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Neurosurgical Focus Aug 2023The objective of this review was to describe the immunological changes that take place in the dura mater in response to metastatic disease that seeds the CNS. The... (Review)
Review
OBJECTIVE
The objective of this review was to describe the immunological changes that take place in the dura mater in response to metastatic disease that seeds the CNS. The authors hypothesized that the dura's anatomy and resident immune cell population play a role in enabling metastasis to the brain and leptomeninges.
METHODS
An extensive literature search was conducted to identify evidence that supports the dura's participation in metastasis to the CNS. The authors' hypothesis was informed by a recent upsurge in studies that have investigated the dura's role in metastatic development, CNS infections, and autoimmunity. They reviewed this literature as well as the use of immunotherapy in treating brain metastases and how these therapies change the meningeal immune landscape to overcome and reverse tumor-promoting immunosuppression.
RESULTS
Evidence suggests that the unique architecture and immune cell profile of the dura, compared with other immune compartments within the CNS, facilitate entry of metastatic tumor cells into the brain. Once these tumor cells penetrate the dural barrier, they propagate an immunosuppressive tumor microenvironment. Therefore, immunotherapy may serve to overcome this immunosuppressive environment and liberate proinflammatory immune cells in an effort to combat metastatic disease.
CONCLUSIONS
Within the next few years, the authors expect the addition of several more scientific studies into the literature that further underscore the dura as a chief participant and neuroanatomical barrier in neuro-oncology.
Topics: Humans; Dura Mater; Brain Neoplasms; Brain; Supratentorial Neoplasms; Tumor Microenvironment
PubMed: 37527680
DOI: 10.3171/2023.5.FOCUS23229 -
AJNR. American Journal of Neuroradiology Sep 2021Synthetic MRI enables the generation of various contrast-weighted images and quantitative data in a reasonable scanning time. We aimed to use synthetic MRI to assess the...
BACKGROUND AND PURPOSE
Synthetic MRI enables the generation of various contrast-weighted images and quantitative data in a reasonable scanning time. We aimed to use synthetic MRI to assess the detection and underlying tissue characteristics of focal areas of signal intensity and normal-appearing brain parenchyma and morphometric alterations in the brains of patients with neurofibromatosis type 1.
MATERIALS AND METHODS
Conventional MR imaging and synthetic MRI were prospectively obtained from 19 patients with neurofibromatosis type 1 and 18 healthy controls. Two neuroradiologists independently evaluated focal areas of signal intensity on both conventional MR imaging and synthetic MRI. Additionally, automatically segmented volume calculations of the brain in both groups and quantitative analysis of myelin, including the focal areas of signal intensity and normal-appearing brain parenchyma, of patients with neurofibromatosis type 1 were performed using synthetic MRI.
RESULTS
The comparison of conventional MR imaging and synthetic MRI showed good correlation in the supratentorial region of the brain (κ = 0.82-1). Automatically segmented brain parenchymal volume, intracranial volume, and GM volumes were significantly increased in the patients with neurofibromatosis type 1 (< .05). The myelin-correlated compound, myelin fraction volume, WM fraction volume, transverse relaxation rate, and longitudinal relaxation rate values were significantly decreased in focal areas of signal intensity on myelin and WM maps (< .001); however, GM, GM fraction volume, and proton density values were significantly increased on the GM map (< .001).
CONCLUSIONS
Synthetic MRI is a potential tool for the assessment of morphometric and tissue alterations as well as the detection of focal areas of signal intensity in patients with neurofibromatosis type 1 in a reasonable scan time.
Topics: Brain; Humans; Magnetic Resonance Imaging; Myelin Sheath; Neurofibromatosis 1; Protons
PubMed: 34266869
DOI: 10.3174/ajnr.A7214 -
Child's Nervous System : ChNS :... Jul 2020Myelomeningocele (MMC) is often related to hydrocephalus and Chiari malformation (CM) type 2; however, other brain abnormalities have been reported in this population....
BACKGROUND
Myelomeningocele (MMC) is often related to hydrocephalus and Chiari malformation (CM) type 2; however, other brain abnormalities have been reported in this population. In order to better understand and quantify other forebrain abnormalities, we analyzed magnetic resonance imaging (MRI) of MMC patients treated in utero or postnatal.
