The Objective Assessment of Event-Related Potentials: An Influence of Chronic Pain on ERP Parameters / 神经科学通报·英文版

The article presents an original method for the automatic assessment of the quality of event-related potentials (ERPs), based on the calculation of the coefficient ε, which describes the compliance of recorded ERPs with some statistically significant parameters. This method was used to analyze the neuropsychological EEG monitoring of patients suffering from migraines. The frequency of migraine attacks was correlated with the spatial distribution of the coefficients ε, calculated for EEG channels. More than 15 migraine attacks per month was accompanied by an increase in calculated values in the occipital region. Patients with infrequent migraines exhibited maximum quality in the frontal areas. The automatic analysis of spatial maps of the coefficient ε demonstrated a statistically significant difference between the two analyzed groups with different means of migraine attack numbers per month.

Dynamic analysis of epileptic causal brain networks based on directional transfer function / 生物医学工程学杂志

Epilepsy is a neurological disease with disordered brain network connectivity. It is important to analyze the brain network mechanism of epileptic seizure from the perspective of directed functional connectivity. In this paper, causal brain networks were constructed for different sub-bands of epileptic electroencephalogram (EEG) signals in interictal, preictal and ictal phases by directional transfer function method, and the information transmission pathway and dynamic change process of brain network under different conditions were analyzed. Finally, the dynamic changes of characteristic attributes of brain networks with different rhythms were analyzed. The results show that the topology of brain network changes from stochastic network to rule network during the three stage and the node connections of the whole brain network show a trend of gradual decline. The number of pathway connections between internal nodes of frontal, temporal and occipital regions increase. There are a lot of hub nodes with information outflow in the lesion region. The global efficiency in ictal stage of α, β and γ waves are significantly higher than in the interictal and the preictal stage. The clustering coefficients in preictal stage are higher than in the ictal stage and the clustering coefficients in ictal stage are higher than in the interictal stage. The clustering coefficients of frontal, temporal and parietal lobes are significantly increased. The results of this study indicate that the topological structure and characteristic properties of epileptic causal brain network can reflect the dynamic process of epileptic seizures. In the future, this study has important research value in the localization of epileptic focus and prediction of epileptic seizure.

Remarkable Clinical Improvement Following Microsurgical Resection of Left Lingual Gyrus Cerebral Cavernous Malformation: A Case Report

Moyamoya disease is a chronic and unusual cerebrovascular disorder characterized by progressive stenosis and occlusion of the distal portions of internal carotid arteries and its main branches within the circle of Willis. Posterior circulation (vertebral and basilar arteries) may also be affected; however, this presentation is uncommon. As well as stenosis of the terminal portion of intracranial arteries, it is seen the development of a network of collateral vessels abnormally dilated at the base of the brain with an aspect of a "puff of smoke," whose term in Japanese is described as "moyamoya." The present study aims to report two consecutive cases of patients who presented to our service with different clinical manifestations. Further investigation with digital subtraction angiography showed a moyamoya pattern.

Brain Abscess Caused by Nocardia: Case Report and Literature Review

Nocardia brain abscess is a rare clinical entity, accounting for 2% of all brain abscesses, associated with high morbidity and amortality rate 3 times higher than brain abscesses caused by other bacteria. Proper investigation and treatment, characterized by a longterm antibiotic therapy, play an important role on the outcome of the patient. The authors describe a case of a patient without neurological comorbidities who developed clinical signs of right occipital lobe impairment and seizures, whose investigation demonstrated brain abscess caused by Nocardia spp. The patient was treated surgically followed by antibiotic therapy with a great outcome after 1 year of follow-up.

Topography of Visual Features in the Human Ventral Visual Pathway / 神经科学通报·英文版

Visual object recognition in humans and nonhuman primates is achieved by the ventral visual pathway (ventral occipital-temporal cortex, VOTC), which shows a well-documented object domain structure. An on-going question is what type of information is processed in the higher-order VOTC that underlies such observations, with recent evidence suggesting effects of certain visual features. Combining computational vision models, fMRI experiment using a parametric-modulation approach, and natural image statistics of common objects, we depicted the neural distribution of a comprehensive set of visual features in the VOTC, identifying voxel sensitivities with specific feature sets across geometry/shape, Fourier power, and color. The visual feature combination pattern in the VOTC is significantly explained by their relationships to different types of response-action computation (fight-or-flight, navigation, and manipulation), as derived from behavioral ratings and natural image statistics. These results offer a comprehensive visual feature map in the VOTC and a plausible theoretical explanation as a mapping onto different types of downstream response-action systems.

