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Anatomical Record (Hoboken, N.J. : 2007) Jun 2024The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate... (Review)
Review
The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate leptomeningeal layer between the arachnoid and pia mater in mouse and human brains, which divides the subarachnoid space (SAS) into two functional compartments. Being a macroscopic structure, having missed detection in previous studies is surprising. We systematically reviewed the published reports in animals and humans to explore whether prior descriptions of this meningeal layer were reported in some way. A comprehensive search was conducted in PubMed/Medline, EMBASE, Google Scholar, Science Direct, and Web of Science databases using combinations of MeSH terms and keywords with Boolean operators from inception until 31 December 2023. We found at least eight studies that provided structural evidence of an intermediate leptomeningeal layer in the brain or spinal cord. However, unequivocal descriptions for this layer all along the central nervous system were scarce. Obscure names like the epipial, intermediate meningeal, outer pial layers, or intermediate lamella were used to describe it. Its microscopic/ultrastructural details closely resemble the recently reported SLYM. We further examined the counterarguments in current literature that are skeptical of the existence of this layer. The potential physiological and clinical implications of this new meningeal layer are significant, underscoring the urgent need for further exploration of its structural and functional details.
PubMed: 38924700
DOI: 10.1002/ar.25524 -
Child's Nervous System : ChNS :... Jun 2024Pediatric non-galenic pial arteriovenous fistulas (pAVFs) are rare vascular malformations that are characterized by a pial arterial-venous connection without an... (Review)
Review
INTRODUCTION
Pediatric non-galenic pial arteriovenous fistulas (pAVFs) are rare vascular malformations that are characterized by a pial arterial-venous connection without an intervening capillary bed. Outcomes and treatment strategies for pAVFs are highly individualized, owing to the rarity of the disease and lack of large-scale data guiding optimal treatment approaches.
METHODS
We performed a systematic review of pediatric patients (< 18 years at diagnosis) diagnosed with a pAVF by digital subtraction angiogram (DSA). The demographics, treatment modalities, and outcomes were documented for each patient and clinical outcome data was collected. Descriptive information stratified by outcome scores were classified as follows: 1 = excellent (no deficit and full premorbid activity), 2 = good (mild deficit and full premorbid activity), 3 = fair (moderate deficit and impaired activity), 4 = poor (severe deficit and dependent on others), 5 = death.
RESULTS
A total of 87 studies involving 231 patients were identified. Median age at diagnosis was 3 years (neonates to 18 years). There was slight male preponderance (55.4%), and 150 subjects (81.1%*) experienced excellent outcomes after treatment. Of the 189 patients treated using endovascular approaches, 80.3% experienced excellent outcomes and of the 15 patients surgically treated subjects 75% had an excellent outcome. The highest rate of excellent outcomes was achieved in patients treated with Onyx (95.2%) and other forms of EvOH (100%). High output heart failure and comorbid vascular lesions tended to result in worse outcomes, with only 54.2% and 68% of subjects experiencing an excellent outcome, respectively. *Outcomes were reported in only 185 patients.
CONCLUSION
pAVFs are rare lesions, necessitating aggregation of patient data to inform natural history and optimal treatment strategies. This review summarizes the current literature on pAVF in children, where children presenting with heart failure as a result of high flow through the lesion were less likely to experience an excellent outcome. Prospective, large-scale studies would further characterize pediatric pAVFs and enable quantitative analysis of outcomes to inform best treatment practices.
Topics: Humans; Child; Arteriovenous Fistula; Pia Mater; Child, Preschool; Adolescent; Infant; Female; Infant, Newborn; Treatment Outcome; Male; Intracranial Arteriovenous Malformations
PubMed: 38506930
DOI: 10.1007/s00381-024-06352-5 -
Frontiers in Neurology 2023Relapsing polychondritis (RP) is a rare rheumatologic disorder that may affect the neurological system with various presentations. In this study, we present a case and...
BACKGROUND AND PURPOSE
Relapsing polychondritis (RP) is a rare rheumatologic disorder that may affect the neurological system with various presentations. In this study, we present a case and summarize the clinical characteristics of RP-associated meningoencephalitis.
CASE PRESENTATION
A 48-year-old man presented with first-ever seizures that were well controlled by valproate. Physical examination results were unremarkable, except for binaural deformation. The initial brain magnetic resonance imaging (MRI) without contrast and electroencephalogram (EEG) findings were normal. However, the patient subsequently developed recurrent fever, scleritis, headache, lethargy, and left arm paresis. Repeated brain MRI with contrast demonstrated increased enhancement of the pia mater and abnormal diffusion-weighted imaging (DWI) signals in the bilateral auricles. The cerebrospinal fluid (CSF) analysis showed 2 leukocytes/μL, 736.5 mg/L of protein, and no evidence of infectious disease or autoimmune encephalitis. Meningoencephalitis secondary to RP was considered. The patient's condition improved significantly and quickly with the administration of dexamethasone (10 mg per day). Oral methylprednisolone was continued, and the patient remained well without relapse during the 9-month follow-up period.
