S100 proteins and their implication in the thalamus: an integrative review / Las proteínas S100 y su implicación en el tálamo: una revisión integradora

SUMMARY: S100 proteins belong group of calcium-binding proteins and are present in physiological intracellular and extracellular regulatory activities, such as cell differentiation, and act in inflammatory and neoplastic pathological processes. Recently, its expressions in the nervous system have been extensively studied, seeking to elucidate its action at the level of the thalamus: A structure of the central nervous system that is part of important circuits, such as somatosensory, behavioral, memory and cognitive, as well as being responsible for the transmission and regulation of information to the cerebral cortex. This article is an integrative review of scientific literature, which analyzed 12 studies present in Pubmed. The analysis showed that the relationship of S100 proteins and the thalamus has been described in neoplastic processes, mental disorders, hypoxia, trauma, stress, infection, Parkinson's disease and epilepsy. In summary, it is possible to conclude that this protein family is relevant as a marker in processes of thalamic injury, requiring further studies to better understand its clinical, preclinical meanings and its prognostic value.

Las proteínas S100 pertenecen al grupo de proteínas fijadoras de calcio y están presentes en actividades reguladoras fisiológicas intracelulares y extracelulares, como la diferenciación celular, y actúan en procesos patológicos inflamatorios y neoplásicos. Recientemente, sus expresiones en el sistema nervioso han sido ampliamente estudiadas, buscando dilucidar su acción a nivel del tálamo: una estructura del sistema nervioso central que forma parte de importantes circuitos, como el somatosensorial, conductual, de memoria y cognitivo, así como además de ser responsable de la transmisión y regulación de la información a la corteza cerebral. Este artículo es una revisión integradora de la literatura científica, que analizó 12 estudios presentes en Pubmed. El análisis mostró que la relación de las proteínas S100 y el tálamo ha sido descrita en procesos neoplásicos, trastornos mentales, hipoxia, trauma, estrés, infección, enfermedad de Parkinson y epilepsia. En resumen, es posible concluir que esta familia de proteínas es relevante como marcador en procesos de lesión talámica, requiriendo más estudios para comprender mejor su significado clínico, preclínico y su valor pronóstico.

Thalamocortical Circuit Controls Neuropathic Pain via Up-regulation of HCN2 in the Ventral Posterolateral Thalamus / 神经科学通报·英文版

The thalamocortical (TC) circuit is closely associated with pain processing. The hyperpolarization-activated cyclic nucleotide-gated (HCN) 2 channel is predominantly expressed in the ventral posterolateral thalamus (VPL) that has been shown to mediate neuropathic pain. However, the role of VPL HCN2 in modulating TC circuit activity is largely unknown. Here, by using optogenetics, neuronal tracing, electrophysiological recordings, and virus knockdown strategies, we showed that the activation of VPL TC neurons potentiates excitatory synaptic transmission to the hindlimb region of the primary somatosensory cortex (S1HL) as well as mechanical hypersensitivity following spared nerve injury (SNI)-induced neuropathic pain in mice. Either pharmacological blockade or virus knockdown of HCN2 (shRNA-Hcn2) in the VPL was sufficient to alleviate SNI-induced hyperalgesia. Moreover, shRNA-Hcn2 decreased the excitability of TC neurons and synaptic transmission of the VPL-S1HL circuit. Together, our studies provide a novel mechanism by which HCN2 enhances the excitability of the TC circuit to facilitate neuropathic pain.

Auditory response of the reticular nucleus of thalamus in awake mice / 生理学报

This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.

Ventromedial Thalamus-Projecting DCN Neurons Modulate Associative Sensorimotor Responses in Mice / 神经科学通报·英文版

The deep cerebellar nuclei (DCN) integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning. However, the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood. Here, we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial (Vm) thalamus (DCNVm neurons), and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning (tEBC), a classical associative sensorimotor learning task. Upon conditioning, the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses (CRs). Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs, respectively. Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination. Furthermore, optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex, a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC. Together, our data highlights DCNVm neurons' function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.

