Argentina-Alzheimer's Disease Neuroimaging Initiative: pioneering Alzheimer's Research in Latin America and its Implications for Regional Advancement.

The Alzheimer's Disease Neuroimaging Initiative (ADNI) has fostered collaboration among researchers around the world, catalyzing innovation and accelerating progress in the field. In Latin America, this initiative advanced the validation and development of Alzheimer's disease biomarkers for the first time in our region. In 2011, as part of the international ADNI, Argentina-ADNI (Arg-ADNI) was founded. The following years were characterized by strong support from entities such as the Alzheimer's Association, transforming into the emergence of several multinational studies focusing on prevention and diagnosis, and treatment of dementias. These studies are heirs to the tradition of Arg-ADNI: the Dominantly Inherited Alzheimer Network, Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline, Longitudinal Early-Onset Alzheimer's Disease Study, and Initiative for the Study of Down Syndrome and Alzheimer's Disease. These initiatives have contributed significantly to the development of regional research and serve as essential tools for health policy planning in Latin America. HIGHLIGHTS: In Latin America, the Alzheimer's Disease Neuroimaging Initiative (ADNI) advanced the validation and development of Alzheimer's disease biomarkers for the first time in our region. ADNI has been the basis that boosted several multinational studies focusing on both prevention and diagnosis, and treatment of dementias (Dominantly Inherited Alzheimer Network, LatAm-FINGER, LEADS). These initiatives with the support from the Alzheimer's Association have contributed significantly to the development of regional research This is an example of collaboration between high-income countries with low- and middle-income countries aimed at global scientific development and inclusion.

Contributions of neuroimaging in central poststroke pain: a review.

BACKGROUND: Central neuropathic poststroke pain (CNPSP) affects up to 12% of patients with stroke in general and up to 18% of patients with sensory deficits. This pain syndrome is often incapacitating and refractory to treatment. Brain computed tomography and magnetic resonance imaging (MRI) are widely used methods in the evaluation of CNPSP. OBJECTIVE: The present study aims to review the role of neuroimaging methods in CNPSP. METHODS: We performed a literature review of the main clinical aspects of CNPSP and the contribution of neuroimaging methods to study its pathophysiology, commonly damaged brain sites, and possible differential diagnoses. Lastly, we briefly mention how neuroimaging can contribute to the non-pharmacological CNPSP treatment. Additionally, we used a series of MRI from our institution to illustrate this review. RESULTS: Imaging has been used to explain CNPSP pathogenesis based on spinothalamic pathway damage and connectome dysfunction. Imaging locations associated with CNPSP include the brainstem (mainly the dorsolateral medulla), thalamus (especially the ventral posterolateral/ventral posteromedial nuclei), cortical areas such as the posterior insula and the parietal operculum, and, more recently, the thalamocortical white matter in the posterior limb of the internal capsule. Imaging also brings the prospect of helping search for new targets for non-pharmacological treatments for CNPSP. Other neuropathic pain causes identified by imaging include syringomyelia, multiple sclerosis, and herniated intervertebral disc. CONCLUSION: Imaging is a valuable tool in the complimentary evaluation of CNPSP patients in clinical and research scenarios.

ANTECEDENTES: A dor neuropática central pós-acidente vascular cerebral (DNPAVC) afeta até 12% dos pacientes com AVC em geral e até 18% dos pacientes com déficits sensoriais. Essa síndrome dolorosa costuma ser incapacitante e refratária ao tratamento. A tomografia computadorizada e a ressonância magnética do cérebro são métodos amplamente utilizados na avaliação da DNPAVC. OBJETIVO: Este estudo tem como objetivo revisar o papel dos métodos de neuroimagem na DNPAVC. MéTODOS: Realizamos uma revisão da literatura sobre os principais aspectos clínicos da DNPAVC e a contribuição dos métodos de neuroimagem para estudar a fisiopatologia da DNPAVC, locais cerebrais comumente lesados na DNPAVC e possíveis diagnósticos diferenciais. Por fim, mencionamos brevemente como a neuroimagem pode contribuir no tratamento não farmacológico da DNPAVC. Além disso, utilizamos uma série de imagens de ressonância magnética da nossa instituição para ilustrar esta revisão. RESULTADOS: Os exames de imagem têm sido usados para explicar a patogênese da DNPAVC com base no dano da via espinotalâmica e na disfunção do conectoma. Os locais de imagem associados à DNPAVC incluem o tronco cerebral (principalmente o bulbo dorsolateral), o tálamo (especialmente os núcleos ventral posterolateral/ventral posteromedial), áreas corticais como a ínsula posterior e o opérculo parietal e, mais recentemente, a substância branca tálamo-cortical no membro posterior da cápsula interna. Os exames de imagem também trazem a perspectiva de auxiliar na busca de novos alvos para tratamentos não farmacológicos para DNPAVC. Outras causas de dor neuropática identificadas por exames de imagem incluem siringomielia, esclerose múltipla e hérnia de disco intervertebral. CONCLUSãO: Os exames de imagem são uma ferramenta valiosa na avaliação complementar de pacientes com DNPAVC em cenários clínicos e de pesquisa.

