Modern concepts of CSF disorders in monosutural craniosynostosis.

Arachnoid cysts are usually asymptomatic, and the mechanisms leading to symptomatic presentation remain unclear. Although post-traumatic onset has been reported, it is often related to hemorrhagic complications such as chronic subdural hematoma. Prolonged post-concussive symptoms in children are clinically significant; however, reports linking such symptoms to arachnoid cysts without hemorrhage are rare. Case 1: A 17-year-old male developed headache and dizziness after being struck on the head during baseball practice. Imaging revealed a middle cranial fossa arachnoid cyst without traumatic changes. He was initially managed conservatively, but symptoms persisted for four months and progressively worsened, preventing practice participation. Craniotomy with cyst fenestration resulted in complete symptom resolution and return to training. Case 2: A 15-year-old female developed similar symptoms after colliding with a teammate during a softball game. Imaging showed a posterior cranial fossa arachnoid cyst without traumatic changes. Conservative management failed as symptoms persisted for four months, precluding sports participation. Craniotomy with cyst fenestration led to full recovery and return to training. In both cases, previously asymptomatic arachnoid cysts became symptomatic after head trauma, presenting with prolonged concussion-like symptoms although no traumatic changes were observed on imaging. Symptoms resolved immediately after surgical intervention. These cases may suggest that their prolonged concussion-like symptoms derived from arachnoid cysts and highlight the importance of careful clinical observation and operative indication.

Arachnoid cysts are congenital, cerebrospinal fluid-filled sacs, predominantly asymptomatic and often detected incidentally. Spontaneous rupture of arachnoid cysts is an exceedingly rare complication, particularly in pediatric patients, and may present with acute neurological symptoms, including cranial nerve palsies. We report a 7-year-old male with a large, left middle fossa arachnoid cyst, initially asymptomatic and followed conservatively for five years. The patient developed resistant headache, vomiting, and right sixth cranial nerve palsy. Neuroimaging revealed spontaneous cyst rupture with resultant subdural hygroma and midline shift. The patient underwent successful endoscopic cyst fenestration with significant symptomatic improvement and complete resolution of cranial nerve palsy at six-month follow-up. A review of the literature identified fewer than ten pediatric cases of spontaneous arachnoid cyst rupture associated with cranial nerve deficits. Trauma is the most commonly reported precipitant; however, non-traumatic rupture mechanisms such as increased intracranial pressure have been postulated. Surgical intervention remains the mainstay treatment in symptomatic ruptures, typically yielding favorable outcomes. Spontaneous rupture of arachnoid cysts, although rare, should be considered in patients presenting with new neurological symptoms during follow-up. Early recognition and prompt surgical management are essential to prevent potentially severe complications. Close clinical surveillance is recommended even in asymptomatic cases to detect subtle clinical changes indicative of rupture.

Abstract Arachnoid cysts are a relatively common finding in the general population. Primary arachnoid cysts are congenital malformations and are commonly intracranial cysts. Secondary arachnoid cysts develop as a result of an osseous defect and inadequate dural closure. Intradiploic arachnoid cysts are rare lesions of the skull that are typically seen in posttraumatic cases. Extracranial arachnoid cysts, when suspected, should be studied thoroughly on imaging, and they should be explored beyond the extracranial compartment to provide permanent treatment of this problem. The dura should be explored even if the underlying bone looks intact because if not explored and a possible rent is not treated, the extracranial cyst has the potential to recur. To the best of our knowledge, this type of unusual pathology has not been reported earlier. We hereby report a case of successfully treated recurrent extracranial arachnoid cyst in an adult patient.

