Arachnoid cysts

Staged neurosurgical approach for giant and progressive neonatal arachnoid cysts: a case series and review of the literature

OBJECTIVES

Prenatally diagnosed complex arachnoid cysts are very rare. While the true prenatal incidence is still unknown, they account for approximately 1% of intracranial masses in newborns. They rarely exhibit rapid growth or cause obstructive hydrocephalus, but if they increase to such a dimension during pregnancy, the ideal management is not well established. We present our detailed perinatal experience, covering prenatal diagnosis, a compassionate delivery process, and neonatal stabilization. Finally, a thorough postnatal neurosurgical intervention was performed. Initially, our focus was on the gradual reduction of cyst size as a primary effort, followed by subsequent definitive surgical treatment.

METHODS

This case series shows the treatment course of three fetuses with antenatally diagnosed large arachnoid cysts. We present pre- and postnatal management and imaging, as well as the surgical treatment plan and the available clinical course during follow-up.

RESULTS

Two girls and one boy were included in the current review. All three cases presented with prenatally diagnosed complex arachnoid cysts that increased in size during pregnancy. The mean gestational age at delivery was 35 weeks (range 32 to 37 weeks), and all patients were delivered by a caesarian section. Increasing head circumference and compression of brain structures were indications for delivery, as they are associated with a high risk of excess intracranial pressures and CSF diapedesis, as well as traumatic delivery and maternal complications. All cysts were supratentorial in location; one expanded into the posterior fossa, and one was a multicompartment cyst. All children underwent an initial surgical procedure within the first days of life. To relieve cyst pressure and achieve a reduction in head circumference, an ultrasound-guided or endoscopic-assisted internal shunt with drainage of the cyst to the ventricles or subdural/subarachnoid space was inserted. Definite surgical therapy consisted of cyst marsupialization and/or cysto-peritoneal shunt implantation. All children survived without severe neurodevelopmental impairments.

CONCLUSION

With the cases presented, we demonstrate that the slow reduction of immense cyst size as an initial procedure until optimal requirements for final surgical treatment were achieved has proven to be optimal for neurological outcome. Special emphasis has to be taken on the delicate nature of premature newborn babies, and surgical steps have to be thoroughly considered within the interdisciplinary team.

Effect of continuous drainage of cranial arachnoid cysts into the ventricular system by stereotactic placed catheters

Background: Surgical treatment of intracranial arachnoid cysts (iACs) is challenging. Microsurgical resection, endoscopic fenestration and cysto-peritoneal shunting are the most frequently used methods, each implying their own drawbacks. Stereotactic-guided cysto-ventricular drainage has been described as an alternative method. Here we describe our experience with this technique and how we conducted volumetric measurements to evaluate the effect of permanent drainage.Methods: Standardized stereotactic planning was performed. The planned trajectory included both the iAC and the ventricle system. The catheter was shortened to the defined length and was further fenestrated along its planned course through the iAC to allow drainage into the ventricular system. Clinical and radiological control was performed on outpatient basis after a mean follow-up of 2 (1-3) months. The overall mean follow-up was 32 months (6-59). The measurement of the cyst volume was conducted by the ABC/2-method.Results: Six patients with symptomatic arachnoid cysts (4 f, 2 m) were treated between 2010 and 2016. The overall postoperative reduction in cyst volume at the first follow-up was 36.04% (at the long-term follow-up: 38.57%). Decrease of the midline-shift was achieved in all cases and averaged 57.83% (long term: 81.88%). Clinical improvement of related symptoms could be achieved in all patients (4 patients were symptom free, two patients had alleviated symptoms). There was no case of over-drainage. The catheter had to be removed after 6 months in one case due to infection.Conclusions: We demonstrate successful symptom control and volume reduction in a small series of iACs by continuous drainage into the CSF-system through stereotactic placed catheters. This method may facilitate a self-regulated egress of entrapped cyst fluid in symptomatic patients without risk of over-drainage. A literature survey of the success rate and the complications of this approach is provided. It is concluded that this minimally- invasive method may be an alternative to established fenestration techniques especially for patients with arachnoid cysts that aren't directly adjacent to a cisternal or ventricular CSF space.

Evaluation of surgical treatment strategies and outcome for cerebral arachnoid cysts in children and adults

OBJECTIVE

The best treatment strategies for cerebral arachnoid cysts (CAC) are still up for debate. In this study, we present CAC management, outcome data, and risk factors for recurrence after surgical treatment, focusing on microscopic/endoscopic approaches as compared to minimally invasive stereotactic procedures in children and adults.