Association between neuroimaging and clinical outcomes in individuals with central nervous system cryptococcosis.

BACKGROUND: The radiological manifestations of central nervous system (CNS) cryptococcosis are diverse and often subtle. There is heterogeneity on how different neuroimaging patterns impact prognosis. This study aims to assess the association between the neuroimaging and clinical outcomes of CNS cryptococcosis. METHODS: All patients with CNS cryptococcosis between July 2017 and April 2023 who underwent brain magnetic resonance imaging (MRI) were included. The primary outcome was mortality during hospitalisation. Secondary outcomes were readmission, ventricular shunting, duration of hospitalisation and time to the first negative cerebrospinal fluid culture. We compared the outcomes for each of the five main radiological findings on the brain MRI scan. RESULTS: We included 46 proven CNS cryptococcosis cases. The two main comorbidity groups were HIV infection (20, 43%) and solid organ transplantation (10, 22%), respectively. Thirty-nine patients exhibited at least one radiological abnormality (85%), with the most common being meningeal enhancement (34, 74%). The mortality rates occurred at 11% (5/46) during hospitalisation. We found no significant disparities in mortality related to distinct radiological patterns. The presence of pseudocysts was significantly associated with the need for readmission (p = .027). The ventricular shunting was significantly associated with the presence of pseudocysts (p = .005) and hydrocephalus (p = .044). CONCLUSION: In this study, there is no association between brain MRI findings and mortality. Larger studies are needed to evaluate this important issue.

Increasing Use of Rapid Magnetic Resonance Imaging for Children with Blunt Head Injury.

OBJECTIVE: To increase the percentage of patients who undergo rapid magnetic resonance imaging (rMRI) rather than computed tomography (CT) for evaluation of mild traumatic brain injury (TBI) from 45% in 2020 to 80% by December 2021. STUDY DESIGN: This was a quality improvement initiative targeted to patients presenting to the pediatric emergency department presenting with mild TBI, with baseline data collected from January 2020 to December 2020. From January 2021 to August 2021, we implemented a series of improvement interventions and tracked the percentage of patients undergoing neuroimaging who received rMRI as their initial study. Balancing measures included proportion of all patients with mild TBI who underwent neuroimaging of any kind, proportion of patients requiring sedation, emergency department length of stay, and percentage with clinically important TBI. RESULTS: The utilization of rMRI increased from a baseline of 45% to a mean of 92% in the intervention period. Overall neuroimaging rates did not change significantly after the intervention (19.8 vs 23.2%, P = .24). There was no difference in need for anxiolysis (12 vs 7%, P = .30) though emergency department length of stay was marginally increased (1.4 vs 1.7 hours, P = < 0.01). CONCLUSION: In this quality improvement initiative, transition to rMRI as the primary imaging modality for the evaluation of minor TBI was achieved at a level 1 pediatric trauma center with no significant increase in overall use of neuroimaging.

Clinical, neuroimaging and genetic findings in Brazilian patients with neurodegeneration with brain iron accumulation.

Neurodegeneration with brain iron accumulation (NBIA) encompasses a clinically and genetically heterogeneous group of rare disorders. Here, we report clinical, neuroimaging and genetic studies in twenty three Brazilian NBIA patients. In thirteen subjects, deleterious variants were detected in known NBIA-causing genes (PANK2, PLA2G6, C9ORF12, WDR45 and FA2H), including previously unreported variants in PANK2 and PLA2G6. Two patients carried rare, likely pathogenic variants in genes not previously associated with NBIA: KMT2A c.11785A > C (p.Ile3929Leu), and TIMM8A c.127T > C (p.Cys43Arg), suggesting an expansion of their associated phenotypes to include NBIA. In eight patients the etiology remains unsolved, suggesting variants undetectable by the adopted methods, or the existence of additional NBIA-causing genes.

Clinical and Genetic Aspects of Juvenile Amyotrophic Lateral Sclerosis: A Promising Era Emerges.

