Importance of Ophthalmological Evaluation in the Conservative Management of Increased Intracranial Pressure from a Ruptured Arachnoid Cyst.

Arachnoid cysts (ACs) are cerebrospinal fluid collections between the two layers of the normal arachnoid membrane. Although they are often asymptomatic with a stationary course, eventual complications may occur. Herein, we report the case of a 9-year-old boy who developed bilateral papilloedema secondary to spontaneous rupture of an AC in the left middle cranial fossa. Although the papilloedema worsened during follow-up, his visual field remained bilaterally stable, supporting the expectant management and obviating the potential morbidity associated with neurosurgical intervention. This case report highlights the importance of a multidisciplinary approach to patients with secondary intracranial hypertension, including serial ophthalmological examinations, which provide a useful guide to surgical decision-making.

Dorsal arachnoid web of the thoracic spine associated with an arachnoid cyst and a presyrinx state as an unexplained cause of thoracic myelopathy: illustrative case.

BACKGROUND: Dorsal thoracic arachnoid web is a rare diagnosis and is not commonly seen in neurosurgical practice. Patients can present with symptoms and signs of thoracic myelopathy in the setting of an arachnoid cyst and a presyrinx state. OBSERVATIONS: A 57-year-old male with a 10-year history of worsening bilateral leg weakness and chronic back pain re-presented to the neurosurgery clinic after being seen by neurology and orthopedic spine surgery. Initial imaging was concerning for myelomalacia and syringomyelia, and repeat delayed computed tomography myelography findings were consistent with an evolving thoracic arachnoid web, now demonstrating spinal cord compression secondary to arachnoid cyst formation and consistent with the signs of thoracic myelopathy. Intraoperative ultrasound displayed the arachnoid web as the cause of the evolving arachnoid cyst, edematous spinal cord, and a presyrinx-like state. The patient underwent surgical decompression, which restored cerebrospinal fluid (CSF) dynamics, resulting in clinical improvement. LESSONS: Dorsal thoracic arachnoid web is a dynamic condition that can occur in the setting of an arachnoid cyst. There appears to be a relationship between dorsal thoracic arachnoid web formation and the presence of an arachnoid cyst resulting from a ball-valve mechanism leading to the creation of a pressure gradient effect that alters CSF fluid dynamics. https://thejns.org/doi/10.3171/CASE24313.

Technical note: durable resolution of hydrocephalus after ultrasound-guided percutaneous fenestration of giant suprasellar arachnoid cyst in a neonate.

Arachnoid cysts are relatively common, but rarely require intervention. While most arachnoid cysts in typical middle or posterior cranial fossa locations are seldom symptomatic, suprasellar cysts may become symptomatic due to the potential for ventricular outflow obstruction and hydrocephalus. Typical standard of care for the treatment of these lesions is endoscopic fenestration with third ventriculostomy, or the placement of ventriculoperitoneal or cystoperitoneal shunts. The surgical and anaesthetic risks of traditional interventions may be higher in the early neonatal period, including leak of cerebrospinal fluid, infection, and premature failure of ventriculostomy or shunts. This note describes a novel bedside ultrasound-guided technique to percutaneously fenestrate large suprasellar arachnoid cysts under local anaesthesia. The technique involves insertion of a 25-g spinal needle until contact with the membrane of the arachnoid cyst medially, followed by a lateral sweeping to widely incise/fenestrate the lesion into the ventricular space under continuous ultrasound visualisation. This note describes an example case which demonstrates durable radiological and clinical improvement after 2 years of follow-up. This may represent a management option to temporise, or perhaps definitively manage suprasellar arachnoid cysts in the neonatal period.

Neurosurgical intervention for giant arachnoid cyst-induced hydrocephalus in a teenager: Delving into Pandora's box.

Early recognition and prompt surgical intervention are crucial in managing giant arachnoid cysts causing obstructive hydrocephalus, as illustrated in this case of a 17-year-old male. Timely treatment can alleviate symptoms and prevent neurologic complications, ensuring favorable outcomes in affected patients.

Atypical Presentation of Idiopathic Intracranial Hypertension: A Case Series and Literature Review.

