Bilateral Parietal Regions Research Articles

Functional MRI-based biomarkers of insomnia with objective short sleep duration phenotype

BackgroundInsomnia disorder with objective short sleep duration (ISS) phenotype is a more serious biological subtype than insomnia with objective normal sleep duration (INS) phenotype, and the neuroimaging data is helpful to understand the pathophysiology of the ISS phenotype. This study was to compare the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) between the ISS phenotype and the INS phenotype. MethodsIn this cross-sectional study, 55 patients with insomnia disorder were recruited, and 22 of them were defined as the ISS phenotype by the objective cardiopulmonary coupling (CPC) technique. The blood oxygen level-dependent (BOLD) sequences of all participants were obtained using the 3.0 T magnetic resonance imaging system. We analyzed and compared the ALFF, ReHo, and FC between the ISS phenotype and the INS phenotype. We also conducted Pearson's correlation analysis between significant neuroimaging biomarkers and the CPC parameters. ResultsThe differences were not significant in ALFF (PFWE-corr＞0.05) or ReHo (PFWE-corr＞0.05) between the ISS phenotype and the INS phenotype. For the FC analysis, the ISS phenotype had a Hub-node of the left inferior occipital gyrus (IOG.L), with significantly decreased connections (p＜0.001) in the bilateral occipital, parietal, and temporal regions. The significant FCs were closely related to sleep parameters. ConclusionThe left inferior occipital gyrus (IOG.L), as a Hub-node with decreased functional connections, may be a potential fMRI-based biomarker of the ISS phenotype.

Contrast-induced transient cortical blindness

A 58-year-old Malay man with a history of ischemic heart disease, well-controlled diabetes mellitus, and hypertension presented with sudden loss of vision after he underwent angiogram (cardiac catheterization) with contrast. Post-angiogram, his visual acuity deteriorated gradually to no perception of light bilaterally within 1 h duration. Clinically, there was no new intraocular pathology and neurologic examination was normal. An urgent noncontract computed tomography (CT) scan of the brain showed the presence of contrast in the venous sinuses but no obvious acute intracranial hemorrhage. Bilateral frontal and anterior parietal regions appeared hypodense with loss of gray white matter differentiation and relative effacement of the sulci. CT brain reported that infarction or cerebral edema may represent. Patient’s condition was observed, and after 24 h, his vision recovered to baseline and he was discharged well.

Kearns–Sayre Syndrome with Bilateral Ptosis and External Ophthalmoplegia: A Rare Case Report

Abstract
 Introduction : Kearns-Sayre syndrome (KSS) is a rare genetic disorder caused by a deletion of mitochondrial DNA (mtDNA) segment, typically characterized by a triad of symptoms includes external ophthalmoplegia, pigmentary retinopathy and appeared before the age of 20. The prevalence rate is about 1–3 per 100.000 individuals. It was diagnosed based on clinical features and supported by biochemical, radiological, histologic, and molecular genetic tests.
 Case Illustration : 26-year-old male with bilateral ptosis, chronic progressive external ophthalmoplegia, pigmentary retinopathy was shown from ophthalmology examination and associated with hearing loss. Physical examination showed short stature, wasting, and weakness of limb muscles. MRI examination revealed focal brain atrophy on bilateral parietal regions.
 Discussion : Mitochondrial DNA defect led to dysfunction of the central nervous system, endocrine system, extraocular muscle, myocardium, skeletal muscle, and other multiple systems. The clinical findings in this patient are appropriate for classical signs and symptoms of KSS. Central nervous involvementis shown by the neuroimaging result. There is no cardiac involvement suggested by normal cardiology examination. Although muscle pathology and molecular genetic analysis can play a great role to diagnose KSS, the classical triad of clinical signs plus one of the other symptoms could establish KSS diagnosis.
 Conclusion : KSS is a rare genetic disorder and challenging to diagnose. However, if a patient presents with the classic triad of symptoms, clinicians should have a high level of suspicion for the disorder. Additionally, It is important to perform a thorough evaluation to rule out other conditions that can cause similar symptoms.

Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults

Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines.

Neural Correlates of Semantic Interference and Phonological Facilitation in Picture Naming: A Systematic Review and Coordinate-Based Meta-analysis.

