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    APPlications of amyloid-β precursor protein metabolites in macrocephaly and autism spectrum disorder
    (Frontiers Media, 2023-09-20) Sokol, Deborah K.; Lahiri, Debomoy K.; Neurology, School of Medicine
    Metabolites of the Amyloid-β precursor protein (APP) proteolysis may underlie brain overgrowth in Autism Spectrum Disorder (ASD). We have found elevated APP metabolites (total APP, secreted (s) APPα, and α-secretase adamalysins in the plasma and brain tissue of children with ASD). In this review, we highlight several lines of evidence supporting APP metabolites’ potential contribution to macrocephaly in ASD. First, APP appears early in corticogenesis, placing APP in a prime position to accelerate growth in neurons and glia. APP metabolites are upregulated in neuroinflammation, another potential contributor to excessive brain growth in ASD. APP metabolites appear to directly affect translational signaling pathways, which have been linked to single gene forms of syndromic ASD (Fragile X Syndrome, PTEN, Tuberous Sclerosis Complex). Finally, APP metabolites, and microRNA, which regulates APP expression, may contribute to ASD brain overgrowth, particularly increased white matter, through ERK receptor activation on the PI3K/Akt/mTOR/Rho GTPase pathway, favoring myelination.
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    Mechanisms of ARIA: is it time to focus on the unique immune environment of the neurovascular unit?
    (BMC, 2023-10-20) Foley, Kate E.; Weekman, Erica M.; Wilcock, Donna M.; Neurology, School of Medicine
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    Resting-State Functional Connectivity Disruption as a Pathological Biomarker in Autosomal Dominant Alzheimer Disease
    (Mary Ann Liebert, 2021) Smith, Robert X.; Strain, Jeremy F.; Tanenbaum, Aaron; Fagan, Anne M.; Hassenstab, Jason; McDade, Eric; Schindler, Suzanne E.; Gordon, Brian A.; Xiong, Chengjie; Chhatwal, Jasmeer; Jack, Clifford, Jr.; Karch, Celeste; Berman, Sarah; Brosch, Jared R.; Lah, James J.; Brickman, Adam M.; Cash, David M.; Fox, Nick C.; Graff-Radford, Neill R.; Levin, Johannes; Noble, James; Holtzman, David M.; Masters, Colin L.; Farlow, Martin R.; Laske, Christoph; Schofield, Peter R.; Marcus, Daniel S.; Morris, John C.; Benzinger, Tammie L. S.; Bateman, Randall J.; Ances, Beau M.; Neurology, School of Medicine
    Aim: Identify a global resting-state functional connectivity (gFC) signature in mutation carriers (MC) from the Dominantly Inherited Alzheimer Network (DIAN). Assess the gFC with regard to amyloid (A), tau (T), and neurodegeneration (N) biomarkers, and estimated years to symptom onset (EYO). Introduction: Cross-sectional measures were assessed in MC (n = 171) and mutation noncarrier (NC) (n = 70) participants. A functional connectivity (FC) matrix that encompassed multiple resting-state networks was computed for each participant. Methods: A global FC was compiled as a single index indicating FC strength. The gFC signature was modeled as a nonlinear function of EYO. The gFC was linearly associated with other biomarkers used for assessing the AT(N) framework, including cerebrospinal fluid (CSF), positron emission tomography (PET) molecular biomarkers, and structural magnetic resonance imaging. Results: The gFC was reduced in MC compared with NC participants. When MC participants were differentiated by clinical dementia rating (CDR), the gFC was significantly decreased in MC CDR >0 (demented) compared with either MC CDR 0 (cognitively normal) or NC participants. The gFC varied nonlinearly with EYO and initially decreased at EYO = −24 years, followed by a stable period followed by a further decline near EYO = 0 years. Irrespective of EYO, a lower gFC associated with values of amyloid PET, CSF Aβ1–42, CSF p-tau, CSF t-tau, 18F-fluorodeoxyglucose, and hippocampal volume. Conclusions: The gFC correlated with biomarkers used for defining the AT(N) framework. A biphasic change in the gFC suggested early changes associated with CSF amyloid and later changes associated with hippocampal volume.