Biological and Clinical Markers in Panic Disorder

OBJECTIVE: Classifying mental disorders on the basis of objective makers might clarify their aetiology, help in making the diagnosis, identify “at risk” individuals, determine the severity of mental illness, and predict the course of the disorder. This study aims to review biological and clinical markers of panic disorder (PD). METHODS: A computerized search was carried out in PubMed and Science Direct using the key words: “marker/biomarker/clinical marker/neurobiology/staging” combined using Boolean AND operator with “panic.” In addition, the reference lists from existing reviews and from the articles retrieved were inspected. Only English language papers published in peer-reviewed journals were included. RESULTS: Structural changes in the amygdala, hippocampus, cerebral blood level in the left occipital cortex, serotonin 5-TH and noradrenergic systems activation, aberrant respiratory regulation, hearth rate variability, blood cells and peripheral blood stem cells, hypothalamic–pituitary–adrenal axis dysregulation were identified as potential candidate biomarkers of PD. Staging was identified as clinical marker of PD. According to the staging model, PD is described as follows: prodromal phase (stage 1); acute phase (stage 2); panic attacks (stage 3); chronic phase (stage 4). CONCLUSION: The clinical utility, sensitivity, specificity, and the predictive value of biomarkers for PD is still questionable. The staging model of PD might be a valid susceptibility, diagnostic, prognostic, and predictive marker of PD. A possible longitudinal model of biological and clinical markers of PD is proposed.

Fear Network Model in Panic Disorder: The Past and the Future

The core concept for pathophysiology in panic disorder (PD) is the fear network model (FNM). The alterations in FNM might be linked with disturbances in the autonomic nervous system (ANS), which is a common phenomenon in PD. The traditional FNM included the frontal and limbic regions, which were dysregulated in the feedback mechanism for cognitive control of frontal lobe over the primitive response of limbic system. The exaggerated responses of limbic system are also associated with dysregulation in the neurotransmitter system. The neuroimaging studies also corresponded to FNM concept. However, more extended areas of FNM have been discovered in recent imaging studies, such as sensory regions of occipital, parietal cortex and temporal cortex and insula. The insula might integrate the filtered sensory information via thalamus from the visuospatial and other sensory modalities related to occipital, parietal and temporal lobes. In this review article, the traditional and advanced FNM would be discussed. I would also focus on the current evidences of insula, temporal, parietal and occipital lobes in the pathophysiology. In addition, the white matter and functional connectome studies would be reviewed to support the concept of advanced FNM. An emerging dysregulation model of fronto-limbic-insula and temporooccipito-parietal areas might be revealed according to the combined results of recent neuroimaging studies. The future delineation of advanced FNM model can be beneficial from more extensive and advanced studies focusing on the additional sensory regions of occipital, parietal and temporal cortex to confirm the role of advanced FNM in the pathophysiology of PD.

Effects of Amisulpride Adjunctive Therapy on Working Memory and Brain Metabolism in the Frontal Cortex of Patients with Schizophrenia: A Preliminary Positron Emission Tomography/Computerized Tomography Investigation

OBJECTIVE: Dopamine plays a significant role in working memory by acting as a key neuromodulator between brain networks. Additionally, treatment of patients with schizophrenia using amisulpride, a pure dopamine class 2/3 receptor antagonist, improves their clinical symptoms with fewer side effects. We hypothesized that patients with schizophrenia treated with amisulpride and aripiprazole show increased working memory and glucose metabolism compared with those treated with cognitive behavioral therapy (CBT) and aripiprazole instead. METHODS: Sixteen patients with schizophrenia (eight in the amisulpride group [aripiprazole+amisulpride] and eight in the CBT group [aripiprazole+CBT]) and 15 age- and sex-matched healthy control subjects were recruited for a 12-week-long prospective trial. An [18F]-fluorodeoxyglucose-positron emission tomography/computerized tomography scanner was used to acquire the images. RESULTS: After 12 weeks of treatment, the amisulpride group showed greater improvement in the Letter-Number Span scores than the CBT group. Additionally, although brain metabolism in the left middle frontal gyrus, left occipital lingual gyrus, and right inferior parietal lobe was increased in all patients with schizophrenia, the amisulpride group exhibited a greater increase in metabolism in both the right superior frontal gyrus and right frontal precentral gyrus than the CBT group. CONCLUSION: This study suggests that a small dose of amisulpride improves the general psychopathology, working memory performance, and brain glucose metabolism of patients with schizophrenia treated with aripiprazole.