Semantic interference (SI) and phonological facilitation (PF) effects occur when multiple representations are co-activated simultaneously in complex naming paradigms, manipulating the context in which word production is set. Although the behavioral consequences of these psycholinguistic effects are well-known, the involved brain structures are still controversial. This paper aims to provide a systematic review and a coordinate-based meta-analysis of the available functional neuroimaging studies investigating SI and PF in picture naming paradigms. The included studies were fMRI experiments on healthy subjects, employing paradigms in which co-activations of representations were obtained by manipulating the naming context using semantically or phonologically related items. We examined the principal methodological aspects of the included studies, emphasizing the existing commonalities and discrepancies across single investigations. We then performed an exploratory coordinate-based meta-analysis of the reported activation peaks of neural response related to SI and PF. Our results consolidated previous findings regarding the involvement of the left inferior frontal gyrus and the left middle temporal gyrus in SI and brought out the role of bilateral inferior parietal regions in PF.

Reduced slow wave density is associated with worse positive symptoms in clinical high risk: An objective readout of symptom severity for early treatment interventions?

Individuals at clinical high risk for psychosis (CHR) present subsyndromal psychotic symptoms that can escalate and lead to the transition to a diagnosable psychotic disorder. Identifying biological parameters that are sensitive to these symptoms can therefore help objectively assess their severity and guide early interventions in CHR. Reduced slow wave oscillations (∼1 Hz) during non-rapid eye movement sleep were recently observed in first-episode psychosis patients and were linked to the intensity of their positive symptoms. Here, we collected overnight high-density EEG recordings from 37 CHR and 32 healthy control (HC) subjects and compared slow wave (SW) activity and other SW parameters (i.e., density and negative peak amplitude) between groups. We also assessed the relationships between clinical symptoms and SW parameters in CHR. While comparisons between HC and the entire CHR group showed no SW differences, CHR individuals with higher positive symptom severity (N = 18) demonstrated a reduction in SW density in an EEG cluster involving bilateral prefrontal, parietal, and right occipital regions compared to matched HC individuals. Furthermore, we observed a negative correlation between SW density and positive symptoms across CHR individuals, suggesting a potential target for early treatment interventions.

Transferring a deep learning model from healthy subjects to stroke patients in a motor imagery brain–computer interface

Objective. Motor imagery (MI) brain–computer interfaces (BCIs) based on electroencephalogram (EEG) have been developed primarily for stroke rehabilitation, however, due to limited stroke data, current deep learning methods for cross-subject classification rely on healthy data. This study aims to assess the feasibility of applying MI-BCI models pre-trained using data from healthy individuals to detect MI in stroke patients. Approach. We introduce a new transfer learning approach where features from two-class MI data of healthy individuals are used to detect MI in stroke patients. We compare the results of the proposed method with those obtained from analyses within stroke data. Experiments were conducted using Deep ConvNet and state-of-the-art subject-specific machine learning MI classifiers, evaluated on OpenBMI two-class MI-EEG data from healthy subjects and two-class MI versus rest data from stroke patients. Main results. Results of our study indicate that through domain adaptation of a model pre-trained using healthy subjects’ data, an average MI detection accuracy of 71.15% ( ±12.46% ) can be achieved across 71 stroke patients. We demonstrate that the accuracy of the pre-trained model increased by 18.15% after transfer learning (p < 0.001). Additionally, the proposed transfer learning method outperforms the subject-specific results achieved by Deep ConvNet and FBCSP, with significant enhancements of 7.64% (p < 0.001) and 5.55% (p < 0.001) in performance, respectively. Notably, the healthy-to-stroke transfer learning approach achieved similar performance to stroke-to-stroke transfer learning, with no significant difference (p > 0.05). Explainable AI analyses using transfer models determined channel relevance patterns that indicate contributions from the bilateral motor, frontal, and parietal regions of the cortex towards MI detection in stroke patients. Significance. Transfer learning from healthy to stroke can enhance the clinical use of BCI algorithms by overcoming the challenge of insufficient clinical data for optimal training.

Deep medullary veins score is associated with atrophy in patients with cerebral small vessel disease.