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    Successful conduct of an acute stroke clinical trial during COVID
    (Public Library of Science, 2021-01-15) Yamal, Jose-Miguel; Parker, Stephanie A.; Jacob, Asha P.; Rajan, Suja S.; Bowry, Ritvij; Bratina, Patti; Wang, Mengxi; Nour, May; Mackey, Jason; Collins, Sarah; Jones, William; Schimpf, Brandi; Ornelas, David; Spokoyny, Ilana; Fung Im, Jenny; Gilbert, Greg; Eisshofer, Michael; Grotta, James C.; Neurology, School of Medicine
    Most clinical research stopped during COVID due to possible impact on data quality and personnel safety. We aimed to assess the impact of COVID on acute stroke clinical trial conduct at sites that continued to enroll patients during the pandemic. BEST-MSU is an ongoing study of Mobile Stroke Units (MSU) vs standard management of tPA-eligible acute stroke patients in the pre-hospital setting. MSU personnel include a vascular neurologist via telemedicine, and a nurse, CT technologist, paramedics and emergency medicine technicians on-board. During COVID, consent, 90-day modified Rankin Scale (mRS) and EQ5D were obtained by phone instead of in-person, but other aspects of management were similar to the pre-COVID period. We compared patient demographics, study metrics, and infection of study personnel during intra- vs pre-COVID eras. Five of 6 BEST-MSU sites continued to enroll during COVID. There were no differences in intra- (n = 57) vs pre- (n = 869) COVID enrolled tPA eligible patients' age, sex, race (38.6% vs 38.0% Black), ethnicity (15.8% vs 18.6% Hispanic), or NIHSS (median 11 vs 9). The percent of screened patients enrolled and adjudicated tPA eligible declined from 13.6% to 6.6% (p < .001); study enrollment correlated with local stay-at-home and reopening orders. There were no differences in alert to MSU arrival or arrival to tPA times, but MSU on-scene time was 5 min longer (p = .01). There were no differences in ED door to CT, tPA treatment or thrombectomy puncture times, hospital length of stay, discharge disposition, or remote vs in-person 90-day mRS or EQ5D. One MSU nurse tested positive but did not require hospitalization. Clinical research in the pre-hospital setting can be carried out accurately and safely during a pandemic. tPA eligibility rates declined, but otherwise there were no differences in patient demographics, deterioration of study processes, or serious infection of study staff.
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    Predictors of early, recurrent, and intractable seizures in low-grade glioma
    (Oxford University Press, 2020-08-29) Jo, Jasmin; Nevel, Kathryn; Sutyla, Ryan; Smolkin, Mark; Lopes, M. Beatriz; Schif, David; Neurology, School of Medicine
    Background: Seizures are common among patients with low-grade glioma (LGG) and can significantly affect morbidity. We sought to determine the association between the clinical and molecular factors with seizure incidence and refractoriness in LGG patients. Methods: We conducted a retrospective review at the University of Virginia in patients with LGG (World Health Organization, WHO Grade II) evaluated between 2002 and 2015. Descriptive statistics were calculated for variables of interest, and the Kaplan-Meier method was used to estimate survival curves, which were compared with the log-rank test. Results: A total of 291 patients were included; 254 had molecular testing performed for presence of an isocitrate dehydrogenase (IDH) mutation and/or 1p/19q codeletion. Sixty-eight percent of patients developed seizures prior to LGG diagnosis; 41% of all patients had intractable seizures. Using WHO 2016 integrated classification, there was no significant difference in seizure frequency during preoperative and postoperative periods or in developing intractable seizures, though a trend toward increased preoperative seizure incidence among patients with the IDH mutation was identified (P = .09). Male sex was significantly associated with higher seizure incidence during preoperative (P < .001) and postoperative periods (P < .001); men were also more likely to develop intractable seizures (P = .01). Conclusions: Seizures are common among patients with LGG. Differences in preoperative or postoperative and intractable seizure rates by WHO 2016 classification were not detected. Our data showed a trend toward higher seizure incidence preoperatively in patients with IDH-mutant LGG. We describe a unique association between male sex and seizure incidence and intractability that warrants further study.