Idiopathic intracranial hypertension (IIH) is a condition in which intracranial pressure (ICP) increases without an apparent cause. Typically, patients present with headaches, dizziness, pulsatile tinnitus, visual disturbances, blurred vision, diplopia, photophobia, visual field defects, and papilledema on fundoscopy. The association between IIH, spontaneous cerebrospinal fluid (CSF) rhinorrhea, and arachnoid cysts has been discussed in the literature; however, there is no clear explanation for this association. We aimed to present a series of four patients with a confirmed diagnosis of IIH with atypical presentations, discuss the management of each case, and provide an explanation for this association to alert clinicians to the atypical presentation of IIH and facilitate early diagnosis and proper treatment of this condition by CSF diversion. This was a retrospective case series of all patients who were diagnosed with IIH and showed improvement after ventriculoperitoneal shunt insertion after failure of at least one operative intervention resulting from primary radiological and clinical findings in 2001 to 2022. Data on demographics, clinical presentation, radiological findings, surgical management, and diagnostic criteria for IIH were recorded. We identified four patients with a confirmed diagnosis of IIH who presented with atypical presentations as follows: intracranial arachnoid cyst, cervical spine arachnoid cyst, giant Virchow perivascular space, and spontaneous CSF (CSF) rhinorrhea. All patients responded to CSF diversion after failure of surgical treatment targeting the primary pathology. IIH should be suspected after the failure of primary surgical treatment in cases of spontaneous CSF rhinorrhea, spinal and cranial arachnoid cysts, and symptomatic ventriculoperitoneal shunt. Treatment in such situations should be directed toward IIH with CSF diversion.

Massive traumatic epidural hematoma in a child with suprasellar arachnoid cyst and hydrocephalus.

We present a case of a child with a suprasellar arachnoid cyst and hydrocephalus who developed a massive traumatic epidural hematoma following a fall. This represents the first reported case of such a condition. The case is characterized by a progressive increase in hemorrhage leading to a massive hematoma, yet with relatively mild clinical symptoms. The hemorrhage originated from extensive blood seepage from the dura mater. Intraoperative hemostasis was challenging, and there was a large residual cavity of the epidural hematoma without repositioning of brain tissue after removal of the hematoma. Surgical measures such as extensive continuous compression hemostasis with Surgicel, the half-suspension technique, and continuous external drainage were employed to address these challenges. A second-stage surgery for the treatment of the suprasellar arachnoid cyst was performed 1.5 months after hematoma evacuation, utilizing neuroendoscopic ventriculocisternostomy (VCC). We recommend that for patients with traumatic brain injury and hydrocephalus, especially those with skull fractures or minimal intracranial hemorrhage, relying solely on clinical symptom observation and monitoring is insufficient. Timely and close monitoring with cranial CT is crucial for the early detection of progressive intracranial hemorrhage.

Simultaneous resolution of arachnoid cyst and chronic subdural hematoma after middle meningeal artery embolization: illustrative case.

BACKGROUND: Arachnoid cysts are cerebrospinal fluid-filled spaces that are typically congenital and treated conservatively or with fenestration when symptomatic. Chronic subdural hematomas (cSDHs) can arise in the presence of arachnoid cysts due to fragile leptomeningeal vessels or veins within the cyst wall or cyst lumen, leading to bleeding and subsequent hematoma formation. Middle meningeal artery (MMA) embolization is regularly used for the treatment of cSDH as an alternative to craniotomy and evacuation. OBSERVATIONS: Here, the authors present the first known report of the simultaneous resolution of an arachnoid cyst and cSDH following MMA embolization in an adult. A 24-year-old male presented to the emergency department with 1 month of worsening headaches. Imaging revealed the presence of a cSDH and ipsilateral arachnoid cyst. The cSDH was treated with MMA embolization using coils exclusively. Follow-up imaging 4 months after embolization demonstrated simultaneous resolution of both the hematoma and the arachnoid cyst. LESSONS: MMA embolization has been used for the treatment of cSDH. In cases in which the hematoma is related to an arachnoid cyst, MMA embolization can also lead to the concurrent resolution of both pathologies. https://thejns.org/doi/10.3171/CASE24192.

