Children With Intracranial Arachnoid Cysts: Classification and Treatment

Optic Nerve Edema in Pediatric Middle Cranial Fossa Arachnoid Cysts: Report of 51 Patients From a Single Institution

BACKGROUND

Middle fossa arachnoid cysts (MFACs) are rare, congenital lesions that may rupture and cause symptoms of elevated intracranial pressure. We sought to describe the presence of and factors associated with optic nerve edema in MFACs, focusing on the utility of ophthalmologic evaluations for guiding cyst management.

METHODS

We reviewed clinical and radiographic information for all patients with MFACs with ophthalmologic evaluations at our institution. Headache, cranial nerve palsy, emesis, altered mental status, fatigue, and seizures were considered MFAC-related symptoms. Univariate and multivariable analyses evaluated factors associated with optic edema.

RESULTS

Fifty-one patients between 2003 and 2022 were included. Cysts were a median volume of 169.9 cm3 (interquartile range: 70.5, 647.7). Evidence of rupture with subdural hematoma/hygroma occurred in 19 (37.3%) patients. Eighteen (35.3%) patients underwent surgery for their cyst and/or rupture-associated intracranial bleed. Eleven (21.6%) patients had optic edema; all were symptomatic and experienced cyst rupture. Ten of these patients received surgery. Postoperatively, optic edema resolved in 80% of cases. Cyst volume and symptoms were not associated with optic edema; however, patients with ruptured cysts, particularly those with traumatic rupture, were more likely to have optic edema and receive surgery (P < 0.001).

CONCLUSIONS

We found optic edema in 21.6% of evaluated MFACs, and this comprised of 57.9% of ruptured cases. Optic edema was not found in unruptured cysts. Cyst fenestration improved optic edema and patient symptoms. In conjunction with clinical history and neuroimaging, optic edema may help guide MFAC management, particularly in patients with cyst rupture.

Intracranial Arachnoid Cyst in Children: Clinical Presentation and Risk Factors for Surgical Intervention

INTRODUCTION

Intracranial arachnoid cysts (IAC) in children are a common incidental finding on imaging. Most IACs are asymptomatic and can be monitored; however, a small percentage may enlarge and require surgical intervention. This study aimed to identify clinical risk factors in patients with IAC who underwent surgery versus those who did not.

METHODS

We conducted a retrospective chart review from 2009 to 2021 at a free-standing children's hospital. A total of 230 patients diagnosed with an IAC aged 0-21 years of age were included in the study. Data on demographics, imaging, and neurological follow-up were analyzed.

RESULTS

Out of 230 patients, 45 (19.6%) underwent surgery. At time of IAC diagnosis, the surgical patients were younger (median age 1.1 years), and their median cyst volume was larger (41.7 cm3), compared to nonsurgical patients (median age 5.9 years, volume 11.8 cm3, respectively). Headache was the most common reason for initial imaging in nonsurgical patients (54/185, 29.2%) while prenatal ultrasound (11/45, 24.4%) and macrocephaly (11/45, 24.4%) were the most common reasons for surgical patients. The majority of both surgical and nonsurgical patients had the IAC incidentally found (41/45, 91.1% and 181/185, 97.8%, respectively). Surgery relieved symptoms in 38/45 (84.4%) patients. Cyst volume and age were predictors of increased odds of having surgery.

DISCUSSION/CONCLUSION

Patients who underwent surgery were younger and had larger cyst volumes at time of diagnosis. The majority of the IAC were found incidentally and remained stable over prolonged follow-up. The majority of the patients experienced relief of symptoms postsurgical intervention. There is a greater odds of having surgical treatment with decreased age and greater cyst volume at diagnosis, and therefore these patients should be monitored closely for development of symptoms indicating need for surgical intervention.

Familial and syndromic forms of arachnoid cyst implicate genetic factors in disease pathogenesis

Arachnoid cysts (ACs) are the most common space-occupying lesions in the human brain and present significant challenges for clinical management. While most cases of ACs are sporadic, nearly 40 familial forms have been reported. Moreover, ACs are seen with increased frequency in multiple Mendelian syndromes, including Chudley-McCullough syndrome, acrocallosal syndrome, and autosomal recessive primary ciliary dyskinesia. These findings suggest that genetic factors contribute to AC pathogenesis. However, traditional linkage and segregation approaches have been limited in their ability to identify causative genes for ACs because the disease is genetically heterogeneous and often presents asymptomatically and sporadically. Here, we comprehensively review theories of AC pathogenesis, the genetic evidence for AC formation, and discuss a different approach to AC genomics that could help elucidate this perplexing lesion and shed light on the associated neurodevelopmental phenotypes seen in a significant subset of these patients.

