, AND PARTICIPANTS: Data on participants included in this study were obtained from the National Alzheimer Coordinating Center's Uniform Data Set, which comprises longitudinal clinical assessments performed at the AD centers funded by the National Institute on Aging. Neuropathology data are available for the subset of participants who died. A total of 100 APOE4 noncarriers and 100 APOE4 carriers had the primary clinical diagnosis of mild to moderate Alzheimer dementia at their last visit, known APOE4 genotype, died within the ensuing 24 months, and underwent neuropathologic evaluation on autopsy. The study was conducted from September 1, 2005, to September 1, 2012; analysis was performed from October 9, 2012, to March 20, 2015. MAIN OUTCOMES AND MEASURES: Standardized histopathologic assessments of AD neuropathologic changes were the primary measures of interest in this study, specifically Consortium to Establish a Registry for Alzheimer's Disease neuritic plaque density score, diffuse plaque density score, and Braak stage for neurofibrillary degeneration. The distributions of scores for these measures were the primary outcomes. RESULTS: Of the 37 APOE4 noncarriers with minimal neuritic plaques, 16 individuals (43.2%) had Braak stages III to VI ratings, and 15 of the others (75.0%) met neuropathologic criteria for other dementia-related diseases. Of the 13 APOE4 carriers with minimal neuritic plaques, 6 individuals (46.2%) had Braak stages III to VI ratings and met neuropathologic criteria for other dementia-related diseases. Similarly, of the 7 APOE4 carriers with minimal neuritic plaques and Braak stages 0 to II, 4 participants (57.1%) were thought to have pathologic changes and alterations resulting from non-AD neuropathologic features. CONCLUSIONS AND RELEVANCE: In this study, more than one-third of APOE4 noncarriers with the primary clinical diagnosis of mild to moderate Alzheimer dementia had minimal Aß plaque accumulation in the cerebral cortex and, thus, may show limited or no benefit from otherwise effective anti-Aß treatment. Almost half of the participants with a primary clinical diagnosis of mild to moderate Alzheimer dementia and minimal Aß plaque accumulation had an extensive topographic distribution of neurofibrillary degeneration. Additional studies are needed to better understand and provide treatment for patients with this unexpectedly common cliniconeuropathologic condition.

Arizona Study of Aging and Neurodegenerative Disorders and Brain and Body Donation Program.

The Brain and Body Donation Program (BBDP) at Banner Sun Health Research Institute (http://www.brainandbodydonationprogram.org) started in 1987 with brain-only donations and currently has banked more than 1600 brains. More than 430 whole-body donations have been received since this service was commenced in 2005. The collective academic output of the BBDP is now described as the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND). Most BBDP subjects are enrolled as cognitively normal volunteers residing in the retirement communities of metropolitan Phoenix, Arizona. Specific recruitment efforts are also directed at subjects with Alzheimer's disease, Parkinson's disease and cancer. The median age at death is 82. Subjects receive standardized general medical, neurological, neuropsychological and movement disorders assessments during life and more than 90% receive full pathological examinations by medically licensed pathologists after death. The Program has been funded through a combination of internal, federal and state of Arizona grants as well as user fees and pharmaceutical industry collaborations. Subsets of the Program are utilized by the US National Institute on Aging Arizona Alzheimer's Disease Core Center and the US National Institute of Neurological Disorders and Stroke National Brain and Tissue Resource for Parkinson's Disease and Related Disorders. Substantial funding has also been received from the Michael J. Fox Foundation for Parkinson's Research. The Program has made rapid autopsy a priority, with a 3.0-hour median post-mortem interval for the entire collection. The median RNA Integrity Number (RIN) for frozen brain and body tissue is 8.9 and 7.4, respectively. More than 2500 tissue requests have been served and currently about 200 are served annually. These requests have been made by more than 400 investigators located in 32 US states and 15 countries. Tissue from the BBDP has contributed to more than 350 publications and more than 200 grant-funded projects.

Association of pituitary adenylate cyclase-activating polypeptide with cognitive decline in mild cognitive impairment due to Alzheimer disease.