METHODS
Between January 2014 and March 2017, 59 MMC were treated in our hospital. Thirty-seven patients (32 postnatal and 5 intrautero repair) had brain MRI and were enrolled at the study. MRI was analyzed by two experienced neuroradiologists to identify the supra and infratentorial brain abnormalities.
RESULTS
A wide range of brain abnormalities was consistently identified in MMC patients. As expected, the most common were hydrocephalus (94.5%) and CM type II (89.1%). Of note, we found high incidence of corpus callosum abnormalities (86.4%), mostly represented by dysplasia (46%).
CONCLUSIONS
The data are consistent with the concept that brain abnormalities related to MMC can be both infratentorial and supratentorial, cortical, and subcortical. More studies are needed to correlate these forebrain abnormalities to long-term functional outcome and their prognostic value for these patients.
Topics: Arnold-Chiari Malformation; Brain; Humans; Hydrocephalus; Meningomyelocele; Retrospective Studies
PubMed: 31664560
DOI: 10.1007/s00381-019-04386-8 -
Neurology India 2022New controversies have raised on brain death (BD) diagnosis when lesions are localized in the posterior fossa. (Review)
Review
BACKGROUND
New controversies have raised on brain death (BD) diagnosis when lesions are localized in the posterior fossa.
OBJECTIVE
The aim of this study was to discuss the particularities of BD diagnosis in patients with posterior fossa lesions.
MATERIALS AND METHODS
The author made a systematic review of literature on this topic.
RESULTS AND CONCLUSIONS
A supratentorial brain lesion usually produces a rostrocaudal transtentorial brain herniation, resulting in forebrain and brainstem loss of function. In secondary brain lesions (i.e., cerebral hypoxia), the brainstem is also affected like the forebrain. Nevertheless, some cases complaining posterior fossa lesions (i.e., basilar artery thrombotic infarcts, or hemorrhages of the brainstem and/or cerebellum) may retain intracranial blood flow and EEG activity. In this article, I discuss that if a posterior fossa lesion does not produce an enormous increment of intracranial pressure, a complete intracranial circulatory arrest does not occur, explaining the preservation of EEG activity, evoked potentials, and autonomic function. I also addressed Jahi McMath, who was declared braindead, but ancillary tests, performed 9 months after initial brain insult, showed conservation of intracranial structures, EEG activity, and autonomic reactivity to "Mother Talks" stimulus, rejecting the diagnosis of BD. Jahi McMath's MRI study demonstrated a huge lesion in the pons. Some authors have argued that in patients with primary brainstem lesions it might be possible to find in some cases partial recovery of consciousness, even fulfilling clinical BD criteria. This was the case in Jahi McMath.
Topics: Brain; Brain Death; Brain Diseases; Brain Stem; Humans; Intracranial Pressure
PubMed: 35532637
DOI: 10.4103/0028-3886.344634 -
Radiology Oct 2020Diffuse leukoencephalopathy and juxtacortical and/or callosal microhemorrhages were brain imaging features in critically ill patients with coronavirus disease 2019....
Diffuse leukoencephalopathy and juxtacortical and/or callosal microhemorrhages were brain imaging features in critically ill patients with coronavirus disease 2019. Coronavirus disease 2019 (COVID-19) has been reported in association with a variety of brain imaging findings such as ischemic infarct, hemorrhage, and acute hemorrhagic necrotizing encephalopathy. Herein, the authors report brain imaging features in 11 critically ill patients with COVID-19 with persistently diminished mental status who underwent MRI between April 5 and April 25, 2020. These imaging features include confluent T2 hyperintensity and mild restricted diffusion in bilateral supratentorial deep and subcortical white matter (in 10 of 11 patients) and multiple punctate microhemorrhages in juxtacortical and callosal white matter (in seven of 11 patients). The authors also discuss potential pathogeneses.
Topics: Adult; Betacoronavirus; Brain; COVID-19; Cerebral Hemorrhage; Coronavirus Infections; Encephalitis; Female; Humans; Leukoencephalopathies; Magnetic Resonance Imaging; Male; Middle Aged; Pandemics; Pneumonia, Viral; Retrospective Studies; SARS-CoV-2
PubMed: 32437314
DOI: 10.1148/radiol.2020202040 -
Pediatric Neurology Dec 2023Acute flaccid myelitis (AFM) presents with acute onset of flaccid paralysis with involvement of the gray matter on magnetic resonance imaging (MRI) of the spinal cord.... (Review)
Review
BACKGROUND
Acute flaccid myelitis (AFM) presents with acute onset of flaccid paralysis with involvement of the gray matter on magnetic resonance imaging (MRI) of the spinal cord. Studies have reported brain MRI abnormalities, but the characteristics have not been fully defined. In this multicenter study, we assessed the acute features and evolution of brain MRI abnormalities in AFM.