The physiological and psychological mechanisms of infra-slow oscillation / 生理学报

Infra-slow oscillation (ISO) is a kind of brain rhythm between 0.01 and 0.5 Hz. ISO is widely distributed in multiple brain regions. As an important psychophysiological activity, the ISO interacts with high-frequency neural rhythm via cross-frequency coupling, but has different activity patterns from high-frequency neural activity. Physiologically, the ISO may be generated by the dynamic activity of thalamus, glia, and ions. Psychologically, the frequency, amplitude, and phase of ISO could all regulate cognitive activities, but in different ways. Investigations on the ISO expands the neural rhythm research to lower frequency range, further promoting the construction of rhythmic theory of brain function.

Magnetic resonance spectroscopy features of the thalamus and the cerebellum and their association with clinical features in children with autism spectrum disorder: a prospective study / 中国当代儿科杂志

OBJECTIVES@#To study the changes in biochemical metabolites in the thalamus and the cerebellum and their association with clinical features in children with autism spectrum disorder (ASD).@*METHODS@#In this prospective study, magnetic resonance spectroscopy (MRS) with point-resolved spatial selection was used to analyze the thalamus and the cerebellum at both sides in 50 children with ASD aged 2-6 years. Creatine (Cr) was as the internal standard to measure the relative values of N-acetylaspartate (NAA)/Cr, choline (Cho)/Cr, myoinositol (MI)/Cr, and glutamine and glutamate complex (Glx)/Cr, and the differences in metabolites and their association with clinical symptoms were compared.@*RESULTS@#In the children with ASD, NAA/Cr in the left thalamus was positively correlated with the scores of hearing-language and hand-eye coordination in the Griffiths Development Scales-Chinese (@*CONCLUSIONS@#There are metabolic disorders in the cerebellum and the thalamus in children with ASD, and there is a correlation between the changes of metabolites in the left cerebellum and the left thalamus. Some metabolic indexes are related to the clinical symptoms of ASD. MRS may reveal the pathological basis of ASD and provide a basis for diagnosis and prognosis assessment of ASD as a noninvasive and quantitative detection method.

Infarto da artéria de Percheron: relato de caso / Percheron´s artery infarction: a case report

O infarto da artéria de Percheron é uma apresentação rara de acidente vascular cerebral, caracterizado principalmente por isquemia talâmica bilateral. A apresentação clinica desse infarto se apresenta de maneira inesperada e variável. Relata-se um caso de um paciente masculino, idoso, acometido por diversas comorbidades, admitido na emergência em coma e hemiplégico a direita, demonstrando acometimento neurológico. A condição clínica do paciente variou durante a hospitalização, apresentando melhora do quadro neurológico focal e midríase fixa à direita, levando a um diagnóstico tardio. Paciente evoluiu ao óbito devido a causas não neurológicas.

The artery of Percheron infarct is a rare presentation of stroke, featured mainly by thalamic bilateral ischemia. The clinical presentation of this infarct is unexpected and variable. It's reported a case of a male patient, elderly, affected with several comorbidities, admitted to the emergency in comatose state and right hemiplegic, proving neurological involvement. The patient's clinical condition has fluctuated throughout the hospitalization presenting improvement of the focal neurologic implication and right mydriasis, culminating in a lagged diagnosis. Patient's death due to non neurologic causes.

Tálamo según Galeno: una metáfora controversial / Thalamus according to Galen: a controversial metaphor

