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Fluids and Barriers of the CNS Mar 2023The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater,...
BACKGROUND
The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater, the cerebrospinal fluid (CSF)-filled subarachnoid space (SAS) features a variety of trabeculae, septae and pillars. Like the arachnoid and the pia mater, these structures are covered with leptomeningeal or meningothelial cells (MECs) that form a barrier between CSF and the parenchyma of the optic nerve (ON). MECs contribute to the CSF proteome through extensive protein secretion. In vitro, they were shown to phagocytose potentially toxic proteins, such as α-synuclein and amyloid beta, as well as apoptotic cell bodies. They therefore may contribute to CSF homeostasis in the SAS as a functional exchange surface. Determining the total area of the SAS covered by these cells that are in direct contact with CSF is thus important for estimating their potential contribution to CSF homeostasis.
METHODS
Using synchrotron radiation-based micro-computed tomography (SRµCT), two 0.75 mm-thick sections of a human optic nerve were acquired at a resolution of 0.325 µm/pixel, producing images of multiple terabytes capturing the geometrical details of the CSF space. Special-purpose supercomputing techniques were employed to obtain a pixel-accurate morphometric description of the trabeculae and estimate internal volume and surface area of the ON SAS.
RESULTS
In the bulbar segment, the ON SAS microstructure is shown to amplify the MECs surface area up to 4.85-fold compared to an "empty" ON SAS, while just occupying 35% of the volume. In the intraorbital segment, the microstructure occupies 35% of the volume and amplifies the ON SAS area 3.24-fold.
CONCLUSIONS
We provided for the first time an estimation of the interface area between CSF and MECs. This area is of importance for estimating a potential contribution of MECs on CSF homeostasis.
Topics: Humans; Optic Nerve; Tomography, X-Ray; Amyloid beta-Peptides
PubMed: 36944985
DOI: 10.1186/s12987-023-00423-6 -
Journal of Personalized Medicine Feb 2023Para-pharyngeal space (PPS) tumors include an heterogeneous group of neoplasms, accounting for approximatively 0.5-1.5% of all head and neck tumors. Management of these...
Para-pharyngeal space (PPS) tumors include an heterogeneous group of neoplasms, accounting for approximatively 0.5-1.5% of all head and neck tumors. Management of these neoplasms requires a careful diagnostic workout and an appropriate surgical approach to obtain good outcomes associated with minimal aesthetic drawbacks. In this study we investigated clinical onset, histologic features, surgical treatment outcomes, peri operative complications and follow up of 98 patients treated for PPS tumors in our Centre between 2002 and 2021. Furthermore, we reviewed our preliminary experience of preoperative embolization of hyper vascular PPS tumors trough SQUID12, an ethylene vinyl alcohol copolymers (EVOH) which exhibits many advantages over other embolic agents, due to its better devascularization rate and lower risk of systemic complications. Our data support the hypothesis that transoral surgery scenario should be significantly revised, as it could represent a valid treatment for tumors located in lower and prestyloyd portion of PPS. Moreover, SQUID12, a novel embolization agent, may be a very promising choice for PPS hyper vascularized tumors, ensuring higher devascularization rate, safer procedures and lower risk of systemic dispersion compared to traditional Contour treatment.
PubMed: 36836517
DOI: 10.3390/jpm13020283 -
Current Opinion in Neurobiology Apr 2023The spatial and temporal development of the brain, overlying meninges (fibroblasts, vasculature and immune cells) and calvarium are highly coordinated. In particular,... (Review)
Review
The spatial and temporal development of the brain, overlying meninges (fibroblasts, vasculature and immune cells) and calvarium are highly coordinated. In particular, the timing of meningeal fibroblasts into molecularly distinct pia, arachnoid and dura subtypes coincides with key developmental events in the brain and calvarium. Further, the meninges are positioned to influence development of adjacent structures and do so via depositing basement membrane and producing molecular cues to regulate brain and calvarial development. Here, we review the current knowledge of how meninges development aligns with events in the brain and calvarium and meningeal fibroblast "crosstalk" with these structures. We summarize outstanding questions and how the use of non-mammalian models to study the meninges will substantially advance the field of meninges biology.
Topics: Meninges; Dura Mater; Arachnoid; Brain
PubMed: 36773497
DOI: 10.1016/j.conb.2023.102676 -
Surgical Neurology International 2022Frontotemporal dementia (FTD) is a highly disabling neurologic disorder characterized by behavioral alterations and movement disorders, involving patients with a mean...
BACKGROUND
Frontotemporal dementia (FTD) is a highly disabling neurologic disorder characterized by behavioral alterations and movement disorders, involving patients with a mean age of 58 years. We present a unique case of a patient suffering from FTD who developed post traumatic bilateral hygromas.