METHODS
We reviewed brain MRIs of patients with AFM who presented to four referral hospitals between 2012 and 2018. Cases met established criteria for AFM. We analyzed the initial and follow-up brain MRIs. Areas were divided into supratentorial, infratentorial, and subdivisions within those regions.
RESULTS
A total of 66 patients were included. Brain MRI abnormalities were present in 34 (52%). Infratentorial abnormalities were more common, occurring in 33 (97%) cases with the dorsal pons being the most frequently affected area (88%). Abnormalities were also present in the medulla (74%), cerebellum (41%), and midbrain (38%). Nine subjects (26%) exhibited both supratentorial and infratentorial abnormalities, whereas isolated supratentorial changes were present in only one (3%). Contrast-enhancing abnormalities were encountered in 9% of cases and meningeal involvement in 6%. On follow-up, most abnormalities, 20 of 24 (83%), were stable, improving, or had resolved.
CONCLUSIONS
Brain MRI abnormalities occur in about half of the cases of AFM and commonly resolve with time. Dorsal pontine involvement is a characteristic MRI feature, whereas isolated supratentorial abnormalities are rare. Clinicians should consider that brain imaging abnormalities do not exclude a diagnosis of AFM in patients with typical presentations.
Topics: Humans; Magnetic Resonance Imaging; Nervous System Malformations; Neuromuscular Diseases; Brain Diseases; Cerebellum; Multicenter Studies as Topic
PubMed: 37797356
DOI: 10.1016/j.pediatrneurol.2023.08.021 -
Journal of Anatomy Jul 2021Supratentorial sensory perception, including pain, is subserved by the trigeminal nerve, in particular, by the branches of its ophthalmic division, which provide an... (Review)
Review
Supratentorial sensory perception, including pain, is subserved by the trigeminal nerve, in particular, by the branches of its ophthalmic division, which provide an extensive innervation of the dura mater and of the major brain blood vessels. In addition, contrary to previous assumptions, studies on awake patients during surgery have demonstrated that the mechanical stimulation of the pia mater and small cerebral vessels can also produce pain. The trigeminovascular system, located at the interface between the nervous and vascular systems, is therefore perfectly positioned to detect sensory inputs and influence blood flow regulation. Despite the fact that it remains only partially understood, the trigeminovascular system is most probably involved in several pathologies, including very frequent ones such as migraine, or other severe conditions, such as subarachnoid haemorrhage. The incomplete knowledge about the exact roles of the trigeminal system in headache, blood flow regulation, blood barrier permeability and trigemino-cardiac reflex warrants for an increased investigation of the anatomy and physiology of the trigeminal system. This translational review aims at presenting comprehensive information about the dural and brain afferents of the trigeminovascular system, in order to improve the understanding of trigeminal cranial sensory perception and to spark a new field of exploration for headache and other brain diseases.
Topics: Brain; Cerebral Arteries; Dura Mater; Headache; Humans; Trigeminal Nerve
PubMed: 33604906
DOI: 10.1111/joa.13413 -
The Surgeon : Journal of the Royal... Oct 202315-30% of primary cancers metastasise to the brain. Of these, 10-25% involve the posterior fossa. It remains unclear whether patients undergoing resection for...
OBJECTIVE
15-30% of primary cancers metastasise to the brain. Of these, 10-25% involve the posterior fossa. It remains unclear whether patients undergoing resection for infratentorial brain metastases experience poorer prognosis than those with supratentorial lesions. We compare the post-operative outcomes of these two groups.
METHODS
We searched the electronic health records of all patients undergoing brain metastases resection at our regional neurosurgical centre between February 2014 and August 2019. Clinical data was collected on 85 consecutive patients (61 supratentorial, 24 infratentorial metastases). Outcome measures included overall survival, post-operative complications, and performance status. Patients were followed up until 21/04/2020.