Intracranial dermoid cysts are rare, benign congenital lesions that can rupture spontaneously, leading to dissemination of fatty contents within the subarachnoid or ventricular spaces. Though often asymptomatic, rupture can produce a range of neurological symptoms and distinct imaging features. We aim to evaluate the clinical presentation, imaging characteristics, and outcomes of patients with ruptured intracranial dermoid cysts. We conducted a retrospective review of patients diagnosed with ruptured intracranial dermoid cysts at a tertiary academic medical center from July 1997 to July 2024. Rupture was confirmed by the presence of fat droplets in the CSF spaces on CT and/or MRI. Imaging findings were independently reviewed by two radiologists. Twenty-two patients (14 female, 8 male; mean age 51.7years) met inclusion criteria. The most common presenting symptoms were headaches (31.8%). Imaging revealed intraventricular fat in 72.7% of cases and subarachnoid fat in 81.8%, with visible primary cysts in 31.8%. MRI findings included T1 hyperintense fat droplets in all cases, hypointense rims on T2 in 35% of cases, and susceptibility signal loss on SWI in 71%. Follow-up imaging (available in 14 cases) did not show complete resolution of fat droplets, though a reduction in the number of droplets was observed over time. Ruptured intracranial dermoid cysts are rare but recognizable by their characteristic imaging features, particularly on T1-weighted MRI. While symptoms often improve, residual fat globules persist for years.

Intraosseous or intradiploic arachnoid cysts of the cranial vault are extremely rare lesions, representing herniations of the arachnoid membrane through a dural and inner table defect. A 35-year-old woman presented with progressive headaches and a slowly enlarging, non-tender left parietal swelling without any history of trauma. Imaging revealed a left parietal intraosseous cystic lesion with CSF-like signal intensity, thinning of the outer table, and communication with the subarachnoid space. Surgical exploration confirmed multiple small openings in the outer table with CSF outflow and an underlying dural defect. The cyst was excised, the dura repaired watertight, and the cranial vault reconstructed. The postoperative course was uneventful, and follow-up imaging at three months showed no recurrence. This case highlights an exceptional presentation of an intraosseous arachnoid cyst with dural communication. Recognition of this rare entity is essential for accurate diagnosis and proper surgical management.

Background: Spinal extradural arachnoid cysts (SEACs) represent <1% of all spinal epidural lesions. They mostly occur in the thoracic region and occasionally are thoracolumbar in location. Typically, patients may be asymptomatic or exhibit pain with/without a neurological deficit. Case Description: A 44-year-old female presented with a 5-year history of chronic low back pain and intermittent dysesthesia but had no neurological deficits. The magnetic resonance revealed an extradural cyst at D12-L1, isointense to cerebrospinal fluid (CSF) and displacing the dural sac ventrally. The patient underwent a D12-L1 hemilaminectomy for excision of a thin-walled cyst; there were adhesions to the conus, and we encountered no CSF leakage. Postoperatively, pain rapidly improved, and the patient remains asymptomatic. Conclusion: A 44-year-old female presented with pain attributed to a T12-L1 dorsal extradural cyst that was successfully removed through a hemilaminectomy, resulting in full resolution of her pain complaints.

The present study aimed to investigate the clinical characteristics, diagnosis, and treatment of arachnoid cyst complicated with subdural hematoma in children.Clinical characteristics of arachnoid cyst complicated with subdural hematoma in children were summarized by retrospectively analyzing the clinical data of 25 patients, including their onset characteristics, presence or absence of inducing factors, clinical manifestations, and imaging features. All patients underwent craniotomy for subdural hematoma removal along with arachnoid cystectomy.Following the surgical procedure, all 25 patients showed significant improvements in preoperative symptoms, without any severe complications, and were discharged smoothly. Postoperative follow-up ranged from 3 months to 10 years. Head computed tomography (CT) or magnetic resonance imaging (MRI) reexamination revealed that arachnoid cysts were significantly reduced or disappeared completely after surgery in all 25 patients. None of the patients experienced recurrence of subdural hematoma, and all have resumed normal study, work, and daily life.Subdural hematoma in children is usually secondary to head trauma or strenuous exercise. Arachnoid cyst is a critical risk factor for intracranial hemorrhage. The combined application of head CT and MRI is an important approach to confirm the diagnosis of this disease. Due to its definitive therapeutic effect and low postoperative recurrence rate, craniotomy for subdural hematoma removal in combination with arachnoid cystectomy plus cisternal communication surgery is the preferred treatment method for pediatric patients with intracranial hypertension, significant space-occupying effect of the arachnoid cyst, and compression of the surrounding brain tissues.