To explore the relationship between the deep medullary vein (DMV) score and atrophy in patients with cerebral small vessel disease (CSVD). Imaging and clinical data from 125 patients with CSVD from January to December 2022 were reviewed. Normalized gray matter volume (GM_N) was calculated by dividing the gray matter volume by the whole brain volume. DMV scoring is conducted using susceptibility-weighted magnetic resonance imaging, wherein the DMV area is partitioned into six distinct regions: bilateral frontal, parietal, and occipital regions. Each region undergoes assessment based on the clarity and consistency of DMV visibility. Subsequently, the scores from these six regions are summed, resulting in a score ranging from 0 to 18 points. DMV score was associated with GM_N (r = -0.376, p < 0.001). Comparisons among patients according to GM_N tertiles, differences in gender, age, current smoking, DMV score, and total CSVD magnetic resonance imaging score were demonstrated (p < 0.05). Adjusting for age, gender, vascular risk factors, and total CSVD MR score, the DMV score was independently associated with GM_N [β (95% CI): -0.347 (-0.525, -0.168), p < 0.001]. DMV scores are independently associated with GM_N, and DMV dysfunction may play a role in brain atrophy.

Differential effects of ageing on the neural processing of speech and singing production.

Understanding healthy brain ageing has become vital as populations are ageing rapidly and age-related brain diseases are becoming more common. In normal brain ageing, speech processing undergoes functional reorganisation involving reductions of hemispheric asymmetry and overactivation in the prefrontal regions. However, little is known about how these changes generalise to other vocal production, such as singing, and how they are affected by associated cognitive demands. The present cross-sectional fMRI study systematically maps the neural correlates of vocal production across adulthood (N=100, age 21-88 years) using a balanced 2x3 design where tasks varied in modality (speech: proverbs / singing: song phrases) and cognitive demand (repetition / completion from memory / improvisation). In speech production, ageing was associated with decreased left pre- and postcentral activation across tasks and increased bilateral angular and right inferior temporal and fusiform activation in the improvisation task. In singing production, ageing was associated with increased activation in medial and bilateral prefrontal and parietal regions in the completion task, whereas other tasks showed no ageing effects. Direct comparisons between the modalities showed larger age-related activation changes in speech than singing across tasks, including a larger left-to-right shift in lateral prefrontal regions in the improvisation task. The present results suggest that the brains' singing network undergoes differential functional reorganisation in normal ageing compared to the speech network, particularly during a task with high executive demand. These findings are relevant for understanding the effects of ageing on vocal production as well as how singing can support communication in healthy ageing and neurological rehabilitation.

Dengue Causing Posterior Reversible Encephalopathy Syndrome: A Case Report from India

Background: Posterior reversible encephalopathy syndrome (PRES) is characterized by altered mental status, headaches, visual disturbances, and seizures and caused due edema affecting mainly the parietal and occipital lobes of the brain. This clinical entity is increasingly established due to improvements in radiological investigations. Patient’s Concern: We present a 22-year-old female with 9-month amenorrhea with altered sensorium; the noncontrast computed tomography head showed ill-defined hypodensities in the bilateral occipital and parietal region suggestive of the PRES. Intervention: The patient was managed immediately with an injection of levetiracetam with intravenous (IV) fluids, antibiotics, and IV steroids. The patient had gross improvement in the sensorium and vision within 24 h. The patient was discharged on the 10th day of admission with 100% recovery. Follow-ups at 2 and 4 weeks were uneventful. Lesson Learnt: Even dengue can cause PRES, so the clinical entity should be recognized as early as possible. The treatment should be initiated urgently; knowledge of this can easily prevent unnecessary morbidity and mortality with complete recovery.

Regional Cortical Thickness Correlates of Intellectual Abilities Differ in Children With Traumatic Brain Injury Versus Those With Orthopedic Injury in the Chronic Post-Injury Phase.