Evaluation of Metabolite Changes in the Occipital Cortex of Patients with Idiopathic Infantile Nystagmus or Bilateral Ametropic Amblyopia by Magnetic Resonance Spectroscopy

PURPOSE: To evaluate the effects of idiopathic infantile nystagmus (IN) and bilateral ametropic amblyopia on metabolites in the occipital cortex by magnetic resonance spectroscopy. METHODS: The children included in this prospective study were divided into three groups. Group 1 consisted of 11 patients with idiopathic IN, group 2 consisted of 10 patients with bilateral ametropic amblyopia and group 3 consisted of nine normal children. A single-voxel magnetic resonance spectroscopy examination was performed by placing a region of interest on the occipital cortex of each participant. N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) concentrations were measured in the occipital cortex. This was followed by calculating and comparing the NAA/Cr and Cho/Cr ratios between the three groups. The Kruskal-Wallis test, Mann-Whitney U-test, and chi-square test were used for statistical analysis. RESULTS: There was no statistically significant difference in NAA/Cr ratios between patients with idiopathic IN and normal children, but there was a statistically significant difference between these groups when Cho/Cr ratios were compared; the ratio was higher in the idiopathic IN group. There were no statistically significant differences in NAA/Cr or Cho/Cr ratios between patients with bilateral ametropic amblyopia and normal children. CONCLUSIONS: Our findings suggest that the neurochemical profile of the occipital cortex is partially affected by idiopathic IN, but not by bilateral ametropic amblyopia.

Altered Regional Cerebral Blood Flow Associated with Mood and Sleep in Shift Workers: Cerebral Perfusion Magnetic Resonance Imaging Study

BACKGROUND AND PURPOSE: Shift work disrupts the body's circadian rhythms and increases the risk of health problems. Despite evidence of neuropsychological disturbances in shift workers (SW), the brain functional status as measured by brain perfusion in chronic shift work has not been evaluated previously. We investigated the regional cerebral blood flow (rCBF) in SW using perfusion MRI (pMRI) and evaluated the relationships between altered rCBF and sleep, mood, psychometric measures, and quality of life. METHODS: Fifteen rotational SW and 15 day workers (DW) were enrolled. The participants were all female nurses working at a university-affiliated hospital. During 2 weeks of actigraphy they underwent pMRI scanning and psychometric testing on the last day immediately after working. Demographic characteristics, insomnia, daytime sleepiness, and mood were compared between the groups. RESULTS: The participants were aged 35.3±2.9 years (mean±SD) and had been performing their current work for more than 2 years. The demographic characteristics did not differ between SW and DW, but the levels of insomnia, anxiety, depression, and hyperactivity-restlessness in psychometric measures were higher in SW than in DW. Cerebral perfusion in SW was significantly decreased in the cuneus, fusiform/parahippocampal gyri, and cerebellum of the right hemisphere, while it was increased in the inferior occipital gyrus of the left hemisphere. Perfusion changes in SW were significantly correlated with depression and insomnia severity. The onset and duration irregularity of sleep among SW were related to insomnia, mood, hyperactivity/ restlessness, and quality of life. CONCLUSIONS: SW experience considerably more insomnia and mood disturbances than do DW, and this is significantly related to perfusion changes in multiple brain areas.

