Deep White Matter Research Articles

Characterizing T1 in the fetal brain and placenta over gestational age at 0.55T.

T1 mapping and T1-weighted contrasts have a complimentary but currently under utilized role in fetal MRI. Emerging clinical low field scanners are ideally suited for fetal T1 mapping. The advantages are lower T1 values which results in higher efficiency and reduced field inhomogeneities resulting in a decreased requirement for specialist tools. In addition the increased bore size associated with low field scanners provides improved patient comfort and accessibility. This study aims to demonstrate the feasibility of fetal brain T1 mapping at 0.55T. An efficient slice-shuffling inversion-recovery echo-planar imaging (EPI)-based T1-mapping and postprocessing was demonstrated for the fetal brain at 0.55T in a cohort of 38 fetal MRI scans. Robustness analysis was performed and placental measurements were taken for validation. High-quality T1 maps allowing the investigation of subregions in the brain were obtained and significant correlation with gestational age was demonstrated for fetal brain T1 maps ( ) as well as regions-of-interest in the deep gray matter and white matter. Efficient, quantitative T1 mapping in the fetal brain was demonstrated on a clinical 0.55T MRI scanner, providing foundations for both future research and clinical applications including low-field specific T1-weighted acquisitions.

Non‐invasive Assessment of Cerebral Hemodynamics Using Resting‐State Functional Magnetic Resonance Imaging in Multiple Sclerosis and Age‐Related White Matter Lesions

ABSTRACTPerfusion changes in white matter (WM) lesions and normal‐appearing brain regions play an important pathophysiological role in multiple sclerosis (MS). However, most perfusion imaging methods require exogenous contrast agents, the repeated use of which is discouraged. Using resting‐state functional MRI (rs‐fMRI), we aimed to investigate differences in perfusion between white matter lesions and normal‐appearing brain regions in MS and healthy participants. A total of 41 MS patients and 41 age‐ and sex‐matched healthy participants received rs‐fMRI, from which measures of cerebral hemodynamics and oxygenation were extracted and compared across brain regions and study groups using within‐ and between‐group nonparametric tests, linear mixed models, and robust multiple linear regression. We found longer blood arrival times and lower blood volumes in lesions than in normal‐appearing WM. Higher blood volumes were found in MS patients' deep WM lesions compared to healthy participants, and blood arrival time was more delayed in MS patients' deep WM lesions than in healthy participants. Delayed blood arrival time in the cortical grey matter was associated with greater cognitive impairment in MS patients. Perfusion imaging using rs‐fMRI is useful for WM lesion characterization. rs‐fMRI‐based blood arrival times and volumes are associated with cognitive function.

Dopamine transporter availability based on white matter hyperintensity during early to mid-stage Parkinson's disease and multiple system atrophy: a case control study.

To evaluate the association of white matter hyperintensity (WMH) with dopamine transporter (DAT) availability in patients with early to mid-stage parkinson's disease (PD) and multiple system atrophy (MSA). The clinical and imaging data of 55 patients were collected, including 38 PD and 17 MSA patients and the clinical features of the two groups were compared. DAT specific binding ratio (SBR) were compared between severe and non-severe WMH groups, and between PD and MSA groups. The relationships of WMH with DAT availability and basic clinical characteristics were analyzed. Multiple linear regression analysis showed that age was the only significant variable showing correlation WMH. Age was the only clinical variable significantly correlated with WMH in PD patients (coefficient for periventricular white matter hyperintensity: 0.430, P = 0.007; coefficient for deep white matter hyperintensity: 0.381, P = 0.018). There was no significant correlation between WMH and SBRs and age in MSA patients. The SBR of the caudate nucleus and anterior putamen was significantly lower in the severe WMH group of patients than in the non-severe WMH group (P < 0.05). The values of the caudate nucleus, anterior putamen, and anterior putamen/posterior putamen were significantly lower in PD patients with than without severe WMH (P < 0.05), and the damage to the striatal DAT in MSA patients with severe WMH was similar to the non-severe patients (P>0.05). Patients with PD and a high WMH score had lower DAT availability. WMH affected the availability of DAT in patients with early to mid-stage PD compared to MSA.

Microstructural Alterations of Gray and White Matter in Active Young Boxers with Sports-Related Concussions.

