Posterior Limb Of The Internal Capsule Research Articles

Clinical and neuroimaging characteristics of primary lateral sclerosis with overlapping features of progressive supranuclear palsy.

Primary lateral sclerosis (PLS) is a neurodegenerative disorder that primarily affects the central motor system. In rare cases, clinical features of PLS may overlap with those of progressive supranuclear palsy (PSP). We investigate neuroimaging features that can help distinguish PLS with overlapping features of PSP (PLS-PSP) from PSP. Six patients with PLS-PSP were enrolled between 2019 and 2023. We compared their clinical and neuroimaging characteristics with 18 PSP-Richardson syndrome (PSP-RS) patients and 20 healthy controls. Magnetic resonance imaging, 18F-flortaucipir positron emission tomography (PET), quantitative susceptibility mapping, and diffusion tensor imaging tractography (DTI) were performed to evaluate eight brain regions of interest. Area under the receiver operating characteristic curve (AUROC) was calculated. Five of the six PLS-PSP patients (83.3%) were male. Median age at symptom onset was 61.5 (52.5-63) years, and all had mixed features of PLS and PSP. Volumes of the pallidum, caudate, midbrain, and cerebellar dentate were smaller in PSP-RS than PLS-PSP, providing good discrimination (AUROC = 0.75 for all). The susceptibilities in pallidum, midbrain, and cerebellar dentate were greater in PSP-RS compared to PLS-PSP, providing excellent discrimination (AUROC ≥ 0.90 for all). On DTI, fractional anisotropy (FA) in the posterior limb of the internal capsule from the corticospinal tract was lower in PLS-PSP compared to PSP-RS (AUROC = 0.86), but FA in the superior cerebellar peduncle was lower in PSP-RS (AUROC = 0.95). Pallidum flortaucipir PET uptake was greater in PSP-RS compared to PLS-PSP (AUROC = 0.74). Regional brain volume, tractography, and magnetic susceptibility, but not tau-PET, are useful in distinguishing PLS-PSP from PSP.

Decreased Cerebral Perfusion in Chronic Migraine: A Voxel-based Cerebral Blood Flow Analysis Using 3D Pseudo-continuous Arterial Spin Labeling.

A contrast agent-free approach would be preferable to the frequently used invasive approaches for evaluating cerebral perfusion in chronic migraineurs (CM). In this work, non-invasive quantitative volumetric perfusion imaging was used to evaluate alterations in cerebral perfusion in CM. We used conventional brain structural imaging sequences and 3D pseudo-continuous arterial spin labeling (3D PCASL) to examine thirteen CM patients and fifteen normal controls (NCs). The entire brain gray matter underwent voxel-based analysis, and the cerebral blood flow (CBF) values of the altered positive areas were retrieved to look into the clinical variables' significant correlation. Brain regions with the decreased perfusion were located in the left postcentral gyrus, bilateral middle frontal gyrus, left middle occipital gyrus, left superior parietal lobule, left medial segment of superior frontal gyrus, and right orbital part of the inferior frontal gyrus. White matter fibers with decreased perfusion were located in bilateral superior longitudinal tracts, superior corona radiata, external capsules, anterior and posterior limbs of the internal capsule, anterior corona radiata, inferior longitudinal fasciculus, and right corticospinal tract. However, the correlation analysis showed no significant correlation between the CBF value of the above positive brain regions with clinical variables (p > 0.05). The current study provided more useful information to comprehend the pathophysiology of CM and revealed a new insight into the neural mechanism of CM from the pattern of cerebral hypoperfusion.

