-
Journal of Anatomy Mar 2024In humans and most mammals, there is a notch-like portal, the foramen of Luschka (or lateral foramen), which connects the lumen of the fourth ventricle with the subdural...
In humans and most mammals, there is a notch-like portal, the foramen of Luschka (or lateral foramen), which connects the lumen of the fourth ventricle with the subdural space. Gross dissection, light and scanning electron microscopy, and μCT analysis revealed the presence of a foramen of Luschka in the American alligator (Alligator mississippiensis). In this species, the foramen of Luschka is a notch in the dorsolateral wall of the pons immediately caudal to the peduncular base of the cerebellum, near the rostral end of the telovelar membrane over the fourth ventricle. At the foramen of Luschka there was a transition from a superficial pia mater lining to a deep ependymal lining. There was continuity between the lumen of the fourth ventricle and the subdural space, via the foramen of Luschka. This anatomical continuity was further demonstrated by injecting Evans blue into the lateral ventricle which led to extravasation through the foramen of Luschka and pooling of the dye on the lateral surface of the brain. Simultaneous subdural and intraventricular recordings of cerebrospinal fluid (CSF) pressures revealed a stable agreement between the two pressures at rest. Perturbation of the system allowed for static and dynamic differences to develop, which could indicate varying flow patterns of CSF through the foramen of Luschka.
Topics: Animals; Humans; Alligators and Crocodiles; Subdural Space; Cerebellum; Fourth Ventricle; Ependyma; Mammals
PubMed: 37965891
DOI: 10.1111/joa.13972 -
ACS Applied Materials & Interfaces Mar 2024The capacitance of electrode materials used in electrochemical double-layer capacitors (EDLCs) is currently limited by several factors, including inaccessible isolated...
The capacitance of electrode materials used in electrochemical double-layer capacitors (EDLCs) is currently limited by several factors, including inaccessible isolated micropores in high-surface area carbons, the finite density of states resulting in a quantum capacitance in series to Helmholtz double-layer capacitance, and the presence of surface impurities, such as functional groups and adsorbed species. To unlock the full potential of EDLC active materials and corresponding electrodes, several post-production treatments are commonly proposed to improve their capacitance and, thus, the energy density of the corresponding devices. In this work, we report a systematic study of the effect of a prototypical treatment, namely H-assisted thermal treatment, on the chemical, structural, and thermal properties of activated carbon and corresponding electrodes. By combining multiple characterization techniques, we clarify the actual origins of the improvement of the performance (e.g., > +35% energy density for the investigated power densities in the 0.5-45 kW kg range) of the EDLCs based on treated electrodes compared to the case based on the pristine electrodes. Contrary to previous works supporting a questionable graphitization of the activated carbon at temperatures <1000 °C, we found that a "surface graphitization" of the activated carbon, detected by spectroscopic analysis, is mainly associated with the desorption of surface contaminants. The elimination of surface impurities, including adsorbed species, improves the surface capacitance of the activated carbon () by +37.1 and +36.3% at specific currents of 1 and 10 A g, respectively. Despite the presence of slight densification of the activated carbon upon the thermal treatment, the latter still improves the cell gravimetric capacitance normalized on the mass of the activated carbon only (), e.g., + 28% at 1 A g. Besides, our holistic approach identifies the change in the active material and binder contents as a concomitant cause of the increase of cell gravimetric capacitance (), accounting for the mass of all of the electrode materials measured for treated electrodes compared to pristine ones. Overall, this study provides new insights into the relationship between the modifications of the electrode materials induced by H-assisted thermal treatments and the performance of the resulting EDLCs.
PubMed: 38458613
DOI: 10.1021/acsami.3c18629 -
Cureus Sep 2023Leptomeningeal carcinomatosis (LC) is an uncommon sequelae of metastatic cancer affecting the pia and arachnoid mater. It has been postulated that recent improvements...
Leptomeningeal carcinomatosis (LC) is an uncommon sequelae of metastatic cancer affecting the pia and arachnoid mater. It has been postulated that recent improvements in cancer patient survival time have increased the frequency of LC and other rare metastatic conditions that patients previously would not have lived long enough to experience. LC carries a universally poor prognosis with a mean survival of between two to four months if treated; however, the recent increase in incidence has allowed for further research into the condition and potential treatments. Options for administering chemotherapy have been limited in the past, but recent developments in surgical chemotherapeutic ports have allowed for intrathecal delivery of drugs like methotrexate without systemic exposure. In fact, innovative delivery systems undergoing clinical trials can deliver these drugs in a metronomic fashion to limit the leukoencephalopathy complications of methotrexate. Primary breast cancer is the most common source of metastatic leptomeningeal lesions, and such a lesion was observed by the authors in the cadaver of a 70-year-old Caucasian female with unspecified breast cancer in a medical school anatomic laboratory. The cause of death was listed as "complication of malignant neoplasm of unspecified site of unspecified female breast." Through this case report, we seek to develop our understanding of this rare metastatic phenomenon and highlight the importance of student cadaveric dissection.