El vocabulario técnico-científico, uno de ellos la Terminologia Anatomica, tiene un legado lingüístico de idiomas clásicos en general y del latín y griego en particular. En este contexto, la metáfora ha cumplido un importante rol en la denominación de ciertas estructuras del cuerpo humano. El análisis de estas metáforas ha permitido conocer el origen etimológico de numerosos términos anatómicos derivados de esta práctica frecuente durante la historia. Este estudio tuvo como objetivo analizar y reflexionar acerca de la utilización del término tálamo y comentar la similitud formal de esta metáfora con las características neuroanatómicas. El nombre tálamo fue asignado por Claudio Galeno (130 - 200 a. C.); procede de un lenguaje común de orden material, el cual ha sido mencionado por autores clásicos, principalmente, como "cámara interna o cámara nupcial" y llevado a un lenguaje técnico-científico a través de una metáfora motivada por una disposición espacial o entendida como una expresión de imagen o similitud formal. Si Galeno utilizó esta metáfora considerando una similitud formal, el término tálamo sería equívoco, ya que no hay correspondencia estructural del término debido a que el tálamo neuroanatómico no es una cámara, sino una estructura diencefálica compacta y esferoidal u ovalada. Bajo este contexto, el término tálamo es confuso, ya que esta metáfora se condice más bien con el tercer ventrículo. Considerando lo anterior, invitamos a reflexionar sobre una propuesta basada en una característica morfológica de la estructura, en la cual se reemplace el término tálamo por neuroovoide.

The technical-scientific vocabulary, one of them the Anatomical Terminology, has a linguistic legacy of classical languages in general and of Latin and Greek in particular. In this context, the metaphor has played an important role in the naming of certain structures of the human body. The analysis of these metaphors has allowed us to know the etymological origin of numerous anatomical terms derived from this frequent practice throughout history. The purpose of this study was to analyze and reflect on the use of the term thalamus and to comment on the formal similarity of this metaphor with the neuroanatomical characteristics. The name thalamus was assigned by Claudio Galeno (130-200 BC); It comes from a common language of material order, which has been mentioned by classical authors, mainly, as "internal chamber or bridal chamber" and brought to a technicalscientific language through a metaphor motivated by a spatial arrangement or understood as a image expression or formal similarity. If Galen used this metaphor considering a formal similarity, the term thalamus would be misleading, since there is no structural correspondence to the term because the neuroanatomical thalamus is not a chamber, but a compact, spheroidal or oval diencephalic structure. In this context, the term thalamus is confusing, since this metaphor is more consistent with the third ventricle. Considering the above, we invite you to reflect on a proposal based on a morphological characteristic of the structure, in which the term thalamus is replaced by neuroovoid.

Altered thalamic neurotransmitters metabolism and functional connectivity during the development of chronic constriction injury induced neuropathic pain

BACKGROUND: To investigate the thalamic neurotransmitters and functional connections in the development of chronic constriction injury (CCI)-induced neuropathic pain. METHODS: The paw withdrawal threshold was measured by mechanical stimulation the right hind paw with the von frey hair in the rats of CCI-induced neuropathic pain. The N-acetylaspartate (NAA) and Glutamate (Glu) in thalamus were detected by magnetic resonance spectrum (MRS) process. The thalamic functional connectivity with other brain regions was scanned by functional magnetic resonance image (fMRI). RESULTS: The paw withdrawal threshold of the ipsilateral side showed a noticeable decline during the pathological process. Increased concentrations of Glu and decreased levels of NAA in the thalamus were significantly correlated with mechanical allodynia in the neuropathic pain states. The thalamic regional homogeneity (ReHo) decreased during the process of neuropathic pain. The functional connectivity among the thalamus with the insula and somatosensory cortex were significantly increased at different time points (7, 14, 21 days) after CCI surgery. CONCLUSION: Our study suggests that dynamic changes in thalamic NAA and Glu levels contribute to the thalamic functional connection hyper-excitation during CCI-induced neuropathic pain. Enhanced thalamus-insula functional connection might have a significant effect on the occurrence of neuropathic pain.