The existing research on the microstructural alterations associated with sport-related concussions (SRCs) has primarily focused on deep white matter (DWM) fibers, while the impact of SRCs on the superficial white matter (SWM) and gray matter (GM) remains unknown. This study aimed to characterize the altered metrics obtained from neurite orientation dispersion and density imaging (NODDI) in boxers with SRCs, and thereby determine whether distinct regional patterns of microstructural alterations can offer valuable insights for accurate diagnosis and prognosis. Concussed boxers (n = 56) and healthy controls (HCs) with typically developing (n = 72) underwent comprehensive neuropsychological assessment and magnetic resonance imaging (MRI) examinations. The tract-based spatial statistics approach was used to investigate alterations in the DWM and SWM, while the gray matter-based spatial statistics approach was used to examine changes in the GM. The median time from the last SRC to MRI in the SRC group was 33.5 days (interquartile range, 45.25). In comparison with HCs, the SRC group exhibited lower fractional anisotropy (FA), neurite density index (NDI), and isotropic volume fraction (ISOVF), as well as higher mean diffusivity, axial diffusivity (AD), and radial diffusivity in both the DWM and SWM. Moreover, the SRC group exhibited lower FA, NDI, orientation dispersion index, and ISOVF in the GM, as well as higher AD. The altered microstructure of both gray and white matter was found to be associated with deficits in working memory and vocabulary memory among boxers. In addition to characterizing the DWM impairment, NODDI further elucidated the effects of SRCs on the microstructure of GM and SWM, offering a reliable imaging biomarker for SRC diagnosis and shedding light on the pathophysiological changes underlying SRCs.

Comparison of Syn T2-FLAIR and Syn DIR with conventional T2-FLAIR in displaying white matter hyperintensities in migraine patients.

Young migraine patients often present with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI). This study aimed to analyze whether synthetic (Syn) T2-FLAIR and Syn double inversion recovery (DIR) can reveal WMHs more clearly and sensitively than conventional T2-FLAIR. Conventional MRI and Syn MRI data from 50 young migraine patients were analyzed prospectively. WMHs in each anatomical region (periventricular, deep white matter, and juxtacortical) were recorded separately. The differences in the clarity of lesion boundaries and the number of lesions displayed in the three sequences in the same anatomical region were analyzed. A total of 80 (periventricular area, 15; deep white matter, 31; juxtacortical area, 34), 163 (17, 50, 96), and 134 (18, 42, 74) lesions were observed with conventional T2-FLAIR, Syn T2-FLAIR, and Syn DIR, respectively. Syn T2-FLAIR and Syn DIR can show lesions more clearly than conventional T2-FLAIR (all P < 0.001). There was no significant difference in the number of lesions observed in the periventricular white matter among the three sequences (P = 0.159, 0.083, 0.322). Syn T2-FLAIR and Syn DIR can detect more lesions in the deep white matter than conventional T2-FLAIR (P < 0.001, P = 0.006). Syn T2-FLAIR revealed more lesions in the juxtacortical white matter than Syn DIR and conventional T2-FLAIR imaging (all P < 0.001), and conventional T2-FLAIR revealed the fewest lesions (P < 0.001). Syn T2-FLAIR and Syn DIR sequences can clearly and sensitively detect WMHs, especially in deep and juxtacortical white matter areas.

Choroid Plexus Volume in Rural Chinese Older Adults: Distribution and Association With Cardiovascular Risk Factors and Cerebral Small Vessel Disease.