PubMed: 37790014
DOI: 10.7759/cureus.44533 -
The Neurologist Dec 2023Glial fibrillary acidic protein (GFAP) astrocytopathy, an autoimmune central nervous system disorder characterized by the development of immunoglobulin G reactive with...
A Mild Phenotype of Overlapping Syndrome With Myelin-Oligodendrocyte Glycoprotein and Glial Fibrillary Acidic Protein Immunoglobulin G: Mimicking Viral Meningitis in a Patient.
INTRODUCTION
Glial fibrillary acidic protein (GFAP) astrocytopathy, an autoimmune central nervous system disorder characterized by the development of immunoglobulin G reactive with GFAP, has received growing attention in recent years. It is documented that GFAP-immunoglobulin G and other autoantibodies can be both detected in some patients. However, the coexistence of anti-myelin-oligodendrocyte glycoprotein (MOG) and GFAP antibodies is rarely reported.
CASE
A 45-year-old man presented with headache, fever, backache, dysuria, tremble of hands, numbness of lower limbs, without diplopia, decreased vision, or other manifestations of optic neuritis. He was initially diagnosed with viral meningitis. After antiviral therapy, his headache, fever, and dysuria were improved, but the tremble of his upper limbs and numbness of his lower limbs still existed. A lumbar puncture was further performed and found both anti-GFAP and anti-MOG antibodies in the cerebrospinal fluid. No evidence of other immune disorders or infectious diseases was revealed. Meanwhile, a magnetic resonance scan showed enhancement of spinal pia mater in cervical, thoracic, and lumbar segments. He was then treated with immunoglobulin (intravenous immunoglobulin) therapy (25 g for 5 d), and steroid pulse therapy (methylprednisolone, 1 g for 5 d), followed by a gradual tapering of oral prednisolone.
CONCLUSION
We reported a case of overlapping anti-GFAP and anti-MOG antibody-associated syndrome. This case enriches our understanding of the clinical manifestations of overlapping syndrome and expands the spectrum of this disorder.
PubMed: 38126409
DOI: 10.1097/NRL.0000000000000547 -
The Neuroradiology Journal Oct 2023Leptomeningeal myelomatosis is a rare complication of multiple myeloma (<1% of the patients). There was an increase in the incidence of leptomeningeal myelomatosis...
Leptomeningeal myelomatosis is a rare complication of multiple myeloma (<1% of the patients). There was an increase in the incidence of leptomeningeal myelomatosis during the last decade; the prognosis of leptomeningeal myelomatosis remains poor, (overall median survival from the time of diagnosis of 2 months). We discuss a rare case of a monoclonal gammopathy evolving into multiple myeloma and finally into a rapidly progressing leptomeningeal disease. A 76 year-old woman in hematologic follow-up for advanced stage multiple myeloma in sixth-line treatment had an episode of generalized tonic-clonic seizure with sphincter release followed by altered state of consciousness. The unenhanced head CT scan showed a mild enlargement of the ventricular system without intra-axial or extra-axial hemorrhages nor significant changes in brain parenchyma. The subsequent contrast-enhanced brain MRI revealed a widespread nodular leptomeningeal enhancement characterized by contrast-enhancement of the pia mater extended into the subarachnoid spaces of the sulci and cisterns, involving supra- and sub-tentorial regions and the statoacoustic nerve in the inner ear canal bilaterally. The fluid-attenuated inversion recovery MRI images demonstrated an abnormally elevated signal within the sulci in the parieto-occipital regions. The radiological diagnosis of leptomeningeal myelomatosis was made. The patient died 4 days after the examination. In patients with long-lasting multiple myeloma and onset of neurological signs or symptoms, a contrast-enhanced brain MRI should be performed to assess the actual burden of central nervous system involvement in leptomeningeal myelomatosis; CT may provide a clue to the diagnosis when progressive enlargement of the ventricles over time is noted.
PubMed: 36627179
DOI: 10.1177/19714009221150849 -
Interventional Neuroradiology : Journal... Jun 2024Cerebral pial arteriovenous fistulas (pAVFs) are rare and complex high-flow vascular malformations found in pediatric and adolescent populations. They are often divided...