The association between neuroimaging data and presence of lateropulsion after stroke

ABSTRACT Background Post-stroke lateropulsion is prevalent and has been associated with varied lesion locations, but existing imaging studies are limited by small participant cohorts. Evidence to guide lateropulsion rehabilitation is also limited. Improved understanding of lesion localization associated with lateropulsion post-stroke may inform more targeted intervention approaches. Objectives This study investigated the associations between stroke neuroimaging data and presence of lateropulsion at inpatient rehabilitation admission. Methods This prospective, observational study included participants aged ≥65 years, admitted for inpatient stroke rehabilitation. Using routinely collected clinical neuroimaging data, stroke type, location, and volume were reported, and their association with lateropulsion presence (Four-Point Pusher Score − 4PPS) at admission was explored. Results Of 144 included participants, 82 (56.9%) had lateropulsion (4PPS ≥1). Lateropulsion presence was univariately associated with hemorrhagic stroke (p = 0.002), frontal cortical involvement (OR = 2.17, 95%CI 1.02–6.46), and white matter involvement (OR = 2.45, 95%CI 1.24–4.85), particularly frontal white matter (p = 0.021). Lesions involving the posterior limb of the internal capsule (OR = 2.88, 95% CI 1.14–7.27) and those involving the entire thalamus (OR = 1.0, p = 0.03) were associated with lateropulsion presence. When stratified by stroke type, no specific location was significantly associated with lateropulsion presence in hemorrhagic strokes. Among participants with ischemic stroke, involvement of the pre-central gyrus (OR = 2.45, 95%CI 1.05–5.76), post-central gyrus (OR = 2.76, 95%CI 1.15–6.60), inferior parietal cortex (OR = 3.95, 95%CI 1.43–10.90), and supramarginal gyrus (OR = 3.73, 95%CI 1.25–11.13) were associated with lateropulsion presence. The stroke laterality and size were not significantly associated with lateropulsion presence. Conclusions The findings indicate a role of network disconnection in the post-stroke lateropulsion presence. Future, larger-cohort lesion-network mapping studies are recommended.

Be Alert to ALERD: Acute Leukoencephalopathy with Restricted Diffusion—Atypical Presentation of a Rare Case

AbstractAcute leukoencephalopathy with restricted diffusion (ALERD) is a novel entity observed in children with acute encephalopathy. It is characterized by diffusion restriction on magnetic resonance imaging (MRI), which can be the distinctive and sometimes the only imaging finding. Other routine MRI sequences may appear normal. ALERD can have infectious or noninfectious causes. In this case, we present a patient with infectious ALERD associated with influenza B virus. A 10-year-old boy presented to the emergency room with a brief history of fever and cough, followed by altered sensorium. He was irritable and ataxic. Neck stiffness was elicited upon examination. An MRI of the brain showed extensive symmetric diffusion restriction in the periventricular and deep white matter, corpus callosum, posterior limb of the internal capsule, and cerebral peduncles of both cerebral hemispheres. Cerebrospinal fluid study, blood and urine toxicology panels were noncontributory. The respiratory panel test was positive for influenza B. A diagnosis of infectious ALERD was made. Following treatment with steroids, intravenous immunoglobulin, antiglutamate agents, and supportive measures, he showed clinical and radiological improvement. The reporting of ALERD has risen in recent years due to its increased detection using MRI. Diffusion-weighted image plays the key role in the final diagnosis. Supportive care and prompt treatment of seizures are very important for better outcome. Follow-up imaging is also required to assess reappearance of white matter edema and development of cerebral atrophy or gliosis.

Dominant CST3 variants cause adult onset leukodystrophy without amyloid angiopathy.

Leukodystrophies are rare genetic white matter disorders that have been regarded as mainly occurring in childhood. Recent years altered this perception, as a growing number of leukodystrophies was described to have an onset at adult ages. Still, many adult patients presenting with white matter changes remain without a specific molecular diagnosis. We describe a novel adult onset leukodystrophy in 16 patients from eight families carrying one of four different stop-gain or frameshift dominant variants in the CST3 gene. Clinical and radiological features differ markedly from the previously described Icelandic Cerebral Amyloid Angiopathy that was found in patients carrying p.Leu68Asn substitution in CST3. The clinical phenotype consists of recurrent episodes of hemiplegic migraine associated with transient unilateral focal deficits and slowly progressing motor symptoms and cognitive decline in mid-old adult ages. In addition, in some cases acute onset clinical deterioration led to a prolonged episode with reduced consciousness and even early death. Radiologically, pathognomonic changes are found at typical predilection sites involving the deep cerebral white matter sparing a periventricular and directly subcortical rim, the middle blade of corpus callosum, posterior limb of the internal capsule, middle cerebellar peduncles, cerebral peduncles, and specifically the globus pallidus. Histopathologic characterization in two autopsy cases did not reveal angiopathy, but instead micro- to macrocystic degeneration of the white matter. Astrocytes were activated at early stages and later on displayed severe degeneration and loss. In addition, despite loss of myelin, elevated numbers of partly apoptotic oligodendrocytes were observed. A structural comparison of the variants in CST3 suggests that specific truncations of Cystatin C result in an abnormal function, possibly by rendering the protein more prone to aggregation. Future studies are required to confirm the assumed effect on the protein and to determine pathophysiologic downstream events at the cellular level.