Áreas exofocales de lesión a mediano y largo término post-isquemia cerebral / Exofocal areas of medium- and long-term injury after cerebral ischemia

La isquemia cerebral es el tipo de accidente cerebrovascular más común, generando altas tasas de mortalidad y morbilidad a nivel mundial. El entendimiento de la fisiopatología de la lesión cerebral ha requerido de la implementación de modelos experimentales que permitan evaluar los fenómenos celulares, sobre todo aquellos a largo plazo. Por tal razón, el objetivo del presente trabajo fue evaluar las áreas exofocales a un mes y cuatro meses post-isquemia cerebral en un modelo experimental. Ratas Wistar fueron sometidas a una isquemia focal transitoria (t-MCAo) y un grupo fueron sacrificados al mes y otro grupo a los cuatro meses post-isquemia para su posterior análisis histológico. Los cortes fueron teñidos con Nissl y se realizó inmunohistoquímica de la proteína Tau. Nuestros resultados muestran tres áreas de lesión exofocal tanto al mes como a los cuatro meses post-isquemia: el giro dentado, la amígdala y el tálamo. Estas regiones se han asociado al control emocional, lo cual sugiere que a largo término post-isquemia se tengan en cuenta hallazgos clínicos que evalúen cambios emocionales en los pacientes que han sufrido un evento isquémico cerebral.

Cerebral ischemia is the most common type of stroke, which generates high mortality and morbidity rates worldwide. The understanding of the pathophysiology of brain injury has required the implementation of experimental models that allow the evaluation of cellular phenomena, especially those in the long-term. For this reason, the objective of the present work was to evaluate the exofocal areas at one month and four months after cerebral ischemia. Wistar rats were subjected to transient focal ischemia (t-MCAo) and one group was sacrificed one month and another group at four months' post-ischemia for subsequent histological analysis. The cuts were stained with Nissl and immunohistochemistry of the Tau protein was performed. Our results show three areas of exofocal lesion both one month and four months' post-ischemia: the thalamus, the dentate gyrus, and the amygdala. These regions have been associated with emotional control, which suggests that in the long-term post-ischemia clinical findings that evaluate emotional changes in patients who have suffered a cerebral ischemic event should be considered.

Aderência intertalâmica e Alzheimer: estudo preliminar / Interthalamic adhesion and Alzheimer's: preliminary study

Objetivo: Descrever dimensões e prevalência da Aderência Intertalâmica (AI) em cadáveres do Serviço de Verificação de Óbitos da Capital - USP, considerando idade, sexo, peso, altura e histórico pessoal de doença de Alzheimer (DA). Métodos: Cinquenta e sete cadáveres (31H/26M) foram incluídos no estudo, com média de idade de 66,2 anos (variando entre 15 e 91 anos). A análise da AI foi feita após secção transversal da calota craniana e incisão axial no limite inferior do tronco encefálico seguida de retirada do encéfalo de sua cavidade. Cinquenta e quatro encéfalos foram submetidos a incisão sagital mediana, dois encéfalos foram submetidos a cortes axiais, e um encéfalo a secção coronal. Dados quantitativos foram comparadas pelo teste t de student, e dados qualitativos pelo teste de Qui Quadrado. A análise idade vs área foi feita por regressão linear. Resultados: A prevalência de AI foi de 79%, não havendo diferença significativa entre os sexos (p=0,68).  Observou-se associação entre menores áreas de secção sagital e idades mais avançadas (p=0,02). Não houve diferença significativa na prevalência de AI nem na área de secção transversal em pacientes com DA. Discussão: Ao contrário de estudos prévios, que associaram maior prevalência e tamanho de AI com sexo feminino, isso não foi observado em nossa casuística. Apesar de não ser estatisticamente significativa nota-se uma diferença importante nas áreas médias de secção sagital dos grupos com e sem DA, o que aponta para a necessidade de estudos subsequentes com amostras maiores