The choroid plexus (CP) is involved in neurodegenerative diseases. However, the association of CP with cardiovascular risk factors and cerebral small vessel disease in older adults remains unclear. This population-based study included 1263 participants (60 years and older) from the MIND-China (Multimodal Interventions to Delay Dementia and Disability in Rural China) substudy (2018-2020), of which 111 individuals completed diffusion tensor imaging examination. CP volume was automatically segmented. White matter hyperintensities (WMHs), enlarged perivascular spaces (EPVS), cerebral microbleeds, and lacunes were assessed following the Standards for Reporting Vascular Changes on Neuroimaging 1. Peak width of skeletonized mean diffusivity and free water were derived from diffusion tensor imaging images. We used linear regression models to evaluate the association between CP volume and cardiovascular risk factors, WMH volumes, and diffusion tensor imaging metrics, and logistic regression models to examine the association between CP volume and EPVS, cerebral microbleeds, and lacunes. The CP volume increased with age (P<0.001). Men (β coefficient=0.47 [95% CI, 0.29-0.64]) and participants with diabetes (β coefficient=0.16 [95% CI, 0.01-0.31]) had larger CP volumes than women and individuals without diabetes, respectively (P<0.05). Greater CP volume was significantly associated with larger total and periventricular WMH volumes and moderate to severe EPVS in basal ganglia (P<0.05) but not with deep WMHs, EPVS in centrum semiovale, lacunes, or cerebral microbleeds. In the diffusion tensor imaging subsample, enlarged CP was significantly associated with higher peak width of skeletonized mean diffusivity and free water of periventricular and deep white matter (P<0.05). An enlarged CP is associated with larger global and periventricular WMH volume and higher likelihoods of EPVS in basal ganglia and impaired white matter integrity, suggesting that an enlarged CP may represent a precursor of cerebral small vessel disease.

Neuroradiologic, clinic and genetic characterization of cerebellar heterotopia: a pediatric multicentric study.

Background and purpose:Cerebellar heterotopia (CH) is a neuroradiological abnormality poorly reported and investigated in the literature. It can be observed as an isolated finding, but it has been mainly reported in the context of cerebellar dysgenesis and in syndromic conditions. The aim of this study is to provide a comprehensive neuroradiological, clinical, and genetic characterization of a cohort of pediatric patients with cerebellar heterotopia.Materials and methods:Patients with a diagnosis of CH were systematically selected from the neuroimaging databases of the four Italian Centers participating in this retrospective study. For each patient, information regarding demographic, clinical, genetic and neuroradiological data were collected.Results:Thirty-two pediatric patients were recruited and subdivided into two groups: patients with isolated CH and/or cerebellar malformations (n= 18) and patients with CH associated with cerebral malformations (n=14). Isolated CH consistently showed a peripheral subcortical localization in the inferior portion of cerebellar hemispheres, with either unilateral or bilateral distribution. Ten patients belonging to the second group had a diagnosis of CHARGE syndrome, and their nodules of CH were mainly but not exclusively bilateral, symmetric, located in the peripheral subcortical zone and in the inferior portion of the cerebellar hemispheres; the remaining 4 patients of the second group, showed either bilateral or unilateral CH, located in both peripheral cortex and deep white matter and in the superior and inferior portions of cerebellum. Patients with isolated CH showed high prevalence of language development delay; neurodevelopmental disorders were the most represented clinical diagnoses. Recurring features were behavioral problems and motor difficulties. A conclusive genetic diagnosis was found in 18/32 patients.Conclusions:We found distinctive neuroradiological patterns of CH. Genetic results raise the possibility of a correlation between cerebellar morphological and functional developmental disruption, underscoring the importance of CH detection and reporting to orient the diagnostic path.Abbreviations CH Cerebellar heterotopia; MRI Magnetic resonance imaging; CC Corpus callosum; ASD autism spectrum disorder; IVH inferior vermian hypoplasia.

PROLONGED SURVIVAL IN IDH-WILDTYPE GLIOBLASTOMA: CASE REPORTS, LITERATURE REVIEW AND CURRENT PERSPECTIVES OF MOLECULAR BEHAVIOR