METHODS

In our single-institution retrospective database, we identified all patients treated surgically for newly diagnosed CAC between 2000 and 2022. Microscopic/endoscopic surgery (ME) aimed for safe cyst wall fenestration. Stereotactic implantation of an internal shunt catheter (STX) to drain CAC into the ventricles and/or cisterns was used as an alternative procedure in patients aged ≥ 3 years. Treatment decisions in favor of ME vs. STX were made by interdisciplinary consensus. The primary study endpoint was time to CAC recurrence (TTR). Secondary endpoints were outcome metrics including clinical symptoms and MR-morphological analyses. Data analysis included subdivision of the total cohort into three distinct age groups (AG1, < 6 years; AG2, 6-18 years; AG3, ≥ 18 years).

RESULTS

Sixty-two patients (median age 26.5 years, range 0-82 years) were analyzed. AG1 included 15, AG2 10, and AG3 37 patients, respectively. The main presenting symptoms were headache and vertigo. In AG1 hygromas, an increase in head circumference and thinning of cranial calvaria were most frequent. Thirty-five patients underwent ME and 27 STX, respectively; frequency did not differ between AGs. There were two (22.2%) periprocedural venous complications in infants (4- and 10-month-old) during an attempt at prepontine fenestration of a complex CAC, one with fatal outcome in a 10-month-old boy. Other complications included postoperative bleeding (2, 22.2%), CSF leaks (4, 44.4%), and meningitis (1, 11.1%). Overall, clinical improvement and significant volume reduction (p = 0.008) were seen in all other patients; this did not differ between AGs. Median follow-up for all patients was 25.4 months (range, 3.1-87.1 months). Recurrent cysts were seen in 16.1%, independent of surgical procedure used (p = 0.7). In cases of recurrence, TTR was 7.9 ± 12.7 months. Preoperative ventricular expansion (p = 0.03), paresis (p = 0.008), and age under 6 years (p = 0.03) were significant risk factors for CAC recurrence in multivariate analysis.

CONCLUSIONS

In patients suffering from CAC, both ME and STX can improve clinical symptoms at low procedural risk, with equal extent of CAC volume reduction. However, in infants and young children, CAC are more often associated with severe clinical symptoms, stereotactic procedures have limited use, and microsurgery in the posterior fossa may bear the risk of severe venous bleeding.

Fallopian canal arachnoid cyst with acute facial nerve paralysis in children: a report of two cases and literature review

Introduction

Symptoms induced by arachnoid cysts in the fallopian canal are uncommon, and facial nerve paralysis without cerebrospinal fluid otorrhea is comparatively rarer.

Methods

Herein, we present two cases of arachnoid cysts in the fallopian canal with acute severe facial nerve paralysis and review the relevant literature.

Results

The symptoms and imaging findings of these two cases resembled those of facial nerve schwannomas. Cerebrospinal fluid otorrhea occurred upon removal of the arachnoid cyst, and the facial nerve was observed to be separated into multiple filaments or compressed and atrophied. Facial-hypoglossal nerve anastomosis and decompression were conducted after packing the dehiscence of cerebrospinal fluid otorrhea for the two cases.

Conclusion

Arachnoid cysts of the fallopian canal rarely cause facial nerve paralysis. Enhanced magnetic resonance imaging is vital for differentiating schwannomas. Different treatment strategies should be adopted for patients with different degrees of facial nerve paralysis; however, concurrent repair of cerebrospinal fluid otorrhea and facial nerves during surgery can occasionally be challenging.

Endoscopy-assisted purely total outer wall excision for pediatric Sylvian arachnoid cysts

BACKGROUND

To present a novel endoscopy-assisted surgical strategy of Sylvian arachnoid cysts (ACs).

CASE PRESENTATION

Endoscopy-assisted surgery was performed on 9 children (May 2019-December 2021). All patients were evaluated with CT and/or MRI and had regular follow-up examinations. The procedure consisted of performing a small temporal craniotomy (2 cm) behind the hairline. After dural opening, the surgery was performed with the assistance of a rigid 30-degree transcranial endoscope, self-irrigating bipolar forceps, and other standard endoscopic instruments. Steps included total excision of the AC outer wall and dissection of arachnoid adhesion around the cystic edge to communicate the residual cyst cavity with subdural space. Compared with the microscopical procedure, a 30-degree transcranial endoscope provides a wider view, especially for the lateral part exposure of the outer wall. The average age of the patients was 27.7 months (range 13-44 months). The Sylvian AC was in the right hemisphere in three patients and six in the left, respectively. 1 patient suffered transient postoperative epilepsy. There was no mortality or additional postoperative neurological deficit in this series. All of the patients achieved significant clinical improvement after surgery. Radiological examination after the operation showed a significant reduction in all cases (100%, 9/9) and disappearance in one case (11.1%, 1/9). Postoperative subdural fluid collection occurred in six cases and completely resolved spontaneously in 9 months.

