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Clinical Neurology and Neurosurgery Jul 2024The Liliequist membrane (LM) represents a crucial yet challenging anatomical structure in neuroanatomy. First observed in 1875 and later elucidated by Bengt Liliequist... (Review)
Review
BACKGROUND
The Liliequist membrane (LM) represents a crucial yet challenging anatomical structure in neuroanatomy. First observed in 1875 and later elucidated by Bengt Liliequist in 1956, the LM's precise anatomical description and boundaries remain complex. Its significance extends to neurosurgery, impacting various procedures like endoscopic third ventriculocisternostomies, aneurysm and tumor surgeries, treatment of suprasellar arachnoid cysts, and managing perimesencephalic hemorrhages. However, a comprehensive understanding of the LM is hindered by inconsistent anatomical descriptions and limitations in available literature, warranting a systematic review.
METHODS
A systematic review was conducted by searching PubMed, Science Direct, and Google Scholar for articles pertaining to Liliequist's membrane. The search employed Mesh terms like "Liliequist membrane," "Liliequist's diaphragm," and related variations. Inclusion criteria encompassed studies exploring the historical evolution, anatomical structure, radiological characteristics, and clinical implications of the LM in neurosurgery.
RESULTS
The search yielded 358 articles, with 276 unique articles screened based on relevance. Following a meticulous screening process, 72 articles underwent full-text assessment, resulting in the inclusion of 5 articles meeting the eligibility criteria. The selected studies varied in methodology, including anatomical dissections, radiological evaluations, and clinical significance in neurosurgical procedures. Insights were derived on LM's anatomical variations, radiological visualization, and its critical role in guiding neurosurgical interventions.
CONCLUSIONS
Despite advancements in understanding its clinical significance and radiological visualization, challenges persist in precisely delineating its boundaries. Further research, especially on embryological development and histological characterization, is essential. Enhancing comprehension of LM-related pathologies is crucial for accurate preoperative planning and optimizing patient outcomes in neurosurgery.
Topics: Humans; Neurosurgical Procedures; History, 20th Century; History, 19th Century; Clinical Relevance
PubMed: 38795689
DOI: 10.1016/j.clineuro.2024.108322 -
World Neurosurgery Feb 2024The role of surgical management of arachnoid cyst (AC) of the cerebellopontine angle (CPA) is uncertain. This topic has remained controversial with varying contradictory...
OBJECTIVE
The role of surgical management of arachnoid cyst (AC) of the cerebellopontine angle (CPA) is uncertain. This topic has remained controversial with varying contradictory recommendations in the literature, which is limited to mostly case reports. We aimed to provide a comprehensive summary and analysis of symptoms, operative techniques, outcomes, and recurrence of all available surgical cases of AC of the CPA to date.
METHODS
A systematic literature search was performed in May 2022 querying several scientific databases. Inclusion criteria specified all studies and case reports of patients with AC located at the CPA for which any relevant surgical procedures were performed.
RESULTS
A total of 55 patients from the literature and 5 treated at our institution were included. Mean patient age was 29 years (range, 0.08-79 years), with nearly twice (1.7×) as many female as male patients (37 female, 22 male). Headaches (35%), hearing loss (30%), vertigo (22%), and ataxia (22%) were the most common presentations. Following surgery, 95% experienced symptom improvement, with complete resolution in 64%. Of patients with hearing loss, 44% reported a return to normal. The rate of mortality was 1.69%, and 10% of tumors recurred (mean follow-up 2.3 years [range, 0-15 years].
CONCLUSIONS
Symptomatic AC of the CPA is rare. It exhibits a proclivity for females and commonly manifests with headache, hearing loss, vertigo, and ataxia. While careful selection for surgical candidacy is needed and intervention should be reserved for patients with severe symptoms, surgical decompression is an effective tool for symptom alleviation and recovery.
Topics: Humans; Male; Female; Infant, Newborn; Infant; Child, Preschool; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged; Cerebellopontine Angle; Hearing Loss; Headache; Vertigo; Deafness; Arachnoid Cysts; Ataxia
PubMed: 38070740
DOI: 10.1016/j.wneu.2023.12.018 -
The Spine Journal : Official Journal of... Aug 2023Secondary spinal arachnoid cysts have rarely been reported but present significant challenges for management. These cysts could be anteriorly located with long... (Review)
Review
BACKGROUND CONTEXT
Secondary spinal arachnoid cysts have rarely been reported but present significant challenges for management. These cysts could be anteriorly located with long rostral-caudal extensions and many are related to arachnoiditis, leading to difficult-to-treat disorders. Thus far, due to the scarcity of reports, the features of the disease and the optimal therapeutic strategies remain unclear.