Juvenile Amyotrophic Lateral Sclerosis is a genetically heterogeneous neurodegenerative disorder, which is frequently misdiagnosed due to low clinical suspicion and little knowledge about disease characteristics. More than 20 different genetic loci have been associated with both sporadic and familial juvenile Amyotrophic Lateral Sclerosis. Currently, almost 40% of cases have an identifiable monogenic basis; type 6, associated with FUS gene variants, is the most prevalent globally. Despite several upper motor neuron-dominant forms being generally associated with long-standing motor symptoms and slowly progressive course, certain subtypes with lower motor neuron-dominant features and early bulbar compromise lead to rapidly progressive motor handicap. For some monogenic forms, there is a well-established genotypic-phenotypic correlation. There are no specific biochemical and neuroimaging biomarkers for the diagnosis of juvenile Amyotrophic Lateral Sclerosis. There are several inherited neurodegenerative and neurometabolic disorders which can lead to the signs of motor neuron impairment. This review emphasizes the importance of high clinical suspicion, assessment, and proper diagnostic work-up for juvenile Amyotrophic Lateral Sclerosis.

[Natural history of mucopolysaccharidosis type III in a series of Colombian patients]. / Historia natural de la mucopolisacaridosis III en una serie de pacientes colombianos.

INTRODUCTION: Mucopolysaccharidosis type III (MPS III), also known as Sanfilippo syndrome, is a lysosomal storage disease with progressive neurodegenerative features, predominantly affecting the central nervous system. Diagnosis is based on clinical features, with neurodevelopmental and neuropsychiatric alterations taking precedence, including over phenotype alterations. The disease is confirmed by biochemical analysis to identify the type of glycosaminoglycans present, enzyme assay and molecular genetic studies. CASE REPORTS: A clinical description was performed for eight patients diagnosed with MPS III in Colombia. Their initial symptoms were related to developmental delay and behavioural disorders presenting between 3 and 8 years of age, associated in all cases with coarse facial features, thick eyebrows, hepatomegaly and progressive hearing loss. One of the patients presented cardiac anomalies; two presented focal epilepsy; and one presented optic atrophy. They all presented neuroimaging alterations, with evidence of parenchymal volume loss, corpus callosum atrophy and cortical thinning; the diagnosis was performed by biochemical glycosaminoglycan chromatography studies, and all patients have a confirmatory genetic study. CONCLUSIONS: MPS III is a challenge for diagnosis, particularly in its early stages and in patients in which the course of the disease is attenuated. This is due to its variable course, non-specific early neuropsychiatric symptoms, and the absence of obvious somatic features compared to other types of MPS. After a definitive diagnosis has been made, interdisciplinary care must be provided for the patient and their family, and support given for the treatment of physical symptoms, ensuring the best possible care and quality of life for the patient and their family, as the condition is neurodegenerative.

TITLE: Historia natural de la mucopolisacaridosis III en una serie de pacientes colombianos.Introducción. La mucopolisacaridosis de tipo III (MPS III), o síndrome de Sanfilippo, es un trastorno de almacenamiento lisosómico con características neurodegenerativas progresivas, predominante del sistema nervioso central. Su diagnóstico se basa en el cuadro clínico, y priman alteraciones en el neurodesarrollo y neuropsiquiátricas, incluso antes de la presencia de alteraciones fenotípicas. El análisis bioquímico para identificar el tipo de glucosaminoglucanos presente, la determinación enzimática y el estudio de genética molecular confirman la enfermedad. Casos clínicos. Se realiza la descripción clínica de ocho pacientes con diagnóstico de MPS III en Colombia, con síntomas iniciales en relación con retraso del desarrollo y trastornos comportamentales evidenciados entre los 3 y 8 años, asociado a facies toscas, cejas pobladas, hepatomegalia y pérdida auditiva progresiva en todos los casos. Uno de los pacientes presentó anomalías cardíacas; dos de ellos, epilepsia focal; y en uno se evidenció atrofia óptica. Todos presentaron alteraciones en las neuroimágenes con evidencia de pérdida del volumen parenquimatoso, atrofia del cuerpo calloso y adelgazamiento cortical; el diagnostico se realizó a través de estudios bioquímicos de cromatografía de glucosaminoglucanos y todos cuentan con un estudio genético confirmatorio. Conclusiones. La MPS III es un desafío diagnóstico, particularmente en pacientes con un curso atenuado de la enfermedad, debido al curso variable, síntomas neuropsiquiátricos tempranos inespecíficos y falta de características somáticas evidentes en comparación con otros tipos de MPS. Cuando se tiene el diagnóstico definitivo, es fundamental brindar atención interdisciplinaria para el paciente y la familia, y apoyar el tratamiento de los síntomas físicos, garantizando ofrecer el mejor cuidado posible y la mejor calidad de vida para el paciente y su familia, al tratarse de una condición neurodegenerativa.

Frailty and brain changes in older adults without cognitive impairment: A scoping review.