Abstract AIMS Glioblastoma remains one of the most aggressive primary brain tumours, with a median survival of around 12 months despite advances in treatment. However, rare cases of long-term survival challenge this prognosis. The evaluation of age, tumour location, surgical approach and strategies, adjuvant therapy, and molecular behavior provides valuable prognostic and predictive information in patients with glioblastoma. METHOD We present a case report of two patients diagnosed with wild-type glioblastoma who have survived over 10 years post-primary surgery. A review of epidemiological data, preoperative and postoperative radiological reports, surgical approach, and histology reports were studied. Additionally, we review the current literature to explore current nuances in High-Grade Glioma Wild Type prognosis and potential future directions. Three major medical database engines, PubMed (Medline), Scopus (ELSEVIER), and Cochrane were used to conduct a thorough literature search. RESULTS Both patients underwent maximal safe resection followed by the Stupp Protocol, comprising adjuvant chemotherapy with temozolomide and radiotherapy. Our case report highlights two exceptional cases of prolonged survival in Glioblastoma patients, both under 51 years-old at the moment of diagnosis, early diagnosis with isolated lobar lesions, no compromise of deep white matter, and achieving maximal safe resection and functional independence. Molecular analysis revealed specific genetic in common, including IDH Wild Type, p53 mutation, retained ATRX expression, TERT mutation, and MGMT promoter methylation, consistent with a favourable prognosis. Moreover, patients without recurrence often exhibit distinct molecular profiles, such as MGMT promoter methylation, suggesting a potential subtype associated with prolonged survival. CONCLUSION Our case reports and literature review highlight the possibility of prolonged survival in Glioblastoma patients. The age, tumor location at the time of diagnosis, comprehensive treatment approaches, may contribute to improved outcomes. Molecular profiling, particularly assessing genetic mutations and MGMT promoter methylation, holds promise for identifying patients with a higher likelihood of prolonged survival.

Microangiopathy in temporal lobe epilepsy with diffusion MRI alterations and cognitive decline

White matter microvascular alterations in temporal lobe epilepsy (TLE) may be relevant to acquired neurodegenerative processes and cognitive impairments associated with this condition. We quantified microvascular changes, myelin, axonal, glial and extracellular-matrix labelling in the gyral core and deep temporal lobe white matter regions in surgical resections from 44 TLE patients with or without hippocampal sclerosis. We compared this pathology data with in vivo pre-operative MRI diffusion measurements in co-registered regions and neuropsychological measures of cognitive impairment and decline. In resections, increased arteriolosclerosis was observed in TLE compared to non-epilepsy controls (greater sclerotic index, p < 0.001), independent of age. Microvascular changes included increased vascular densities in some regions but uniformly reduced mean vascular size (quantified with collagen-4, p < 0.05–0.0001), and increased pericyte coverage of small vessels and capillaries particularly in deep white matter (quantified with platelet-derived growth factor receptorβ and smooth muscle actin, p < 0.01) which was more marked the longer the duration of epilepsy (p < 0.05). We noted increased glial numbers (Olig2, Iba1) but reduced myelin (MAG, PLP) in TLE compared to controls, particularly prominent in deep white matter. Gene expression analysis showed a greater reduction of myelination genes in HS than non-HS cases and with age and correlation with diffusion MRI alterations. Glial densities and vascular size were increased with increased MRI diffusivity and vascular density with white matter abnormality quantified using fixel-based analysis. Increased perivascular space was associated with reduced fractional anisotropy as well as age-accelerated cognitive decline prior to surgery (p < 0.05). In summary, likely acquired microangiopathic changes in TLE, including vascular sclerosis, increased pericyte coverage and reduced small vessel size, may indicate a functional alteration in contractility of small vessels and haemodynamics that could impact on tissue perfusion. These morphological features correlate with white matter diffusion MRI alterations and might explain cognitive decline in TLE.

Quantitative Analysis of White Matter Hyperintensities as a Predictor of 1-Year Risk for Ischemic Stroke Recurrence.

This study evaluates the role of quantitative characteristics of white matter hyperintensities (WMHs) in predicting the 1-year recurrence risk of ischemic stroke. We conducted a retrospective analysis of 1061 patients with ischemic stroke from January 2018 to April 2021. WMHs were automatically segmented using a cluster-based method to quantify their volume and number of clusters (NoC). Additionally, two radiologists independently rated periventricular and deep WMHs using the Fazekas scale. The cohort was divided into a training set (70%) and a testing set (30%). We employed Cox proportional hazards models to develop predictors based on quantitative WMH characteristics, Fazekas scores, and clinical factors, and compared their performance using the concordance index (C-index). A total of 180 quantitative variables related to WMHs were extracted. A higher NoC in deep white matter and brainstem, advanced age (>90years old), specific stroke subtypes, and absence of discharge antiplatelets showed stronger associations with the risk of ischemic stroke recurrence within 1year. The nomogram incorporating quantitative WMHs data showed superior discrimination compared to those based on the Fazekas scale or clinical factors alone, with C-index values of 0.709 versus 0.647 and 0.648, respectively, in the testing set. Notably, a combined model including both WMHs and clinical factors achieved the highest predictive accuracy, with a C-index of 0.735 in the testing set. Quantitative assessment of WMHs provides a valuable neuro-imaging tool for enhancing the prediction of ischemic stroke recurrence risk.