Alterations in the white matter structure of major depressive disorder patients and their link to childhood trauma.

Major Depressive Disorder (MDD) is significantly influenced by childhood trauma (CT), affecting brain anatomy and functionality. Despite the unique disease trajectory in MDD patients with CT, the underlying neurobiological mechanisms remain unclear. Our objective is to investigate CT's impact on the white matter structure of the brain in patients with MDD. This research employed tract-based spatial statistics (TBSS) to detect variations between groups in Fractional Anisotropy (FA) throughout the whole brain in 71 medication-free MDD patients and 97 HCs. Participants filled out the Childhood Trauma Questionnaire (CTQ) and assessments for depression and anxiety symptoms. The relationship between FA and CTQ scores was explored with partial correlation analysis, adjusting for factors such as age, gender, educational background, and length of illness. Compared to HCs, the MDD group showed decreased FA values in the right posterior limb of the internal capsule (PLIC), the inferior fronto-occipital fasciculus (IFOF), and bilateral superior longitudinal fasciculus (SLF). Simple effects analysis revealed that compared to HC-CT, the MDD-CT group demonstrated decreased FA values in right PLIC, IFOF, and bilateral SLF. The MDD-nCT group showed decreased FA values in right PLIC and IFOF compared to HC-nCT. The total scores and subscale scores of CTQ were negatively correlated with the FA in the right SLF. The right SLF may potentially be influenced by CT during the brain development of individuals with MDD. These results enhance our knowledge of the role of the SLF in the pathophysiology of MDD and the neurobiological mechanisms by which CT influences MDD.

Neuropathological characteristics of abnormal white matter functional signaling in adolescents with major depression.

Major depression disorder (MDD) constitutes a significant mental health concern. Epidemiological surveys indicate that the lifetime prevalence of depression in adolescents is much higher than that in adults, with a corresponding increased risk of suicide. In studying brain dysfunction associated with MDD in adole-scents, research on brain white matter (WM) is sparse. Some researchers even mistakenly regard the signals generated by the WM as noise points. In fact, studies have shown that WM exhibits similar blood oxygen level-dependent signal fluctuations. The alterations in WM signals and their relationship with disease severity in adolescents with MDD remain unclear. To explore potential abnormalities in WM functional signals in adolescents with MDD. This study involved 48 adolescent patients with MDD and 31 healthy controls (HC). All participants were assessed using the Patient Health Questionnaire-9 Scale and the mini international neuropsychiatric interview (MINI) suicide inventory. In addition, a Siemens Skyra 3.0T magnetic resonance scanner was used to obtain the subjects' image data. The DPABI software was utilized to calculate the WM signal of the fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity, followed by a two-sample t-test between the MDD and HC groups. Independent component analysis (ICA) was also used to evaluate the WM functional signal. Pearson's correlation was performed to assess the relationship between statistical test results and clinical scales. Compared to HC, individuals with MDD demonstrated a decrease in the fALFF of WM in the corpus callosum body, left posterior limb of the internal capsule, right superior corona radiata, and bilateral posterior corona radiata [P < 0.001, family-wise error (FWE) voxel correction]. The regional homogeneity of WM increased in the right posterior limb of internal capsule and left superior corona radiata, and decreased in the left superior longitudinal fasciculus (P < 0.001, FWE voxel correction). The ICA results of WM overlapped with those of regional homo-geneity. The fALFF of WM signal in the left posterior limb of the internal capsule was negatively correlated with the MINI suicide scale (P = 0.026, r = -0.32), and the right posterior corona radiata was also negatively correlated with the MINI suicide scale (P = 0.047, r = -0.288). Adolescents with MDD involves changes in WM functional signals, and these differences in brain regions may increase the risk of suicide.