Extradural spinal cyst in a pediatric patient: A case report.

Background: Spinal extradural arachnoid cysts comprise <1% of all spinal lesions and are rare findings in pediatric patients. The pathogenesis of spinal extradural arachnoid cysts is not well known but is thought to most commonly be due to congenital dural defects. Other origins include trauma, inflammation, or infection, such as arachnoiditis. Spinal magnetic resonance imaging is the gold standard for diagnosis, showing a fluid-filled space dorsal to the spinal cord with signal intensity akin to cerebrospinal fluid (CSF) and often the site of dural defect with CSF leak. While most spinal extradural arachnoid cysts are asymptomatic, large cysts can compress the spinal cord or nerve roots, leading to myelopathy, radiculopathy, or focal pain symptoms. In such cases, surgical management is indicated. Case Description: Here, we present a case of a 15-year-old female who presented with lower back pain radiating to her bilateral posterior thighs and knees, with imaging indicating a thoracolumbar spinal extradural arachnoid cyst. After failed conservative treatment, surgical intervention in the form of laminectomy, fenestration of the arachnoid cyst, and repair of the dural defect was required, resolving the patient's symptoms with no recurrence of the cyst. Conclusion: Complete resolution of pain in our patient following surgical management of spinal arachnoid cyst suggests that treatment of the arachnoid cyst can be achieved through minimal exposure to the site of the CSF leak to fenestrate the cyst and repair the leak.

Long term clinical and radiological outcomes following surgical treatment of symptomatic cranial arachnoid cyst: A population based consecutive cohort study.

OBJECTIVE: Symptomatic intracranial arachnoid cysts are treated mainly through surgical resection, endoscopic fenestration, or by implanting cystoperitoneal (CP) shunt. However, the use of a specific technique remains controversial. The purpose of this study is to discuss these surgical modalities in symptomatic patients with intracranial arachnoid cysts (ACs) and investigate which has better outcomes and less complications by comparing variable preoperative and postoperative parameters. METHODS: An analysis of thirty-nine symptomatic patients who underwent intracranial arachnoid cyst surgery in the department of neurosurgery between 2009 and 2023 was performed. Patients were retrospectively compared based on age group, gender, anatomical location, laterality, type of intervention, clinical and volumetric changes, postoperative complications and outcome. RESULTS: Of the 39 patients, 20 patients (51.28 %) received CP shunt. Eleven patients (28.2 %) underwent endoscopic fenestration, and 8 patients (20.5 %) had surgical resection. The age at the time of first operation ranged from 1 month to 59.9 years (mean age: 16.8 years), and the pediatric patients were 25 (64.1 %). The most common initial symptom was headache which was observed in 19 patients (48.7 %), followed by seizure in 12 patients (30.8 %), vomiting in 11 patients (28.2 %), visual dysfunction in 8 patients (20.5 %), drowsiness in 8 patients (20.5 %), visual symptoms in 8 patients (20.5 %), cognitive impairment in 4 patients (10.3 %), focal neurological deficits in 3 patients (7.7 %), and cranial nerve involvement in 1 patient (2.6 %). 24 patients (61.5 %) showed improvement while in 15 patients (38.5 %) the symptoms persisted or worsened. Postoperatively, patients were followed up for an average of one year. The highest improvement rate was noted in endoscopic fenestration with 9 improved patients (81.8 %), followed by surgical resection with 5 symptom-free patients (62.5 %). The worst outcomes were seen in cystoperitoneal shunt with only half of the patients were relieved (50 %). Complications developed in 2 patients (25 %) who underwent surgical resection, 5 patients (45.5 %) who had endoscopic fenestration, and 13 patients (65 %) who had cystoperitoneal shunting. CONCLUSION: Endoscopic fenestration has the highest improvement rate, the lowest serious complications along with being the least invasive technique. These features make it the optimal modality in treatment of ACs. Surgical resection or cystoperitoneal shunt can be considered as secondary techniques when patients report unchanged or worsening symptoms.