CONCLUSION
RP-associated meningoencephalitis is rare but fatal. Although symptoms vary, red or deformed ears remain the most common and suggestive features. Non-specific parenchymal changes and/or meningeal enhancement can be observed on brain MRI scans. CSF lymphocytic pleocytosis with mild protein elevation was observed in most patients.
PubMed: 38033767
DOI: 10.3389/fneur.2023.1265345 -
Cancer Medicine Feb 2023Leptomeningeal metastasis (LM) refers to the dissemination of malignant cells in the subarachnoid space, pia, and arachnoid mater and is a severe condition associated... (Review)
Review
Leptomeningeal metastasis (LM) refers to the dissemination of malignant cells in the subarachnoid space, pia, and arachnoid mater and is a severe condition associated with metastatic solid tumors. The most common solid tumor that develops into LM is lung cancer and the incidence increased in patients with advanced non-small-cell lung cancer (NSCLC) with targetable mutations. However, tissue biopsy of LM is inaccessible, leading to the paucity of genomic profiles of LM to guide targeted treatments and explore biological mechanisms. In recent years, liquid biopsy is considered a minimally invasive and dynamic method to trace the genomic alterations of cancer cells and some studies started to perform sequencing of cerebrospinal fluid (CSF) in patients with LM to reveal the targeted mutations and genomic profiles. In this review, we focused on studies performed sequencing of CSF in NSCLC patients with LM and summarized the sequencing results and their commonality. As the only way to reveal the genomic landscapes of LM, our review provided evidence that sequencing of CSF is a promising management method in LM patients to dynamically guide target therapy and monitor intracranial tumor response. Furthermore, it reveals a unique genomic profile of LM including driver genes, drug-resistant mutations, and a number of copy number variations. Sequencing of CSF in LM patients seems to provide more comprehensive genomic information than we expected and the biological significance behind the genomic alternations needs further study.
Topics: Humans; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; DNA Copy Number Variations; Meningeal Carcinomatosis; Mutation
PubMed: 36000927
DOI: 10.1002/cam4.5163 -
World Neurosurgery Sep 2021Primary intraparenchymal meningiomas are exceedingly rare and often challenging to diagnose, given their misleading radiologic features. It is hypothesized that they...
BACKGROUND
Primary intraparenchymal meningiomas are exceedingly rare and often challenging to diagnose, given their misleading radiologic features. It is hypothesized that they arise from the cap cells of the pia mater that enter the brain via penetrating blood vessels during brain development. We systematically reviewed and analyzed previously reported features of primary intraparenchymal meningiomas in terms of radiography, presenting symptoms, and histopathology.
METHODS
A literature search of the Web of Science and PubMed databases and crossed references was performed in March 2021, per PRISMA guidelines, with no restrictions regarding publication date. Data regarding demographic features, clinical, radiographic, and histopathologic characteristics were extracted.
RESULTS
A total of 52 patients (including the reported case) were included in this review. The mean age was 21.1 years (range, 0.3-66 years) with a male/female ratio of 1.9:1. The most common localizations of intraparenchymal meningiomas were in the frontal (30.8%) and temporal (21.2%) lobes. Cyst formation was more readily observed and was noted in 51.4% of patients. Histopathology showed a higher incidence of World Health Organization grade II (14/52, 26.9%) and World Health Organization grade III (7/52, 13.5%) of primary intraparenchymal meningiomas.
CONCLUSIONS
We present a comprehensive analysis of every reported primary intraparenchymal meningioma. Because of their rarity and capacity to mimic other more common intra-axial tumors, they represent a diagnostic challenge. This systematic review highlights the importance of paying attention to atypical intra-axial lesions, with a particular reflection on the discrepancy between clinical characteristics and imaging features.
Topics: Adult; Brain Neoplasms; Cerebral Cortex; Humans; Male; Meningeal Neoplasms; Meningioma
PubMed: 34242832
DOI: 10.1016/j.wneu.2021.06.139 -
Annals of Gastroenterology 2021The frequency of inflammatory bowel disease (IBD) is increased after marriage to an individual with the disease. Importantly, the offspring of these couples have a...
BACKGROUND
The frequency of inflammatory bowel disease (IBD) is increased after marriage to an individual with the disease. Importantly, the offspring of these couples have a significant risk for developing the disease. Herein, we aimed to better characterize conjugal IBD.