Diffusion kurtosis imaging of brain white matter alteration in patients with coronary artery disease based on the TBSS method.

The aim of our study was to examine the alterations in microstructure in patients with coronary artery disease (CAD) and cognitive impairment (CI) using diffusion kurtosis imaging (DKI). Additionally, we aimed to investigate the potential correlation between DKI parameters and cognitive function. A total of 28 CAD patients and 30 healthy controls (HC) were prospectively enrolled in our study. All participants underwent routine and diffusion sequences of head imaging. DKE software was utilized to generate various diffusion kurtosis imaging parameters (DKI), including kurtosis fractional anisotropy (KFA), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), fractional anisotropy (FA), and mean diffusivity (MD). Nonparametric tests were conducted using tract-based spatial statistics (TBSS) to compare the parameter values between the two groups. The parameter values of the significantly different fiber tracts were extracted and correlated with the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. Compared to the HC group, patients with coronary artery disease exhibited significant reductions in FA values in the bilateral Superior corona radiata, bilateral Anterior corona radiata, bilateral Posterior corona radiata, corpus callosum, left Posterior thalamic radiation, right Posterior limb of internal capsule, Anterior limb of internal capsule, and Cerebral peduncle, as well as in the left Superior longitudinal fasciculus. Additionally, KFA values decreased in the bilateral Anterior corona radiata, bilateral Anterior limb of internal capsule, and Genu of the corpus callosum. The MK values decreased in the right Posterior corona radiata, Retrolenticular part of the internal capsule, Posterior thalamic radiation (including optic radiation), Superior longitudinal fasciculus, and left Posterior thalamic radiation (including optic radiation). Moreover, the RK values decreased in the bilateral Retrolenticular part of the internal capsule, right Posterior thalamic radiation (including optic radiation), and Superior longitudinal fasciculus, as well as in the left Superior longitudinal fasciculus and Posterior thalamic radiation (including optic radiation) (p < 0.01, TFCE corrected), while no significant differences were observed in other parameter values (p > 0.01, TFCE corrected). The FA values of the right posterior limb of the internal capsule (r = 0.610, p = 0.001) and the right cerebral peduncle (r = 0.622, p < 0.001) were positively correlated with MMSE scores. Additionally, a significant correlation between kurtosis and diffusion coefficient parameters (FA and KFA) was observed. CAD patients showed radial shrinkage and complexity of brain white matter microstructure. Whole-brain white matter analysis based on TBSS DKI can objectively reflect the characteristics of white matter damage in CAD patients, providing a basis for the auxiliary diagnosis of CAD with CI.

Dexterity in the Acute Phase of Stroke: Impairments and Neural Substrates

Background Stroke can impair manual dexterity, leading to loss of independence following incomplete recovery. Enhancing our understanding of dexterity impairment may improve neurorehabilitation. Objectives The study aimed to measure dexterity components in acute stroke patients with and without hand motor deficits, compare them to those of healthy controls (HC), and to explore the neural substrates involved in specific components of dexterity. Methods We used the Dextrain Manipulandum to quantify fine finger force control, finger selection accuracy, coactivation, and reaction time (RT). Dexterity was evaluated twice (2 days apart) in 74 patients and 14 HC. Voxel-Lesion-Symptom-Mapping (VLSM) was used to analyze the relationship between tissue damage and dexterity. Results. Due to severe paresis or fatigue, 24 patients could not perform these tasks. In 50 patients (included 4.6 ± 3.3 days post-stroke), finger force control improved (P < .001), as it did in HC (P = .03) who performed better than patients on both evaluations. Accuracy of finger selection did not improve significantly in any group, but the HC performed better on both evaluations. Unexpectedly, coactivation was better in patients than in HC at D3 (P = .03). There were no between-group differences in RT. VLSM showed that damage to the superior temporal gyrus (STG) impaired finger force control while damage to the posterior limb of the internal capsule (PLIC) impaired finger selectivity. Conclusions Acute stroke affecting the STG or PLIC impaired selective components of dexterity. Patients with mild to moderate impairment showed better finger force control and accuracy selection within 48 hours, suggesting the feasibility of detecting early dexterity improvements.