A Case of the Anti-aquaporine-4 Antibody-negative Neuromyelitis Optica Spectrum Disorders Associated with Atopic Disease with High Concentration of Anti-IgE Autoantibody and HyperIgEemia

We report a 70-year-old male patient with the sero-negative neuromyelitis optica spectrum disorders (NMOSD) associated with atopic disease (AD). He was diagnosed with allergic rhinitis at the age of 20. When he was 61 years old, he subacutely developed orthostatic hypotension, bilateral optic neuritis, quadriparesis, urinary retention, and constipation. The laboratory results revealed allergen-specific IgE positivity for cryptomeria japonica and hinoki, hyperIgEemia, and Th (helper T cell) 1 dominance. The serological tests for autoantibodies revealed negative anti-aquaporine 4 antibody, and high concentration of anti-IgE autoantibody (anti-IgE AAb). Cerebrospinal fluid was negative for anti-myelin-oligodendrocyte glycoprotein antibody and glial fibrillary acidic protein antibody. Fluid-attenuated inversion recovery on brain magnetic resonance imaging (MRI) showed high signal intensities in bilateral cerebral deep white matter. T2 weighted image on spine MRI showed longitudinally extensive high signal intensities in the spinal cord, specifically involving C1 vertebral level to conus medullaris. Intravenous methylprednisolone (IVMP) and plasma exchange resulted in partial improvement. Following the onset of NMOSD, he had relapse of NMOSD four times. In each episode, IVMP was to be partially effective with anti-IgE AAb reduction. Anti-IgE AAb may be a reasonable clinical indicator of increased disease activity in the sero-negative NMOSD associated with AD.

Quantification of white matter hyperintensities in type 1 diabetes and its relation to neuropathy and clinical characteristics

AimsThe aims were to quantify periventricular and deep white matter hyperintensities (WMHs) in adults with type 1 diabetes with different neuropathic phenotypes and to correlate WMH measurements to explanatory factors in diabetes. MethodsWMH measurements were obtained from brain magnetic resonance imaging of 56 adults with type 1 diabetes in subgroups including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN and 20 healthy controls using Fazekas scale and automatic segmentation analysis. ResultsNo differences in Fazekas assessed WMHs were found (individuals with periventricular lesions: diabetes 66 % vs. controls 40 %,p = 0.063, deep lesions: diabetes 52 % vs. controls 50 %,p = 1.0). Using automatic detection, there were no significant differences in count of periventricular (p = 0.30) or deep (p = 0.31) WMHs. Higher periventricular lesion burden was present in diabetes compared with controls (0.21 % vs. 0.06 %,p = 0.048), which was associated with more severe DPN, increased age, decreased cognitive function, and reduced volumetric and metabolic brain measures (all p < 0.05). ConclusionsOur findings indicate increased burden of periventricular WMHs in diabetes which were associated to DPN severity and measures reflecting neurodegeneration. Deep WMHs, often considered as chronic ischemic, were not significantly different. Mechanisms reflecting neurodegeneration and accelerated brain aging could be an overlooked aspect of peripheral and central neuropathy.

Characterizing the clinical, radiological and serological features of children diagnosed with neuromyelitis optica spectrum disorder at pediatric neurology unit

Background. Neuromyelitis optica spectrum disorder is a rare autoimmune disease with a chronic inflammatory demyelinating characteristics that affects the central nervous. The aim of the study is to characterize the clinical, serological and radiological features of neuromyelitis optica disease in a sample of children from Iraq. Methods. A cross-sectional descriptive study has been carried out in the period from August 2019 to September 2020, in pediatric neurology ward in Children Welfare Teaching Hospital, Baghdad. In 12 retrospectively gathered cases, the medical registration of the ward was assessed. A total of 13 patients, aged 3-16 years were included. Results. Among the patients, girls represented 61.5% (8), and the females: males ration was (1.6:1). The patients' ages ranged from 3 to 16 years (mean 9.3 ± 4.02 years). All patients younger than 6 years were AQP-ve, in contrast to 15.3% in those older than 6 years. Negative AQP patients equally distributed between males and females. While females predominated in those with AQP positive status (5,71.4%). Weakness of the limbs and sphincteric disturbance were the first two common clinical features in both AQP positive and negative patients. The three most common brain sites insulted were deep white matter (10, 76.9%), periaqueductal area (5, 38.4%), and brainstem (4, 30.7%). All patients showed long spinal lesions, affecting predominantly the cervico-thoracic (61.53%). Conclusion. The demographic characteristics of the present cohort were comparative to that reported in the literature. Transverse myelitis phenotype was the most common and consistent one. Vomiting was more common in AQP +ve patients.