RESULTS
Median post-operative survival of patients with supratentorial metastases was 323 days (95% CI 235-411), compared to 277 days (95% CI 195-359) for those with infratentorial metastases. These two groups experienced comparable survival (log rank = 0.276, p = 0.60) on univariate analysis. Infratentorial metastasis location was not associated with a change in survival using a Cox proportional hazards model incorporating age, sex and extracranial disease activity (HR = 1.39, 95% CI 0.777-2.486) (p = 0.27). However, neurological and non-neurological post-operative complications were more frequent in patients with infratentorial metastases (neurological = 21% vs 13%, non-neurological = 25% vs 2%, p = 0.002).
CONCLUSION
Patients with supra- and infratentorial metastases experienced comparable post-operative survival but posterior fossa metastasis location was associated with a 2.5 times higher risk of neurological and/or non-neurological post-operative complications. A better understanding of the precise indications for safe and effective surgical intervention for posterior fossa metastases is required.
Topics: Humans; Brain Neoplasms; Brain; Retrospective Studies
PubMed: 36805302
DOI: 10.1016/j.surge.2023.01.006 -
Brain and Behavior Nov 2019The main culprit lesion causing hiccup in patients with ischemic stroke is thought to involve the medulla oblongata, but some cases of hiccups caused by damage to the...
BACKGROUNDS
The main culprit lesion causing hiccup in patients with ischemic stroke is thought to involve the medulla oblongata, but some cases of hiccups caused by damage to the supratentorial cortex have been reported. The present study aimed to address the clinical and radiological characteristics of acute stroke patients accompanied by hiccups caused by supratentorial lesions.
METHOD
We retrospectively studied 5,309 consecutive patients with acute ischemic stroke or transient ischemic attack who were admitted to our institute within 7 days after onset between April 2006 and September 2017. We searched for the term "hiccup" in prospectively collected descriptive datasets and analyzed associations between hiccup and clinical and radiological findings, with particular focus on patients with supratentorial lesions.
RESULTS
We finally selected 16 stroke patients accompanied by hiccup. Nine patients had infarcts in the lateral medulla oblongata, and others had supratentorial infarcts (three patients with cortical infarcts, four patients with subcortical infarcts). Moreover, the right hemisphere was frequently damaged in this series (6/7, 86%).
CONCLUSIONS
Hiccup could be caused by supratentorial infarcts including the insular cortex, temporal lobe, and subcortex.
Topics: Aged; Aged, 80 and over; Cerebral Cortex; Cerebral Infarction; Hiccup; Humans; Male; Medulla Oblongata; Middle Aged; Retrospective Studies; Temporal Lobe
PubMed: 31617326
DOI: 10.1002/brb3.1439 -
World Neurosurgery May 2020Cerebellar ectopy is a rare finding, with few cases previously reported. Intraventricular localized cerebellar ectopy was described in only 1 case within the fourth...
BACKGROUND
Cerebellar ectopy is a rare finding, with few cases previously reported. Intraventricular localized cerebellar ectopy was described in only 1 case within the fourth ventricle.
CASE DESCRIPTION
A 9-year-old girl suffered for 2 years from bilateral frontoparietal headaches, sometimes accompanied by vomiting and photophobia. Magnetic resonance imaging demonstrated an oval-shaped lesion within the left lateral ventricle, characterized by well-defined margins without a clear cleavage plane from the adjacent choroid plexus. The mass presented an intermediate signal on T1- and T2-weighted sequences, similar to gray matter, and reduced ADC values on ADC maps compared with white matter, with no enhancement after gadolinium-based contrast injection. After resection, macroscopic examination revealed an organoid structure with leptomeningeal lining and a clear-cut cortex and white matter components. Histology demonstrated normal cerebellum with a double-layered cortex and normal underlying white matter. The cerebellar ectopy was focally covered by bundles of capillary vascular structures covered by a monostratified ependymal cell lining, consistent with choroid plexus.
CONCLUSIONS
We describe, for the first time to our knowledge, the case of a child with ectopic cerebellar tissue harboring the supratentorial ventricular system. Plausible etiologic mechanism consists in the herniation of the cerebellar germinal tissue into the ventricular system through the ependyma, allowing cell migration to the supratentorial compartment, followed by maturation into the normal cerebellum.
Topics: Cerebellum; Child; Choristoma; Female; Headache; Humans; Lateral Ventricles; Magnetic Resonance Imaging; Neurosurgical Procedures
PubMed: 31996339
DOI: 10.1016/j.wneu.2020.01.127