CONCLUSION

The study demonstrated the minimally invasive, safety, and effectivity of the endoscopy-assisted purely total outer wall excision.

Arachnoid cysts in paediatrics

PURPOSE OF REVIEW

Arachnoid cysts are incidentally found on neuroimaging at an increasing rate in the paediatric population. Hence, learning their clinical implications to better inform families is important. The purpose of this review is to outline the current understanding of epidemiology, disease and clinical features based on location, imaging and management of arachnoid cysts in paediatrics.

RECENT FINDINGS

The prevalence of arachnoid cysts is 2.6% in paediatrics, with greater than 90% being asymptomatic. When they do cause symptoms, it is based primarily on their location and size. The most accurate diagnostic modality is MRI. Recent literature focuses primarily on the origin of arachnoid cysts, new approaches to treating symptomatic arachnoid cysts and long-term implications for patients.

SUMMARY

Incidental arachnoid cysts are being found most often due to the more frequent use of neuroimaging. There is a higher prevalence for arachnoid cysts in men and they are more commonly found on the left side. Despite their impressive size or location, greater than 90% of these lesions are asymptomatic and require no intervention. However, follow up with neurosurgery to help determine the clinical significance of these lesions is essential.

Arachnoid Cyst: A Sudden Deterioration

Arachnoid cysts are relatively rare and usually asymptomatic. It can only be diagnosed through radiological imaging modalities. Some patients may develop symptoms such as seizures, headache, dizziness, or psychiatric symptoms. We present a case of a 25-year-old male, previously healthy, who presented with sudden, repetitive episodes of seizure without regaining his consciousness. Computed tomography (CT) head scan showed a large cystic lesion that showed a rightward midline shift. Treatment was done surgically via endoscopic fenestration, and the patient remained symptom-free for one year. Most arachnoid cysts tend to remain asymptomatic throughout a patient's life span, allowing them to lead everyday normal lives; however, when these symptoms surface, they tend to be of a sudden nature requiring urgent surgical intervention. Our report follows the case of a young patient whose symptoms appear suddenly with triggers that led to status epilepticus. Our patient continued to suffer from multiple seizure attacks despite being on multiple anti-convulsive medications, and his symptoms eventually subsided via surgical intervention.

Right Trochlear Nerve Palsy as an Uncommon Manifestation of Arachnoid Cyst

The majority of arachnoid cysts are congenital intracranial lesions that develop in the early embryonic stages as a result of a slight irregularity in the cerebrospinal fluid's (CSF) passage through the embryonic mesenchyme. Most of the time, these cysts are asymptomatic all throughout life. Diplopia caused by an arachnoid cyst is extremely rare. We present a rare event of isolated fourth nerve palsy in a 56-year-old woman brought on by an intracranial arachnoid cyst. Her only presenting symptom was vertical diplopia for one week. She denied any history of trauma. Ocular motility revealed limitation of abduction in her right eye. We proceeded with neuroimaging and the magnetic resonance imaging (MRI) confirmed the presence of a well-circumscribed left retro-cerebellar lesion which follows the CSF signal intensity in all sequences causing compression onto the posterior aspect of the left cerebellum, keeping with the diagnosis of an arachnoid cyst. This uncommon pathology tends to be difficult to diagnose and treat.

The Efficacy and Tolerability of Electroconvulsive Therapy in Psychiatric Patients with Arachnoid Cysts: A Retrospective Chart Study

Electroconvulsive therapy (ECT) is an effective therapy for many psychiatric illnesses. However, intracranial occupying lesions are a relative contraindication to ECT. Arachnoid cysts are benign, congenital, and space-occupying lesions. Our study aimed to evaluate the efficacy and tolerability of ECT in psychiatric patients with arachnoid cysts. We retrospectively identified 62 psychiatric patients with arachnoid cysts; 43 of them underwent ECT and 19 did not. Their conditions were assessed by CGI-S and different scales depending on different diagnoses (PANSS for schizophrenia; HAMD for depression; YMRS for bipolar disorder). The side effect was assessed by TESS. Significant differences were shown in the reduced scores of the CGI-S between patients who underwent ECT and those who did not (p = 0.001), while, at the same time, there was no significant difference in their TESS score (p = 0.297). The current study found that ECT is an effective and tolerable therapy for psychiatric patients with arachnoid cysts.