A Comprasion of the Activation of Mirror Neurons Induced by Action Observation between Simple and Complex Hand Movement

PURPOSE: We compared the activation pattern of the mirror neurons (MN) between two types of hand movement according to action observation using functional MRI. METHODS: Twelve right-handed healthy subjects (5 male and 7 female, mean age 21.92±2.02 years) participated in the experiment. During fMRI scanning, subjects underwent two different stimuli on the screen: 1) video clips showing repeated grasping and releasing of the ball via simple hand movement (SHM), and (2) video clips showing an actor performing a Purdue Pegboard test via complex hand movement (CHM). paired t-test in statistical parametric mapping (SPM) was used to compare the activation differences between the two types of hand movement. RESULTS: CHM as compared with the SHM produced a higher blood oxygen level dependent (BOLD) signal response in the right superior frontal gyrus, left inferior and superior parietal lobules, and lingual gyrus. However, no greater BOLD signal response was found by SHM compared with CHM (FWE corrected, p<0.05). CONCLUSION: Our findings provided that the activation patterns for observation of SHM and CHM are different. CHM also elicited boarder or stronger activations in the brain, including inferior parietal lobule called the MN region.

Posterior reversible encephalopathy syndrome in a woman who used gonadotropin-releasing hormone agonists: a case report

Posterior reversible encephalopathy syndrome (PRES) is a newly described adverse effect possibly associated with gonadotropin-releasing hormone (GnRH) agonist therapy. We report a case of PRES after 2 doses of depot GnRH agonists in a 44-year-old woman with a huge myoma uteri and iron-deficiency anemia. Brain magnetic resonance imaging showed high signal lesions in both occipital lobes on fluid-attenuated inversion-recovery (FLAIR) images, compatible with PRES. After treatment with anticonvulsant, she recovered both radiographically and clinically. The association between PRES and GnRH agonist use is still enigmatic, and thus should be further clarified.

Homonymous Quadrantanopia Caused by Occipital Lobe Ulegyria

PURPOSE: We report a case of homonymous quadrantanopia caused by occipital lobe ulegyria. CASE SUMMARY: A 23-year-female was referred to our clinic because of a visual field defect incidentally discovered during preoperative evaluation for refractive surgery at another clinic. However, she did not report any symptoms. She had no systemic diseases. Visual acuity was 20/20 in both eyes, and the color vision test was normal. Both pupils exhibited normal responses to light and near stimulations. In fundus examinations, the right optic disc was normal and the left contained drusen. Automated perimetry revealed right lower homonymous quadrantanopia with macular sparing. Brain magnetic resonance imaging revealed areas of ulegyria involving the left occipital lobe, consistent with the visual field defect. A follow-up visual field test performed 5 months later yielded the same result. CONCLUSIONS: Neuroimaging should be performed in patients with homonymous visual field defects to determine the location and etiology of the brain lesions. Occipital lobe ulegyria can cause homonymous quadrantanopia in the absence of any neurological problem.

Bilateral Occipital Lobe Infarction Presenting as Bilateral Inferior Altitudinal Defects

PURPOSE: Horizontal visual field defects are generally caused by lesions before the optic chiasm, but we report a case with bilateral inferior altitudinal defects secondary to bilateral occipital lobe infarction. CASE SUMMARY: A 57-year-old male with a history of diabetes and hypertension presented with a month of blurring in the inferior visual field. His corrected visual acuity was 1.0 in the right eye and 0.63 in the left eye, and the intraocular pressure was normal in each eye. Pupillary response, ocular movement, and color vision tests were normal in both eyes. There was no specific finding of the optic disc and macula on fundus examination. Visual field examination revealed an inferior congruous homonymous hemianopia with horizontal meridian sparing and a left incongruous homonymous quadrantanopia. Optical coherence tomography for peripapillary retinal nerve fiber layer thickness revealed a mild decrease in the inferior disc of both eyes. Brain magnetic resonance imaging confirmed the presence of an acute infarction confined with upper medial calcarine fissures of bilateral occipital lobe and the right splenium of the corpus callosum, which were consistent with inferior altitudinal hemianopia and left superior incongruous quadrantanopia, respectively. Brain magnetic resonance angiography showed multiple stenosis of bilateral posterior cerebral arteries. CONCLUSIONS: The altitudinal visual field defects could be caused by the occipital lesion medial to the calcarine fissure, and unusual visual defects could be due to a combination of multiple lesions.