Spontaneous regression of an interhemispheric arachnoid cyst: illustrative case.

BACKGROUND: Intracranial arachnoid cysts are benign collections of cerebrospinal fluid that are often asymptomatic and discovered incidentally. An interhemispheric location of these lesions is rare, with only a few such cases reported in the literature. Though spontaneous regression of arachnoid cysts has been described in other locations, to date this phenomenon has not been reported in interhemispheric fissure cysts. OBSERVATIONS: In this report, we describe a patient with a large, multiloculated interhemispheric arachnoid cyst diagnosed on prenatal ultrasound. She did not exhibit neurologic deficits or signs of increased intracranial pressure and was observed with serial imaging. After several years of observation, imaging revealed spontaneous and progressive decrease in the cyst size. LESSONS: We illustrate a case of regression of an interhemispheric arachnoid cyst in a pediatric patient. To our knowledge, this is the first reported case of spontaneous shrinkage of an arachnoid cyst in this location. Although the current presentation is rare, this reporting adds to the current understanding of natural history of arachnoid cysts and provides an example of radiographical improvement without intervention of a cyst located within the interhemispheric fissure.

Arachnoid cyst in the pediatric patient: What the radiologist needs to know.

Arachnoid cysts are the most common incidentally discovered intracranial lesions on imaging and the most common cystic intracranial lesions. They may be developmental or secondary. A relative lack of recent literature and any comprehensive radiological review on arachnoid cysts has led to a general lack of awareness among radiologists of symptomatic or complicated arachnoid cysts. This is particularly concerning in pediatric patients. While arachnoid cysts are asymptomatic in most cases, they can cause clinical symptoms in a minority of cases, especially when they occur in unusual sites. These include intraventricular locations where they may cause hydrocephalus, the basal cisterns where they may compress cranial nerves, the cerebellopontine angle where they have to be differentiated from a number of cystic lesions, the cavum septum pellucidum or cavum velum interpositum, the choroid fissure where they can entrap the temporal horn and compress the hippocampus, the posterior fossa where they need to be differentiated from other posterior fossa cystic lesions, and within the spinal canal where there is a concern for cord or nerve root compression. Larger cysts are more prone to complications such as mass effect, hemorrhage, and rupture. Hemorrhage and rupture often present with acute symptoms. Ruptured cysts lose their characteristic imaging appearance and can mimic several ominous pathologies. It therefore becomes vital to accurately diagnose these cases as complications of pre-existing arachnoid cysts for appropriate management. A detailed review of all diagnostic imaging aspects of arachnoid cysts will help fill in the existing information void on this important entity.

Subarachnoid Neurocysticercosis Case Series Reveals a Significant Delay in Diagnosis-Requiring a High Index of Suspicion Among Those at Risk.

Subarachnoid neurocysticercosis can be challenging to recognize, which often leads to a delay in diagnosis. We report 3 cases presenting as chronic headache disorders that highlight the unique manifestations seen with this form of neurocysticercosis and the role that the infectious diseases consultant can play in ensuring a timely diagnosis.

Description and clinical relevance of the variable conformation of canine spinal arachnoid diverticula.

The conformation of spinal arachnoid diverticula (SAD) and their clinical implications are poorly characterized in dogs. This retrospective cross-sectional study describes different SAD conformations in dogs and aims to identify if there is an association between SAD conformation and clinical features, localization, syringomyelia (SM) presence, concurrent vertebral condition, treatment option, and short as well as long-term outcome. Sixty-two dogs were included (12 cervical and 50 thoracolumbar SAD). All dogs with a cervical SAD had a cranial tethered conformation and were not included in the statistical analysis. Half of the dogs with a thoracolumbar SAD were cranial tethered, and the other half were caudal tethered. SM associated with SAD had a moderate prevalence in the cervical region (58.3%) and a high prevalence in the thoracolumbar region (82%). All dogs with the presence of SM and caudal tethered SAD had a cranial positioned SM, and all dogs with SM and a cranial tethered SAD had a caudal positioned SM. The SM absolute length and SM length/L2 ratio were significantly higher (P = .018, respectively) in the caudal tethered SAD compared with the cranial tethered SAD. The short-term outcome was statistically different (P = .045) between caudal and cranial tethered thoracolumbar SAD, but not the long-term outcome (P = .062). Multivariable logistic regression identified thoracolumbar caudal tethered SAD conformation had a better short-term outcome (P = 0.017, OR: 0.043, CI: 0.003-0.563), independently of SM length measurements. SAD conformation in dogs can influence SM formation. A possible link between short-term outcome and SAD conformation was found, but further research is warranted.