METHODS
A systematic literature search was conducted with predetermined search criteria. Relevant manuscripts reporting on couples with IBD and their offspring were selected. Concomitantly, a cross-sectional survey was conducted of couples where both members were affected with IBD, as well as their offspring, and electronically distributed by patients' associations.
RESULTS
We identified 20 reports of IBD in couples, for a total of 68 couples. Of these, 66% were concordant regarding IBD type and 66% were diagnosed after cohabitation. The overall prevalence of IBD in the offspring of these couples was 29%. Our survey identified 58 couples with IBD, with 62% being concordant regarding IBD type; 42.9% were diagnosed prior to cohabitation, in 12.5% one spouse was diagnosed before and the other after cohabitation, and in 44.6% the onset of disease occurred after cohabitation for both. The prevalence of IBD in children born from these couples was 10%. The probability of developing disease in the progeny was 2% at 10 years, 12% at 15 years, and 16% at 20 years of age.
CONCLUSIONS
IBD in couples occurs mostly after marriage to an individual with disease or after many years of cohabitation. In a modern cohort, the risk for the progeny was around 16% by the age of 20, lower than previously reported.
PubMed: 33948061
DOI: 10.20524/aog.2021.0598 -
Journal of Neurotrauma Jun 2021The meninges are membranous tissues that are pivotal in maintaining homeostasis of the central nervous system. Despite the importance of the cranial meninges in nervous...
The meninges are membranous tissues that are pivotal in maintaining homeostasis of the central nervous system. Despite the importance of the cranial meninges in nervous system physiology and in head injury mechanics, our knowledge of the tissues' mechanical behavior and structural composition is limited. This systematic review analyzes the existing literature on the mechanical properties of the meningeal tissues. Publications were identified from a search of Scopus, Academic Search Complete, and Web of Science and screened for eligibility according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The review details the wide range of testing techniques employed to date and the significant variability in the observed experimental findings. Our findings identify many gaps in the current literature that can serve as a guide for future work for meningeal mechanics investigators. The review identifies no peer-reviewed mechanical data on the falx and tentorium tissues, both of which have been identified as key structures in influencing brain injury mechanics. A dearth of mechanical data for the pia-arachnoid complex also was identified (no experimental mechanics studies on the human pia-arachnoid complex were identified), which is desirable for biofidelic modeling of human head injuries. Finally, this review provides recommendations on how experiments can be conducted to allow for standardization of test methodologies, enabling simplified comparisons and conclusions on meningeal mechanics.
Topics: Animals; Arachnoid; Biomechanical Phenomena; Brain; Dura Mater; Humans; Meninges; Pia Mater
PubMed: 33191848
DOI: 10.1089/neu.2020.7288 -
World Neurosurgery Aug 2019Acquired pial arteriovenous fistula (pAVF) is an extremely rare intracranial vascular malformation, with few case reports in the English literature. This study presents...
OBJECTIVE
Acquired pial arteriovenous fistula (pAVF) is an extremely rare intracranial vascular malformation, with few case reports in the English literature. This study presents a thorough review and analysis of all acquired pAVF cases from the literature in addition to an illustrated case.
METHODS
We report a case with de novo development of intracranial pAVF after craniotomy. A medical literature database search between 1975 and 2018, including the Medline, Ovid, and PubMed databases, was performed to identify all reports with possible acquired lesions. Differences between these acquired lesions and previously reported primary lesions were evaluated.
RESULTS
A total of 8 patients with de novo formation of acquired pAVF were included in this series. Most of these pAVFs were fed and drained via a similar arteriovenous pattern, from distal/cortical branches of the middle cerebral artery (6/8, 75%) to the superficial middle cerebral vein (6/8, 75%). Compared with a previously reported primary pAVF series, acquired pAVF tended to be asymptomatic (P < 0.0001) and found essentially in adults (P = 0.0061). Fewer venous varices (P = 0.0049) and associated intracranial mass effect (P = 0.0189) were found in the cases of acquired pAVF. All 4 reported acquired pAVFs that were treated microsurgically resulted in complete angiographic obliteration (4/4, 100%). The overall outcome was good or stable even with observation only (7/8, 87.5%).
CONCLUSIONS
Acquired pAVF is highly correlated with sentinel neurosurgical procedures or venous occlusion events. These lesions should be regarded as a different disease entity from primary pAVF because of the relatively low-flow shunting and benign clinical course.
Topics: Adult; Angiography, Digital Subtraction; Arteriovenous Fistula; Cerebral Angiography; Cerebral Hemorrhage; Cerebral Veins; Computed Tomography Angiography; Humans; Intracranial Arteriovenous Malformations; Male; Middle Cerebral Artery; Neurosurgical Procedures; Pia Mater; Postoperative Complications
PubMed: 31026655
DOI: 10.1016/j.wneu.2019.04.135