Little is known about changes in the brain associated with frailty, in particular, which brain areas could be related to frailty in older people without cognitive impairment. This scoping review mapped evidence on functional and/or structural brain changes in frail older adults without cognitive impairment. The methodology proposed by the JBI® was used in this study. The search in PubMed, PubMed PMC, BVS/BIREME, EBSCOHOST, Scopus, Web of Science, Embase, and PROQUEST was conducted up to January 2023. Studies included following the population, concepts, context and the screening and data extraction were performed by two independent reviewers. A total of 9,912 records were identified, 5,676 were duplicates and were excluded. The remaining articles were screened; 31 were read in full and 17 articles were included. The results showed that lesions in white matter hyperintensities, reduced volume of the hippocampus, cerebellum, middle frontal gyrus, low gray matter volume, cortical atrophy, decreased connectivity of the supplementary motor area, presence of amyloid-beta peptide (aß) in the anterior and posterior putamen and precuneus regions were more frequently observed in frail older adults, compared with non-frail individuals. Studies have suggested that such findings may be of neurodegenerative or cerebrovascular origin. The identification of these brain alterations in frail older adults through neuroimaging studies contributes to our understanding of the underlying mechanisms of frailty. Such findings may have implications for the early detection of frailty and implementation of intervention strategies.

Factores de riesgo y biomarcadores de la enfermedad de Alzheimer / Risk factors and biomarkers of Alzheimer's disease

Introducción: La enfermedad de Alzheimer, constituye un problema sanitario y social de gran magnitud; precisa de diagnóstico y terapéutica precoces. Se realizó una búsqueda de artículos sobre factores de riesgo y biomarcadores de la enfermedad en las bases de datos PubMed/Medline, Scopus, Scielo y Lilacs, y mediante el buscador Google académico; desde el año 2017 hasta el 2023, en idioma español, inglés y portugués. Objetivo: Analizar los factores de riesgo y los biomarcadores de la enfermedad de Alzheimer. Desarrollo: Los principales factores de riesgo encontrados son edad avanzada, menor educación, poca actividad física, hábito de fumar, consumo excesivo de alcohol, hipertensión arterial, diabetes, obesidad, depresión, pérdida o disminución de la audición, aislamiento social, los traumas craneales y la contaminación ambiental. Los biomarcadores fundamentales son: los marcadores que se utilizan en los estudios de neuroimágenes como la PET Amiloide, PET tau, PET FDG; y en LCR y plasma: Aß42, Aß42/Aß40, p tau 217, p tau 181, GFAP, y neurofilamentos de cadena ligeras. Conclusiones: Se requieren estudios longitudinales, a partir de la presencia de los factores de riesgo asociados a biomarcador, desde edades pregeriátricas en pacientes sanos, que tengan como salidas el deterioro cognitivo y el desarrollo de la demencia, para construir un modelo de predicción(AU)

Introduction: Alzheimer's disease is a health and social problem of great magnitude; it requires early diagnosis and therapy. A search for articles on risk factors and biomarkers of the disease was conducted; in the databases PubMed/Medline, Scopus, Scielo and Lilacs, and through the Google scholar search engine; from 2017 to 2023, in Spanish, English and Portuguese. Objective: To analyze the risk factors and biomarkers of Alzheimer's disease. Development: The main risk factors found are advanced age, lower education, little physical activity, smoking, excessive alcohol consumption, high blood pressure, diabetes, obesity, depression, hearing loss or decrease, social isolation, head trauma and environmental pollution. The fundamental biomarkers are: markers used in neuroimaging studies such as amyloid PET, tau PET, FDG PET; and in CSF and plasma: Aß42, Aß42/Aß40, p tau 217, p tau 181, GFAP, and light chain neurofilaments. Conclusions: Longitudinal studies are required, based on the presence of risk factors associated with biomarkers, from pregeriatric ages in healthy patients, which have cognitive impairment and the development of dementia as outputs, to build a prediction model(AU)

Racial and Ethnic Differences in Hospital Admission and Diagnostic Evaluation for Febrile Seizures in the Emergency Department.

OBJECTIVE: To examine differences in hospital admission and diagnostic evaluation for febrile seizure by race and ethnicity. STUDY DESIGN: We conducted a cross-sectional study among children 6 months to 6 years with simple or complex febrile seizure between January 1, 2016, and December 31, 2021, using data from the Pediatric Health Information System. The primary outcome was hospital admission. Secondary outcomes included the proportion of encounters with neuroimaging or lumbar puncture. We used mixed-effects logistic regression model with random intercept for hospital and patient to estimate the association between outcomes and race and ethnicity after adjusting for covariates, including seizure type. RESULTS: In total, 94 884 encounters were included. Most encounters occurred among children of non-Hispanic White (37.0%), Black (23.9%), and Hispanic/Latino (24.6%) race and ethnicity. Black and Hispanic/Latino children had 29% (aOR 0.71; 95% CI 0.66-0.75) and 26% (aOR 0.74; 95% CI 0.69-0.80) lower odds of hospital admission compared with non-Hispanic White children, respectively. Black and Hispanic/Latino children had 21% (aOR 0.79; 95% CI 0.73-0.86) and 22% (aOR 0.78; 95% CI 0.71-0.85) lower adjusted odds of neuroimaging compared with non-Hispanic White children. For complex febrile seizure, the adjusted odds of lumbar puncture was significantly greater among Asian children (aOR 2.12; 95% CI 1.19-3.77) compared with non-Hispanic White children. There were no racial differences in the odds of lumbar puncture for simple febrile seizure. CONCLUSIONS: Compared with non-Hispanic White children, Black and Hispanic/Latino children with febrile seizures are less likely to be hospitalized or receive neuroimaging.