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    Endocrine and Growth Abnormalities in 4H Leukodystrophy Caused by Variants in POLR3A, POLR3B, and POLR1C
    (The Endocrine Society, 2021) Pelletier, Félixe; Perrier, Stefanie; Cayami, Ferdy K.; Mirchi, Amytice; Saikali, Stephan; Tran, Luan T.; Ulrick, Nicole; Guerrero, Kether; Rampakakis, Emmanouil; van Spaendonk, Rosalina M. L.; Naidu, Sakkubai; Pohl, Daniela; Gibson, William T.; Demos, Michelle; Goizet, Cyril; Tejera-Martin, Ingrid; Potic, Ana; Fogel, Brent L.; Brais, Bernard; Sylvain, Michel; Sébire, Guillaume; Lourenço, Charles Marques; Bonkowsky, Joshua L.; Catsman-Berrevoets, Coriene; Pinto, Pedro S.; Tirupathi, Sandya; Strømme, Petter; de Grauw, Ton; Gieruszczak-Bialek, Dorota; Krägeloh-Mann, Ingeborg; Mierzewska, Hanna; Philippi, Heike; Rankin, Julia; Atik, Tahir; Banwell, Brenda; Benko, William S.; Blaschek, Astrid; Bley, Annette; Boltshauser, Eugen; Bratkovic, Drago; Brozova, Klara; Cimas, Icíar; Clough, Christopher; Corenblum, Bernard; Dinopoulos, Argirios; Dolan, Gail; Faletra, Flavio; Fernandez, Raymond; Fletcher, Janice; Garcia, Maria Eugenia; Gasparini, Paolo; Gburek-Augustat, Janina; Gonzalez Moron, Dolores; Hamati, Aline; Harting, Inga; Hertzberg, Christoph; Hill, Alan; Hobson, Grace M.; Innes, A. Micheil; Kauffman, Marcelo; Kirwin, Susan M.; Kluger, Gerhard; Kolditz, Petra; Kotzaeridou, Urania; La Piana, Roberta; Liston, Eriskay; McClintock, William; McEntagart, Meriel; McKenzie, Fiona; Melançon, Serge; Misbahuddin, Anjum; Suri, Mohnish; Monton, Fernando I.; Moutton, Sebastien; Murphy, Raymond P. J.; Nickel, Miriam; Onay, Hüseyin; Orcesi, Simona; Özkınay, Ferda; Patzer, Steffi; Pedro, Helio; Pekic, Sandra; Pineda Marfa, Mercedes; Pizzino, Amy; Plecko, Barbara; Poll-The, Bwee Tien; Popovic, Vera; Rating, Dietz; Rioux, Marie-France; Rodriguez Espinosa, Norberto; Ronan, Anne; Ostergaard, John R.; Rossignol, Elsa; Sanchez-Carpintero, Rocio; Schossig, Anna; Senbil, Nesrin; Sønderberg Roos, Laura K.; Stevens, Cathy A.; Synofzik, Matthis; Sztriha, László; Tibussek, Daniel; Timmann, Dagmar; Tonduti, Davide; van de Warrenburg, Bart P.; Vázquez-López, Maria; Venkateswaran, Sunita; Wasling, Pontus; Wassmer, Evangeline; Webster, Richard I.; Wiegand, Gert; Yoon, Grace; Rotteveel, Joost; Schiffmann, Raphael; van der Knaap, Marjo S.; Vanderver, Adeline; Martos-Moreno, Gabriel Á.; Polychronakos, Constantin; Wolf, Nicole I.; Bernard, Geneviève; Neurology, School of Medicine
    Context: 4H or POLR3-related leukodystrophy is an autosomal recessive disorder typically characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism, caused by biallelic pathogenic variants in POLR3A, POLR3B, POLR1C, and POLR3K. The endocrine and growth abnormalities associated with this disorder have not been thoroughly investigated to date. Objective: To systematically characterize endocrine abnormalities of patients with 4H leukodystrophy. Design: An international cross-sectional study was performed on 150 patients with genetically confirmed 4H leukodystrophy between 2015 and 2016. Endocrine and growth abnormalities were evaluated, and neurological and other non-neurological features were reviewed. Potential genotype/phenotype associations were also investigated. Setting: This was a multicenter retrospective study using information collected from 3 predominant centers. Patients: A total of 150 patients with 4H leukodystrophy and pathogenic variants in POLR3A, POLR3B, or POLR1C were included. Main outcome measures: Variables used to evaluate endocrine and growth abnormalities included pubertal history, hormone levels (estradiol, testosterone, stimulated LH and FSH, stimulated GH, IGF-I, prolactin, ACTH, cortisol, TSH, and T4), and height and head circumference charts. Results: The most common endocrine abnormalities were delayed puberty (57/74; 77% overall, 64% in males, 89% in females) and short stature (57/93; 61%), when evaluated according to physician assessment. Abnormal thyroid function was reported in 22% (13/59) of patients. Conclusions: Our results confirm pubertal abnormalities and short stature are the most common endocrine features seen in 4H leukodystrophy. However, we noted that endocrine abnormalities are typically underinvestigated in this patient population. A prospective study is required to formulate evidence-based recommendations for management of the endocrine manifestations of this disorder.