IMPORTANCE: There is a deficit of pituitary adenylate cyclase-activating polypeptide (PACAP) in patients with neuropathologically confirmed Alzheimer dementia. However, whether this deficit is associated with the earlier stages of Alzheimer disease (AD) is unknown. This study was conducted to clarify the association between PACAP biomarkers and preclinical, mild cognitive impairment (MCI), and dementia stages of AD in postmortem brain tissue. OBJECTIVES: To examine PACAP and PACAP receptor levels in postmortem brain tissues and cerebrospinal fluid from cognitively and neuropathologically normal control individuals, patients with MCI due to AD (MCI-AD), and individuals with AD; analyze the relationship between PACAP, cognitive, and pathologic features; and propose a model to assess these relationships. DESIGN, SETTING, AND PARTICIPANTS: We measured PACAP and its receptor (PAC1) levels using enzyme-linked immunoassay. A total of 35 cases were included. All the brain tissue and cerebrospinal fluid samples were selected from Banner Sun Health Research Institute Brain and Body Donation Program. All cognitive test results were in record with the Arizona Alzheimer's Consortium. MAIN OUTCOMES AND MEASURES: A comparison of PACAP and PAC1 levels among the healthy controls, MCI-AD, and AD dementia groups, as well as a systematic correlation analysis between PACAP level, cognitive performance, and pathologic severity. RESULTS: The PACAP levels in cerebrospinal fluid, the superior frontal gyrus, and the middle temporal gyrus were inversely related to dementia severity. The PACAP levels in cerebrospinal fluid correlated with the Mattis Dementia Rating Scale score (Pearson r = 0.50; P = .03) and inversely correlated with total amyloid plaques (Pearson r = -0.48; P < .01) and tangles (Pearson r = -0.55; P = .01) in the brain. The PACAP in the superior frontal gyrus and middle temporal gyrus correlated with the Stroop Color-Word Interference Test (Pearson r = 0.58; P < .01) and the Auditory Verbal Learning Test-Total Learning (Pearson r = 0.33; P = .02), respectively. The PACAP in the primary visual cortex did not correlate with the Judgment of Line orientation test (P = .14). Furthermore, the PAC1 level in the superior frontal gyrus showed an upregulation in MCI-AD but not in AD. The pharmacodynamic model of the PACAP-PAC1 interaction best predicted cognitive function in the superior frontal gyrus, but it was less predictive in the middle temporal gyrus and failed to be predictive in the primary visual cortex. CONCLUSIONS AND RELEVANCE: Deficits in PACAP are associated with clinical severity in the MCI and dementia stages of AD. Additional studies are needed to clarify the role of PACAP deficits in the predisposition to, pathogenesis of, and treatment of AD.

Pituitary adenylate cyclase-activating polypeptide is reduced in Alzheimer disease.

OBJECTIVES: There is growing evidence that pituitary adenylate cyclase-activating polypeptide (PACAP) is associated with Alzheimer disease (AD) pathology in animal models, but human studies are needed. METHODS: We studied the brains of patients with pathologically confirmed late-onset AD and age-matched cognitively normal (CN) subjects to investigate the expression of PACAP messenger RNA (34 AD and 14 CN) and protein (12 AD and 11 CN) in a case-control study. RESULTS: We report that PACAP levels are reduced in multiple brain regions, including the entorhinal cortex, the middle temporal gyrus, the superior frontal gyrus, and the primary visual cortex. This reduction is correlated with higher amyloid burden (CERAD plaque density) in the entorhinal cortex and superior frontal gyrus but not in the primary visual cortex, a region spared in most cases of AD. PACAP expression is lower in advanced Braak stages (V and VI) than in moderate stages (III and IV). Increased PACAP levels are associated with decreased scores on the Dementia Rating Scale, a global cognitive measure. Finally, CSF levels paralleled brain levels in AD but not in Parkinson dementia or frontotemporal dementia brains. CONCLUSIONS: The close relationship between PACAP reduction and the severity of AD pathology suggests that downregulation of PACAP may contribute to AD pathogenesis.

Does an Alzheimer's disease susceptibility gene influence the cognitive effects of cancer therapy?

The apolipoprotein E (APOE) e4 allele is the most prevalent genetic risk factor for Alzheimer's disease (AD). APOE e4 carriers suffer greater morbidity from head trauma, stroke, and carbon monoxide poisoning, yet possible interactions between APOE genotype and cancer therapy on cognition are unclear. Neuropathological and biomarker studies of young asymptomatic APOE e4 carriers that show elevated neocortical amyloid and medial temporal neurofibrillary tangles and longitudinal neuropsychological studies that show accelerated memory decline beginning around age 55-60 years define preclinical AD and have set the stage for assessing the potential adverse cognitive effects of cancer therapy in APOE e4 carriers.

Characterizing the preclinical stages of Alzheimer's disease and the prospect of presymptomatic intervention.