Dose-dependent Effect of Current Smoking on Enlarged Perivascular Space Identified on Brain MRI.

Cerebral small-vessel disease (CSVD) is a common cause of cognitive decline and stroke. Several studies have shown that smoking is a risk factor for CSVD progression. However, the extent to which smoking exacerbates CSVD lesions remains unclear. In this study, we aimed to clarify the association between total smoking exposure and the severity of CSVD in healthy participants. We analyzed the data of participants aged ≥ 50 years who underwent brain screening. The participants' age, sex, body mass index, alcohol consumption history, and medical history (hypertension, diabetes mellitus, and dyslipidemia) were investigated. Smoking status was assessed in pack-years, and smokers were classified as current or past smokers. CSVD findings on magnetic resonance imaging were used to evaluate the severity of periventricular hyperintensity (PVH), deep subcortical white matter hyperintensity (DSWMH), and enlarged perivascular spaces (EPVSs). The EPVSs were measured in the basal ganglia and centrum semiovale regions. Multivariable ordinal logistic regression analyses were performed to evaluate the effect of smoking, adjusted for the participants' baseline characteristics. A total of 2,137 participants were included in this study. The mean age of the participants was 58.7 years. The mean pack-years were 20.5 for past smokers and 26.8 for current smokers. Among current smokers, increased pack-years were significantly associated with a high EPVS burden in the basal ganglia (odds ratio: 1.14, 95% confidence interval: 1.00-1.28), whereas no such significant association was found for past smokers. No statistically significant association was found between pack-years and the risks of PVH, DSWMH, or EPVS in the centrum semiovale. Current smoking was associated with a dose-dependent risk of EPVS in the basal ganglia in healthy participants.

Temporopolar blurring signifies abnormalities of white matter in mesial temporal lobe epilepsy.

The single-center retrospective cohort study investigated underlying pathogenic mechanisms and clinical significance of patients with temporal lobe epilepsy and hippocampal sclerosis (TLE-HS), in the presence/absence of gray-white matter abnormalities (usually called "blurring"; GMB) in ipsilateral temporopolar region (TPR) on MRI. The study involved 105 patients with unilateral TLE-HS (60 GMB+ and 45 GMB-) who underwent standard anterior temporal lobectomy, along with 61 healthy controls. Resected specimens were examined under light microscope. With combined T1-weighted and DTI data, we quantitatively compared large-scale morphometric features and exacted diffusion parameters of ipsilateral TPR-related superficial and deep white matter (WM) by atlas-based segmentation. Along-tract analysis was added to detect heterogeneous microstructural alterations at various points along deep WM tracts, which were categorized into inferior longitudinal fasciculus (ILF), uncinate fasciculus (UF), and temporal cingulum. Comparable seizure semiology and postoperative seizure outcome were found, while the GMB+ group had significantly higher rate of HS Type 1 and history of febrile seizures, contrasting with significantly lower proportion of interictal contralateral epileptiform discharges, HS Type 2, and increased wasteosomes in hippocampal specimens. Similar morphometric features but greater WM atrophy with more diffusion abnormalities of superficial WM was observed adjacent to ipsilateral TPR in the GMB+ group. Moreover, microstructural alterations resulting from temporopolar GMB were more localized in temporal cingulum while evenly and widely distributed along ILF and UF. Temporopolar GMB could signify more severe and widespread microstructural damage of white matter rather than a focal cortical lesion in TLE-HS, affecting selection of surgical procedures.

Increased extracellular free water is related to white matter hyperintensity burden.