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    Telemedicine for Neuro-Ophthalmology: challenges and opportunities
    (Wolters Kluwer, 2021) Liu, Yin Allison; Ko, Melissa W.; Moss, Heather E.; Neurology, School of Medicine
    Purpose of review: Telemedicine for neuro-ophthalmology (tele-neuro-ophthalmology) has the potential to increase access to neuro-ophthalmic care by improving efficiency and decreasing the need for long-distance travel for patients. Requirements for decreased person-to-person contacts during the COVID-19 pandemic accelerated adoption of tele-neuro-ophthalmology. This review highlights the challenges and opportunities with tele-neuro-ophthalmology. Recent findings: Tele-neuro-ophthalmology programs can be used for triage, diagnostic consultation, and long-term treatment monitoring. Formats include telephone appointments, interprofessional collaborations, remote data interpretation, online asynchronous patient communication, and video visits. Barriers to long-term implementation of tele-neuro-ophthalmology arise from data quality, patient engagement, workflow integration, state and federal regulations, and reimbursement. General neurologists may collaborate with local eye care providers for ophthalmic examination, imaging, and testing to facilitate efficient and effective tele-neuro-ophthalmology consultation. Summary: Tele-neuro-ophthalmology has tremendous potential to improve patient access to high-quality cost-effective neuro-ophthalmic care. However, many factors may impact its long-term sustainability.
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    Confounding factors of Alzheimer’s disease plasma biomarkers and their impact on clinical performance
    (Wiley, 2023) Pichet Binette, Alexa; Janelidze, Shorena; Cullen, Nicholas; Dage, Jeffrey L.; Bateman, Randall J.; Zetterberg, Henrik; Blennow, Kaj; Stomrud, Erik; Mattsson-Carlgren, Niklas; Hansson, Oskar; Neurology, School of Medicine
    Introduction: Plasma biomarkers will likely revolutionize the diagnostic work-up of Alzheimer's disease (AD) globally. Before widespread use, we need to determine if confounding factors affect the levels of these biomarkers, and their clinical utility. Methods: Participants with plasma and CSF biomarkers, creatinine, body mass index (BMI), and medical history data were included (BioFINDER-1: n = 748, BioFINDER-2: n = 421). We measured beta-amyloid (Aβ42, Aβ40), phosphorylated tau (p-tau217, p-tau181), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP). Results: In both cohorts, creatinine and BMI were the main factors associated with NfL, GFAP, and to a lesser extent with p-tau. However, adjustment for BMI and creatinine had only minor effects in models predicting either the corresponding levels in CSF or subsequent development of dementia. Discussion: Creatinine and BMI are related to certain plasma biomarkers levels, but they do not have clinically relevant confounding effects for the vast majority of individuals. Highlights: Creatinine and body mass index (BMI) are related to certain plasma biomarker levels. Adjusting for creatinine and BMI has minor influence on plasma-cerebrospinal fluid (CSF) associations. Adjusting for creatinine and BMI has minor influence on prediction of dementia using plasma biomarkers.