Longitudinal assessment of chemotherapy-induced brain connectivity changes in cerebral white matter and its correlation with cognitive functioning using the GQI.

Breast cancer was the most prevalent type of cancer and had the highest incidence rate among women worldwide. The wide use of adjuvant chemotherapy might have a detrimental effect on the human brain and result in chemotherapy-related cognitive impairment (CICI) among breast cancer patients. Furthermore, prior to chemotherapy, patients reported cancer-related cognitive impairment (CRCI), which might be due to physiological factors or mood symptoms. The present longitudinal study aimed to investigate microstructural and macroscale white matter alterations by generalized q-sampling imaging (GQI). The participants were categorized into a pre-chemotherapy group (BB) if they were diagnosed with primary breast cancer and an age-matched noncancer control group (HC). Some participants returned for follow-up assessment. In the present follow up study, 28 matched pairs of BB/BBF (follow up after chemotherapy) individuals and 28 matched pairs of HC/HCF (follow up) individuals were included. We then used GQI and graph theoretical analysis (GTA) to detect microstructural alterations in the whole brain. In addition, we evaluated the relationship between longitudinal changes in GQI indices and neuropsychological tests as well as psychiatric comorbidity. The results showed that disruption of white matter integrity occurred in the default mode network (DMN) of patients after chemotherapy, such as in the corpus callosum (CC) and middle frontal gyrus (MFG). Furthermore, weaker connections between brain regions and lower segregation ability were observed in the post-chemotherapy group. Significant correlations were observed between neuropsychological tests and white matter tracts of the CC, MFG, posterior limb of the internal capsule (PLIC) and superior longitudinal fasciculus (SLF). The results provided evidence of white matter alterations in breast cancer patients, and they may serve as potential imaging markers of cognitive changes. In the future, the study may be beneficial to create and evaluate strategies designed to maintain or improve cognitive function in breast cancer patients undergoing chemotherapy.

The effect of intrathecal recombinant arylsulfatase A therapy on structural brain magnetic resonance imaging in children with metachromatic leukodystrophy.

This study aimed to evaluate the effect of intrathecal (IT) recombinant human arylsulfatase A (rhASA) on magnetic resonance imaging (MRI)-assessed brain tissue changes in children with metachromatic leukodystrophy (MLD). In total, 510 MRI scans were collected from 12 intravenous (IV)rhASA-treated children with MLD, 24 IT rhASA-treated children with MLD, 32 children with untreated MLD, and 156 normally developing children. Linear mixed models were fitted to analyze the time courses of gray matter (GM) volume and fractional anisotropy (FA) in the posterior limb of the internal capsule. Time courses for demyelination load and FA in the centrum semiovale were visualized using locally estimated scatterplot smoothing regression curves. All assessed imaging parameters demonstrated structural evidence of neurological deterioration in children with MLD. GM volume was significantly lower at follow-up (median duration, 104 weeks) in IV rhASA-treated versus IT rhASA-treated children. GM volume decline over time was steeper in children receiving low-dose (10 or 30 mg) versus high-dose (100 mg) IT rhASA. Similar effects were observed for demyelination. FA in the posterior limb of the internal capsule showed a higher trend over time in IT rhASA-treated versus children with untreated MLD, but FA parameters were not different between children receiving the low dosesversus those receiving the high dose. GM volume in IT rhASA-treated children showed a strong positive correlation with 88-item Gross Motor Function Measure score over time. In some children with MLD, IT administration of high-dose rhASA may delay neurological deterioration (assessed using MRI), offering potential therapeutic benefit.