PURPOSE
To investigate clinical features and the optimal treatment modalities of secondary spinal arachnoid cysts compared with primary spinal arachnoid cysts.
STUDY DESIGN
Systematic review.
PATIENT SAMPLE
Systematic review identified 103 secondary cases from 80 studies and reports.
OUTCOME MEASURES
Condition of symptom relief and duration of treatment response were analyzed.
METHODS
An electronic literature search of the PubMed database was conducted for studies on secondary spinal arachnoid cysts between 1990 and 2022. Non-English publications, nonhuman studies, reports of a primary cyst, studies not including case details, and studies of nonsymptomatic cases were excluded.
RESULTS
This systematic review included 103 secondary cases. The most commonly reported etiologies were iatrogenic factors, trauma, and subarachnoid hemorrhage, accounting for 88 intradural extramedullary, 11 extradural, one intradural/extradural, one interdural, and one intramedullary spinal arachnoid cyst after a median duration of 30, 12, and 9 months, respectively. Extradural cysts were more prone to occur at dorsal locations and affect thoracic segments (mean cyst length: 3.4 segments). Intradural cysts showed a relatively higher ventral/dorsal ratio (1:1.09, 1.75:1, and 3.50:1 for cysts occurring from iatrogenic factors, trauma, and subarachnoid hemorrhage, respectively) and thoracic distribution, with a mean cyst length of 4.3 segments (5.1 for ventral and 3.5 for dorsal cysts). For intradural cysts, recurrence risk was lower after surgical resection than after fenestration/marsupialization (12-month recurrence risk: 21.43% vs 50.72%, log-rank test: p=.0248, Gehan-Breslow-Wilcoxon test: p=.0126). In cases treated with shunting, one recurrence (1/8 cases) was noted after external shunting and two recurrences (2/5 cases) after internal shunting at a median follow up of 12 months.
CONCLUSIONS
Secondary spinal arachnoid cysts, particularly intradural cysts, are rarer and more challenging to treat than primary spinal cysts. Although fenestration/marsupialization is the commonly adopted treatment, the recurrence rate is high. For unresectable cysts, shunting procedures, particularly shunting into a body cavity (eg, pleural or peritoneal cavity) away from the subarachnoid space, could be a therapeutic alternative besides fenestration/marupialization, yet its efficacy requires confirmation by more data.
Topics: Humans; Arachnoid Cysts; Subarachnoid Hemorrhage; Spinal Cord Diseases; Neurosurgical Procedures; Iatrogenic Disease; Magnetic Resonance Imaging
PubMed: 36924909
DOI: 10.1016/j.spinee.2023.03.002 -
Surgical Neurology International 2022Idiopathic spinal epidural arachnoid cysts (SEACs) are rare and may cause myelopathy and cord compression. They typically arise from a congenital defect in the dura that... (Review)
Review
BACKGROUND
Idiopathic spinal epidural arachnoid cysts (SEACs) are rare and may cause myelopathy and cord compression. They typically arise from a congenital defect in the dura that communicates with the intrathecal subarachnoid space. Although the ideal treatment of SEACs is direct dural repair and cyst excision, there is as yet no clear standard of care for the management of these lesions.
METHODS
A 47-year-old female presented with myelopathy attributed to an magnetic resonance imaging-documented posterior epidural T12-L2 cyst (i.e., 1.1 × 6 × 3.3 cm) lesion. The patient underwent a direct dural repair of the fistulous communication between the subarachnoid space and the cyst, along with cyst drainage/ excision through a right-sided laminotomy. Postoperatively, the patient was asymptomatic. We additionally reviewed the literature regarding the management of SEACs.
RESULTS
Our review yielded 14 articles involving 18 patients with predominantly thoracolumbar (57%) SEACs that were either communicating (61%) or not communicating (39%) with the subarachnoid space. They averaged 35.5 years of age and exhibited a male preponderance (66%). Symptoms typically included pain (78%), followed by weakness/myelopathy (42%). Surgery frequently included bilateral laminectomies (57%) followed by unilateral laminectomies (50%) that typically resulted in symptom resolution.
CONCLUSION
SEACs are rare typically thoracolumbar lesions that may cause myelopathy which resolves following direct dural closure/subarachnoid fistulous occlusion.
PubMed: 36761263
DOI: 10.25259/SNI_928_2022 -
Operative Neurosurgery (Hagerstown, Md.) Jan 2023Middle meningeal artery (MMA) embolization is becoming increasingly studied as a safe, effective treatment for chronic subdural hematoma (cSDH) in adults. Among...
BACKGROUND
Middle meningeal artery (MMA) embolization is becoming increasingly studied as a safe, effective treatment for chronic subdural hematoma (cSDH) in adults. Among pediatric patients, however, MMA embolization for cSDH has been rarely described, and the potential benefit of this approach for pediatric patients remains unknown.