Expanding the genetic spectrum of giant axonal neuropathy: Two novel variants in Iranian families

BACKGROUND

Giant axonal neuropathy (GAN) is a progressive childhood hereditary polyneuropathy that affects both the peripheral and central nervous systems. Disease-causing variants in the gigaxonin gene (GAN) cause autosomal recessive giant axonal neuropathy. Facial weakness, nystagmus, scoliosis, kinky or curly hair, pyramidal and cerebellar signs, and sensory and motor axonal neuropathy are the main symptoms of this disorder. Here, we report two novel variants in the GAN gene from two unrelated Iranian families.

METHODS

Clinical and imaging data of patients were recorded and evaluated, retrospectively. Whole-exome sequencing (WES) was undertaken in order to detect disease-causing variants in participants. Confirmation of a causative variant in all three patients and their parents was carried out using Sanger sequencing and segregation analysis. In addition, for comparing to our cases, we reviewed all relevant clinical data of previously published cases of GAN between the years 2013-2020.

RESULTS

Three patients from two unrelated families were included. Using WES, we identified a novel nonsense variant [NM_022041.3:c.1162del (p.Leu388Ter)], in a 7-year-old boy of family 1, and a likely pathogenic missense variant [NM_022041.3:c.370T>A (p.Phe124Ile)], in two affected siblings of the family 2. Clinical examination revealed typical features of GAN-1 in all three patients, including walking difficulties, ataxic gait, kinky hair, sensory-motor polyneuropathy, and nonspecific neuroimaging abnormalities. Review of 63 previously reported cases of GAN indicated unique kinky hair, gait problem, hyporeflexia/areflexia, and sensory impairment were the most commonly reported clinical features.

CONCLUSIONS

One homozygous nonsense variant and one homozygous missense variant in the GAN gene were discovered for the first time in two unrelated Iranian families that expand the mutation spectrum of GAN. Imaging findings are nonspecific, but the electrophysiological study in addition to history is helpful to achieve the diagnosis. The molecular test confirms the diagnosis.

Acetazolamide to treat symptomatic ruptured arachnoid cysts: illustrative cases

BACKGROUND

Arachnoid cysts are benign, often asymptomatic intracranial mass lesions that, when ruptured, may cause seizures, raised intracranial pressure, hemorrhage, and/or loss of consciousness. There is no widely agreed upon treatment, and there is debate as to whether a nonoperative or surgical approach is the best course of action. The carbonic anhydrase inhibitor acetazolamide may be an effective nonoperative approach in treating ruptured arachnoid cysts.

OBSERVATIONS

The Pediatric Neurosurgery Clinical Database at BC Children’s Hospital from 2000 to 2020 was queried, and four pediatric patients who were treated with acetazolamide after presentation with a ruptured middle cranial fossa arachnoid cyst were identified. All patients showed some degree of symptom improvement. Three of the patients showed complete reabsorption of their subdural collections in the ensuing 6 months. One patient had an inadequate response to acetazolamide and required surgical management.

LESSONS

Acetazolamide is a safe and reasonable primary treatment option in pediatric patients with ruptured middle cranial fossa arachnoid cysts, and it may help avoid the need for surgery.

Do arachnoid cysts grow? A retrospective volumetric study

OBJECTIVE

Arachnoid cysts (ACs) are frequent incidental findings and may be associated with neuropsychiatric symptoms. Usually growth of the ACs with pressure on adjacent brain tissue is regarded as cause of the symptoms. This study was undertaken to identify if and which ACs grow with time.

METHODS

We used a large database of cranial MRIs for a retrospective analysis.

RESULTS

During a period of 10 years, we collected 166 ACs of 50 persons, mean observational period was 2.5 years. Among these, only larger cysts at the temporal pole, i.e., Galassi II ACs, grew with a rate of 0.3 ml a year (β = 0.32, SE 0.07, p = 0.003); all other ACs remained constant in size or became smaller. All cysts were clinically silent.

CONCLUSIONS

Most ACs remain constant in size or become smaller.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that the majority of arachnoid cysts does not grow.

Endoscopic Treatment of Intracranial Arachnoid Cysts: A Retrospective Analysis of a 25-Year Experience

BACKGROUND

Since the development of neuroendoscopy, pure endoscopic fenestration for intracranial arachnoid cysts (ACs) became more and more popular and is actually preferred by many neurosurgeons.