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.

Late onset epilepsia partialis continua in a middle-aged patient with huge arachnoid cyst

Background:

Arachnoid cysts are congenital or acquired cerebrospinal fluid (CSF) filled intra arachnoidal lesions, included 1% of all infantile intracranial masses and were discovered incidentally in MRI or CT-scan. The vast majority of these lesions are generally asymptomatic but some patients with arachnoid cyst have headache, dizziness, seizure (or epilepsy), vestibular symptoms and cognitive impairment.

Case Presentation:

We present a case of a 43-year-old woman who has late onset epilepsia partialis continua and had right spastic cerebral palsy due to huge arachnoid cyst. Surprisingly without any history of seizure, her first seizure presents with sustained seizures (epilepsia partialis continua) and occur in the middle age for the first time.

Conclusion:

Most arachnoid cysts are asymptomatic and may not produce any symptoms throughout life. In our case, the late onset epilepsia partialis continua in the 5^th decade of life with probably a large arachnoid cyst without any history of seizure before that is unusual. Conservative approaches usually made for the management of arachnoid cysts as patients with these cysts usually maintain the vital neurological functions.

[Endoscopic fenestration of arachnoid cyst of posterior cranial fossa through third ventriculostomy]

Arachnoid cysts (AC) are spaces with cerebrospinal fluid covered with arachnoid membrane. Most cysts are supratentorial and only 10-12% of ACs are found in posterior cranial fossa. This disease is usually diagnosed in childhood. In adults, ACs make up 1.4% of all focal lesions. ACs of posterior cranial fossa are often localized behind the cerebellum or in cerebellopontine angle. Most patients with cysts do not have permanent symptoms and should be followed-up. Surgery is indicated for cysts complicated by focal and hydrocephalic-hypertension symptoms. Microsurgical or endoscopic procedures are used. Surgical approach is determined by the closest location of cyst to brain surface. The authors report non-standard surgical approach for giant AC of posterior cranial fossa complicated by obstructive hydrocephalus, intracranial hypertension and visual function impairment. Endoscopic third ventriculostomy was followed by AC fenestration through ventriculostomy. Symptoms disappeared within 6 months after surgery.

Infection of a sylvian Galassi II arachnoid cyst after craniotomy for resection of a parasagittal meningioma

Arachnoid cysts are CSF-containing entities that rarely are symptomatic or warrant neurosurgical intervention. In addition, infection of these lesions is an even rarer event, with only four reports in the literature capturing this. In this report, we present the case of a 79-year-old man presenting with paraparesis, secondary to a right parasagittal meningioma, with an incidental asymptomatic right sylvian arachnoid cyst (Galassi type II). The initially planned surgery was postponed for 3 months, due to COVID-19 restrictions, and he was kept on high dose of steroids. Following tumour resection, the patient developed bilateral subdural empyemas with involvement of the arachnoid cyst, requiring bilateral craniotomies for evacuation of the empyemas and drainage of the arachnoid cyst. Suppuration of central nervous system arachnoid cysts is a very rare complication following cranial surgery with the main working hypotheses including direct inoculation from surrounding inflamed meninges or haematogenous spread secondary to systemic bacteraemia, potentiated by steroid-induced immunosuppression. Even though being a rarity, infection of arachnoid cysts should be considered in immunosuppressed patients in the presence of risk factors such as previous craniotomy.

Long-term outcome of large sylvian arachnoid cysts: the role of surgery has been exaggerated

OBJECTIVE

The surgical indications for some arachnoid cysts (ACs) are controversial. While surgical procedures can be effective when an AC is a definite cause of hydrocephalus or papilledema, most ACs do not cause any symptoms or signs. Some surgeons perform several procedures to treat ACs because of their large size. The purpose of this study was to compare the long-term outcomes of Galassi type III ACs between surgery and nonsurgery groups.

METHODS

The medical records of 60 patients diagnosed with sylvian ACs (Galassi type III) who visited Seoul National University Children's Hospital from July 1990 to March 2018 were analyzed. The authors compared the outcomes between those treated with surgery and those not treated with surgery.

RESULTS

Of the 60 patients, 27 patients had no symptoms, 19 patients had vague symptoms and signs associated with ACs, and the remaining 14 patients had definite AC-related symptoms and signs. Thirty-eight patients underwent surgery, and 22 patients underwent observation. Some operations were accompanied by complications. Among the 33 patients in the surgery group, excluding 5 with hydrocephalus or papilledema, 8 patients needed 18 additional operations. However, there were no patients in the nonsurgery group who needed surgical intervention during the follow-up period (mean 67.5 months), although the size of the AC increased in 2 patients. Changes in AC size were not correlated with symptom relief.