This scoping review aims to map the existing evidence on Galassi III arachnoid cysts and identify knowledge gaps in the current literature. Galassi III arachnoid cysts are rare intracranial lesions characterized by significant midline displacement and associated with space-occupying effects. Despite their rarity, they have higher intervention rates than other types, yet optimal management remains unclear. Understanding their prevalence, pathophysiology, clinical characteristics, natural history, management strategies, and outcomes is critical for enhancing research on evidence-based management strategies aimed to improve patient care. This review will include clinical studies and review articles investigating patients with Galassi III arachnoid cysts. Studies should address the prevalence, pathophysiology, physical characteristics, natural history, presenting symptoms, treatment strategies, and/or outcomes associated with Galassi III arachnoid cysts. Studies published in English or Spanish will be included. This scoping review will follow JBI methodology and will be reported according to PRISMA-ScR guidelines. A comprehensive search will be conducted in the PubMed, Scopus, and Web of Science Core Collection databases using a structured electronic search strategy developed in collaboration with a research librarian. Gray literature will be incorporated by searching clinical trial registries for studies involving patients with Galassi III arachnoid cysts. No publication date restrictions will be applied. The selection process will involve 3 steps, and Relevant data from included studies will be extracted using a standardized form. Quantitative and qualitative methods will be employed to synthesize the data. Results will be presented in graphic, tabular, and narrative formats. OSF https://osf.io/EVBQK/overview.

INTRODUCTION . Arachnoid cysts are benign intracranial lesions formed by splitting of the arachnoid membrane with cerebrospinal fluid accumulation. According to MRI data, the prevalence among children ranges from 1.1–2.6 %. The choice of optimal surgical approach remains controversial, particularly in pediatric practice. AIM . To analyze clinical and epidemiological characteristics and comparatively evaluate the efficacy of different surgical methods for treating symptomatic arachnoid cysts in children and adolescents. MATERIALS AND METHODS . A retrospective cohort study was conducted on 66 patients under 18 years of age (51 boys, 15 girls) who underwent treatment in Morozov Children’s City Clinical Hospital (Moscow) between 2019–2025. Three methods were employed: endoscopic fenestration (n=43), microsurgical fenestration (n=11), and shunt procedures (n=12). Long-term outcomes were assessed up to 2 years. RESULTS . Male patients predominated (77.3 %), with the middle cranial fossa being the most common location (54.5 %). Endoscopic fenestration demonstrated the best outcomes: complete recovery in 81.3% of patients, minimal blood loss ((25±5) mL), short operative time ((85±15) min), and hospitalization duration ((7.2±2.1) days). However, children under 2 years of age showed a high recurrence rate (83.3 %), warranting preference for shunt procedures in this age group. CONCLUSION . Endoscopic fenestration is the method of choice for children over 2 years of age. In patients under 2 years, primary shunt intervention is advisable. Patients following arachnoid cyst removal demonstrate high rehabilitation potential regardless of location and extent of surgical intervention.

Neurofibromatosis 1 (NF1) is one of the most common genetic diseases of the central nervous system. The nature of intracranial lesions that are associated with NF1 are yet to be fully defined. Arachnoid, velum interpositum, and odontogenic cysts are among the more common intracranial cystic lesions that can be congenital. Although odontogenic cysts are well known to be associated with Gorlin-Goltz syndrome, the possibilities of other genetic disorders in patients with odontogenic and other intracranial cystic lesions have continued to stir research interests. Here, we report 2 cases of unrelated patients, each patient having concurrent intracranial cystic lesions in the setting of a diagnosis of NF1. Individual I had concomitant arachnoid and odontogenic cysts in parallel with a novel heterozygous germline NF1 pathogenic frameshift variant, NF1 [NM_000267.3] c.40del (p.Val14Serfs*10). Individual II had concomitant arachnoid and vellum interpositum cysts in the context of a heterozygous likely pathogenic NF1 germline variant [NF1 (NM_000267.3) c.4265C>T, p.(Ser1422Leu)]. Our observations suggest that clinicians should consider NF1 among the differential diagnosis for intracranial cystic lesions such as arachnoid, vellum interpositum, and odontogenic cysts.