A decline in intellectual functioning (intelligence quotient [IQ]) is often observed following more severe forms of traumatic brain injury (TBI) and is a useful index for long-term outcome. Identifying brain correlates of IQ can serve to inform developmental trajectories of behavior in this population. Using magnetic resonance imaging (MRI), we examined the relationship between intellectual abilities and patterns of cortical thickness in children with a history of TBI or with orthopedic injury (OI) in the chronic phase of injury recovery. Participants were 47 children with OI and 58 children with TBI, with TBI severity ranging from complicated-mild to severe. Ages ranged from 8 to 14 years old, with an average age of 10.47 years, and an injury-to-test range of ∼1-5 years. The groups did not differ in age or sex. The intellectual ability estimate (full-scale [FS]IQ-2) was derived from a two-form (Vocabulary and Matrix Reasoning subtests) Wechsler Abbreviated Scale of Intelligence (WASI). MRI data were processed using the FreeSurfer toolkit and harmonized across data collection sites using neuroComBat procedures, while holding demographic features (i.e., sex, socioeconomic status [SES]), TBI status, and FSIQ-2 constant. Separate general linear models per group (TBI and OI) and a single interaction model with all participants were conducted with all significant results withstanding correction for multiple comparisons via permutation testing. Intellectual ability was higher (p < 0.001) in the OI group (FSIQ-2 = 110.81) than in the TBI group (FSIQ-2 = 99.81). In children with OI, bi-hemispheric regions, including the right pre-central gyrus and precuneus and bilateral inferior temporal and left occipital areas were related to IQ, such that higher IQ was associated with thicker cortex in these regions. In contrast, only cortical thickness in the right pre-central gyrus and bilateral cuneus positively related to IQ in children with TBI. Significant interaction effects were found in the bilateral temporal, parietal, and occipital lobes and left frontal regions, indicating that the relationship between IQ and cortical thickness differed between groups in these regions. Changes in cortical associations with IQ after TBI may reflect direct injury effects and/or adaptation in cortical structure and intellectual functioning, particularly in the bilateral posterior parietal and inferior temporal regions. This suggests that the substrates of intellectual ability are particularly susceptible to acquired injury in the integrative association cortex. Longitudinal work is needed to account for normal developmental changes and to investigate how cortical thickness and intellectual functioning and their association change over time following TBI. Improved understanding of how TBI-related cortical thickness alterations relate to cognitive outcome could lead to improved predictions of outcome following brain injury.

Cerebritis as an initial presentation of systemic lupus erythematosus

Systemic lupus erythematosus (SLE), an autoimmune disease with multi-system manifestations, has several clinical presentations varying from mild muco-cutaneous involvement to severe multi-organ involvement. We report the case of an 18-year-old girl who presented generalized tonic clonic fits. She gave a history of generalized headaches, recurrent painless oral ulcers, photosensitivity, joint pains and low-grade intermittent fever. Magnetic resonance imaging (MRI) scan of the brain revealed T2WI/FLAIR hyperintense signals in bilateral frontal, parietal and occipital regions and magnetic resonance angiography of the brain demonstrated mild areas of luminal narrowing in M1 and M2 segments of middle cerebral arteries bilaterally, suggestive of lupus cerebritis. Anti-nuclear antibody (ANA) and Anti-DsDNA antibodies were positive. She was diagnosed as SLE and was prescribed corticosteroids, cyclophosphamide and hydroxychloroquine. This case highlights cerebritis as initial presentation of SLE.&#x0D; Abbreviations: ANA- Anti-nuclear antibody; CRP- C-reactive protein; FLAIR- Fluid attenuated inversion recovery; SLE- Systemic lupus erythematosus;&#x0D; Key words: ANA; Cerebritis; Headache; Systemic Lupus Erythematosus&#x0D; Citation: Ashfaq F, Butt NI, Rasheed MB, Ghoauri MSA, Anser A. Cerebritis as initial presentation of systemic lupus erythematosus. Anaesth. pain intensive care 2023;27(4):604−608; DOI: 10.35975/apic.v27i4.2214&#x0D; Received: May 23, 2023; Reviewed: May 28, 2023; Accepted: July 08, 2023

Aberrant age-related alterations in spontaneous cortical activity in participants with cerebral palsy.