Extracellular free water (FW) has important roles in the occurrence and development of white matter hyperintensity (WMH). To explore the correlations between FW and WMH burden. A prospective analysis was conducted using magnetic resonance imaging (MRI) data from 126 individuals. WMH burden was determined based on WMH volumes and Fazekas scores from deep and periventricular white matter hyperintensity (DWMH and PWMH, respectively) in fluid-attenuated inversion recovery (FLAIR) images. FW values were taken from diffusion tensor imaging (DTI). Univariate analysis showed that FW values were correlated with WMH burden, including WMH volumes and DWMH and PWMH Fazekas scores (P < 0.05). After multivariate analysis, FW values were correlated with WMH volumes and DWMH and PWMH Fazekas scores when adjusted for age and hypertension (P < 0.05). Using MRI, increasing extracellular FW was related to WMH burden.

Different Glymphatic Kinetics in Spontaneous Intracranial Hypotension.

The glymphatic (glia-lymphatic) system is a paravascular pathway for the clearance of waste metabolites including amyloid β from the brain. Serial T1 relaxation time measurements after the intrathecal injection of gadolinium-based contrast agents facilitate the analysis of the temporal dynamics that may be different in patients with spontaneous intracranial hypotension (SIH) and those without SIH. 3D T1-weighted magnetization-prepared 2 rapid gradient echo sequences were acquired in 4 patients with SIH with proved CSF leaks and 12 patients without SIH before, 2-4, 6-8, and 24-48 hours after intrathecal gadobutrol injection. MR scans were warped to the Montreal Neurological Institute space and serial scans were coregistered. T1 relaxation times were measured in predefined ROIs including the subarachnoid space, cortex, white matter, and cervical lymph nodes. In the subarachnoid space and cortex, T1 relaxation times decreased after 2-4 and 6-8 hours before they increased again. In contrast, in the white matter of the temporal lobe T1 relaxation time still decreased after 24-48 hours. There was a striking difference in patients with SIH who did not show a clear contrast distribution within the brain parenchyma. T1 relaxation time curves are compatible with a convective flow driven by arterial pulsations via paravascular spaces surrounding penetrating arteries into the brain's interstitial fluid in the deep white matter. Different curves in patients with SIH and those without SIH indicate that the CSF pressure also impacts the temporal kinetics of the glymphatic system.

Exploring arterial anatomy of the internal capsule: an analysis of the deep vascular structures and related white matter pathways.

The internal capsule is supplied by perforators originating from the internal carotid artery, middle cerebral artery, anterior choroidal artery and anterior cerebral artery. The aim of this study is to examine the vascular anatomy of the internal capsule, along with its related white matter anatomy, in order to prevent potential risks and complications during surgical interventions. Twenty injected hemispheres prepared according to the Klingler method were dissected. Dissections were photographed at each stage. The findings obtained from the dissections were illustrated to make them more understandable. Additionally, the origins of the arteries involved in the vascularization of the internal capsule, their distances to bifurcations, and variations in supplying territories have been thoroughly examined. The insular cortex and the branches of the middle cerebral artery on the insula and operculum were observed. Following decortication of the insular cortex, the extreme capsule, claustrum, external capsule, putamen and globus pallidus structures were exposed. The internal capsule is shown together with the lenticulostriate arteries running on the anterior, genu and posterior limbs. Perforators supplying the internal capsule originated from the middle cerebral artery, anterior cerebral artery, internal carotid artery and anterior choroidal artery. The internal capsule's vascular supply varied, with the medial lenticulostriate arteries (MLA) and lateral lenticulostriate arteries (LLA) being the primary arteries. The anterior limb was most often supplied by the MLA, while the LLA and anterior choroidal artery dominated the genu and posterior limb. The recurrent artery of Heubner originated mostly from the A2 segment. The distance from the ICA bifurcation to the origin of the first LLA on M1 is 9.55 ± 2.32mm, and to the first MLA on A1 is 5.35 ± 1.84mm. MLA branching from A1 and proximal A2 ranged from 5 to 9, while LLA originating from the MCA ranged from 7 to 12. This study provides comprehensive understanding of the arterial supply to the internal capsule by combining white matter dissection. The insights gained from this study can help surgeons plan and execute procedures including oncological, psychosurgical, and vascular more accurately and safely. The illustrations derived from the dissections serve as valuable educational material for young neurosurgeons and other medical professionals.