Deep learning-based diffusion tensor image generation model: a proof-of-concept study

This study created an image-to-image translation model that synthesizes diffusion tensor images (DTI) from conventional diffusion weighted images, and validated the similarities between the original and synthetic DTI. Thirty-two healthy volunteers were prospectively recruited. DTI and DWI were obtained with six and three directions of the motion probing gradient (MPG), respectively. The identical imaging plane was paired for the image-to-image translation model that synthesized one direction of the MPG from DWI. This process was repeated six times in the respective MPG directions. Regions of interest (ROIs) in the lentiform nucleus, thalamus, posterior limb of the internal capsule, posterior thalamic radiation, and splenium of the corpus callosum were created and applied to maps derived from the original and synthetic DTI. The mean values and signal-to-noise ratio (SNR) of the original and synthetic maps for each ROI were compared. The Bland–Altman plot between the original and synthetic data was evaluated. Although the test dataset showed a larger standard deviation of all values and lower SNR in the synthetic data than in the original data, the Bland–Altman plots showed each plot localizing in a similar distribution. Synthetic DTI could be generated from conventional DWI with an image-to-image translation model.

Quantitative Magnetic Resonance Imaging for Neurodevelopmental Outcome Prediction in Neonates Born Extremely Premature-An Exploratory Study.

Neonates born at < 28weeks of gestation are at risk for neurodevelopmental delay. The aim of this study was to identify quantitative MR-based metrics for the prediction of neurodevelopmental outcomes in extremely preterm neonates. T1-/T2-relaxation times (T1R/T2R), ADC, and fractional anisotropy (FA) of the left/right posterior limb of the internal capsule (PLIC) and the brainstem were determined at term-equivalent ages in asample of extremely preterm infants (n = 33). Scores for cognitive, language, and motor outcomes were collected at one year corrected-age. Pearson's correlation analyses detected relationships between quantitative measures and outcome data. Stepwise regression procedures identified imaging metrics to estimate neurodevelopmental outcomes. Cognitive outcomes correlated significantly with T2R (r = 0.412; p = 0.017) and ADC (r = -0.401; p = 0.021) (medulla oblongata). Furthermore, there were significant correlations between motor outcomes and T1R (pontine tegmentum (r = 0.346; p = 0.049), midbrain (r = 0.415; p = 0.016), right PLIC (r = 0.513; p = 0.002), and left PLIC (r = 0.504; p = 0.003)); T2R (right PLIC (r = 0.405; p = 0.019)); ADC (medulla oblongata (r = -0.408; p = 0.018) and pontine tegmentum (r = -0.414; p = 0.017)); and FA (pontine tegmentum (r = -0.352; p = 0.045)). T2R/ADC (medulla oblongata) (cognitive outcomes (R2 = 0.296; p = 0.037)) and T1R (right PLIC)/ADC (medulla oblongata) (motor outcomes (R2 = 0.405; p = 0.009)) revealed predictive potential for neurodevelopmental outcomes. There are relationships between relaxometry‑/DTI-based metrics determined by neuroimaging near term and neurodevelopmental outcomes collected at one year of age. Both modalities bear prognostic potential for the prediction of cognitive and motor outcomes. Thus, quantitative MRI at term-equivalent ages represents apromising approach with which to estimate neurologic development in extremely preterm infants.

Lead Encephalopathy in a 73-year-old Man Manifesting as Acute Disturbance of Consciousness with a Unique Magnetic Resonance Imaging Appearance.

A 73-year-old man was admitted with Cheyne-Stokes respiration and progressive disturbance of consciousness over the course of a month. Cranial magnetic resonance imaging revealed signs suggestive of angioedema in the posterior limb of the internal capsule, external capsule, and subcortical white matter. Acute lead encephalopathy was diagnosed based on abnormally high plasma lead levels. After methylprednisolone pulse therapy followed by chelation therapy, the patient fully recovered. In this case, the angioedema with a distinctive magnetic resonance imaging appearance was attributed to the cytotoxic effects of lead on the nervous system, which responded well to methylprednisolone pulse therapy.

Diagnostic MR imaging features of hypomyelination of early myelinating structures: A case report.

Hypomyelination of early myelinating structures (HEMS) has recently been defined as a new genetic disorder accompanied by clinical and MR imaging characteristics. However, no studies have focused on diffusion-weighted imaging (DWI) findings of HEMS. We would like to propose a "sheep sign," which is formed by DWI hyperintensity in the medial medullary lamina along with alternating high-low-high (HLH) intensity stripes in the posterior limb of the internal capsule. We believe the presence of the "sheep sign" on DWI in combination with alternating HLH intensity stripes may be a valuable tool for diagnosing HEMS.