Background Diffusion-tensor image (DTI) analysis along the perivascular space (ALPS) is a noninvasive but not well-validated method proposed to evaluate glymphatic function. Purpose To assess ALPS indexes across participant groups and compare them with measures of cerebrospinal fluid (CSF) tracer enrichment and clearance obtained by intrathecal contrast-enhanced MRI (glymphatic MRI [gMRI]). Materials and Methods This secondary analysis of a prospective observational study included participants who underwent clinical work-up for CSF disorders from September 2015 to December 2019. MRI scans were acquired before injection and 24 and 48 hours after intrathecal injection of 0.5 mmol of gadobutrol. DTI scans were preprocessed and segmented using the FMRIB Software Library. Intrathecal contrast-enhanced MRI (ie, gMRI) scans were registered to the baseline T1-weighted image, and cortex and white matter (WM) were segmented with FreeSurfer. ALPS indexes were compared with relative changes in normalized T1-weighted signal intensity at 24 and 48 hours in regions of the cortex, subcortical WM, and deep WM where the ALPS regions of interest are located by using regression analysis. Results A total of 56 participants were included (mean age, 48 years ± 20 [SD]; 36 women): 16 with idiopathic normal pressure hydrocephalus (iNPH), 10 with arachnoid cysts, 11 with idiopathic intracranial hypertension, and 19 reference participants. The ALPS index was lower in the iNPH group than in the reference group (ALPS index, 1.26 and 1.68, respectively; P < .001). Across groups, the ALPS index and degree of CSF tracer enrichment at 24 hours in deep WM were negatively associated (β = -48; P < .001). However, mean tracer enrichment in the ALPS regions of interest was low (10%), in some participants close to 0, whereas enrichment in the cortex ranged from 68% to 81%. Across groups, there was no evidence of associations between the ALPS index and measures of CSF tracer dynamics at 48 hours in any region (|β| ≤ 8; P ≥ .55). Conclusion CSF tracer enhancement in the ALPS regions of interest was sparse across groups, and the association between the ALPS index and gMRI markers of glymphatic function was limited. © The Author(s) 2026. Published by the Radiological Society of North America under a CC BY 4.0 license. Supplemental material is available for this article.

Arachnoid cysts by virtue of their volume and intracystic tension, produce local mass effect, and impair the perfusion of surrounding brain parenchyma.The magnetic resonance (MR) perfusion parameters cerebral blood flow (CBF), relative cerebral blood volume (rCBV), and mean transit time (MTT) of brain parenchyma contiguous with the arachnoid cyst were compared with corresponding contralateral hemisphere. Twenty cases of arachnoid cyst were treated using endoscopic techniques. The perfusion changes in parenchyma were assessed 3 months postoperatively. Clinical outcomes were assessed at 6 months' postsurgery.Headache was the predominant symptom (85%), with Sylvian fissure representing the most frequent anatomical location (65%). Endoscopic procedure was successful in 80% of the cases, whereas 20% of the cases required conversion to minicraniotomy and microsurgical cyst excision. Preoperatively, mean CBF (mL/100 g/min), rCBV (mL/100 g), MTT (seconds) in perilesional brain area were 42.58 ± 7.17, 4.48 ± 1.25, 5.56 ± 1.72, respectively, and 3 months postoperatively were 45.83 ± 8.87, 4.48 ± 1.62, 4.37 ± 1.68, respectively. The mean CBF (mL/100 g/min), rCBV (mL/100 g), MTT (seconds) in corresponding contralateral hemisphere was 46.77 ± 10.85, 4.29 ± 1.35, 5.24 ± 1.104, respectively, whereas postoperatively they were 46.29 ± 8.49, 5.03 ± 1.16, 5.49 ± 1.97, respectively. The p-value, however, was not significant. Headache improved in 87.5%, whereas seizure in 60% of the cases.Endoscopic treatment of arachnoid cyst is an optimally invasive procedure. The perfusion study is a valuable tool in evaluation of arachnoid cysts. MR perfusion highlights regions of impaired blood flow and focal brain dysfunction. Additionally, changes in perfusion can help assess the therapeutic impact of surgery on the compressed brain tissue.