The Knowledge Translation of Early Cerebral Palsy (KiTE CP) Study: Implementing Screening Among a High-Risk Prospective Cohort of Australian Infants.

OBJECTIVE: To describe the implementation of the international guidelines for the early diagnosis of cerebral palsy (CP) and engagement in the screening process in an Australian cohort of infants with neonatal risk factors for CP. STUDY DESIGN: Prospective cohort study of infants with neonatal risk factors recruited at <6 months corrected age from 11 sites in the states of Victoria, New South Wales, and Queensland, Australia. First, we implemented a multimodal knowledge translation strategy including barrier identification, technology integration, and special interest groups. Screening was implemented as follows: infants with clinical indications for neuroimaging underwent magnetic resonance imaging and/or cranial ultrasound. The Prechtl General Movements Assessment (GMA) was recorded clinically or using an app (Baby Moves). Infants with absent or abnormal fidgety movements on GMA videos were offered further assessment using the Hammersmith Infant Neurological Examination (HINE). Infants with atypical findings on 2/3 assessments met criteria for high risk of CP. RESULTS: Of the 597 infants (56% male) recruited, 95% (n = 565) received neuroimaging, 90% (n = 537) had scorable GMA videos (2% unscorable/8% no video), and 25% (n = 149) HINE. Overall, 19% of the cohort (n = 114/597) met criteria for high risk of CP, 57% (340/597) had at least 2 normal assessments (of neuroimaging, GMA or HINE), and 24% (n = 143/597) had insufficient assessments. CONCLUSIONS: Early CP screening was implemented across participating sites using a multimodal knowledge translation strategy. Although the COVID-19 pandemic affected recruitment rates, there was high engagement in the screening process. Reasons for engagement in early screening from parents and clinicians warrant further contextualization and investigation.

Factors Associated with Pathway-Concordant Neuroimaging for Pediatric Ischemic Stroke.

OBJECTIVE: To determine factors associated with magnetic resonance imaging (MRI) and noninvasive diagnostic angiography among children presenting to the emergency department (ED) with acute ischemic stroke. STUDY DESIGN: We performed a cross-sectional study using data from >50 US children's hospitals. We included children 29 days through 17 years old hospitalized from the ED with an International Classification of Diseases, Tenth Revision, Clinical Modification, diagnosis code for acute ischemic stroke between October 1, 2015, and November 30, 2022. We excluded children with a principal diagnosis code of trauma/external injury, without neuroimaging on day of presentation, and into-ED transfers. Our outcomes were defined as acquisition of MRI (vs computed tomography only) and angiography (vs no angiography) on day of presentation. We performed generalized linear mixed modeling with hospital as a random effect to determine the association of demographics, known comorbidities, and treatment factors with each outcome. RESULTS: We included 1601 children. In multivariable analysis, younger age, mechanical ventilation, and Black race were associated with lower odds of MRI acquisition, whereas history of moyamoya disease and sickle cell disease were associated with greater odds. Younger age, mechanical ventilation, Hispanic ethnicity, Black race, other races, history of metabolic disease, and history of seizures were associated with lower odds of angiography. CONCLUSIONS: Younger and non-White children experienced lower odds of MRI and angiography, which may be driven by health system limitations or provider implicit biases or both. Our results expose risk factors for underdiagnosis of ischemic stroke and provide opportunities to tailor institutional pathways reflective of underlying pathophysiology.

"Clock dial pattern", a radiologic clue to neuro-chikungunya diagnosis: a case series.