OBJECTIVE
To systematically review the literature and identify cases of pediatric MMA embolization for cSDH. We also report our experience with pediatric MMA embolization.
METHODS
A systematic review of the literature was performed to identify cases of pediatric MMA embolization for cSDH. Inclusion criteria included English language availability and pediatric age defined as less than 18 years. A pediatric patient treated with MMA embolization was also identified at our institution.
RESULTS
Five cases of pediatric MMA embolization for cSDH were identified in the literature. Two were associated with arachnoid cysts, 2 with antiplatelet/anticoagulation therapy, and 1 with abusive head trauma. There were no adverse events, and all patients demonstrated clinical and radiological improvement on follow-up. At our institution, a previously healthy 8-year-old male was found to have a right-sided acute-on-chronic SDH during a headache evaluation. A diagnostic angiogram was performed to rule out a dural arteriovenous fistula, and right-sided MMA embolization was performed concurrently. Rapid clinical and radiological improvement was observed, with complete resolution by 6 months.
CONCLUSION
MMA embolization may represent a treatment option for pediatric patients with cSDH.
Topics: Male; Adult; Humans; Child; Adolescent; Meningeal Arteries; Hematoma, Subdural, Chronic; Embolization, Therapeutic; Treatment Outcome; Central Nervous System Vascular Malformations
PubMed: 36519875
DOI: 10.1227/ons.0000000000000446 -
Brain & Spine 2022Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management. (Review)
Review
INTRODUCTION
Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management.
RESEARCH QUESTION
We analyzed our experiences from a case series and provide a systematic review to determine 1) Demographic and clinical features of SACs, 2) Optimal imaging for diagnosis and operative planning, 3) Optimal management of SACs, and 4) Clinical outcomes following surgery.
MATERIALS AND METHODS
A single-institution, ambispective analysis of patients with symptomatic SACs surgically managed between May 2005 and May 2019 was performed. Data were collected as per local ethics committee stipulations. A systematic review of SACs in adults was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and a preapproved protocol.
RESULTS
Our series consisted of 11 patients, M:F 8:3, mean age 47.8 years (range 18-73 years). Mean follow-up was 19 months (range 5-36 months). SACs were excised or marsupialised (7), fenestrated (3) or partially excised (1). Eight patients had expansile duroplasty, 3 primary dural closure. One patient had a cystoperitoneal shunt. All patients were AIS D preoperatively; 4 remained unchanged and 7 improved to AIS E at follow-up. Our systematic search retrieved 725 citations. Fourteen case series met the inclusion criteria. There was no evidence to support superiority of one surgical strategy over another. Surgery for symptomatic patients resulted in positive clinical outcomes.
DISCUSSION AND CONCLUSIONS
Symptomatic SACs require surgical intervention. Limited evidence suggests that decompressing the cord, breakdown of arachnoid adhesions, and establishing CSF flow by consideration of expansile duroplasty are important for positive outcomes.
PubMed: 36248116
DOI: 10.1016/j.bas.2022.100904 -
PloS One 2022This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic... (Review)
Review
BACKGROUND & IMPORTANCE
This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.
METHODS
The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.
RESULTS
Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.
DISCUSSION & CONCLUSION
DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.
Topics: Arachnoiditis; Biological Products; Humans; Iatrogenic Disease; Meningitis; Prospective Studies
PubMed: 36178925
DOI: 10.1371/journal.pone.0274634 -
British Journal of Neurosurgery Apr 2023Non-communicating extradural spinal arachnoid cysts (NEACs) are extremely rare aetiology of symptomatic spinal cord compression. The aim of this study was to address...
OBJECTIVE
Non-communicating extradural spinal arachnoid cysts (NEACs) are extremely rare aetiology of symptomatic spinal cord compression. The aim of this study was to address their pathogenesis, optimum management strategy and outcome through systematic review of existing published studies.
MATERIALS AND METHOD
We have found 13 eligible publications by searching through PubMed, ScienceDirect, and Google Scholar databases, published from inception to December 2020. We have analysed the data of 21 patients extracted from those 13 publications by IBM SPSS version 23.
RESULTS
According to our analysis congenital predisposition, trauma, and previous surgery history are the aetiology of NEAC. Clinical presentation of cyst depends upon the location and extent of compression or involvement of the neurovascular structures. Paraparesis with variable degree of sensory disturbance was seen among patients. Based on neuroimaging findings, NEACs are most commonly found at dorsal and dorsolumbar region. Magnetic resonance imaging (MRI) is the diagnostic modalities of choice and CT myelography can demonstrate the communication with the subarachnoid space. Recurrence rate of cyst after surgery is very low as only one out of twenty patients showed recurrence. If dural defect is not accurately addressed, the recurrence rate increased significantly.