IntroductionQuadrigeminal cistern arachnoid cysts (QACs) represent a rare subgroup of arachnoid cysts. Patients may present with headache, visual disturbances, gait imbalance, or nausea, typically secondary to obstructive hydrocephalus. Hydrocephalus is frequently assessed using the Evans Index (EI). Vertebral artery hypoplasia (VAH) is generally defined as a decrease in the diameter of the vertebral artery. It has been associated with posterior circulation ischemia, vertebrobasilar insufficiency (VBI), vertigo, and headache. However, the relationship between QAC-related mass effect and vascular variants such as VAH has not been systematically evaluated. Mega cisterna magna (MCM) represents another posterior fossa cerebrospinal fluid variant relevant to the differential diagnosis.ObjectiveTo evaluate the relationship between QAC dimensions, EI, vertebral artery diameters, and clinical symptoms, and to assess the coexistence of MCM.MethodsSeventy-three patients (36 females, 37 males; mean age 52.4 ± 19.0 years) with radiologically confirmed QAC were retrospectively reviewed. Clinical symptoms, including headache and VBI, were recorded. Imaging parameters included QAC anteroposterior (AP) diameter, quadrigeminal cistern diameter, EI, vertebral artery diameters, and the presence of MCM. Multivariable logistic regression analysis was performed to identify imaging predictors of clinical symptoms (odds ratio (OR) and confidence interval (CI)).ResultsHeadache was present in 67.1% of patients, VBI in 31.5%, and MCM in 21.9%. Mean QAC AP diameter was 16.9 ± 4.8 mm, quadrigeminal cistern diameter 23.1 ± 5.2 mm, and EI 0.24 ± 0.08. Mean right and left vertebral artery diameters were 2.46 ± 0.83 mm and 2.36 ± 0.73 mm, respectively. Headache showed no independent association with any imaging parameter (p-value > 0.05). VBI was significantly associated with a smaller left vertebral artery diameter (OR 0.32; 95% CI 0.16-0.64; p-value = 0.001).ConclusionIn patients with QAC, headache did not correlate with radiologic measurements, whereas VBI was strongly associated with reduced vertebral artery diameter, particularly on the left side. These findings highlight the importance of incorporating vascular assessment when evaluating symptomatic QAC patients.

Patients with PRKAR1B gene variants can present with a neurodegenerative disease in adults or a cognitive delay, behavioral problems and regression in children causing Marbach-Schaaf Neurodevelopmental Syndrome (MASNS) which is a rare autosomal dominant disease. However with less of 30 reported cases in Literature, the clinical spectrum of PRKAR1B gene mutations remains to be explored, and the treatment remains challenging. In this paper, we report the cases of a Lebanese child with previously unreported missense PRKAR1B variant presenting with a massive arachnoid cyst, speech delay, cognitive delay, behavioral dysregulation and developmental regression at 2 years of age. The patient showed behavioral response to treatment with a low dose of topiramate. This case expands the known genotypic and phenotypic spectrum of this recently described disorder, highlighting the importance of genetic investigation in children with cognitive delay.