CASE DESCRIPTION
A 52-year-old male patient, with an history of head trauma 3 months before, was admitted to our department for recurrent motor seizures. Anamnesis was positive for FTD with severe frontal syndrome. Brain computed tomography and magnetic resonance imaging (MRI) showed the typical "knife-blade" appearance of the cortical atrophy associated to bilateral hemispheric hygromas exerting mild mass effect. Brain MRI showed the signs of the cortical and "anti-cortical" vein. The two subdural collections were evacuated through two bilateral burr holes and controlled drainage. Despite anti-epileptic drugs therapy, in the early postoperative period, the patient presented further tonic-clonic seizures. The patient showed progressive recovery and was transferred to the neurorehabilitation center. After 6-month follow-up, he completely recovered.
CONCLUSION
In FTD, severe cortical atrophy leads to space increase between arachnoid and pia mater that could affect the anatomical integrity especially after trauma, with possible development of hygromas. The coexistence of radiological findings of the cortical vein and sign of the "anti-cortical" vein can make difficult an exact differential diagnosis between a primitive hygroma and a Virchow hygroma from resorption of previous blood collection. Surgical treatment may be indicated in selected patients, but it is burdened by higher postoperative risks compared to the general population.
PubMed: 36761258
DOI: 10.25259/SNI_1056_2022 -
Oncology Letters Feb 2023Multifocal dissemination of cancer cells from the primary tumor sites to the subarachnoid, pia mater and cerebrospinal fluid (CSF) of the brain and spinal cord causes...
Multifocal dissemination of cancer cells from the primary tumor sites to the subarachnoid, pia mater and cerebrospinal fluid (CSF) of the brain and spinal cord causes carcinomatous meningitis (CM). CM is rarely observed in patients with gynecological cancer. The present study described a 59-year-old woman who was diagnosed with CM as a recurrence of stage IIIC ovarian cancer, after presenting with headache and decreased level of consciousness. During adjuvant therapy following surgical debulking, she developed nausea and vomiting. The post-contrast fluid-attenuated inversion-recovery magnetic resonance imaging showed leptomeningeal enhancement on all sulci, particularly around the falx cerebri and cerebellar hemisphere. CM was suspected and CSF cytology revealed adenocarcinoma cells, thus confirming the diagnosis. Overall, although CM is rare, clinicians should be aware of this complication when patients with malignancies experience neurological symptoms, including headache, nausea and vomiting. Knowledge of this clinical entity should assist clinicians in ascertaining accurate diagnoses.
PubMed: 36644158
DOI: 10.3892/ol.2022.13652 -
Journal of the Royal Society, Interface Dec 2022Computational modelling of the brain requires accurate representation of the tissues concerned. Mechanical testing has numerous challenges, in particular for low strain...
Computational modelling of the brain requires accurate representation of the tissues concerned. Mechanical testing has numerous challenges, in particular for low strain rates, like neurosurgery, where redistribution of fluid is biomechanically important. A finite-element (FE) model was generated in FEBio, incorporating a spring element/fluid-structure interaction representation of the pia-arachnoid complex (PAC). The model was loaded to represent gravity in prone and supine positions. Material parameter identification and sensitivity analysis were performed using statistical software, comparing the FE results to human measurements. Results for the brain Ogden parameters , and yielded values of 670 Pa, -19 and 148 kPa, supporting values reported in the literature. Values of the order of 1.2 MPa and 7.7 kPa were obtained for stiffness of the pia mater and out-of-plane tensile stiffness of the PAC, respectively. Positional brain shift was found to be non-rigid and largely driven by redistribution of fluid within the tissue. To the best of our knowledge, this is the first study using human data and gravitational loading in order to estimate the material properties of intracranial tissues. This model could now be applied to reduce the impact of positional brain shift in stereotactic neurosurgery.
Topics: Humans; Pia Mater; Computer Simulation; Brain; Finite Element Analysis; Stress, Mechanical; Biomechanical Phenomena
PubMed: 36514891
DOI: 10.1098/rsif.2022.0557 -
Experimental Eye Research Jan 2023To identify changes in response to experimental intraocular pressure (IOP) elevation associated with the laminin α1 nmf223 mutation in mice. Laminin mutant (LM) mice...