CONCLUSIONS
Our study has highlighted aetiology, treatment strategies, and neurological outcome of NEAC. These findings may help neurosurgeons to manage this rare surgical entity for favourable outcome.
Topics: Humans; Arachnoid Cysts; Spinal Cord Diseases; Spinal Cord Compression; Magnetic Resonance Imaging; Tomography, X-Ray Computed
PubMed: 35766304
DOI: 10.1080/02688697.2022.2090505 -
Acta Neurochirurgica Oct 2022As the volume and fidelity of magnetic resonance imaging (MRI) of the brain increase, observation of incidental findings may also increase. We performed a systematic... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
As the volume and fidelity of magnetic resonance imaging (MRI) of the brain increase, observation of incidental findings may also increase. We performed a systematic review and meta-analysis to determine the prevalence of various incidental findings.
METHODS
PubMed/MEDLINE, EMBASE and SCOPUS were searched from inception to May 24, 2021. We identified 6536 citations and included 35 reports of 34 studies, comprising 40,777 participants. A meta-analysis of proportions was performed, and age-stratified estimates for each finding were derived from age-adjusted non-linear models.
RESULTS
Vascular abnormalities were observed in 423/35,706 participants (9.1/1000 scans, 95%CI 5.2-14.2), ranging from 2/1000 scans (95%CI 0-7) in 1-year-olds to 16/1000 scans (95%CI 1-43) in 80-year-olds. Of these, 204/34,306 were aneurysms (3.1/1000 scans, 95%CI 1-6.3), which ranged from 0/1000 scans (95%CI 0-5) at 1 year of age to 6/1000 scans (95%CI 3-9) at 60 years. Neoplastic abnormalities were observed in 456/39,040 participants (11.9/1000 scans, 95%CI 7.5-17.2), ranging from 0.2/1000 scans (95%CI 0-10) in 1-year-olds to 34/1000 scans (95%CI 12-66) in 80-year-olds. Meningiomas were the most common, in 246/38,076 participants (5.3/1000 scans, 95%CI 2.3-9.5), ranging from 0/1000 scans (95%CI 0-2) in 1-year-olds to 17/1000 scans (95%CI 4-37) in 80-year-olds. Chiari malformations were observed in 109/27,408 participants (3.7/1000 scans, 95%CI 1.8-6.3), pineal cysts in 1176/32,170 (9/1000 scans, 95%CI 1.8-21.4) and arachnoid cysts in 414/36,367 (8.5/1000 scans, 95%CI 5.8-11.8).
CONCLUSION
Incidental findings are common on brain MRI and may result in substantial resource expenditure and patient anxiety but are often of little clinical significance.
Topics: Brain Neoplasms; Child; Humans; Incidental Findings; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Prevalence
PubMed: 35525892
DOI: 10.1007/s00701-022-05225-7 -
Surgical Neurology International 2021Intracranial arachnoid cysts (AC) are benign, cerebrospinal fluid filled spaces within the arachnoid layer of the meninges. Neurosurgical intervention in children and... (Review)
Review
BACKGROUND
Intracranial arachnoid cysts (AC) are benign, cerebrospinal fluid filled spaces within the arachnoid layer of the meninges. Neurosurgical intervention in children and young adults has been extensively studied, but the optimal strategy in the elderly remains unclear. Therefore, we performed a single center retrospective study combined with a systematic review of the literature to compare cystoperitoneal (CP) shunting with other surgical approaches in the elderly cohort.
METHODS
Retrospective neurosurgical database search between January 2005 and December 2018, and systematic review of the literature using PRISMA guidelines were performed. Inclusion criteria: Age 60 years or older, radiological diagnosis of intracranial AC, neurosurgical intervention, and neuroradiological (NOG score)/clinical outcome (COG score). Data from both sources were pooled and statistically analyzed.
RESULTS
Our literature search yielded 12 studies (34 patients), which were pooled with our institutional data (13 patients). CP shunts (7 patients; 15%), cyst fenestration (28 patients; 60%) and cyst marsupialisation/resection (10 patients; 21%) were the commonest approaches. Average duration of follow-up was 23.6, 26.9, and 9.5 months for each approach, respectively. There was no statistically significant association between choice of surgical intervention and NOG score ( = 0.417), COG score ( = 0.601), or complication rate ( = 0.955). However, CP shunting had the lowest complication rate, with only one patient developing chronic subdural haematoma.
CONCLUSION
CP shunting is a safe and effective surgical treatment strategy for ACs in the elderly. It has similar clinical and radiological outcomes but superior risk profile when compared with other approaches. We advocate CP shunting as first line neurosurgical intervention for the management of intracranial ACs in the elderly.
PubMed: 34992940
DOI: 10.25259/SNI_463_2021