Cerebral Palsy (CP) is the most common neurodevelopmental motor disability, resulting in life-long sensory, perception and motor impairments. Moreover, these impairments appear to drastically worsen as the population with CP transitions from adolescents to adulthood, although the underlying neurophysiological mechanisms remain poorly understood. We began to address this knowledge gap by utilizing magnetoencephalographic (MEG) brain imaging to study how the amplitude of spontaneous cortical activity (i.e., resting state) is altered during this transition period in a cohort of 38 individuals with spastic diplegic CP (Age range = 9.80-47.50 years, 20 females) and 67 neurotypical controls (NT) (Age range = 9.08-49.40 years, Females = 27). MEG data from a five-minute eyes closed resting-state paradigm were source imaged, and the power within the delta (2-4 Hz), theta (5-7 Hz), alpha (8-12 Hz), beta (15-29 Hz), and gamma (30-59 Hz) frequency bands were computed. For both groups, the delta and theta spontaneous power decreased in the bilateral temporoparietal and superior parietal regions with age, while alpha, beta, and gamma band spontaneous power increased in temporoparietal, frontoparietal and premotor regions with age. We also found a significant group x age interaction, such that participants with CP demonstrated significantly less age-related increases in the spontaneous beta activity in the bilateral sensorimotor cortices compared to NT controls. Overall, these results demonstrate that the spontaneous neural activity in individuals with CP has an altered trajectory when transitioning from adolescents to adulthood. We suggest that these differences in spontaneous cortical activity may play a critical role in the aberrant motor actions seen in this patient group, and may provide a neurophysiological marker for assessing the effectiveness of current treatment strategies that are directed at improving the mobility and sensorimotor impairments seen in individuals with CP.

An ERP measure of non-conscious memory reveals dissociable implicit processes in human recognition using an open-source automated analytic pipeline.

Non-conscious processing of human memory has traditionally been difficult to objectively measure and thus understand. A prior study on a group of hippocampal amnesia (N = 3) patients and healthy controls (N = 6) used a novel procedure for capturing neural correlates of implicit memory using event-related potentials (ERPs): old and new items were equated for varying levels of memory awareness, with ERP differences observed from 400 to 800 ms in bilateral parietal regions that were hippocampal-dependent. The current investigation sought to address the limitations of that study by increasing the sample of healthy subjects (N = 54), applying new controls for construct validity, and developing an improved, open-source tool for automated analysis of the procedure used for equating levels of memory awareness. Results faithfully reproduced prior ERP findings of parietal effects that a series of systematic control analyses validated were not contributed to nor contaminated by explicit memory. Implicit memory effects extended from 600 to 1000 ms, localized to right parietal sites. These ERP effects were found to be behaviorally relevant and specific in predicting implicit memory response times, and were topographically dissociable from other traditional ERP measures of implicit memory (miss vs. correct rejections) that instead occurred in left parietal regions. Results suggest first that equating for reported awareness of memory strength is a valid, powerful new method for revealing neural correlates of non-conscious human memory, and second, behavioral correlations suggest that these implicit effects reflect a pure form of priming, whereas misses represent fluency leading to the subjective experience of familiarity.

Native language differences in the structural connectome of the human brain

Is the neuroanatomy of the language structural connectome modulated by the life-long experience of speaking a specific language? The current study compared the brain white matter connections of the language and speech production network in a large cohort of 94 native speakers of two very different languages: an Indo-European morphosyntactically complex language (German) and a Semitic root-based language (Arabic). Using high-resolution diffusion-weighted MRI and tractography-based network statistics of the language connectome, we demonstrated that German native speakers exhibited stronger connectivity in an intra-hemispheric frontal to parietal/temporal dorsal language network, known to be associated with complex syntax processing. In comparison, Arabic native speakers showed stronger connectivity in the connections between semantic language regions, including the left temporo-parietal network, and stronger inter-hemispheric connections via the posterior corpus callosum connecting bilateral superior temporal and inferior parietal regions. The current study suggests that the structural language connectome develops and is modulated by environmental factors such as the characteristic processing demands of the native language.