OBJECTIVE

To explore their techniques and experiences with endoscopic treatment of intracranial ACs over a 25-yr period.

METHODS

A total of 95 endoscopic procedures in 87 patients with 88 intracranial ACs performed at the authors’ departments between February 1993 and October 2018 were retrospectively analyzed. Particular respect was given to surgical technique, complications, patients’ outcome, and radiological benefit in relation to cyst location.

RESULTS

Patients’ ages ranged from 23 d to 81 yr (mean: 29.9 yr). Cysts were located temporobasal (n = 31; 35.2%), paraxial supratentorial (n = 14; 15.9%), suprasellar/prepontine (n = 14; 15.9%), quadrigeminal (n = 12; 13.6%), infratentorial (n = 11; 12.5%), and supratentorial intraventricular (n = 6; 6.8%). Four different endoscopic techniques were applied: cystocisternostomies (n = 48; 50.5%), ventriculocystostomies (n = 23; 24.2%), cystoventriculostomies (n = 14; 14.7%), and ventriculocystocisternostomies (n = 10; 10.5%). Pure endoscopic technique was feasible in 89 of the 95 surgeries (93.7%). Clinical improvement was documented after 82 surgeries (86.3%) and radiological benefit after 62 surgeries (65.3%). Recurrences developed in 8 cases (8.4%). Overall complication rate was 21.1% (n = 20), postoperative new shunt dependency was observed in 4.2% of the cases (n = 4).

CONCLUSION

Pure endoscopic AC fenestration is a safe, effective, and less invasive technique providing high success and low permanent complication rates. The most frequent temporobasal cysts are the most difficult to treat endoscopically. A long-term follow-up is recommended because recurrences may occur many years after first treatment.

Safety of Intrathecal Administration of Gadolinium-based Contrast Agents: A Systematic Review and Meta-Analysis

Background The use of MR cisternography with intrathecal administration of gadolinium-based contrast agents (GBCAs) is limited by a lack of understanding of the relationship between intrathecal GBCA exposure and dose-related adverse events. Purpose To perform a systematic review to establish an understanding of the dose-response relationship of intrathecal GBCAs and to characterize related adverse events, particularly at higher doses. Materials and Methods Medline, Embase, CINAHL, and Central databases were searched for studies reporting intrathecal GBCA use. Data extraction included studies focused on rates and types of adverse events after intrathecal GBCA exposure. A two-tailed independent sample t test statistic was used to evaluate the relationship between GBCA dose and the presence of serious versus nonserious adverse events. Meta-analysis was used to determine the overall incidence of adverse events. Study quality and publication bias were assessed using the modified Newcastle-Ottawa scale and a funnel plot (effect size measured using Hedges' g followed by the Egger test), respectively. Results Fifty-three studies with a total of 1036 patients were included for analysis. The overall rate of adverse events after intrathecal administration of GBCA was 13% (95% confidence interval [CI]: 9.3%, 18%). Meta-analysis revealed moderate heterogeneity (I² = 62%). Serious adverse event rates could not be determined with meta-analysis. They were reported in 10 studies and were primarily neurologic in nature, with two cases of coma-one resulting in death. Serious adverse events were associated with significantly higher GBCA doses when compared with nonserious adverse events (mean difference, 4.5 mmol; 95% CI: 2.3 mmol, 6.6 mmol; P = .008). For serious adverse events, there was no clear dose-dependent increase in severity above 2.0 mmol. Conclusion Overall, intrathecal administration of GBCAs at doses greater than 1.0 mmol are associated with serious neurotoxic complications with relative clinical safety at lower doses. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Kanal in this issue.

Postoperative patency assessment of Cystocisternostomy and Cystoventriculostomy stomas in cases with Arachnoidal cyst

PURPOSE

The goal of this study was to determine stoma and flow patency with 3D SPACE T2 and 3D CISS sequences in cases with cystocisternostomy or cystoventriculostomy.

METHODS

A total of sixty three patients (total 106 MRI examinations) with endoscopic cystocisternostomy or cystoventriculostomy of arachnoid cyst underwent 1.5-3 T MRI to determine flow patency between June 2007 and April 2018. Postoperative results, the patients' clinic and arachnoid cyst volume were used to confirm stoma and flow patency in MRI.

