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World Neurosurgery Nov 2023A 62-year-old man presented a diffuse and predominantly cisternal acute nonaneurysmal subarachnoid hemorrhage associated with hydrocephalus. An external ventricular...
A 62-year-old man presented a diffuse and predominantly cisternal acute nonaneurysmal subarachnoid hemorrhage associated with hydrocephalus. An external ventricular drain was placed, followed by clinical deterioration after its removal. At this point, a heavily T2-weighted high-resolution sequence of a brain magnetic resonance imaging showed acute hydrocephalus recrudescence and multiple arachnoid adhesions in the supravermian and interpeduncular cisterns, creating a loculated/cystic appearance. The diagnosis of intracranial arachnoiditis was made. Intracranial arachnoiditis results from meningeal inflammation. Fibrosis and adhesions at the subarachnoid spaces may follow, restricting cerebrospinal fluid circulation, particularly at the cranial base. Hydrocephalus probably resulted from the combination of subarachnoid hemorrhage and extensive scaring at the basal cisterns, precluding transdural and transvenous cerebrospinal fluid efflux. Heavily T2-weighted high-resolution magnetic resonance imaging sequences allow an exquisite depiction of arachnoiditis, displaying obstructive cisternal membranes, and contribute to better etiologic assessment and management of hydrocephalus.
Topics: Male; Humans; Middle Aged; Arachnoiditis; Subarachnoid Hemorrhage; Hydrocephalus; Brain; Inflammation
PubMed: 37516141
DOI: 10.1016/j.wneu.2023.07.106 -
Child's Nervous System : ChNS :... Nov 2021Multiple names within the literature refer to a clinical picture affecting infants and consisting of a large or fast growing head circumference with enlarged cortical... (Review)
Review
PURPOSE
Multiple names within the literature refer to a clinical picture affecting infants and consisting of a large or fast growing head circumference with enlarged cortical subarachnoid spaces (CSAS) while cranial sutures are open. This myriad of terms demonstrates the confusion about the entity, that may even group together different etiological processes. In this review, we aim to shed light on this matter in an effort to restate the defining features of the clinical picture and sum the evidence and current understanding of its pathophysiology and related imaging findings.
METHODS
Extensive and updated review of the literature with special focus on defining features, clinical history with long term evaluation and pathophysiological process.
RESULTS
Functional and molecular CSF studies as well as clinical evidence challenges the common pathophysiological theory based on non-functional arachnoid villi. Conversely, there is increasing evidence supporting cerebro-venous system abnormalities as the main pathophysiological factor. Additionally, long term cohorts studies show that it may have subtle but irreversible neurodevelopmental consequences.
CONCLUSION
Subarachnomegaly is an age-related condition of the infancy with radiological enlargement of CSAS and often self limiting course. However, considering the evidence on pathophysiology as outlined herein and long term outcome reports, further research effort is needed to assess the consequences of venous outflow impairment and enlarged CSAS and how this relates to imaging findings and neurodevelopment test results later in life.
Topics: Humans; Hyperemia; Infant; Subarachnoid Space
PubMed: 34687332
DOI: 10.1007/s00381-021-05328-z -
Current Opinion in Infectious Diseases Oct 2020Subarachnoid neurocysticercosis (SUBNCC) is caused by a morphologically unique proliferative form of Taenia solium involving the subarachnoid spaces. Prolonged therapy... (Review)
Review
PURPOSE OF REVIEW
Subarachnoid neurocysticercosis (SUBNCC) is caused by a morphologically unique proliferative form of Taenia solium involving the subarachnoid spaces. Prolonged therapy based upon the pathophysiology of SUBNCC and long-term follow-up have shed light on the course of disease and led to highly improved outcomes.
RECENT FINDINGS
SUBNCC has a prolonged incubation period of between 10 and 25 years characterized by cyst proliferation and growth and invasion of contiguous spaces leading to mass effect (Stage 1). With induction of the host-immune responses, cysts degenerate leading to a predominately inflammatory arachnoiditis (Stage 2) causing hydrocephalus, infarcts, and other inflammatory based neurological manifestations. Inactive disease (Stage 3) may occur naturally but mostly is a result of successful treatment, which generally requires prolonged intensive anthelminthic and antiinflammatory treatments. Cerebral spinal fluid cestode antigen or cestode DNA falling to nondetectable levels predicts effective treatment. Prolonged treatment with extended follow-up has resulted in moderate disability and no mortality. Repeated short intensive 8-14-day courses of treatment are also used, but long-term outcomes and safety using this strategy are not reported.
SUMMARY
SUBNCC gives rise to a chronic arachnoiditis. Its unique ability to proliferate and induce inflammatory responses requires long-term anthelmintic and antiinflammatory medications.