Studies of asymptomatic carriers of genes that are known to predispose to Alzheimer's disease (AD) have facilitated the characterization of preclinical AD. The most prevalent genetic risk factor is the ε4 allele of apolipoprotein E (APOE). Neuropathological studies of young deceased ε4 carriers have shown modest but abnormal amounts of neocortical amyloid and medial temporal neurofibrillary tangles that is also reflected in cerebrospinal fluid (CSF) biomarkers, amyloid-ß, and phospho-tau in particular. MRI studies have shown progressive hippocampal and gray matter atrophy with the advent of mild cognitive impairment (MCI), and fluorodeoxyglucose PET scans show reduced cerebral metabolism in posterior cingulate and related AD regions evident even in 30 year olds. Cerebral amyloidosis disclosed by more recent amyloid ligand PET studies in asymptomatic 60 year olds increases in parallel with ε4 gene dose. Longitudinal neuropsychological studies have revealed accelerated memory decline in ε4 carriers beginning around age 55-60 years whose severity again parallels ε4 gene dose. The clinico-pathological correlation of declining memory and AD-like neuropathological change defines preclinical AD and has set the stage for the accelerated evaluation of presymptomatic AD treatments. In this article, we briefly consider some of the earliest detectable changes associated with the predisposition to AD, and some of the prevention trial strategies that have been proposed to help find treatments to reduce the risk, postpone the onset of, or completely prevent AD symptoms as soon as possible.

Autoimmune encephalopathy.

Autoimmune encephalopathy represents a complex category of disease with diverse immunologic associations, clinical manifestations, and therapeutic outcomes. Three main subgroups include autoimmune encephalopathies without cancer but with neural nonspecific serologic evidence of autoimmunity (encompassing "Hashimoto's encephalopathy") that is the main focus of this review, paraneoplastic encephalopathies, and central nervous system (CNS) vasculitis (primary or secondary). Diagnosis of autoimmune encephalopathy can be suspected based on the clinical course, serologic evidence of autoimmunity, severe but nonspecific slowing on electroencephalography, and evidence of intrathecal inflammation in the cerebrospinal fluid. Rarely, there will be evidence of meningeal enhancement or increased fluid attenuated inversion-recovery signal in symptomatic regions on magnetic resonance imaging, but diagnosis may require brain biopsy demonstration of perivascular lymphocytic infiltrates. Nonspecific autoimmune encephalopathies are generally much more therapeutically responsive than paraneoplastic and vasculitic encephalopathies, so that high-dose corticosteroids may produce dramatic improvement within as little as a few days, although exceptional patients can require months of therapy. Paraneoplastic syndromes typically require tumor removal and often prove fatal. CNS vasculitides may respond to steroid therapy, but often require a second agent such as cyclophosphamide.

Childhood-onset multiple sclerosis with progressive dementia and pathological cortical demyelination.

OBJECTIVE: To describe a case of childhood-onset progressive multiple sclerosis with dementia and evidence of extensive cortical demyelination from brain biopsy specimen. DESIGN: Case report. SETTING: Mayo Clinic, Rochester, Minnesota. PATIENT: A 26-year-old man with a history of behavioral changes starting at the age of 13 years followed by progressive dementia. INTERVENTIONS: Neurological examination, magnetic resonance imaging, cerebrospinal fluid studies, neuropsychological testing, and brain biopsy. RESULTS: Magnetic resonance imaging scans showed numerous T2-weighted hyperintensities throughout the central nervous system not associated with contrast enhancement. Brain biopsy specimens showed cortical and subcortical demyelination. All 3 types of cortical demyelinating lesions were observed: leukocortical, intracortical, and subpial. Lesions were associated with profound microglial activation. The patient continued to progress despite attempts to treat with multiple sclerosis disease-modifying therapies. CONCLUSIONS: Multiple sclerosis should be considered in the diagnosis of progressive dementia in children and young adults. Cortical demyelination may contribute to cognitive decline in patients with dementia due to multiple sclerosis.

Novel mutations in TARDBP (TDP-43) in patients with familial amyotrophic lateral sclerosis.

The TAR DNA-binding protein 43 (TDP-43) has been identified as the major disease protein in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin inclusions (FTLD-U), defining a novel class of neurodegenerative conditions: the TDP-43 proteinopathies. The first pathogenic mutations in the gene encoding TDP-43 (TARDBP) were recently reported in familial and sporadic ALS patients, supporting a direct role for TDP-43 in neurodegeneration. In this study, we report the identification and functional analyses of two novel and one known mutation in TARDBP that we identified as a result of extensive mutation analyses in a cohort of 296 patients with variable neurodegenerative diseases associated with TDP-43 histopathology. Three different heterozygous missense mutations in exon 6 of TARDBP (p.M337V, p.N345K, and p.I383V) were identified in the analysis of 92 familial ALS patients (3.3%), while no mutations were detected in 24 patients with sporadic ALS or 180 patients with other TDP-43-positive neurodegenerative diseases. The presence of p.M337V, p.N345K, and p.I383V was excluded in 825 controls and 652 additional sporadic ALS patients. All three mutations affect highly conserved amino acid residues in the C-terminal part of TDP-43 known to be involved in protein-protein interactions. Biochemical analysis of TDP-43 in ALS patient cell lines revealed a substantial increase in caspase cleaved fragments, including the approximately 25 kDa fragment, compared to control cell lines. Our findings support TARDBP mutations as a cause of ALS. Based on the specific C-terminal location of the mutations and the accumulation of a smaller C-terminal fragment, we speculate that TARDBP mutations may cause a toxic gain of function through novel protein interactions or intracellular accumulation of TDP-43 fragments leading to apoptosis.