Cerebral pial arteriovenous fistulas (pAVFs) are rare and complex high-flow vascular malformations found in pediatric and adolescent populations. They are often divided into two groups based on the pattern of venous drainage, galenic or nongalenic. Nongalenic pAVFs are typically supratentorial and carry a high risk of rupture. Their angioarchitecture is very complex with various patterns of feeding arteries and draining veins not originating from dural vessels or the vein of Galen. The natural history has not been well established; however, mortality estimates range as high 63%. Presentations include hemorrhage, seizure, congestive heart failure, and elevated intracranial pressure. We describe the case of an adolescent girl with acute onset of headaches that led to the discovery of an occipital, nongalenic pAVF. Transarterial and transvenous embolizations performed during a single procedure resulted in complete obliteration of the fistula. No complications arose, and the patient remained at her neurological baseline.
Topics: Humans; Female; Embolization, Therapeutic; Arteriovenous Fistula; Adolescent; Pia Mater; Intracranial Arteriovenous Malformations; Cerebral Angiography
PubMed: 36071583
DOI: 10.1177/15910199221122846 -
Oncology Letters Oct 2023Central nervous system (CNS) malignant melanomas are rare tumors of the CNS that are thought to arise from aberrant changes in melanocytes of the neural crest or...
Central nervous system (CNS) malignant melanomas are rare tumors of the CNS that are thought to arise from aberrant changes in melanocytes of the neural crest or melanocytic elements of the pia mater during early embryonic development. As a rare type of CNS malignant melanoma, only a few cases of primary malignant melanoma in the spinal canal have been reported thus far. The majority of these studies have reported on the diagnosis, radiographic features and gross total resection of primary spinal canal malignant melanoma; however, the prognosis and ideal treatment of patients with residual tumors remain elusive. The current study presented the rare case of a patient with primary malignant melanoma originating from the thoracic spinal canal, without any history of irradiation exposure and with an incompletely resected tumor. Disease-free survival of >2.5 years was observed in this patient who was treated with concurrent chemoradiotherapy followed by adjuvant chemotherapy with temozolomide and bevacizumab.
PubMed: 37664668
DOI: 10.3892/ol.2023.14020 -
Cureus Mar 2024Carcinomatous meningitis (CM) is characterized by the multifocal dissemination of malignant cells into the cerebrospinal fluid (CSF), pia mater, and subarachnoid space....
Carcinomatous meningitis (CM) is characterized by the multifocal dissemination of malignant cells into the cerebrospinal fluid (CSF), pia mater, and subarachnoid space. Involvement can occur in the advanced stage of malignancy, causing multifocal involvement and a wide array of symptoms. Diagnosis requires suspicions and a multimodal approach that includes imaging, lumbar puncture, and diagnostic laboratory evaluation. This case represents a female with a history of non-Hodgkin's lymphoma (NHL) and venous thromboembolism on chronic anticoagulation who presented due to acute encephalopathy, hallucinations, and right cranial nerve III palsy for 10 days before arrival. Computed tomography (CT) and angiography of the brain did not show any intracranial abnormalities. Subsequent magnetic resonance imaging (MRI) was without signs of infarction, hemorrhage, or abnormal enhancement, with the MRI of the orbits showing asymmetric linear enhancement anterior to the superior pons and midbrain on the right. Initial differential included a paraneoplastic syndrome, but there was no obvious evidence of pathological enhancement on MRI. Due to progressive bulbar symptoms, a lumbar puncture was performed with cerebrospinal fluid diagnostic workup with cytology showing monoclonal B-cell proliferation consistent with lymphoma. This case illustrates a rare but specific finding of CM as cranial nerve III palsy symptoms in this patient who did not have imaging findings that would reflect her symptoms on the initial MRI of the brain. Furthermore, diagnosing CM is complex and involves a combination of multiple diagnostic and treatment modalities. It is important to recognize the condition early to improve the patient's quality of life, prolong survival, and stabilize neurological deterioration.
PubMed: 38623120
DOI: 10.7759/cureus.56277 -
The American Journal of Pathology Jul 2024Two major constituents of exfoliation material, fibrillin-1 and lysyl oxidase-like 1 (encoded by FBN1 and LOXL1), are implicated in exfoliation glaucoma, yet their...