Topics: Animals; Anthelmintics; Anti-Inflammatory Agents; Antigens, Helminth; Arachnoiditis; Humans; Magnetic Resonance Imaging; Neurocysticercosis; Subarachnoid Space; Taenia solium
PubMed: 32868512
DOI: 10.1097/QCO.0000000000000669 -
The New England Journal of Medicine Aug 2019
Topics: Astrocytoma; Brain Neoplasms; Child, Preschool; Female; Humans; Hydrocephalus; Magnetic Resonance Imaging; Subarachnoid Space; Ventriculostomy
PubMed: 31365804
DOI: 10.1056/NEJMicm1815973 -
Journal of the Neurological Sciences Apr 2020Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges (pia, subarachnoid space and arachnoid mater), and dura.... (Review)
Review
Central nervous system (CNS) metastasis from systemic cancers can involve the brain parenchyma, leptomeninges (pia, subarachnoid space and arachnoid mater), and dura. Leptomeningeal metastases (LM), also known by different terms including neoplastic meningitis and carcinomatous meningitis, occur in both solid tumors and hematologic malignancies. This review will focus exclusively on LM arising from solid tumors with a goal of providing the reader an understanding of the epidemiology, pathophysiology, clinical presentation, prognostication, current management and future directions.
Topics: Arachnoid; Dura Mater; Humans; Meningeal Carcinomatosis; Meningeal Neoplasms; Meninges; Meningitis, Bacterial; Neoplasms
PubMed: 32007755
DOI: 10.1016/j.jns.2020.116706 -
Surgical Neurology International 2022Arachnoiditis refers to chronic inflammation of the arachnoid mater and subarachnoid space due to three major etiologies: chemical, mechanical, and postinfectious. As a... (Review)
Review
BACKGROUND
Arachnoiditis refers to chronic inflammation of the arachnoid mater and subarachnoid space due to three major etiologies: chemical, mechanical, and postinfectious. As a rare disease with variable symptomatology and severity at presentation, arachnoiditis can be extremely debilitating with many complications, prominent among which is syringomyelia.
METHODS
We reviewed current literature concerning postinfectious spinal arachnoiditis and associated syringomyelia with emphasis on the treatment options that have been used to date and discuss their respective benefits and drawbacks.
RESULTS
It is critical to understand the natural history and potential complications of patient with postinfectious arachnoiditis. Surgical and medical treatments both have their own merits and demerits. Different surgical approaches have been employed with variable success rates.
CONCLUSION
At present, no consensus exists regarding management of these patients due to the variable nature of the disease that affects treatment efficacy; however, surgical intervention in selected cases may be beneficial.
PubMed: 35928312
DOI: 10.25259/SNI_383_2022 -
Journal of Neurosurgery. Spine Nov 2019Chiari malformation was first described over a century ago, and consists of posterior fossa anomalies that generally share the feature of cerebellar tonsillar descent... (Review)
Review
Chiari malformation was first described over a century ago, and consists of posterior fossa anomalies that generally share the feature of cerebellar tonsillar descent through the foramen magnum. Our understanding of this disorder was initially based on autopsy studies, and has been greatly enhanced by the advent of MRI. The surgical management of Chiari anomalies has also evolved in a parallel fashion. Although the exact surgical technique varies among individual surgeons, the goals of surgery remain constant and consist of relieving brainstem compression and cranial nerve distortion, restoring the normal flow of CSF across the foramen magnum, and reducing the size of any associated syrinx cavity. Syrinx cavities are most commonly associated with Chiari anomalies, yet primary spinal syringomyelia (PSS) can be caused by traumatic, infectious, degenerative, and other etiologies that cause at least a partial CSF flow obstruction in the spinal subarachnoid space. As with syringomyelia associated with Chiari anomalies, the main goal of PSS surgery is to reestablish CSF flow across the area of obstruction. In addition to MRI, myelography with CT can be very helpful in the evaluation and management of these patients by identifying focal regions of CSF obstruction that may be amenable to surgical intervention. Future directions for the treatment of Chiari anomalies and syringomyelia include the application of advanced imaging techniques, more widespread use of genetic evaluation, large-scale outcome studies, and the further refinement of surgical technique.
Topics: Arnold-Chiari Malformation; Cerebrospinal Fluid Pressure; Foramen Magnum; Humans; Magnetic Resonance Imaging; Subarachnoid Space; Syringomyelia
PubMed: 31675698
DOI: 10.3171/2019.7.SPINE181139 -
Nature Neuroscience Jul 2022The meninges, comprising the leptomeninges (pia and arachnoid layers) and the pachymeninx (dura layer), participate in central nervous system (CNS) autoimmunity, but...
