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Contact sport and blast-related neuropathology
Published in Helen Whitwell, Christopher Milroy, Daniel du Plessis, Forensic Neuropathology, 2021
Daniel du Plessis, Christopher Milroy
Macroscopically there may be no obvious changes (McKee et al. 2015). In the early stages, there may be mild enlargement in the frontal and temporal horns of the lateral ventricles. Perivascular spaces may be prominent in the white matter, most significantly in the temporal lobes. As CTE advances, there is atrophy and brain weight is decreased. The most significant areas affected are grey and white matter in the frontal and anterior temporal lobes. There can be enlargement of the lateral and third ventricles and there may be a cavum septum pellucidum with septal fenestrations. The thalamus is atrophied along with the mammillary bodies and hypothalamus. The substantia nigra and locus coeruleus can become depigmented. The cerebellum is typically normal macroscopically.
CSF Circulation and Disorders
Published in Swati Goyal, Neuroradiology, 2020
Virchow-Robin spaces, also known as perivascular spaces, are well-defined, CSF density spaces that surround perforating vessels. These are usually found in the basal ganglia region and need to be differentiated from lacunar infarcts. Lacunar infarcts are surrounded by areas of encephalomalacia, best seen as high signal intensity on FLAIR sequences. Giant perivascular (tumefactive) spaces − anterior temporal lobe perivascular spaces are rare, and may mimic a cystic tumor.
Radiation Damage of the Nervous System
Published in Kedar N. Prasad, Handbook of RADIOBIOLOGY, 2020
The present concept suggests that the blood-brain barrier is referred to as the absence of a perivascular space. The astrocytic basal lamina is fused with the basement membrane of the endothelial cell, and the barrier function is probably shared by the astrocytes. Thus, radiation damage of the blood-brain barrier may be associated with the delayed necrosis of the CNS.9 Whether the acute and delayed breakdown in blood-brain barrier function is responsible for tissue necrosis is not known. Most investigators believe that damage of the vascular system is the primary factor in the delayed necrosis of the brain.
Primary diffuse leptomeningeal oligodendrogliomatosis with an isolated 1p deletion
Published in British Journal of Neurosurgery, 2023
Samuel Gatzert, Aditya Durgam, Karthikram Raghuram, Amit Agarwal
PDLG is thought to arise from heterotopic glial rests which invaginate along the pia mater and subarachnoid space during elongation and growth of the spinal cord.1 The general clinical presentation of PDLG involves signs of raised intracranial pressure, cranial nerve palsies, and extremity radiculopathies. CSF analysis typically reveals increased protein, decreased glucose, and no evidence of infection. Rarely, malignant cells can be detected (8 cases, Table 1). Repeated or large volume (Loupre, CSF sampling may be useful. When malignant cells are observed, GFAP staining has been used to differentiate PDLG from chronic, aseptic meningitis or non-glial leptomeningeal carcinomatosis.4 The finding of diffuse leptomeningeal enhancement on post-contrast T1-weighted MR imaging and relatively little or no enhancement within the brain itself are the hallmarks of this disease. Some intra-parenchymal enhancement, particularly in cases with advanced disease burden, may indicate spread of the disease along the perivascular spaces. Rarely, PDLG can be MR or biopsy occult, and the diagnosis must be supported by a complete, post-mortem examination (39 cases, Table 1). Cases of non-diagnostic leptomeningeal biopsy (8 cases, Table 1) may be explained, in part, by the predilection of the disease to affect the skull base rather than along the cerebral convexities where biopsies had been routinely performed. Blastic osseous lesions and intraperitoneal metastases have been described.5,6
Clinical neuroimaging in intracerebral haemorrhage related to cerebral small vessel disease: contemporary practice and emerging concepts
Published in Expert Review of Neurotherapeutics, 2022
Martina Goeldlin, Catriona Stewart, Piotr Radojewski, Roland Wiest, David Seiffge, David J Werring
Enlarged perivascular spaces are cerebrospinal fluid-filled spaces surrounding small brain vessels <3 mm wide with round or ovoid appearance in perpendicular and curvilinear appearance in transverse views. They appear isointense to the CSF (hyperintense in T2 and hypointense in T1 sequences) [21,93]. Doubal et al. proposed a 5-grade grading system: Centrum semiovale perivascular spaces and basal ganglia perivascular spaces are assessed separately. For the grading, which is done by localization (centrum semiovale vs. basal ganglia), the hemisphere with the higher count is used [93]. Given their association with CAA-related hemorrhage [94] and pathology-proven CAA [95], centrum semiovale perivascular spaces are included as a supportive feature for CAA diagnosis in the Boston criteria 2.0 [96,97]. Perivascular spaces have recently been identified as a potential novel imaging marker for the risk of ICH among patients taking oral anticoagulants (multivariable HR 8.96, 95% CI 2.41–33.4), underlining their potential role as an imaging marker of severe small vessel disease [98].
The blood–brain and gut–vascular barriers: from the perspective of claudins
Published in Tissue Barriers, 2021
Anna Agata Scalise, Nikolaos Kakogiannos, Federica Zanardi, Fabio Iannelli, Monica Giannotta
The GVB shares many key morphological and functional characteristics with the well-known BBB (Figure 1). The main components of the BBB are the brain endothelial cells, which are in close contact with the pericytes, with both sheathed in the protective protein cover known as the basement membrane, which is produced by both cell types. Pericytes are recruited to vessels early in development, and they stabilize the vessels by their effects on brain endothelial cells, whereby they acquire more BBB characteristics. Brain endothelial cells and pericytes form the vascular unit of the BBB. The end-feet that project from the astrocytes that are attached on these endothelial cells and pericytes then function as a bridge between the vascular unit and the neurons, as well as promoting the maturation of the BBB. The highly coordinated activity that arises from these multiple cell types, which also include the vascular unit, glia and neurons, is known as the neurovascular unit (Figure 1(b)). The perivascular space then lies at the level of the post-capillary vessels, between the vascular unit and the astrocytes, and this is defined by the basement membrane and the parenchymal membrane that is produced by the astrocytes. This space contains antigen-presenting cells (i.e., microglia, macrophages), which have functions in immunosurveillance. Constant communication between the neurovascular unit and the other brain cell types assure the functions of the BBB as a physical, metabolic, transport and immunological barrier (for BBB reviews, see13–16).