RESULTS

The stoma was open and functional in forty three patients. Minimal flow was detected in five patients. Fifteen patients with closed stoma (total 17 MR images) were evaluated with the clinician. Patients' clinic, physical examination, and growth (for pediatric patients) were evaluated. Three of fifteen patients were re-operated. Operative findings and postoperative follow-up MR imaging findings were correlated with our preoperative MRI results. The findings were in compliance in both groups (operated-non-operated groups).

CONCLUSION

3D SPACE T2 and 3D CISS are effective sequences in addition to other routine conventional sequences to evaluate stoma and flow patency.

Evaluation of the Communication Between Arachnoid Cysts and Neighboring Cerebrospinal Fluid Spaces by T2W 3D-SPACE With Variant Flip-Angle Technique at 3 T

PURPOSE

Phase-contrast cine magnetic resonance imaging (PC-MRI) is a widely used technique for determination of possible communication of arachnoid cysts (ACs). Three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions (3D-SPACE) technique is a relatively new method for 3D isotropic scanning of the entire cranium within a short time. In this research, the usage of the 3D-SPACE technique in differentiation of communicating or noncommunicating type ACs was evaluated.

MATERIALS AND METHODS

Thirty-five ACs in 34 patients were retrospectively examined. The 3D-SPACE, PC-MRI, and contrast material-enhanced cisternography (if present) images of the patients were analyzed. Each cyst was described according to cyst size/location, third ventricle diameter, Evans index, and presence of hydrocephalus. Communication was defined as absent (score 0), suspected (score 1), or present (score 2) on each sequence. Results of PC-MRI or cisternography (if available) examinations were used as criterion standard techniques to categorize all cysts as communicating or noncommunicating type. The results of 3D-SPACE were compared with criterion standard techniques. The comparisons between groups were performed using Mann-Whitney and Fisher exact tests.

RESULTS

For demonstration of communication status of the cysts, criterion standard test results and 3D-SPACE findings were almost in perfect harmony (κ[95% confidence interval: 0.94]; P < 0.001). When evaluating the communicative properties, 3D-SPACE findings correlated with other final results at a rate of 97%. There is a positive correlation with third ventricular diameters and Evans index for all patients (r = 0.77, P < 0.001). For other analyzed variables, there is no significant difference or correlation between the groups.

CONCLUSIONS

The 3D-SPACE technique is an easy, useful, and noninvasive alternative for the evaluation of morphology, topographical relationships, and communication status of ACs.

SPECT/CT Detection of a Communicating Arachnoid Cyst in a Patient With Normal Pressure Hydrocephalus

A 59-year-old man with history of multiple sclerosis and residual sensory and motor dysfunction presented with progressive lower-extremity weakness, ataxic gait, and intermittent urinary incontinence. Brain MRI demonstrated volume loss with disproportionate ventricular dilatation, but no evidence of infarction or abnormal enhancement. Radionuclide cisternography showed early and persistent ventricular reflux, poor progression of radiopharmaceutical over convexities, and delayed clearance in a pattern consistent with normal pressure hydrocephalus. Asymmetric activity in the right parietal region was also identified. Fused SPECT/CT, as well as fusion of the SPECT with a previous brain MRI, demonstrated a communicating arachnoidal cyst.

Ophthalmological symptoms in children with intracranial cysts

The purpose of this study was to perform an ophthalmological assessment in children with intracranial cysts and to assess the correlation between the occurrence of cysts and visual disorders. The documentation of 46 children with intracranial cysts, monitored by the Children’s Outpatient Ophthalmology Clinic, Poznan, Poland was analysed. The best corrected visual acuity (BCVA), the alignment of the eyes, visual evoked potentials (VEP), comprehensive eye examination were performed in all patients. Additional ophthalmological tests were conducted to eliminate other causes of decreased visual acuity.Included in the final analysis were 26 children (52 eyes). The average age at the last visit was 10.3 years. Sixteen children (61.5%) had arachnoid cysts located in the posterior cranial fossa, 3 children (11.5%) in the middle cranial fossa, while 7 children (27%) had a pineal cyst. Decreased BCVA was found in 13 children, abnormal VEP in 13, strabismus in 14 patients (53.9%), nystagmus in 5 patients (19.2%), and double vision in 2 patients (7.7%). Numerous visual disorders in children with intracranial cysts suggest the necessity to carry out enhanced ophthalmological diagnostics in these patients. In the examined patient group, visual disorders occurred mostly in the case of arachnoid cysts of the posterior fossa.