Assessing dynamic brain activity during verbal associative learning using MEG/fMRI co-processing

BackgroundThe abilities of individual neuroimaging methods to resolve spatial and temporal contributions of brain regions during cognitive processes are limited. Co-processing of functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) may overcome some of the limitations by utilizing Multiple Sparse Priors (MSP) in a Bayesian framework that takes advantage of the temporal resolution of MEG and spatial resolution of fMRI. Methods24 healthy participants were recruited to perform a paired-associate verbal learning task during fMRI and MEG scans. FMRI data were processed within Group ICA fMRI Toolbox. Independent components (ICs) were temporally sorted by task time series (|r|>0.30 threshold identified task-related ICs). Task-positive (“generate”) ICs were retained as spatial priors for MEG analyses. MEG data were processed by an event-related potential (ERP) approach and with a theta power approach. MEG source reconstructions were constrained within the task-positive ICs for both ERP and theta-power approaches. ResultsFor fMRI, five networks were identified as task-related. Four ICs underlying active generation spanned bilateral parietal, orbitofrontal, medial frontal and superior temporal regions, and occipital lobe. FMRI-constrained MEG source reconstructions using the ERP approach yielded early visual cortex activity followed by left inferior frontal gyrus (IFG) and orbito-frontal cortex (OFC) recruitment to coalesce in the left inferior temporal lobe. For the theta approach, MEG source reconstructions showed a progression of activity from bilateral temporal areas to left OFC and middle temporal gyrus, followed by right IFG. DiscussionMSP analyses informed by fMRI produced more focused regional activity than reconstructions without priors suggesting this approach may result in identifying more relevant semantic information during active generation. Constraining MEG source reconstruction to fMRI priors during active generation indicates fronto-temporal and fronto-parietal networks are interconnected across time and space.

MR Neuroimaging Findings in Adult Diabetic Patients- Two Case Reports

Diabetes Mellitus (DM) can affect any part of the central and peripheral nervous systems. Significant variations in glucose levels are often symptomatic. Hypoglycaemia as well as hyperglycaemia can present a wide variety of clinical symptoms. Imaging helps by suggesting the correct diagnosis and ensuring early treatment. We hereby present two cases, one of hypoglycaemic encephalopathy and a case of diabetic striatopathy. A 40-year-old female with a 25-year-old history of type 2 diabetes was brought into the emergency room in an unresponsive state since afternoon. The blood glucose was 28 mg/dL, and immediate administration of D 25%x2 stat was done. MRI revealed hyperintensities in the bilateral hippocampi and in the cortex of the bilateral high parietal region on T2WI/FLAIR. Despite intensive medical treatment the patient’s neurologic condition didn’t improve, due to irreversible brain tissue damage, and the patient ultimately died. A 63-year-old male was brought by relatives to causality with complaints of involuntary movements of the right-side of the body since three months, but symptoms have exaggerated since three days. Newly diagnosed DM since three months was on medication T.Metformin 500 mg BD. MRI revealed T1 hyperintensities in posterior half of left putamen. Patient was put on Inj. haloperidol 0.5 mg SOS, T.Aspirin 150 mg OD, T.Atorva 20 mg HS, T.sodium valproate 200 mg BD, T.tetrabenazine 25 mg BD and T.Serenace 0.5 mg BD and patient had improved symptomatically after 15 days of treatment. Imaging can play a crucial role in diagnosis and guide treatment and markedly influence the prognosis of patient.

Brain computed tomography perfusion analysis in HIV-seropositive adults with and without neurocognitive impairment in Nigeria: outcomes and challenges of a pilot study.

the significance of cerebrovascular disease in HIV-associated neurocognitive disorder (HAND) in a homogeneous black population has not yet been determined. This incident case-control study used CT perfusion imaging to quantify and compare regional cerebral blood flow parameters in neuro-cognitively impaired and unimpaired HIV+ participants of the Ibadan Cohort on Neuro AIDS (ICON) in Nigeria. this was an incident case-control study consisting of twenty-seven HIV+ adults, classified based on Frascati criteria into neurocognitive impaired (n=18) and unimpaired (n=9) groups, who had brain computed tomographic perfusion (CTP) with a 64-slice Toshiba T scanner. The standard deviation (SD) of regional mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) values were calculated for bilateral basal ganglia (BG), frontal, parietal, temporal, and occipital regions from CT perfusion maps. The regional mean values and variability (SD) in the CTP measures were compared in the groups using an independent student t-test. differentially higher variability in the bilateral CBF measures in the parietal (right; OR = 1.14, x̄ =5.61, p=0.041, CI=0.27-11.35/left; OR = 1.16, x̄=7.01, p=0.03, CI=5.6-13.47) and time to peak (TTP) measures in the basal ganglia (right; OR = 3.78, x̄=0.88, p=0.032, CI=0.081-1.67/left; OR = 2.44, x̄=1.48, p=0.020, CI=0.26-2.71) and occipital (right; OR = 2.18, x̄=1.32, p=0.018, CI=0.25-2.38/left; OR = 1.93, x̄=1.08, p=0.034, CI=0.086-2.06) regions were observed in the cognitively impaired group compared to the unimpaired group. the study evidence suggests that alterations in cerebral perfusion implicated in HIV-associated neurocognitive disorder may be possibly demonstrated using CTP, a readily available resource in most African countries saddled with the highest burden of HIV.