Objective: Identifying the prevalence and dimensions of the Interthalamic Adhesion (ITA) in corpses from the "Serviço de Verificação de Óbitos da Capital - USP", considering factors as age, sex, weight, height, and diagnosis of Alzheimer's disease (AD). Methods: Fifty-seven corpses (31M/26F) were included in the study. The mean age was 66.2 (varying between 15 and 91). The analysis of the ITA was made after the encephalon's removal from its cavity, which occurred by the transversal section of the skullcap, and, next, an axial incision in the inferior limit of the pons to separate the encephalon from the spinal cord. Fifty-four encephalons were submitted to medial sagittal incisions, two encephalons were submitted to axial cuts and one to a coronal section. Quantitative data were compared by the Student's T Test, and qualitative data by the Chi-squared test. The Age vs Area analysis was made by linear regression. Results: the prevalence of the ITA was 79%, not having differences in prevalence between sexes (p=0.68). Advanced ages presented lower areas in sagittal sections (p= 0.02). It does not appear to have a significant alteration in prevalence of the ITA and transversal section aerea in patients with AD. Discussion: Unlike previous studies which observed higher prevalence and size of the ITA in females, differences in this parameters were not obtained in this study. Evidence of correlation between AD and lower sagittal section of the ITA, even without statistic significance, points to the need of further studies.

Cambios estructurales cerebrales en epilepsia generalizada idiopática identificados por análisis de imágenes de resonancia magnética automatizados / Cerebral structural changes in generalized idiopathic epilepsy identified by automated magnetic resonance imaging analysis

El objetivo de este estudio fue combinar dos métodos automatizados de análisis estructural de imágenes de resonancia magnética para identificar cambios estructurales en pacientes nacidos en Argentina con epilepsia generalizada idiopática (EGI) en comparación con un grupo control de adultos sanos. Fueron incluidos 28 pacientes con EGI y 26 controles sin diferencias demográficas significativas. El análisis de las estructuras cerebrales se realizó con dos métodos automatizados de análisis de imágenes de resonancia magnética: la morfometría basada en vóxel y con la herramienta de segmentación y registro integrada FSL (FSL-FIRST). FSL mostró una disminución del volumen en ambos tálamos en EGI en comparación con el grupo control (tálamo izquierdo: 8092 mm³ grupo control vs. 7424 mm³ EGI, p = 0.0015; tálamo derecho: 7951 mm³ grupo control vs. 7247 mm³ EGI, p = 0.0016). Se observó una reducción en el volumen de ambos núcleos caudados (izquierdo: 3612 mm³ grupo control vs. 3376 mm³ EGI, p = 0.01; derecho 3683 mm³ grupo control vs. 3459 mm³ EGI, p = 0.04). La morfometría basada en vóxel mostró una disminución del volumen en ambos núcleos caudados en EGI en comparación con el grupo control. Las otras estructuras cerebrales analizadas no mostraron diferencias significativas entre los grupos. Este estudio muestra la reducción en el volumen en las estructuras subcortical, tálamos y núcleos caudados en pacientes con EGI comparado con un grupo control.

The purpose of this study was to combine two automated methods of magnetic resonance imaging (MRI) structural analysis in order to identify structural changes in patients born in Argentina with idiopathic generalized epilepsy (IGE) compared to a healthy adult control group. Twenty-eight patients with IGE and 26 controls with no significant demographic differences were included. The analysis of the brain structures was conducted with two automated methods of magnetic resonance image analysis: voxel-based morphometry and FSL-integrated registration and segmentation toolbox (FSL-FIRST). FSL showed volume decrease in both thalamus in patients with IGE compared to the control group (left: 8092 mm³ control group vs. 7424 mm³ IGE, p = 0.0015; right: 7951 mm³ control group vs. 7247 mm³ IGE, p = 0.0016). A reduction in the volume of both caudate nuclei was also seen (left: 3612 mm³ control group vs. 3376 mm³ IGE, p = 0.01; right: 3683 mm³ control group vs. 3459 mm³ IGE, p = 0.04). Voxel-based-morphometry showed a volume decrease in both caudate nuclei in patients with IGE compared to the control group. The other cerebral structures analyzed did not show significant differences between the groups. In conclusion, this study shows the reduction in volume in the subcortical, thalamic, and caudate nuclei structures in patients with IGE in comparison to control group. This study conducted in our country delves into the analysis of brain structural changes in patients with EGI compared to healthy subjects.