Arachnoid cyst in the quadrigeminal cistern: A case from Afghanistan.

Arachnoid cysts, fluid-filled lesions within the central nervous system, pose diagnostic challenges. This study examines a unique case of a quadrigeminal arachnoid cyst in a 13-year-old girl, emphasizing accurate identification and treatment. The patient's symptoms of blurred vision and headaches led to the discovery of papilledema and imaging revealing a sizable cyst causing obstructive hydrocephalus. Urgent surgical intervention involved suboccipital craniectomy and infratentorial-supracerebellar cyst drainage, resulting in favorable postoperative outcomes. Further analysis of anatomical variations, age-related factors, and etiological debates deepens understanding. Diagnostic advancements, notably MRI, are crucial for noninvasive characterization. This case offers nuanced insights into managing arachnoid cysts, highlighting the success of tailored surgical strategies. Recognizing clinical subtleties, utilizing diagnostic innovations, and customizing surgical techniques are essential for navigating complexities. This study underscores the importance of a comprehensive approach in addressing the challenges of arachnoid cysts within the central nervous system.

A Technical Note on Alternating Laminectomies Plus Folding Cystectomy: A Novel Technique for Spinal Arachnoid Cyst.

We report the case of a 33-year-old male patient with no past medical history presenting to our tertiary referral center with progressive (two years) deficit of lower limb motor impairment (2/5 Medical Research Council [MRC] scale) and sensory impairment. T2- and T1-weighted MRI images clarified the nature of the cyst from T3 to T8. In our case, surgical management was warranted to relieve tension over the spinal cord, thus improving symptoms. Two multilevel laminectomies were performed, one centered on the proximal pole and the other on the distal pole; subsequently, the epidural cyst was gradually folded until it was totally extracted without complications. In the present study, we discuss a technique of extended spinal compressive arachnoid cyst. To the best of our knowledge, this technique has not been previously described in the existing body of literature. Here, we present a case of a successful procedure that seems both efficient and safe. Further study will be required to confirm its safety and efficacy.

Coexistence of Trigonocephaly and Sylvian Arachnoid Cysts: A Coincidence?

INTRODUCTION: The association between trigonocephaly and Sylvian fissure arachnoid cysts (ACs) has been occasionally reported in the literature. However, the real incidence of this association and its clinical relevance remain unknown. METHODS: The authors collected and retrospectively reviewed all clinical charts and CT scans of patients surgically treated for trigonocephaly at the Pediatric Neurosurgical Department of Fondazione Policlinico Universitario "Agostino Gemelli" IRCCS from January 2014 to June 2023. RESULTS: During the study period, 136 patients with trigonocephaly underwent surgery. Analysis of the clinical charts revealed that in 39.7% of the cases (54/136), preoperative CT scan depicted the presence of a Sylvian fissure AC. Of these, AC was bilateral in 23 cases and unilateral in the remaining 31. All unilateral ACs were on the left side. The ACs were classified as Galassi grade I in 52 cases (96.3%) and Galassi grade II in 2 cases (3.7%). Interestingly, in 1 case we reported a Galassi grade I AC enlargement during follow-up, thereby necessitating surgical fenestration. CONCLUSION: ACs and trigonocephaly are well-known conditions for pediatric neurosurgeons; however, their association is poorly defined. Despite the lack of reports on the incidence and clinical significance of this association, it is worth knowing that radiological follow-up is essential in monitoring AC evolution.

Management of a recurrent spinal arachnoid cyst presenting as arachnoiditis in the setting of spontaneous spinal subarachnoid hemorrhage: illustrative case.