To identify changes in response to experimental intraocular pressure (IOP) elevation associated with the laminin α1 nmf223 mutation in mice. Laminin mutant (LM) mice (Lama1) and C57BL/6J (B6) mice in two age groups each (4-5 months and >1 year) underwent intracameral microbead injections to produce unilaterally elevated IOP. We assessed axonal transport block of immunofluorescently labeled amyloid precursor protein (APP) after 3 days and retinal ganglion cell (RGC) axon loss after 6 weeks. Light, electron and fluorescent microscopy was used to study baseline anatomic differences and effects of 3-day IOP elevation in younger LM mice. In younger mice of both LM and B6 strains, elevated IOP led to increased APP block in the retina, prelaminar optic nerve head (preONH), unmyelinated optic nerve (UON), and myelinated optic nerve (MON). APP blockade not significantly different between younger B6 and LM mouse strains. Older LM mice had greater APP accumulation in both control and glaucoma eyes compared to older B6, however, accumulation was not significantly greater in LM glaucoma eyes compared to LM controls. Axon loss at 6 weeks was 12.2% in younger LM and 18.7% in younger B6 mice (difference between strains, p = 0.22, Mann Whitney test). Untreated LM optic nerve area was lower compared to B6 (nerve area, p < 0.0001, t-test). Aberrant axon bundles, as well as defects, thickening and reduplication of pia mater, were seen in the optic nerves of younger LM mice. Axonal transport blockade significantly differed between old B6 and old LM mice in control and glaucoma eyes, and younger LM mice had abnormal axon paths and lower optic nerve area.
Topics: Animals; Mice; Axons; Disease Models, Animal; Glaucoma; Intraocular Pressure; Mice, Inbred C57BL; Optic Disk; Optic Nerve; Laminin
PubMed: 36476399
DOI: 10.1016/j.exer.2022.109341 -
BMC Neurology Nov 2022Meningeal carcinomatosis is mainly associated with breast cancer, lung cancer, and melanoma. However, meningeal carcinomatosis secondary to a neurenteric cyst with...
BACKGROUND
Meningeal carcinomatosis is mainly associated with breast cancer, lung cancer, and melanoma. However, meningeal carcinomatosis secondary to a neurenteric cyst with malignant features is extremely rare.
CASE PRESENTATION
We report the case of a 35-year-old woman who was admitted to the hospital with a 10-month history of headache, 6-month history of diplopia, 4-month history of hearing loss, and 1-month history of back pain, suggesting a diagnosis of chronic meningitis. Notably, enhanced brain and spinal cord magnetic resonance imaging (MRI) revealed extensive lesions with enhancement signals in the pia mater of the pons and cervical, thoracic, and lumbar spinal cord. The cerebral spinal fluid profile showed that pressure was significantly elevated, with a slight increase in leukocytes that mostly comprised mononuclear cells and decreased glucose concentration. Cytology evaluation showed a small cluster of atypical nuclei, which were suspected to be tumor cells arising from the epithelium. However, no primary tumor was found through comprehensive body and skin screening. After a histopathological biopsy of subarachnoid meninx of the thoracic spinal canal, the cause of meningeal carcinomatosis of this patient was determined as neurenteric cysts with malignant features, which is extremely rare.
CONCLUSION
This is the first case to ever report neurenteric cysts as a cause of leptomeningeal carcinomatosis and the first ever report of neurenteric cysts presenting as leptomeningeal carcinomatosis without typical cyst visible on brain MRI. This extremely rare case provided a novel view on the pathogenesis of meningeal carcinomatosis and clinical presentation of neurenteric cysts, highlighting the value of meningeal biopsy in chronic meningitis of unknown causes.
Topics: Female; Humans; Adult; Meningeal Carcinomatosis; Neural Tube Defects; Cell Transformation, Neoplastic; Magnetic Resonance Imaging; Spinal Cord Diseases; Meningitis
PubMed: 36384561
DOI: 10.1186/s12883-022-02978-7 -
NMC Case Report Journal 2022Leptomeningeal metastasis (LM) is a rare but devastating cancer complication. LM occurs when cancer spreads into the leptomeningeal layer or cerebrospinal fluid....
Leptomeningeal metastasis (LM) is a rare but devastating cancer complication. LM occurs when cancer spreads into the leptomeningeal layer or cerebrospinal fluid. Intracranial magnetic resonance (MR) images of LM are characterized by the diffuse enhancement of the leptomeninges along the cerebral sulci, cerebellar folia, and cranial nerves. Here, we report an extremely rare case of LM with an atypical MR image revealing tumor mass confinement to the arachnoid membrane. The case involves an 85-year-old man who was referred to our hospital with a three-day history of dysarthria. Radiological examination revealed a solid lesion with heterogeneous enhancement and a cystic component in the extra-axial region of the right parietal lobe. Upon subsequent general examination, multiple lung cancer metastases were suspected. The patient underwent gross total resection of the brain mass in the right parietal region. Although the tumor slightly adhered to the dura mater, it was sharply demarcated from the surrounding parenchyma and pia mater. Based on pathological examination, the tumor was diagnosed as small cell lung cancer metastasis. This metastatic brain tumor was exclusively confined to the arachnoid membrane and, except for a few blood vessels, the dura mater was not infiltrated by metastatic tumor cells. To our knowledge, this is the first reported case of LM in which the tumor mass is confined only to the arachnoid membrane. Thus, in cases with atypical MR images, a general examination considering the possibility of LM is important for prompt and accurate diagnosis.
PubMed: 36313794
DOI: 10.2176/jns-nmc.2022-0113