A study on changes of the resting-state brain function network in patients with amnestic mild cognitive impairment

This study aimed to explore the structural and functional characteristics of the neural network of resting-state brain activities in patients with amnestic mild cognitive impairment (aMCI) by functional magnetic resonance imaging (fMRI) technology. Resting state fMRI scanning was performed on 10 clinically diagnosed aMCI patients and 10 healthy volunteers, and the difference in the resting-state brain activities between aMCI patients and healthy volunteers was compared using the brain function network regional homogeneity (ReHo) analysis method. Results of the ReHo analysis of aMCI patients and healthy volunteers revealed that the ReHo value significantly increased in the posterior cingulate gyrus region, medial frontal lobe, medial cortex of the prefrontal lobe, and part of the parietal lobe. Compared with the normal elderlies, ReHo decreased in aMCI patients in the left temporal lobe (middle temporal gyrus and inferior temporal gyrus), left parahippocampal gyrus, occipital lobe, lingual gyrus, precuneus, and other regions while ReHo increased in regions of the right frontal lobe (inferior frontal gyrus), left superior temporal gyrus, precentral gyrus (frontal lobe), right thalamus, left fusiform gyrus, and other regions. In the resting state, there may be regional abnormalities in brain functional areas in aMCI patients, which may be associated with cognitive impairment.

Neurobiological underpinnings of bipolar disorder focusing on findings of diffusion tensor imaging: a systematic review

Objective: To review the available data on diffusion tensor imaging (DTI) of subjects with bipolar disorder (BD), with a particular focus on fractional anisotropy (FA) in white matter (WM) tracts. Methods: The PubMed/MEDLINE database was searched for relevant articles, which were included in a systematic review of the literature. FA reductions and WM abnormalities were divided anatomically into three groups: commissural tracts, association tracts, and projection tracts. Results: Eighteen studies met the inclusion criteria. The corpus callosum was the main impaired commissural tract as demonstrated by FA reductions. Five studies reported FA reductions in the cingulum. Two studies reported decreased FA in the anterior thalamic radiation, and one in the corticospinal tract. Conversely, three studies found increased FA values in WM tracts involved in BD pathophysiology. Conclusion: Despite considerable heterogeneity, these results indicate a direct link between executive cognitive functioning and abnormal WM microstructural integrity of fronto-limbic tracts in patients with remitted BD, providing further evidence of the neuronal disruption that underlies BD symptomatology.

Convenção-Quadro para o Controle do Tabaco: adesão e implantação na América Latina / WHO Framework Convention on Tobacco Control: adherence and establishment in Latin America

OBJETIVO:Traçar o panorama de adesão mundial à Convenção-Quadro para o Controle do Tabaco (CQCT) e descrever a implantação das medidas preconizadas pela CQCT em países latino-americanos. MÉTODOS: Este estudo descritivo baseou-se em análise de dados secundários para determinar o status de adesão, no ano de 2015, dos países das seis regiões definidas pela Organização Mundial da Saúde (OMS) à CQCT. Depois disso, realizou-se um mapeamento da implantação, até o ano de 2012, das medidas preconizadas pela CQCT no total de Estados Partes e particularmente em 12 Estados Partes latino-americanos. Finalmente, Brasil, Chile, Colômbia, México e Venezuela foram avaliados quanto ao grau de implantação da CQCT (incipiente, intermediária e avançada). Foram consideradas neste passo medidas englobadas por quatro eixos - redução da demanda por tabaco, redução da oferta de tabaco, redução dos danos ao ambiente e à saúde das pessoas causados pelo tabaco e apoio ao abandono do tabaco. RESULTADOS: Até agosto de 2015, 180 países haviam ingressado no rol de Estados Partes da CQCT. Considerando os 126 países que enviaram relatórios de progresso global da implantação no ciclo de 2012, as medidas mais prevalentes adotadas referiam-se à proteção contra a exposição à fumaça do tabaco (83,0% para o total de países e 100% para o conjunto de países latinoamericanos). Entre os cinco países selecionados para análise detalhada, as medidas destinadas à redução da demanda e da oferta do tabaco foram as mais frequentes. As medidas relacionadas à redução de danos ao ambiente foram raras. Brasil e México apresentaram a situação mais avançada de implantação entre os países estudados. CONCLUSÕES: A América Latina apresentou uma alta proporção de Estados Partes que implantaram as medidas preconizadas pela CQCT. A heterogeneidade da situação de implantação nos cinco países selecionados sugere que as políticas de controle de tabaco são condicionadas por particularidades nacionais.