Abnormal white and gray matter functional connectivity is associated with cognitive dysfunction in presbycusis.

Presbycusis is characterized by high-frequency hearing loss and is closely associated with cognitive decline. Previous studies have observed functional reorganization of gray matter in presbycusis, but the information transmission between gray matter and white matter remains ill-defined. Using resting-state functional magnetic resonance imaging, we investigated differences in functional connectivity (GM-GM, WM-WM, and GM-WM) between 60 patients with presbycusis and 57 healthy controls. Subsequently, we examined the correlation between these connectivity differences with high-frequency hearing loss as well as cognitive impairment. Our results revealed significant alterations in functional connectivity involving the body of the corpus callosum, posterior limbs of the internal capsule, retrolenticular region of the internal capsule, and the gray matter regions in presbycusis. Notably, disrupted functional connectivity was observed between the body of the corpus callosum and ventral anterior cingulate cortex in presbycusis, which was associated with impaired attention. Additionally, enhanced functional connectivity was found in presbycusis between the internal capsule and the ventral auditory processing stream, which was related to impaired cognition in multiple domains. These two patterns of altered functional connectivity between gray matter and white matter may involve both bottom-up and top-down regulation of cognitive function. These findings provide novel insights into understanding cognitive compensation and resource redistribution mechanisms in presbycusis.

Image Findings as Predictors of Fall Risk in Patients with Cerebrovascular Disease.

This study examined computed tomography findings in patients with cerebrovascular disease and determined predictors for falls. Images of the head were divided into 13 regions, and the relationships between computed tomography findings and the presence or absence of falls were investigated. A total of 138 patients with cerebrovascular disease (66% men, aged 73.8 ± 9.6 years) were included. A comparison between the fall and non-fall groups revealed a significant difference in the total functional independence measure scores and imaging findings at admission. Logistic regression analysis showed that the thalamus (p < 0.001), periventricular lucency (p < 0.001), lateral hemisphere room enlargement (p < 0.05), and age (p < 0.05) were related to the presence or absence of falls. For the 42 patients with cerebral hemorrhage, the thalamus (p < 0.01), periventricular lucency (p < 0.05), lateral ventricle vicinity (p < 0.05), and posterior limb of the internal capsule (p < 0.05) were extracted as factors related to the presence or absence of falls. For the 96 patients with cerebral infarction, the thalamus (p < 0.001), periventricular lucency (p < 0.01), and anterior limb of the internal capsule (p < 0.05) were extracted as factors related to the presence or absence of falls. This study found a relationship between the thalamus, lateral ventricle enlargement, periventricular lucency, and falls. Fall prognosis can potentially be predicted from computed tomography findings at admission.

Myelination of preterm brain networks at adolescence

Prematurity and preterm stressors severely affect the development of infants born before 37 weeks of gestation, with increasing effects seen at earlier gestations. Although preterm mortality rates have declined due to the advances in neonatal care, disability rates, especially in middle-income settings, continue to grow. With the advances in MR imaging technology, there has been a focus on safely imaging the preterm brain to better understand its development and discover the brain regions and networks affected by prematurity. Such studies aim to support interventions and improve the neurodevelopment of preterm infants and deliver accurate prognoses. Few studies, however, have focused on the fully developed brain of preterm born infants, especially in extremely preterm subjects. To assess the long-term effect of prematurity on the adult brain, myelin related biomarkers such as myelin water fraction and g-ratio are measured for a cohort of 19-year-old extremely preterm born subjects. Using multi-modal imaging techniques that combine T2 relaxometry and neurite density information, the results show that specific brain regions associated with white matter injuries due to preterm birth, such as the posterior limb of the internal capsule and corpus callosum, are still less myelinated in adulthood. Furthermore, a weak positive relationship between myelin water fraction values and Full-Scale Intelligence Quotient (FSIQ) scores was found in multiple brain regions previously defined as less myelinated in the Extremely Preterm (EPT) cohort. These findings might suggest altered connectivity in the adult preterm brain and explain differences in cognitive outcomes.