BACKGROUND: Chikungunya is a mosquito-borne disease caused by the chikungunya virus (CHIKV) and can lead to neurological complications in severe cases. OBJECTIVE: This study examined neuroimaging patterns in chikungunya cases during two outbreaks in Brazil to identify specific patterns for diagnosis and treatment of neuro-chikungunya. METHODS: Eight patients with confirmed chikungunya and neurological involvement were included. Clinical examinations and MRI scans were performed, and findings were analyzed by neuroradiologists. Data on age, sex, neurological symptoms, diagnostic tests, MRI findings, and clinical outcomes were recorded. RESULTS: Patients showed different neuroimaging patterns. Six patients exhibited a "clock dial pattern" with hyperintense dotted lesions in the spinal cord periphery. One patient had thickening and enhancement of anterior nerve roots. Brain MRI revealed multiple hyperintense lesions in the white matter, particularly in the medulla oblongata, in six patients. One patient had a normal brain MRI. CONCLUSION: The "clock dial pattern" observed in spinal cord MRI may be indicative of chikungunya-related nervous system lesions. Isolated involvement of spinal cord white matter in chikungunya can help differentiate it from other viral infections. Additionally, distinct brainstem involvement in chikungunya-associated encephalitis, particularly in the rostral region, sets it apart from other arboviral infections. Recognizing these neuroimaging patterns can contribute to early diagnosis and appropriate management of neuro-chikungunya.

ANTECEDENTES: A chikungunya é uma doença transmitida por mosquitos causada pelo vírus chikungunya (CHIKV) e pode levar a complicações neurológicas em casos graves. OBJETIVO: Este estudo examinou padrões de neuroimagem em casos de chikungunya durante dois surtos no Brasil para identificar padrões específicos para o diagnóstico e tratamento de neurochikungunya. MéTODOS: Oito pacientes com chikungunya confirmada e envolvimento neurológico foram incluídos. Exames clínicos e ressonâncias magnéticas (RM) foram realizados, e os achados foram analisados por neurorradiologistas. Dados sobre idade, sexo, sintomas neurológicos, testes diagnósticos, achados de RM e desfechos clínicos foram registrados. RESULTADOS: Os pacientes apresentaram diferentes padrões de neuroimagem. Seis pacientes apresentaram um "padrão de mostrador de relógio" com lesões pontilhadas hiperintensas na periferia da medula espinhal. Um paciente apresentou espessamento e realce das raízes nervosas anteriores. A RM do cérebro revelou múltiplas lesões hiperintensas na substância branca, especialmente no bulbo em seis pacientes. Um paciente apresentou uma RM cerebral normal. CONCLUSãO: O "padrão de mostrador de relógio" observado na RM da medula espinhal pode ser indicativo de lesões do sistema nervoso relacionadas à chikungunya. O envolvimento isolado da substância branca da medula espinhal na chikungunya pode ajudar a diferenciá-la de outras infecções virais. Além disso, o envolvimento distinto do tronco cerebral na encefalite associada à chikungunya, especialmente na região rostral, a distingue de outras infecções por arbovírus. O reconhecimento desses padrões de neuroimagem pode contribuir para o diagnóstico precoce e manejo adequado da neurochikungunya.

Neuroimaging Findings in Fetal Hemimegalencephaly: Case Study and Review.

BACKGROUND: Limited information exists in the prenatal literature regarding the neuroimaging features of fetal hemimegalencephaly. SUMMARY: This report describes ultrasound and magnetic resonance imaging (MRI) findings in a second-trimester fetus with an isolated, severe form of hemimegalencephaly. The most prominent imaging findings included unilateral enlarged cerebral hemisphere and ipsilateral ventriculomegaly causing cerebral asymmetry, midline shift, and macrocephaly. Abnormal cortical development imaging signs were also evident. A literature review encompassing 23 reports describing 36 cases, including ours, is presented. KEY MESSAGES: Characteristic ultrasound findings for the diagnosis of hemimegalencephaly are not always apparent prenatally. Asymmetric ventriculomegaly emerges as the most common but nonspecific presenting feature during routine second- or third-trimester ultrasound scans. Subsequent high-resolution prenatal neurosonography and fetal MRI facilitate definitive prenatal diagnosis, showcasting associated features primarily related to cortical migration, differentiation, and maturation. Postnatally, the prognosis is poor due to intractable seizures, hemiplegia, and progressive neurodevelopmental delay.

PCA and logistic regression in 2-[18F]FDG PET neuroimaging as an interpretable and diagnostic tool for Alzheimer's disease.