OBJECTIVE: To draw an overview of the adherence of countries around the world to the World Health Organization Framework Convention on Tobacco Control (WHO FCTC) and to describe the establishment of WHO FCTC recommended measures in Latin American countries. METHODS: This descriptive study was based on analysis of documents and secondary data to determine the status of countries from the six WHO regions regarding adherence to the FCTC. After that, the establishment of recommended measures until the year 2012 was mapped in all States Parties and particularly in 12 Latin American States Parties. Finally, the degree to which FCTC measures had been established in Brazil, Chile, Colombia, Mexico, and Venezuela was assessed (incipient, intermediate, or advanced). This step took into consideration the measures covered by four domains - reduction in the demand for tobacco, reduction in the offer of tobacco, reduction in damage to the environment and to the health of people caused by tobacco, and support for quitting the use of tobacco. RESULTS: Until August 2015, 180 countries had joined as States Parties to the FCTC. Considering the 126 countries that submitted global progress reports in the 2012 cycle, the most prevalent measures adopted referred to the protection against exposure to tobacco smoke (83.0% for all countries and 100% for the group of Latin American countries). Among the five countries selected for detailed analysis, the measures referring to the reduction of demand and offer of tobacco were the most frequent. Measures focused on reducing environmental damage were rare. Brazil and Mexico had the most advanced FCTC status among the studied countries. CONCLUSIONS: Latin America presented a high proportion of States Parties with established FCTC recommended measures. The heterogeneity of the FCTC status in the five selected countries suggests that the implementation of tobacco control policies depends on specific aspects of each country.

Abnormal Brain Activity in Social Reward Learning in Children with Autism Spectrum Disorder: An fMRI Study

PURPOSE: We aimed to determine whether Autism Spectrum Disorder (ASD) would show neural abnormality of the social reward system using functional MRI (fMRI). MATERIALS AND METHODS: 27 ASDs and 12 typically developing controls (TDCs) participated in this study. The social reward task was developed, and all participants performed the task during fMRI scanning. RESULTS: ASDs and TDCs with a social reward learning effect were selected on the basis of behavior data. We found significant differences in brain activation between the ASDs and TDCs showing a social reward learning effect. Compared with the TDCs, the ASDs showed reduced activity in the right dorsolateral prefrontal cortex, right orbitofrontal cortex, right parietal lobe, and occipital lobe; however, they showed increased activity in the right parahippocampal gyrus and superior temporal gyrus. CONCLUSION: These findings suggest that there might be neural abnormality of the social reward learning system of ASDs. Although this study has several potential limitations, it presents novel findings in the different neural mechanisms of social reward learning in children with ASD and a possible useful biomarker of high-functioning ASDs.

Unilateral ataxia following herpes zoster of spinal C4 segment.

Focal lesions of central nervous system are extremely rare following cutaneous herpes zoster. A 55 year old male developed cerebellar speech, right sided ataxia and intention tremor, three weeks after herpes zoster of right spinal C4 segment. Clinical examination and investigations confirmed a focal vascular lesion in the midbrain suggestive of granulomatous angiitis which can cause focal neurological defect after herpes zoster.

Internal capsular lesion associated with dizziness

It has been known that the vestibular system is concerned with feelings of dizziness or vertigo. The vestibulo-thalamic pathway has also been described previously. However, there has been no confirmative report so far regarding the pathway through the internal capsule to the cortex. We have experienced 13 patients with symptoms of dizziness and/or vertigo whose lesions are located only around the internal capsule, mainly at the posterior limb and/or the genu. It is suggestive that fibers with dizziness may pass through a part of the internal capsule, probably through some part of the posterior limb and/or the genu.

Habituación del reflejo acústico-palpebral en la enfermedad de Parkinson / Habituation of the acoustic-blink reflex in Parkinson's disease

La oclusión palpebral ante un estímulo auditivo sorpresivo es una respuesta refleja [RAP] polisináptica de integración mesencefálica que tiende a desaparecer frente a estímulos repetidos. Este reflejo transcurre a través del núcleo coclear, cuerpo trapezoide, collículo inferior y sus conexiones, y está sujeto a influencias supramesencefálicas. En el estudio presente, se evaluaron electrofisiológicamente 6 individuos normales y 6 pacientes con enfermedad de Parkinson de edades similares. Se aplicaron estímulos tonales registrándose la actividad refleja en el orbicular de los párpados. Se midieron latencia [L], duración [D], amplitud [A] y fases [F] de las respuestas reflejas obtenidas por aplicación de estímulos auditivos a intervalos randomizados, y luego de un período de reposo, se midió el número de respuestas obtenidas [R] aplicando los estímulos a una frecuencia fija de 0,2 Hz. No se observaron diferencias significativas en L,D,A y F, viéndose en cambio, un mayor número de R en los enfermos de Parkinson. Esta observación sugiere una alteración en la habituación a los estímulos auditivos posiblemente debida a fallas en la inhibición de este reflejo por compromiso de estructuras supramesencefálicas

Somatosensory evoked response: application in neurology.

Potencial evocado somato-sensorial (PES) por estimulacao eletrica do nervo mediano e a resposta eletrica produzida pela ativacao do plexo braquial, raizes C6-7, medula cervical, sistema lemniscal do tronco cerebral, talamo e cortex sensorial. Este teste clinico, nao invasivo, permite a avaliacao da integridade funcional da via somato-sensorial possibilitando a localizacao de lesoes nos niveis acima apontados. O PES tem sido util no estudo de comas, esclerose multipla, doencas vasculares e outras patologias do sistema nervoso.PES por estimulacao do nervo peroneiro parece ser muito sensivel na deteccao precoce do comprometimento da medula espinal