Free water alterations in different inflammatory subgroups in schizophrenia

BackgroundAccumulating evidence suggests that inflammatory dysregulation both in blood and the brain is implicated in the pathogenesis of schizophrenia. Alterations in peripheral cytokines are not evident in all patients and there may be discrete altered inflammatory subgroups in schizophrenia. Recent studies using a novel and in vivo free-water imaging to detect inflammatory processes, have shown increased free water in white matter in schizophrenia. However, no studies to date have investigated the free water alterations in different inflammatory subgroups in schizophrenia. MethodsForty-four patients with schizophrenia and 49 controls were recruited. The serum levels of interleukin-1 beta (IL-1β), IL-6, IL-10, and IL-12p70 were measured and used for cluster analysis with K-means and hierarchical algorithms. Diffusion tensor imaging (DTI) images were collected for all participants and voxel-wise free water and fractional anisotropy of tissue (FA-t) were compared between groups with Randomise running in FSL. Partial correlation analysis was employed to explore the association of the peripheral cytokine levels with free water. ResultsWe identified two statistically quantifiable discrete subgroups of patients based on the cluster analysis of cytokine measures. The peripheral levels of IL-1β (P < 0.001), IL-10 (P = 0.041), and IL-12p70 (P < 0.001) showed significant differences between the two different inflammatory subgroups. In the inflammatory subgroup with a predominantly higher IL-1β level, increased free water values in white matter were found mainly in the left posterior limb of the internal capsule, posterior corona radiata, and partly in the left sagittal stratum. These affected areas did not overlap with the regions that showed significant free water differences between patients and healthy controls. In the inflammatory subgroup with lower IL-1β levels, peripheral IL-1β was significantly associated with free water values in white matter while no such association was detected in the patient group. ConclusionsLocalized free water differences were demonstrated between the two identified inflammatory subgroups in our data, and free water appears to be a feasible in vivo neuroimaging biomarker guiding the target of inflammatory intervention and development of new therapeutic strategies in an individualized manner in schizophrenia.

Abstract 352: Automated Deep Learning Algorithms Outperforms Gray-White Matter Ratio for the Detection of Severe Cerebral Edema in Cardiac Arrest Survivors

Introduction: Significant knowledge gaps remain in predicting neurological outcomes for comatose cardiac arrest survivors. Severe cerebral edema (SCE) development offers an objective imaging surrogate for neurologic injury. Aim: We have previously shown that deep learning (DL) algorithms can detect SCE on CT. We aim to determine whether our model will perform equivalently on an independent external cohort. We also compared the performance of the DL model with one based on the gray-white matter ratio (GWR) for detecting SCE. Method: We retrospectively analyzed CT data (299 patients, 55±17 years, 71% male, 65 with SCE). Scans whose radiology reports described herniation or more than minimal ventricular effacement were classified as SCE. Datasets were randomly split (balancing for SCE) into training, validation, and testing cohorts. We used transfer learning with a 3D residual neural network framework to train our model. The probability of SCE was calculated. We applied the model to an external cohort (151 patients, 58±17 years, 63% male, 29 with SCE). Regions of interest (ROIs) were drawn in the caudate nuclei (CN) and posterior limbs of the internal capsule (PLIC). GWR was calculated as the ratio of mean x-ray attenuation values in the CN and the PLIC. Areas under the receiver operating curves (AUC) for the DL and GWR models were compared (bootstrap test). Results: The optimal model achieved comparable accuracies for the internal validation cohort (84% [95% CI: 78-89%], n=60) and reserved test cohort (83% [95% CI: 76 to 89%], n=61). The external cohort consisted of 175 scans. The model’s accuracy was 87% [95% CI: 81% to 91%], comparable to the results from the testing and internal validation cohorts. AUC for DL was significantly greater than for GWR (92% vs. 73%, P=0.001) (see Figure). Conclusions: Our result shows that deep transfer learning is a promising method to automate SCE detection on CT images and outperforms GWR measurements.