Objective.to develop an optimization and training pipeline for a classification model based on principal component analysis and logistic regression using neuroimages from PET with 2-[18F]fluoro-2-deoxy-D-glucose (FDG PET) for the diagnosis of Alzheimer's disease (AD).Approach.as training data, 200 FDG PET neuroimages were used, 100 from the group of patients with AD and 100 from the group of cognitively normal subjects (CN), downloaded from the repository of the Alzheimer's Disease Neuroimaging Initiative (ADNI). Regularization methods L1 and L2 were tested and their respective strength varied by the hyperparameter C. Once the best combination of hyperparameters was determined, it was used to train the final classification model, which was then applied to test data, consisting of 192 FDG PET neuroimages, 100 from subjects with no evidence of AD (nAD) and 92 from the AD group, obtained at the Centro de Diagnóstico por Imagem (CDI).Main results.the best combination of hyperparameters was L1 regularization andC≈ 0.316. The final results on test data were accuracy = 88.54%, recall = 90.22%, precision = 86.46% and AUC = 94.75%, indicating that there was a good generalization to neuroimages outside the training set. Adjusting each principal component by its respective weight, an interpretable image was obtained that represents the regions of greater or lesser probability for AD given high voxel intensities. The resulting image matches what is expected by the pathophysiology of AD.Significance.our classification model was trained on publicly available and robust data and tested, with good results, on clinical routine data. Our study shows that it serves as a powerful and interpretable tool capable of assisting in the diagnosis of AD in the possession of FDG PET neuroimages. The relationship between classification model output scores and AD progression can and should be explored in future studies.

Role of Neural Plasticity of Motor Cortex in Gliomas Evaluated by Brain Imaging and Mapping Techniques in Pre- and Postoperative Period: A Systematic Review.

BACKGROUND: Resection of infiltrative neuroepithelial primary brain tumors, such as low-grade gliomas (LGGs) remains a neurosurgical challenge. Usual lack of clinical deficit despite LGGs growing in eloquent brain areas may be explained by reshaping and reorganization of functional networks. The development of modern diagnostic imaging techniques could disclose better understanding of the rearrangement of the brain cortex; however, mechanisms underlying such compensation and how it occurs in the motor cortex remain unclear. This systematic review aims to analyze the neuroplasticity of motor cortex in patients with LGGs, as determined by neuroimaging and functional techniques. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, medical subject headings (MeSH) and the following terms related to neuroimaging, LGGs and neuroplasticity were used with the Boolean operators AND and OR to synonymous terms in the PubMed database. Among the 118 results, 19 studies were included in the systematic review. RESULTS: Motor function in patients with LGG was characterized by a compensation in the contralateral and supplementary motor areas and premotor functional networks. Furthermore, ipsilateral activation in these types of gliomas was rarely described. Moreover, some studies did not reveal statistical significance in association between functional reorganization and the postoperative period, which can be explained by the low number of patients. CONCLUSION: Our findings suggest a high pattern of reorganization per different eloquent motor areas and gliomas diagnosis. Understanding this process is useful to guide safe surgical resection and to develop protocols that assess the plasticity, even though functional network rearrangement needs to be better characterized by more studies.

Impairment of daily occupations in multiple sclerosis: analysis of neuroimaging, general and social cognition, and reserve.

BACKGROUND: Multiple Sclerosis (MS) can impact performance of daily occupations in both relapsing-remitting (RRMS) and secondary-progressive (SPMS) clinical courses. Work force participation decreases with advancing physical disability but the influence of non-motor factors, neuroimaging, and reserve have been scarcely investigated. We aimed to evaluate MRI, clinical, and cognitive (social and general) factors associated with impairment in different daily occupations and address whether cognitive and brain reserve have a positive impact on the ability to maintain these activities. METHODS: We prospectively enrolled persons with MS (PwMS) who underwent clinical examination (Expanded Disability Status Scale - EDSS; Timed 25-Foot Walk Test - T25FW; and the Nine Hole Peg Test - 9HPT), general neuropsychological assessment (Brief Repeatable Battery of Neuropsychological Tests - BRBN, including the Symbol Digit Modalities Test - SDMT), social cognition evaluation (Reading the Mind in the Eyes Test), cognitive reserve questionnaire, and MRI (FreeSurfer). We also enrolled healthy subjects for comparison as a control group. Daily occupations (employment, money management, and driving abilities) were assessed in all individuals with questionnaires. RESULTS: We included 62 PwMS (32 RRMS and 30 SPMS; mean age 42.8 years; median educational time 12.75 years) and 67 controls (mean age 39.7; median educational time 12.0 years) which were similar regarding demographics, education, and socioeconomic status (p > 0.1). Most PwMS (67.7%) had work-restrictions. They also reported fewer money management and driving abilities than controls (p < 0.001). Work-restriction was associated with physical disability (p = 0.006), SDMT and BRBN performance (p = 0.035 and p = 0.031, respectively), and T2-lesion volume (p = 0.022), with large effect sizes (d > 0.75). After hierarchical linear regression, money management was associated with hand dexterity, general and social cognition, and cognitive reserve (p < 0.03). Variables associated with driving abilities included fatigue, verbal fluency, striatum volume, and brain reserve (p < 0.05). CONCLUSIONS: PwMS have more frequent work-restrictions and impairment in money management and driving abilities compared to controls. Cognitive function, physical disability, and MS-lesion burden are strongly associated with work-restriction. Social cognition can also influence financial capacity. Cognitive and brain reserve can help retain some of these daily occupations.