Background . The prevalence of structural brain abnormalities among Russian children remains unknown, which hinders effective planning for the prevention of severe neurological and neurosurgical complications. The significance of a number of conditionally pathological findings that are accidentally detected by magnetic resonance imaging (MRI) in clinical practice also remains debatable. The aim of the study is to determine the frequency of macrostructural changes in the brain among primary school— age children, detected by MRI of the brain, and to assess their clinical significance in relation to disorders from the group of mild cognitive impairment (MCI) and attention deficit hyperactivity disorder (ADHD). Methods . All participants, 7–8 year old children from Chelyabinsk and Moscow, underwent an MRI scan of the brain, representatives of the Moscow cohort of children additionally underwent an in-depth clinical and psychological examination: consultation with a neurologist/psychiatrist, neuropsychological and speech therapy testing, and Wexler intelligence assessment. Results . 162 children of the combined (Chelyabinsk and Moscow) population sample and 114 Moscow children of the pathology group — ADHD, MCI and their combined variants were examined. A subgroup of 30 neurologically healthy children was also isolated from the Moscow population cohort. The most common findings in the population group were ventricular asymmetries (35.8%), dilation of perivascular spaces (11.1%), epiphysis cysts (4.3%), and an increase in the size of the large brain cistern (4.3%). According to the survey results, 2.5% of the children were referred for in-depth examination in connection with the findings. Conditionally pathological findings in general and specifically perivascular space dilation and arachnoid cysts are significantly more common among children with MCI and combined pathology of MCI + ADHD compared with neurologically healthy children and the general population of children. Conclusion . Continuous screening of Russian children using MRI can identify about 2.5% of children with suspected serious abnormalities requiring specialized monitoring. In addition, some findings that are considered insignificant may signal mild neuropathology.

Introduction:Choroidal fissure cysts are usually incidental findings on imaging studies. They are typically benign lesions, although in some cases they may cause morbidity due to intracranial hypertension. The formation of cysts in this location is related to abnormal development of the choroid tela and the choroidal fissure. Fewer than ten cases have been reported in the literature. Case description: A 3-month-old patient with a small choroidal fissure cyst at birth presented with acute symptoms of intracranial hypertension, nausea, and vomiting. Imaging revealed a rapid and severe enlargement of the arachnoid cyst within just two weeks, reaching a preoperative size of 50 × 35 × 30 mm. The patient underwent endoscopic fenestration of the cyst, resulting in complete resolution of clinical symptoms in the early postoperative period and marked reduction in cyst size on imaging (36 × 21 × 24 mm) one day after surgery.At two-month follow-up, the cyst measured 28 × 21 × 19 mm. Symptomatic choroidal fissure cysts are exceptionally rare, with only eight clinical cases reported to date in the literature. Traditionally, treatment has consisted of cystoperitoneal shunting. We currently believe that endoscopic treatment can be offered as a first-line option, achieving complete clinical resolution without evidence of complications. Conclusion:Symptomatic choroidal fissure cysts are an exceptionally rare pathology. Treatment by endoscopic fenestration provides excellent clinical and radiological resolution without additional short-term complications.

Isolated cerebellar hydatid cyst in a child: a rare case report

An immunocompromised patient presented with acute-on-chronic back pain following minor trauma. The pain was accompanied by worsening right-sided weakness, paraesthesias, progressive gait impairment and hyperreflexia concerning for compressive myelopathy. The patient's spouse also reported months of increasing forgetfulness. Imaging revealed a thoracic arachnoid cyst, which was treated by fenestration and resection of the cyst via laminoplasty. At the time of surgery, the thickened cyst wall was sent off for pathological evaluation. Postoperatively, pathology identified yeast consistent with cryptococcus; a subsequent lumbar puncture confirmed the diagnosis. Aside from mild cognitive impairment and a transient episode of delirium, the patient had no prior cognitive nor cranial nerve deficits. This case highlights the importance of considering subacute, low-grade infection in the differential diagnosis of de novo arachnoid cysts in immunocompromised patients.

Comparative analysis of management techniques in the treatment of pediatric Middle fossa arachnoid cysts: A systematic review and meta-analysis.