The meninges, comprising the leptomeninges (pia and arachnoid layers) and the pachymeninx (dura layer), participate in central nervous system (CNS) autoimmunity, but their relative contributions remain unclear. Here we report on findings in animal models of CNS autoimmunity and in patients with multiple sclerosis, where, in acute and chronic disease, the leptomeninges were highly inflamed and showed structural changes, while the dura mater was only marginally affected. Although dural vessels were leakier than leptomeningeal vessels, effector T cells adhered more weakly to the dural endothelium. Furthermore, local antigen-presenting cells presented myelin and neuronal autoantigens less efficiently, and the activation of autoreactive T cells was lower in dural than leptomeningeal layers, preventing local inflammatory processes. Direct antigen application was required to evoke a local inflammatory response in the dura. Together, our data demonstrate an uneven involvement of the meningeal layers in CNS autoimmunity, in which effector T cell trafficking and activation are functionally confined to the leptomeninges, while the dura remains largely excluded from CNS autoimmune processes.
Topics: Animals; Arachnoid; Autoimmunity; Central Nervous System; Dura Mater; Humans; Meninges; Multiple Sclerosis
PubMed: 35773544
DOI: 10.1038/s41593-022-01108-3 -
Pediatric Radiology May 2021Enlarged subarachnoid spaces are a common finding in infants and young children imaged for macrocephaly or an enlarging head circumference, and benign enlargement of the... (Review)
Review
Enlarged subarachnoid spaces are a common finding in infants and young children imaged for macrocephaly or an enlarging head circumference, and benign enlargement of the subarachnoid spaces is often diagnosed. Infrequently, presumed "spontaneous" subdural hemorrhages or subdural collections might complicate these enlarged subarachnoid spaces. Children with large bilateral subdural collections might also present for imaging with macrocephaly. Each scenario potentially raises concerns for prior injury because subdural hemorrhage is a frequent finding in children with abusive head trauma.
Topics: Child; Child Abuse; Child, Preschool; Craniocerebral Trauma; Hematoma, Subdural; Humans; Infant; Megalencephaly; Subarachnoid Space
PubMed: 33999235
DOI: 10.1007/s00247-020-04848-1 -
Journal of Neurosurgery. Spine Feb 2022Chronic adhesive spinal arachnoiditis (SA) is a complex disease process that results in spinal cord tethering, CSF flow blockage, intradural adhesions, spinal cord...
OBJECTIVE
Chronic adhesive spinal arachnoiditis (SA) is a complex disease process that results in spinal cord tethering, CSF flow blockage, intradural adhesions, spinal cord edema, and sometimes syringomyelia. When it is focal or restricted to fewer than 3 spinal segments, the disease responds well to open surgical approaches. More extensive arachnoiditis extending beyond 4 spinal segments has a much worse prognosis because of less adequate removal of adhesions and a higher propensity for postoperative scarring and retethering. Flexible neuroendoscopy can extend the longitudinal range of the surgical field with a minimalist approach. The authors present a cohort of patients with severe cervical and thoracic arachnoiditis and myelopathy who underwent flexible endoscopy to address arachnoiditis at spinal segments not exposed by open surgical intervention. These observations will inform subsequent efforts to improve the treatment of extensive arachnoiditis.
METHODS
Over a period of 3 years (2017-2020), 10 patients with progressive myelopathy were evaluated and treated for extensive SA. Seven patients had syringomyelia, 1 had spinal cord edema, and 2 had spinal cord distortion. Surgical intervention included 2- to 5-level thoracic laminectomy, microscopic lysis of adhesions, and then lysis of adhesions at adjacent spinal levels performed using a rigid or flexible endoscope. The mean follow-up was 5 months (range 2-15 months). Neurological function was examined using standard measures. MRI was used to assess syrinx resolution.
RESULTS
The mean length of syringes was 19.2 ± 10 cm, with a mean maximum diameter of 7.0 ± 2.9 mm. Patients underwent laminectomies averaging 3.7 ± 0.9 (range 2-5) levels in length followed by endoscopy, which expanded exposure by an average of another 2.4 extra segments (6.1 ± 4.0 levels total). Endoscopic dissection of extensive arachnoiditis in the dorsal subarachnoid space proceeded through a complex network of opaque arachnoidal bands and membranes bridging from the dorsal dura mater to the spinal cord. In less severely problematic areas, the arachnoid membrane was transparent and attached to the spinal cord through multifocal arachnoid adhesions bridging the subarachnoid space. The endoscope did not compress or injure the spinal cord.
CONCLUSIONS
Intrathecal endoscopy allowed visual assessment and safe removal of intradural adhesions beyond the laminectomy margins. Further development of this technique should improve its effectiveness in opening the subarachnoid space and untethering the spinal cord in cases of extensive chronic adhesive SA.
PubMed: 34598155
DOI: 10.3171/2021.4.SPINE21483