Width of sulcus and thickness of gyrus in patients with cerebral atherosclerosis: a new tool for the prevention of vascular cognitive impairment

SUMMARY BACKGROUND AND PURPOSE Cerebral atherosclerosis is the main cause of lesions that contribute to vascular cognitive impairment and vascular dementia, followed by arteriosclerosis of small vessels and cerebral amyloid angiopathy. The purpose of this study was to compare the post-mortem radiological alterations of autopsied adults with the macroscopic alterations in the posterior region of these brains in order to establish a relationship between the two forms of analysis and to discuss the relevance of the prevention of vascular cognitive impairment in patients with encephalic atherosclerosis. MATERIALS AND METHODS Thirteen brains were analysed macroscopically to assess the degree of atherosclerosis of the basilar and the posterior cerebral arteries. The patients were autopsied in the Subject of General Pathology at General Hospital of Triângulo Mineiro Federal University in Uberaba, state of Minas Gerais, Brazil. The qualitative analysis of atherosclerosis was performed with classification into mild, moderate or severe. In the posterior region of the brains, width of sulcus and thickness of gyrus were measured by macroscopic analysis and by tomographic analysis. RESULTS AND CONCLUSIONS There was a decrease in calcarine sulcus width and an increase in medial temporal occipital gyrus thickness in patients with a higher degree of atherosclerosis, macroscopically and in tomography, respectively. Low oxygenation caused by atherosclerosis probably leads to an encephalic parenchyma inflammation that causes microglial cells hypertrophy provoking increase in the gyrus thickness and decrease in the sulcus width, as observed in the present study.

RESUMO INTRODUÇÃO E OBJETIVO A aterosclerose cerebral é a principal causa de lesões que contribuem para o comprometimento cognitivo vascular (CCV) e demência vascular, seguida da arteriosclerose de pequenos vasos e da angiopatia amiloide cerebral. Sendo assim, este estudo comparou as alterações radiológicas post mortem de adultos autopsiados com as alterações macroscópicas na região posterior desses encéfalos a fim de estabelecer uma relação entre as duas formas de análise e discutir sobre a relevância da prevenção do CCV em pacientes com aterosclerose encefálica. MATERIAL E MÉTODOS Treze encéfalos foram analisados macroscopicamente para avaliar o grau de aterosclerose das artérias basilar e cerebral posterior. Os pacientes foram autopsiados na disciplina de Patologia Geral no HC-UFTM em Uberaba, Minas Gerais, Brasil. A análise qualitativa da aterosclerose foi realizada com as classificações discreta, moderada ou acentuada. A espessura dos giros e a largura dos sulcos na região posterior dos encéfalos foram analisadas macroscopicamente e por tomografia computadorizada. RESULTADOS E CONCLUSÃO Houve diminuição na largura do sulco calcarino e aumento na espessura do giro occipital temporal medial de acordo com o aumento do grau de aterosclerose macroscopicamente e por tomografia, respectivamente. A baixa oxigenação causada pela aterosclerose provoca a inflamação do parênquima encefálico, provavelmente levando à hipertrofia das células da micróglia e ao consequente aumento dos giros e estreitamento dos sulcos, como observado no presente estudo.

Unilateral Posterior Reversible Encephalopathy Syndrome Secondary to Renal Artery Obstruction: A Case Report / 대한소아신경학회지

Posterior reversible encephalopathy syndrome (PRES, or posterior leukoencephalopahty syndrome) is a neurological condition caused by reversible cortical/subcortical vasogenic brain edema secondary to hypertension, cytotoxic drugs, immunosuppressants, autoimmune diseases, renal disease, eclampsia or pre-eclampsia. It is characterized by acute neurological symptoms such as headache, seizures, visual disturbances, and impaired levels of consciousness. Brain imaging usually reveals bilateral, cortical/subcortical vasogenic edema. Completely unilateral PRES constituted only 2.6% of the cases in a previous study. Here we report the case of a pediatric patient with completely unilateral PRES. A 13-year-old boy was admitted with acute gastroenteritis. On the fourth day of hospitalization, he started to complain of headache and vomiting. He then developed generalized tonic-clonic seizure 3 times. His blood pressure was 180/121 mmHg during the first seizure, 188/112 mmHg during the second seizure and 152/92 mmHg during the third seizure. T2-weighted imaging with fluid attenuation by inversion recovery (T2 FLAIR) demonstrated high-signal intensity in the cortical gyri of the left frontal, parietal, and occipital lobes. Follow-up magnetic resonance imaging (MRI) was performed 2 weeks after the seizure onset, which indicated a significant improvement in the patient's condition. Abdominal pelvic computed tomography (CT) and renal CT angiography showed abnormal narrowing of the left renal artery. In summary, we present a case report of unilateral PRES secondary to renovascular hypertension due to left renal arterial obstruction.