Anatomia Microquirúrgica y Abordajes al Central Core Cerebral / Microsurgical Anatomy and Approaches to the Central Core Cerebral

Objetivos: A través del estudio cadavérico dividir al central core cerebral (CCC) en diferentes áreas y proponer para cada sector el abordaje neuroquirurgico correspondiente. Como objetivo secundario analizaremos la anatomía neuroquirúrgico cortical y subcortical del CCC. Introducción : El CCC es descripto como un bloque que descansa sobre el tronco del encéfalo. Incluye la ínsula, capsula extrema, claustro, capsula externa, núcleo lenticular, capsula interna, núcleo caudado y el tálamo. Material y Métodos: Se estudiaron 12 hemisferios cerebrales humanos adultos y una cabeza en el ­LaNeMic- de la Universidad de Buenos Aires, analizamos 9 casos de patologías neuroquirúrgicas del CCC y dibujos digitales de los abordajes propuestos para cada sector del CCC. Se tomaron fotografías de cada disección y las mediciones obtenidas con calibre digital. Resultados: Dividimos al CCC en un sector medial, intermedio y lateral; con subdivisiones específicas para el lateral y medial. La proyección lateral del foramen de Monro se encontró en el tercer giro corto de la ínsula con las distancias: MILA: 23,95 mm; MILP: 22,92 mm; SLS: 14,99 mm y SLI: 13,76 mm. Proponemos los siguientes abordajes: abordaje transcalloso homolateral, abordaje transcalloso contralateral, abordaje trans-fisura coroidea, abordaje trans-esplenial, acceso trans-parietal ingresando al surco intraparietal y abordaje trans-silviano. Discusión: Se deben analizar los estudios preoperatorios del paciente, comprendiendo las lesiones según la ubicación y de ese modo seleccionar el abordaje más preciso y seguro. Conclusiones: Se provee a través de este trabajo una descripción de los límites y anatomía del CCC, empleando disecciones cerebrales, análisis de casos operados y de medidas útiles para el neurocirujano.

Objectives: Through the cadaveric study, we divide the cerebral central core (CCC) in different areas and propose the corresponding neurosurgical approach for each sector. As a secondary objective, we will analyze the cortical and subcortical microsurgical anatomy of the CCC. Introduction: The CCC is described as a block that rests on the trunk of the brain. It includes the insula, extreme capsule, claustro, external capsule, lenticular nucleus, internal capsule, caudate nucleusand thalamus. Material and Methods: We studied 12 adult human brain hemispheres and one head in the -LaNeMic- of the University of Buenos Aires, analyzed 9 cases of CCC neurosurgical pathologies and digital drawings of the approaches proposed for each sector of the CCC. Photographs of each dissection and measurements obtained with digital caliber were taken. Results: We divide the CCC into a medial, intermediate and lateral sector; with specific subdivisions for the lateral and medial. The lateral projection of the foramen of Monro was found in the third short gyri of the insula with the distances: MILA: 23.95mm; MILP: 22.92mm; SLS: 14.99mm and SLI: 13.76mm. We propose the following approaches: ipsilateral transcallosal approach, contralateral transcallosal approach, choroidal trans-fissure approach, trans-splennial approach, trans-parietal access entering the intraparietal sulcus, and trans-silvian approach. Discussion: The preoperative studies of the patient should be analyzed, understanding the lesions according to the location and in this way selecting the most accurate and safe approach. Conclusions: A description of the limits and anatomy of the CCC is provided through this work, using brain dissections, analysis of operated cases and useful measurements for the neurosurgeon.