Exploring how visual working memory performance differs with response type

Visual working memory (VWM) holds visual information in mind to achieve task goals. Performance varies based on factors such as stimulus modality and distractor number. Several different tasks have been used to measure VWM, each resulting in differing estimates of capacity. Our goal was to examine how task demands can influence neurocognitive measures of VWM during early childhood. We administered two tasks to 4- and 5-year-olds that were identical during visual encoding and maintenance, only differing in type of response required during recall. In the change detection task (CD), a visual stimulus was compared with a VWM representation. In the cued-recall task (CR) a VWM representation was verbally labeled. Six canonical colors were used (red, orange, yellow, green, blue, purple). Neural data were collected from bilateral frontal, temporal, and parietal regions using functional near-infrared spectroscopy (fNIRS). VWM capacity was estimated to be higher in the change detection task (k4=2.48, k5=2.54) compared to the cued recall task (k4=1.13, k5=1.84) (p < .001). A network of frontal, temporal, and parietal regions was engaged across tasks. When comparing the tasks, CR showed increased activation in both the left supramarginal gyrus, F(1,35) = 11.642, p = 0.002, and the right superior parietal cortex, F(1,35) = 7.915, p = 0.008. Further, higher activation was observed for 5-year-olds during CR in right supramarginal gyrus, F(1,34) = 8.295, p = 0.007. During the CD task, right inferior frontal gyrus showed increased activation at set size two, F(2,64) = 3.643, p = 0.032, which is around capacity for this task. Thus, the CR task was observed to be more difficult than the CD task, and 5-year-olds showed increased activation in right parietal cortex during the CR task. These data suggest that children improve at engaging compensatory neural mechanisms during more challenging tasks involving the labelling of VWM representations.

Case of Dementia with Lewy Bodies in Young Patient with Family History

AbstractBackgroundDementia with Lewy bodies (DLB) is a neurodegenerative disorder characterized by cognitive decline, fluctuating attention, visual hallucinations, and sleep disorders, sometimes with signs of parkinsonism. Pathological evaluation reveals deposition of abnormally metabolized alpha‐synuclein, termed Lewy bodies. Clinical signs of DLB may be misdiagnosed in young patients with coexisting psychiatric disorders. A 43‐year‐old left‐handed man with a history of chronic paranoid schizophrenia, controlled with haloperidol, paroxetine, quetiapine, and clonazepam, presented with a 3‐year history of declining short‐term memory and concentration. He had a twin brother who was diagnosed with DLB and passed away at 40 years of age.MethodsThe patient was evaluated with serum laboratory tests to evaluate for metabolic abnormalities, infection, and heavy metal toxicity, including complete blood count, comprehensive metabolic panel, vitamin B12, folate, thyroid stimulating hormone, copper, and zinc. MRI Brain and subsequent PET‐FDG Brain were also conducted.ResultsThe results of the serum laboratory tests were all normal. MRI Brain was notable for bilateral parieto‐occipital atrophy and minimal chronic microvascular changes. PET‐FDG Brain revealed hypometabolism in bilateral parietal and occipital regions, with a cingulate island sign, indicative of advanced dementia with Lewy bodies.ConclusionDementia with Lewy bodies is a form of dementia that can sometimes present at an early age, and can be associated with psychological comorbidities and genetic risk factors. Further study of this case will include screening for mutations in the GBA gene, which encodes the enzyme beta‐glucocerebrosidease, which is the most frequent genetic association with dementia with Lewy bodies. Counseling on diagnosis and prognosis has been provided to the patient and his family, and he is being managed with rivastigmine 1.5mg twice daily to help slow down cognitive decline.