BACKGROUND: Spontaneous spinal subarachnoid hemorrhage is a rare pathological entity with a variety of presentations depending on the underlying etiology, which often remains cryptogenic. The literature is sparse regarding the most efficacious treatment or management option, and there is no consensus on follow-up time or modalities. Additionally, there are very few reports that include operative videos, which is provided herein. OBSERVATIONS: The authors present a case of spontaneous spinal subarachnoid hemorrhage without an underlying etiology in a patient with progressive myelopathy, back pain, and lower-extremity paresthesias. She presented to our institution, and because of progressive worsening of her symptoms and the development of compressive arachnoid cysts, she underwent thoracic laminectomies for evacuation of subdural fluid, fenestration of the arachnoid cysts, and lysis of significant arachnoid adhesions. Her clinical course was further complicated by the recurrence of worsening myelopathy and the development of a large compressive arachnoid cyst with further arachnoiditis. The patient underwent repeat surgical intervention for cyst decompression with an improvement in symptoms. LESSONS: This case highlights the importance of long-term follow-up for these complicated cases with an emphasis on repeat magnetic resonance imaging. Unfortunately, surgical intervention is associated with short-term relief of the symptoms and no significant nonoperative management is available for these patients.

Improvement in Hearing Loss Following Posterior Fossa Arachnoid Cyst Fenestration: A Case Study.

Arachnoid cysts are abnormal intradural collections of cerebrospinal fluid. For posterior fossa arachnoid cysts (PFACs), symptoms vary greatly, often relating to cranial nerve impingement and/or hydrocephalus. Literature on long-term symptomatic and radiographic follow-up of PFACs is lacking. This case study describes a 32-year-old man who presented with headaches and left-sided hearing loss and was found to have a large left-sided cerebellopontine angle arachnoid cyst with syrinx and ventriculomegaly. After PFAC fenestration and excision, his headaches resolved and his hearing markedly improved. At the one-year postoperative evaluation, symptom improvement persisted, and MRI demonstrated a stable decreased cyst and near-complete resolution of his syrinx.

Nontraumatic symptomatic de novo arachnoid cyst in an adolescent patient treated with cystoperitoneal shunting: illustrative case.

BACKGROUND: Arachnoid cysts are often congenital, asymptomatic lesions detected in the pediatric population. When seen in adults, they usually occur following trauma. De novo formation of arachnoid cysts is uncommon, with only a few instances cited in the literature and most of which occurred in the pediatric population. Treatment options for these lesions include observation, craniotomy for cyst resection, microsurgical/endoscopic fenestration, or shunting. OBSERVATIONS: In this report, the authors describe a female patient with a de novo, symptomatic, enlarging middle cranial fossa arachnoid cyst detected at age 16 years. She was treated with the placement of a cystoperitoneal shunt. After surgery, she experienced clinical and radiological improvement. LESSONS: We illustrate successful shunting of a de novo arachnoid cyst in a symptomatic teen patient. Although arachnoid cysts in certain intracranial locations are more likely to produce symptoms, those in the middle cranial fossa tend to be asymptomatic. To our knowledge, this is the first reported case of a symptomatic de novo arachnoid cyst located in the middle cranial fossa in a postpubertal patient. Although the current presentation is rare, the authors demonstrate an effective surgical treatment of a symptomatic, large, de novo arachnoid cyst in a postpubertal pediatric patient.

Posterior fossa microcystic meningioma mimicking an arachnoid cyst.

Microcystic meningioma is an uncommon subtype of World Health Organization grade 1 meningiomas often associated with a shorter progression-free survival. Diagnosis through imaging alone can often be challenging due to atypical characteristics, especially when found in unexpected locations. Here, we present a 55-year-old woman who was diagnosed, based on imaging, with a posterior fossa arachnoid cyst 5 years prior after complaints of headaches and gait imbalance. After surgical resection of the "arachnoid cyst," the diagnosis of microcystic meningioma was made. This case report emphasizes the clinical importance and challenges associated with diagnosing microcystic meningiomas.