Crossed Aphasia after Right Corpus Callosum Infarction: a Case Report

Crossed aphasia (CA) is defined as language impairment following right-hemispheric brain lesion in right-handed person. Exact mechanism responsible for CA is ambiguous, and recently several brain lesions have been proposed to be associated with aphasia using lesion mapping method. Corpus callosum has dual bloody supply which makes it less vulnerable to infarction. Speech difficulties such as stuttering after corpus callosum infarction have been reported in the past, but aphasia is rare, which makes CA more unique. We report an extraordinary case of CA after right corpus callosum infarction. A 74-year-old female patient with a previous history of right thalamus infarction with no neurologic sequela has developed language disturbance without apraxia 1 month ago and a diffusion-weighted magnetic resonance imaging showed newly developed infarction at right corpus callosum. The aphasia quotient of the Korean version of the Western Aphasia Battery was 2.5, implying severe global aphasia. Positron emission tomography-computed tomography showed decreased metabolism in right corpus callosum and left frontal and temporal cortex, suggesting that interhemispheric diaschisis may be responsible for the CA. This is an extraordinary case report of an isolated manifestation of CA secondary to right corpus callosum infarction.

Isolated Dizziness with Subjective Visual Vertical Tilt in Acute Infarction of Temporo-Parieto-Occipital Junction

Pathological tilts of the subjective visual vertical (SVV) in the roll plane are most sensitive and frequent clinical vestibular signs of unilateral lesions extending from the labyrinths via the brainstem and thalamus to the cortex. SVV deviations in cortical lesion are usually related with the parietoinsular vestibular cortex or superior temporal gyrus. We report isolated dizziness with contralesional SVV tilt with a focal infarction restricted to the right temporo-parieto-occipital junction.

Central Sleep Apnea without Cheyne-Stokes Breathing Following an Acute Cerebral Infarction

Central sleep apnea (CSA) is attributed to medical or neurological conditions including stroke. The association of lesion location and CSA in patients with ischemic stroke has not been well elucidated. A 69-year-old man with a history of hypertension and diabetes mellitus was admitted due to stroke. The brain magnetic resonance imaging showed an acute ischemic stroke in the right ventral thalamus and adjacent hypothalamus. During hospitalization, polysomnography (PSG) was performed because repetitive cessation of respiration during sleep was observed by chance. PSG showed severe CSA; the apnea-hypopnea index (AHI) was 73.5 with a minimum oxygen saturation of 89% and central apnea index (CAI) was 63.0. Two years later, follow-up PSG showed that AHI was 7.2 with a minimum oxygen saturation of 91% and CAI was 1.0. We report the patient with CSA after ischemic stroke with right thalamus and adjacent hypothalamus, which resolved spontaneously with time.

Change of Extracellular Glutamate Level in Striatum during Deep Brain Stimulation of the Entopeduncular Nucleus in Rats

OBJECTIVE: Globus pallidus interna (GPi) is acknowledged as an essential treatment for advanced Parkinson’s disease (PD). Nonetheless, the neurotransmitter study about its results is undiscovered. The goal of this research was to examine influences of entopeduncular nucleus (EPN) stimulation, identical to human GPi, in no-lesioned (NL) rat and 6-hydroxydopamine (6-HD)-lesioned rat on glutamate change in the striatum. METHODS: Extracellular glutamate level changes in striatum of NL category, NL with deep brain stimulation (DBS) category, 6-HD category, and 6-HD with DBS category were examined using microdialysis and high-pressure liquid chromatography. Tyrosine hydroxylase (TH) immunoreactivities in substantia nigra and striatum of the four categories were also analyzed. RESULTS: Extracellular glutamate levels in the striatum of NL with DBS category and 6-HD with DBS category were significantly increased by EPN stimulation compared to those in the NL category and 6-HD category. EPN stimulation had no significant effect on the expression of TH in NL or 6-HD category. CONCLUSION: Clinical results of GPi DBS are not only limited to direct inhibitory outflow to thalamus. They also include extensive alteration within basal ganglia.