Neonatal Hypoxic-Ischemic Encephalopathy Spectrum: Severity-Stratified Analysis of Neuroimaging Modalities and Association with Neurodevelopmental Outcomes.

OBJECTIVE: To compare hypoxic-ischemic injury on early cranial ultrasonography (cUS) and post-rewarming brain magnetic resonance imaging (MRI) in newborn infants with hypoxic-ischemic encephalopathy (HIE) and to correlate that neuroimaging with neurodevelopmental outcomes. STUDY DESIGN: This was a retrospective cohort study of infants with mild, moderate, and severe HIE treated with therapeutic hypothermia and evaluated with early cUS and postrewarming MRI. Validated scoring systems were used to compare the severity of brain injury on cUS and MRI. Neurodevelopmental outcomes were assessed at 18 months of age. RESULTS: Among the 149 included infants, abnormal white matter (WM) and deep gray matter (DGM) hyperechogenicity on cUS in the first 48 hours after birth were more common in the severe HIE group than the mild HIE group (81% vs 39% and 50% vs 0%, respectively; P < .001). In infants with a normal cUS, 95% had normal or mildly abnormal brain MRIs. In infants with severely abnormal cUS, none had normal and 83% had severely abnormal brain MRIs. Total abnormality scores on cUS were higher in neonates with near-total brain injury on MRI than in neonates with normal MRI or WM-predominant injury pattern (adjusted P < .001 for both). In the multivariable model, a severely abnormal MRI was the only independent risk factor for adverse outcomes (OR: 19.9, 95% CI: 4.0-98.1; P < .001). CONCLUSION: The present study shows the complementary utility of cUS in the first 48 hours after birth as a predictive tool for the presence of hypoxic-ischemic injury on brain MRI.

Clinical and neuroimaging correlates in a pilot randomized trial of aerobic exercise for major depression.

BACKGROUND: Aerobic exercise (AE) combined with pharmacotherapy is known to reduce depressive symptoms; however, studies have not focused on long-term AE for volumetric changes of brain regions (amygdala, thalamus, and nucleus accumbens [NAcc]) linked to the control of affective responses and hopelessness in individuals with major depression (MD). In addition, AE with motor complexity (AEMC) would be more effective than AE in causing brain plasticity. We compared the effects of 24 weeks of AE and AEMC combined with pharmacotherapy on clinical and volumetric outcomes in individuals with MD. METHODS: Forty medicated individuals with MD were randomly assigned to nonexercising control (C), AE, and AEMC groups. The training groups exercised for 60 min, twice a week for 24 weeks. Clinical and volumetric outcomes were assessed before and after the 24 weeks. Effect size (ES) and confidence interval (CI) were calculated for within-group and between-groups changes. RESULTS: AE and AEMC reduced hopelessness (ES = -0.73 and ES = -0.62, respectively) and increased affective responses (ES = 1.24 and ES = 1.56, respectively). Only AE increased amygdala (ES = 0.27 left and ES = 0.34 right), thalamus (ES = 0.33 left and ES = 0.26 right) and left NAcc (ES = 0.54) volumes. AE was more effective than the C group in reducing hopelessness and causing brain plasticity. The changes in the right amygdala volume showed a strong trend in explaining 72 % of the changes in affective responses following AE (p = 0.06). LIMITATION: Lack of posttraining follow-up and small sample size. CONCLUSION: These preliminary data indicate that AE combined with pharmacotherapy can cause clinical improvement and brain plasticity in individuals with MD.

The BrainLat project, a multimodal neuroimaging dataset of neurodegeneration from underrepresented backgrounds.

The Latin American Brain Health Institute (BrainLat) has released a unique multimodal neuroimaging dataset of 780 participants from Latin American. The dataset includes 530 patients with neurodegenerative diseases such as Alzheimer's disease (AD), behavioral variant frontotemporal dementia (bvFTD), multiple sclerosis (MS), Parkinson's disease (PD), and 250 healthy controls (HCs). This dataset (62.7 ± 9.5 years, age range 21-89 years) was collected through a multicentric effort across five Latin American countries to address the need for affordable, scalable, and available biomarkers in regions with larger inequities. The BrainLat is the first regional collection of clinical and cognitive assessments, anatomical magnetic resonance imaging (MRI), resting-state functional MRI (fMRI), diffusion-weighted MRI (DWI), and high density resting-state electroencephalography (EEG) in dementia patients. In addition, it includes demographic information about harmonized recruitment and assessment protocols. The dataset is publicly available to encourage further research and development of tools and health applications for neurodegeneration based on multimodal neuroimaging, promoting the assessment of regional variability and inclusion of underrepresented participants in research.