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    Tangent functional connectomes uncover more unique phenotypic traits
    (Elsevier, 2023-08-12) Abbas, Kausar; Liu, Mintao; Wang, Michael; Duong-Tran, Duy; Tipnis, Uttara; Amico, Enrico; Kaplan, Alan D.; Dzemidzic, Mario; Kareken, David; Ances, Beau M.; Harezlak, Jaroslaw; Goñi, Joaquín; Neurology, School of Medicine
    Functional connectomes (FCs) containing pairwise estimations of functional couplings between pairs of brain regions are commonly represented by correlation matrices. As symmetric positive definite matrices, FCs can be transformed via tangent space projections, resulting into tangent-FCs. Tangent-FCs have led to more accurate models predicting brain conditions or aging. Motivated by the fact that tangent-FCs seem to be better biomarkers than FCs, we hypothesized that tangent-FCs have also a higher fingerprint. We explored the effects of six factors: fMRI condition, scan length, parcellation granularity, reference matrix, main-diagonal regularization, and distance metric. Our results showed that identification rates are systematically higher when using tangent-FCs across the “fingerprint gradient” (here including test-retest, monozygotic and dizygotic twins). Highest identification rates were achieved when minimally (0.01) regularizing FCs while performing tangent space projection using Riemann reference matrix and using correlation distance to compare the resulting tangent-FCs. Such configuration was validated in a second dataset (resting-state).
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    Head-to-head comparison between plasma p-tau217 and flortaucipir-PET in amyloid-positive patients with cognitive impairment
    (BMC, 2023-09-22) Mundada, Nidhi S.; Rojas, Julio C.; Vandevrede, Lawren; Thijssen, Elisabeth H.; Iaccarino, Leonardo; Okoye, Obiora C.; Shankar, Ranjani; Soleimani‑Meigooni, David N.; Lago, Argentina L.; Miller, Bruce L.; Teunissen, Charlotte E.; Heuer, Hillary; Rosen, Howie J.; Dage, Jeffrey L.; Jagust, William J.; Rabinovici, Gil D.; Boxer, Adam L.; La Joie, Renaud; Neurology, School of Medicine
    Background: Plasma phosphorylated tau (p-tau) has emerged as a promising biomarker for Alzheimer's disease (AD). Studies have reported strong associations between p-tau and tau-PET that are mainly driven by differences between amyloid-positive and amyloid-negative patients. However, the relationship between p-tau and tau-PET is less characterized within cognitively impaired patients with a biomarker-supported diagnosis of AD. We conducted a head-to-head comparison between plasma p-tau217 and tau-PET in patients at the clinical stage of AD and further assessed their relationships with demographic, clinical, and biomarker variables. Methods: We retrospectively included 87 amyloid-positive patients diagnosed with MCI or dementia due to AD who underwent structural MRI, amyloid-PET (11C-PIB), tau-PET (18F-flortaucipir, FTP), and blood draw assessments within 1 year (age = 66 ± 10, 48% female). Amyloid-PET was quantified in Centiloids (CL) while cortical tau-PET binding was measured using standardized uptake value ratios (SUVRs) referenced against inferior cerebellar cortex. Plasma p-tau217 concentrations were measured using an electrochemiluminescence-based assay on the Meso Scale Discovery platform. MRI-derived cortical volume was quantified with FreeSurfer. Mini-Mental State Examination (MMSE) scores were available at baseline (n = 85) and follow-up visits (n = 28; 1.5 ± 0.7 years). Results: Plasma p-tau217 and cortical FTP-SUVR were correlated (r = 0.61, p < .001), especially in temporo-parietal and dorsolateral frontal cortices. Both higher p-tau217 and FTP-SUVR values were associated with younger age, female sex, and lower cortical volume, but not with APOE-ε4 carriership. PIB-PET Centiloids were weakly correlated with FTP-SUVR (r = 0.26, p = 0.02), but not with p-tau217 (r = 0.10, p = 0.36). Regional PET-plasma associations varied with amyloid burden, with p-tau217 being more strongly associated with tau-PET in temporal cortex among patients with moderate amyloid-PET burden, and with tau-PET in primary cortices among patients with high amyloid-PET burden. Higher p-tau217 and FTP-SUVR values were independently associated with lower MMSE scores cross-sectionally, while only baseline FTP-SUVR predicted longitudinal MMSE decline when both biomarkers were included in the same model. Conclusion: Plasma p-tau217 and tau-PET are strongly correlated in amyloid-PET-positive patients with MCI or dementia due to AD, and they exhibited comparable patterns of associations with demographic variables and with markers of downstream neurodegeneration.