Two major constituents of exfoliation material, fibrillin-1 and lysyl oxidase-like 1 (encoded by FBN1 and LOXL1), are implicated in exfoliation glaucoma, yet their individual contributions to ocular phenotype are minor. To test the hypothesis that a combination of FBN1 mutation and LOXL1 deficiency exacerbates ocular phenotypes, the pan-lysyl oxidase inhibitor β-aminopropionitrile (BAPN) was used to treat adult wild-type (WT) mice and mice heterozygous for a missense mutation in Fbn1 (Fbn1) for 8 weeks and their eyes were examined. Although intraocular pressure did not change and exfoliation material was not detected in the eyes, BAPN treatment worsened optic nerve and axon expansion in Fbn1 mice, an early sign of axonal damage in rodent models of glaucoma. Disruption of elastic fibers was detected only in Fbn1 mice, which increased with BAPN treatment, as shown by histologic and immunohistochemical staining of the optic nerve pia mater. Transmission electron microscopy showed that Fbn1 mice had fewer microfibrils, smaller elastin cores, and a lower density of elastic fibers compared with WT mice in control groups. BAPN treatment led to elastin core expansion in both WT and Fbn1 mice, but an increase in the density of elastic fiber was confined to Fbn1 mice. LOX inhibition had a stronger effect on optic nerve and elastic fiber parameters in the context of Fbn1 mutation, indicating the Marfan mouse model with LOX inhibition warrants further investigation for exfoliation glaucoma pathogenesis.
Topics: Animals; Protein-Lysine 6-Oxidase; Marfan Syndrome; Disease Models, Animal; Mice; Fibrillin-1; Aminopropionitrile; Optic Nerve; Elastic Tissue; Intraocular Pressure; Fibrillins; Mice, Inbred C57BL; Amino Acid Oxidoreductases; Glaucoma; Microfilament Proteins; Adipokines
PubMed: 38548269
DOI: 10.1016/j.ajpath.2024.03.002 -
Neurosurgical Review Apr 2024Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly...
BACKGROUND
Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly connecting to venous drainage without an intermediate nidus. Dural arteriovenous fistulas (dAVFs) can infrequently involve additional pial feeders which can introduce higher flow shunting and increase the associated treatment risk. In the posterior fossa, arteriovenous fistula (AVF) angioarchitecture tends to be particularly complex, involving either multiple arterial feeders-sometimes from both dural and pial origins-or small caliber vessels that are difficult to catheterize and tend to be intimately involved with functionally critical brainstem or upper cervical cord structures. Given their rarity, published experience on microsurgical or endovascular treatment strategies for posterior fossa pAVFs and dAVFs with pial supply remains limited.
METHODS
Retrospective chart review from 2019-2023 at a high-volume center identified six adult patients with posterior fossa pAVFs that were unable to be fully treated endovascularly and required microsurgical disconnection. These cases are individually presented with a technical emphasis and supported by comprehensive angiographic and intraoperative images.
RESULTS
One vermian (Case 1), three cerebellopontine angle (Cases 2-4) and two craniovertebral junction (Cases 5-6) posterior fossa pAVFs or dAVFs with pial supply are presented. Three cases involved mixed dural and pial arterial supply (Cases 1, 4, and 6), and one case involved a concomitant microAVM (Case 2). Endovascular embolization was attempted in four cases (Cases 1-4): The small caliber and tortuosity of the main arterial feeder prevented catheterization in two cases (Cases 1 and 3). Partial embolization was achieved in Cases 2 and 4. In Cases 5 and 6, involvement of the lateral spinal artery or anterior spinal artery created a prohibitive risk for endovascular embolization, and surgical clip ligation was pursued as primary management. In all cases, microsurgical disconnection resulted in complete fistula obliteration without evidence of recurrence on follow-up imaging (mean follow-up 27.1 months). Two patients experienced persistent post-treatment sensory deficits without significant functional limitation.
CONCLUSIONS
This illustrative case series highlights the technical difficulties and anatomical limitations of endovascular management for posterior fossa pAVFs and dAVFs with pial supply and emphasizes the relative safety and utility of microsurgical disconnection in this context. A combined approach involving partial preoperative embolization-when the angioarchitecture is permissive-can potentially decrease surgical morbidity. Larger studies are warranted to better define the role for multimodal intervention and to assess associated long-term AVF obliteration rates in the setting of pial arterial involvement.
Topics: Humans; Male; Female; Middle Aged; Central Nervous System Vascular Malformations; Aged; Pia Mater; Retrospective Studies; Adult; Arteriovenous Fistula; Cranial Fossa, Posterior; Neurosurgical Procedures; Embolization, Therapeutic; Intracranial Arteriovenous Malformations
PubMed: 38658425
DOI: 10.1007/s10143-024-02407-y