Nonvasculitic autoimmune inflammatory meningoencephalitis as a cause of potentially reversible dementia: report of 4 cases.

The aim of this study is to evaluate the presentation of unusual dementias in 4 patients and correlate these presentations with the histopathological findings after brain biopsy sampling to define a diagnostic entity. The authors detail the cases of 4 patients (2 women, 46 and 56 years of age; and 2 men, 67 and 74 years of age) who presented with acute and subsequently subacute encephalopathies. Their bizarre presenting symptom complexes and the results of neurological examinations, radiographic studies, electroencephalography (EEG) recordings, and serological marker tests are reviewed. The diagnostic surgical procedures and successful treatments in these patients are discussed. All 4 patients underwent craniotomy and excisional brain biopsy sampling as part of a comprehensive evaluation. Histopathological confirmation of nonvasculitic autoimmune inflammatory meningoencephalitis (NAIM) by a neuropathologist was present in all 4 patients. All patients were successfully treated with a course of corticosteroid medication. Nonvasculitic autoimmune inflammatory meningoencephalitis is a potentially treatable form of dementia whose salient features include a younger average age at onset, rapid progression with significant cognitive and behavioral features, absence of family history, abnormal EEG findings, and elevated levels of inflammatory markers. Although it is an invasive procedure, brain biopsy sampling is safe and can offer histological confirmation of this condition. This procedure is important because NAIM can be treated successfully if it is distinguished from the nontreatable dementias that mimic it.

GAB2 alleles modify Alzheimer's risk in APOE epsilon4 carriers.

The apolipoprotein E (APOE) epsilon4 allele is the best established genetic risk factor for late-onset Alzheimer's disease (LOAD). We conducted genome-wide surveys of 502,627 single-nucleotide polymorphisms (SNPs) to characterize and confirm other LOAD susceptibility genes. In epsilon4 carriers from neuropathologically verified discovery, neuropathologically verified replication, and clinically characterized replication cohorts of 1411 cases and controls, LOAD was associated with six SNPs from the GRB-associated binding protein 2 (GAB2) gene and a common haplotype encompassing the entire GAB2 gene. SNP rs2373115 (p = 9 x 10(-11)) was associated with an odds ratio of 4.06 (confidence interval 2.81-14.69), which interacts with APOE epsilon4 to further modify risk. GAB2 was overexpressed in pathologically vulnerable neurons; the Gab2 protein was detected in neurons, tangle-bearing neurons, and dystrophic neuritis; and interference with GAB2 gene expression increased tau phosphorylation. Our findings suggest that GAB2 modifies LOAD risk in APOE epsilon4 carriers and influences Alzheimer's neuropathology.

Medical management of frontotemporal dementia.

There are no Food and Drug Administration (FDA)-approved medications for the medical management of frontotemporal dementia and its related disorders, so all management recommendations are necessarily off-label and borrowed from experience with Alzheimer's disease, psychiatric disease, and related medical illnesses. Six areas of pharmacotherapeutic consideration are prevention (primary and secondary), intellectual decline, behavioral disorders (such as depression, anxiety, and psychosis), sleep disorders, frequently associated disorders (including motor neuron disease), and abrupt decline. In addition to pharmacotherapy, important lifestyle issues confronting the clinician include driving cessation, securing any weapons maintained at home, assisted living, and caregiver burnout.

Giant cell arteritis.

Giant cell, or temporal, arteritis is a vasculitis of the medium and large arteries that preferentially involves vessels originating from the arch of the aorta. Classically, this disease manifests in an older individual with new-onset persistent headache, an abnormal temporal artery on examination, and increased serum inflammatory markers. The level of clinical suspicion for giant cell arteritis should be based upon patient age, clinical symptoms, and laboratory evaluation. However, the diagnostic gold standard is achieved by histologic confirmation by temporal artery biopsy. Prompt treatment with corticosteroids is essential in order to minimize the frequency of permanent sequelae such as visual loss and stroke.