The Effect of Leukoaraiosis on the Severity and Course of Delirium / 정신신체의학

OBJECTIVES: The significance of leukoaraiosis on brain magnetic resonance imaging (MRI) is uncertain, but it is often seen with vascular risk factors or in the context of cognitive impairment. We aimed to investigate the effect of leukoaraiosis on the severity and course of delirium. METHODS: Periventricular hyperintensity and deep white matter hyperintensity on brain MRI were rated in 42 patients with delirium by semiquantative visual rating scale. Correlations between their grades and the scores of Korean version of Delirium Rating Scale-Revised-98 (K-DRS-R-98) were analyzed, and the interaction effects between the groups according to the levels of leukoaraiosis and two evaluation points were also analyzed. RESULTS: The grade of deep white matter hyperintensity in the occipital lobe was positively correlated with the scores on the total, severity items, cognitive items, and non-cognitive items of K-DRS-R-98. The cognitive items scores of K-DRS-R-98 in the low grade group of periventricular hyperintensity showed significantly steeper decrease than the high grade group. CONCLUSIONS: A difference in severity or recovery speed of delirium according to the level of leukoaraiosis may result from disruption in brain functional connectivity. Our results have a clinical implication in that the severity and course of delirium can be possibly predicted using the level of leukoaraiosis.

Reduction in Alpha Peak Frequency and Coherence on Quantitative Electroencephalography in Patients with Schizophrenia

BACKGROUND: The aim of the study was to examine the characteristics of alpha wave peak frequency, power, and coherence in patients with schizophrenia. METHODS: Thirty-one patients with schizophrenia and age- and sex-matched subjects with no psychopathology were enrolled. All study participants underwent quantitative electroencephalography (QEEG). Alpha-related values, including peak frequency, power, and coherence, were evaluated. RESULTS: Alpha peak frequency on the Oz area was slower in the schizophrenia group than that in the control group. However, no differences in absolute or relative power were observed between the two groups. Significant reductions in absolute and relative coherence were observed at the C3–C4 and T3–T4 nodes in the patients with schizophrenia. Relative coherence was reduced at the P3–P4 nodes. CONCLUSION: This study focused on alpha variables detected in QEEG as intrinsic values to distinguish schizophrenia from a healthy control. The results suggest decreased alpha peak frequency of the occipital lobe and decreased coherence between the two hemispheres in patients with schizophrenia. A further study could elucidate the causal relationship and biological meaning of the variations in alpha waves in patients with schizophrenia.

FDG PET Findings according to Wandering Patterns of Patients with Drug-naïve Alzheimer's Disease

BACKGROUND AND PURPOSE: To explore anatomic substrate of specific wandering patterns in patients with Alzheimer's disease (AD) by performing positron emission tomography with 18F fluorodeoxyglucose positron emission tomography (FDG PET). METHODS: Drug-naïve AD patients with wandering (n=80) and without wandering (n=262) were recruited. First, the specific pattern of wandering type was operationally classified according to specific wandering score and clinical assessment. Second, brain FDG PET was performed and fluorodeoxyglucose (FDG) uptake differences of specific brain regions according to wandering patterns were compared to those of non-wanderers. RESULTS: In patients with pacing pattern, FDG PET showed significant lower FDG uptake in both middle cingulum and left putamen cluster compared to non-wanderers. The right precuneus and supplementary motor area in patients with random pattern and left calcarine sulcus, right calcarine sulcus, right middle cingulum, and right post central gyrus in patients with lapping pattern had significantly lower FDG uptake compared to non-wanderers. CONCLUSIONS: This study showed that wandering in patients with AD had three distinct patterns. These specific patterns showed significant lower FDG uptake in specific brain areas compared to non-wanderers.