Association between fibrinogen and white matter lesions and cerebral atrophy in patients with acute ischemic stroke

BackgroundInflammation is a potential mechanism underlying the development of white matter lesions (WMLs) and cerebral atrophy. We aimed to investigate the relationship of fibrinogen levels with WMLs and cerebral atrophy in patients with acute ischemic stroke (AIS). MethodsA total of 701 AIS patients were enrolled. Participants were divided into four groups according to the quartiles of fibrinogen levels: Q1 < 2.58 g/L, Q2: 2.58-3.12 g/L, Q3: 3.12-3.67 g/L, Q4: ≥ 3.67 g/L. White matter hyperintensity (WMH), periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH) were defined according to the Fazekas scale. Cerebral atrophy was defined according to global cortical atrophy scores. Univariate and multivariate logistic regression were used to explore the relationship of fibrinogen levels and WMHs, PVH, DWMH and cerebral atrophy. ResultsAmong 701 AIS patients, 498 (71.0 %), 425 (60.6 %), 442 (63.1 %), and 560 (79.9 %) had WMHs, PVH, DWMH and cerebral atrophy, respectively. After adjustment for potential covariates, the highest fibrinogen quartiles were significantly associated with increased risk of WMHs (odds ratio [OR] 1.97, 95 % confidence intervals [CI] 1.10-3.50), PVH (OR 1.85, 95 % CI 1.08-3.16) and cerebral atrophy (OR 2.53, 95 % CI 1.19-5.40) but not DWMH (OR 1.37 95 % CI 0.81-2.31) compared with the lowest fibrinogen quartile. Moreover, the association between elevated fibrinogen levels and the risk of WMLs and cerebral atrophy remained significant as continuous variables. ConclusionsIncreased baseline fibrinogen levels were independently associated with WMHs, PVH and cerebral atrophy in patients with ischemic stroke. Fibrinogen could be the potential blood biomarker of WMLs and cerebral atrophy.

Magnetic resonance imaging patterns and perfusion changes of posterior reversible encephalopathy syndrome in children with clinical outcome correlation.

Posterior reversible encephalopathy syndrome (PRES) in children has a propensity towards atypical features on magnetic resonance (MR) imaging, with limited literature on perfusion changes and clinicoradiological correlation. We aimed to comprehensively study MR imaging patterns of pediatric PRES, including cerebral blood flow variations on arterial spin labeling, and looked for any MR biomarkers of poor clinical outcome. In this retrospective observational study conducted in a tertiary hospital setting, MR records over a 4-year period (May 2019 to May 2023) were systematically searched along with their clinical details. Patients with an age less than 18years and a clinicoradiological constellation consistent with PRES were included. MR scans were analyzed by two neuroradiologists with 8years' and 10years' experience. Association was sought with poor clinical outcome (defined as modified Rankin Scale score at discharge of > 2). A total of 45 patients (29 boys) were included in the study, with a mean age (± standard deviation) of 11.19 (± 4.53) years. On MR imaging, 95.6% of patients (n = 43) showed atypical features and/or atypical areas of involvement. The superior frontal sulcus (n = 18) was the most predominant MR pattern, and cerebellar involvement was not uncommon (n = 15). Unilateral involvement (n = 3), isolated central pattern (n = 1), and spinal cord involvement (PRES-SCI: n = 1) were also encountered. Brainstem involvement (n = 4) showed a characteristic "V-sign" of anterior medullary hyperintensity. Patchy restricted diffusion (46.6%), punctate hemorrhages (37.7%), and leptomeningeal contrast enhancement (36%) were not uncommon. Arterial spin labeling sequence (available in 24 patients) showed increased cerebral blood flow in the involved areas in 79.2% of patients. Univariate analysis showed a significant association of the presence of hemorrhage (P = 0.003), involvement of brainstem (P = 0.007), deep white matter (P = 0.008), and thalamus (P = 0.026) with poor clinical outcome. Multivariate regression analysis found that hemorrhage on MRI (P = 0.011, odds ratio 8) was an independent factor associated with poor clinical outcome. The conventionally described atypical features in PRES are common in children and therefore may no longer be considered exceptions. Raised perfusion on arterial spin labeling sequence was seen in the majority of cases. Hemorrhage on MRI was an independent predictor of poor clinical outcome in pediatric PRES.