Clinical and Radiographic Characteristics of Neuro-Behçet's Disease in South Korea

BACKGROUND AND PURPOSE: Neurological involvement in Behçet's disease [neuro-Behçet's disease (NBD)] is uncommon, but it is worth investigating since it can cause substantial disability. However, difficulties exist in understanding the clinical features of NBD due to regional variations and the lack of studies utilizing well-established diagnostic criteria. We therefore analyzed the clinical features of patients with NBD based on the recent international consensus recommendation. METHODS: We retrospectively searched electronic databases for patients with Behçet's disease (BD) between 2000 and 2017, and reviewed their medical records. Based on the recent international consensus recommendation, patients with definite or probable NBD were included. RESULTS: Of 9,817 patients with the diagnosis code for BD, 1,682 (17.1%) visited the neurology clinic and 110 (1.1%) were classified as NBD. Ninety-eight patients exhibited parenchymal NBD and 12 exhibited nonparenchymal NBD. Their age at the onset of NBD was 37.6±10.6 years and the male-to-female ratio was 1.24:1. Brainstem syndrome (43.9%) was the most common condition in the 98 patients with parenchymal NBD, followed by multifocal (32.7%) and spinal cord (12.2%) syndromes. 72.4% exhibited acute NBD and 27.6% exhibited a progressive disease course. Frequent manifestations included pyramidal signs (52.0%), headache (45.9%), dysarthria (42.9%), and fever (31.6%). A frequent pattern in brain MRI was an upper brainstem lesion extending to the thalamus and basal ganglia. CONCLUSIONS: Approximately 1% of the patients with suspected BD exhibited NBD. Neurologists must understand the clinical characteristics of NBD in order to perform the differential diagnosis and management of these patients.

A Computational Modeling Reveals That Strength of Inhibitory Input, E/I Balance, and Distance of Excitatory Input Modulate Thalamocortical Bursting Properties

The thalamus is a brain structure known to modulate sensory information before relaying to the cortex. The unique ability of a thalamocortical (TC) neuron to switch between the high frequency burst firing and single spike tonic firing has been implicated to have a key role in sensory modulation including pain. Of the two firing modes, burst firing, especially maintaining certain burst firing properties, was suggested to be critical in controlling nociceptive behaviors. Therefore, understanding the factors that influence burst firing properties would offer important insight into understanding sensory modulation. Using computational modeling, we investigated how the balance of excitatory and inhibitory inputs into a TC neuron influence TC bursting properties. We found that intensity of inhibitory inputs and the timing of excitatory input delivery control the dynamics of bursting properties. Then, to reflect a more realistic model, excitatory inputs delivered at different dendritic locations—proximal, intermediate, or distal—of a TC neuron were also investigated. Interestingly, excitatory input delivered into a distal dendrite, despite the furthest distance, had the strongest influence in shaping burst firing properties, suggesting that not all inputs equally contribute to modulating TC bursting properties. Overall, the results provide computational insights in understanding the detailed mechanism of the factors influencing temporal pattern of thalamic bursts.

Bilateral Thalamic Glioma in a Young Woman: a Case Report

Bilateral thalamic gliomas (BTGs) are rare brain tumors. In general, the prognosis is poor because of the involvement of bilateral thalami and limitations of surgical excision. Consequently, patients with symptoms of personality changes and memory impairment must be differentiated from others. Magnetic resonance imaging (MRI) is essential for the diagnosis of BTGs and reveals a hypo-intense lesion on T1-weighted images and a hyper-intense lesion on T2 images. We report a case of a 17-year-old female patient suffering from progressive cognitive dysfunction and personality changes and subsequent rehabilitation treatment. Brain MRI showed an enlarged bilateral thalamus, with hyperintensity on T2-weighted images and iso-intensity on T1-weighted images. A biopsy was performed, and the pathology revealed a high-grade glioma. The patient was referred for radiotherapy and chemotherapy. She also underwent rehabilitation treatment for 5 weeks and showed improvement in standing balance, endurance, and speech fluency. The patient's Modified Barthel Index scores also improved. Cancer rehabilitation is important in brain tumor patients because they have a higher incidence of neurological sequelae than others. Rehabilitation of patients with a malignant brain tumor is also important for improving health-related quality of life by maintaining the general condition and preventing complications during and after cancer treatment.