CONCLUSIONS

When patients with hydrocephalus or papilledema were excluded, there was no difference in the outcomes between the surgery and nonsurgery groups regardless of the size of the sylvian AC. Surgeons should be cautious when deciding whether to operate.

Surgical decompression of arachnoid cysts leads to improved quality of life: a prospective study-long-term follow-up

BACKGROUND

In a previous study, we reported a short-term (6 months) postoperative improvement of health-related quality of life (Qol) in patients operated for an arachnoid cyst (AC). The aim was to investigate whether this initial improvement was permanent.

METHODS

A long-term (5 ± 2 years) prospective study comparing Qol and complaints before and 5 ± 2 years after surgical fenestration for AC in 76 adult patients, using the Short Form 36 (SF-36) scores, Glasgow Benefit Inventory (GBI) questionnaires, and Visual Analogue Scales (VAS) for headache and dizziness, similarly to what they did at short-term follow-up.

RESULTS

At short-term and long-term follow-ups, 73.4% and 82%, respectively, of the patients were better from their headache compared with preoperative scores. The corresponding improvement rates for dizziness were 61.7% (short-term) and 67.9 (long-term). Preoperatively, the mean headache VAS score was 45.6; at short-term follow-up, this was reduced to 25.7, and at long-term follow-up, this further reduced to 24.8. The preoperative mean VAS score for dizziness (35.2) was reduced to 12.2 (short-term) and 13.9 (long-term). The significant postoperative improvement of patient-reported Qol at short-term follow-up remained at long-term follow-up across seven out of eight SF-36 dimensions and three out of four GBI subscale scores. Similar to at short-term follow-up, the Qol improvement is correlated to improvement in headache and/or dizziness.

CONCLUSIONS

The previously reported postoperative, short-term improvement in Qol and complaints appears stable, as the improvement remains at long-term follow-up. This suggests that the beneficial effects of surgical treatment are long-lasting.

Nerve-Sheath-Risen Neuroglial Cyst: A Case Report and Review of the Literature

BACKGROUND

Neuroglial cysts are rare intracranial lesions that are believed to originate from the sequestration of neural tube lining during embryogenesis. They can present anywhere within the neuraxis; however, their most common location is the frontal lobe. Cerebellopontine angle (CPA) neuroglial cysts are extremely rare and to the best of authors' knowledge, there are no previous reports of a neuroglial cyst arising from cranial nerves.

CASE DESCRIPTION

The current study presented a male adolescent with the reoccurrence of an intracranial cyst with symptoms of diplopia and facial numbness primarily treated as CPA arachnoid cyst with fenestration of the cyst 12 months prior to admission to our center. Different magnetic resonance imaging (MRI) sequences showed a thin-walled extra-axial cyst at the right CPA without gadolinium (Gd)-enhancement. Direct visualization of the lesion revealed a cyst arising from the 5th cranial nerve sheath compressing the surrounding structures. The cyst was fenestrated and a biopsy was taken from the cyst wall. The pathological analysis along with specified histological markers indicated the neuroglial nature of the cyst.

CONCLUSION

The rising of a neuroglial cyst from the nerve sheath is a finding that brings other possible origins of neuroglial cysts into consideration.

Prepontine arachnoid cyst presenting with headache and diplopia: A case report study

Background:

Arachnoid cysts are found everywhere in cerebrospinal axis, most often in the middle cranial fossa. They are very rare in prepontine location.

Case Description:

In this study, we report a 26-year-old female presenting with a 3-month history of headache and diplopia. On physical examination, she had clinical manifestations of sixth cranial nerve palsy. Magnetic resonance imaging revealed a prepontine arachnoid cyst with extension into interpeduncular and suprasellar cisterns. Computed tomography scan demonstrated no evidence of hydrocephalus. The patient was treated surgically by endoscopic fenestration of the cyst with endonasal transsphenoidal approach. The cyst was opened to prepontine, interpeduncular, and suprasellar cisterns.

Conclusion:

Endoscopic endonasal fenestration of the cyst to adjacent cistern may be safe in prepontine arachnoid cysts with sellar and suprasellar extension; it may be effective and less invasive compare to transcranial approach.

Atypical Features in a Large Turkish Family Affected with Friedreich Ataxia

Here, we describe the clinical features of several members of the same family diagnosed with Friedreich ataxia (FRDA) and cerebral lesions, demyelinating neuropathy, and late-age onset without a significant cardiac involvement and presenting with similar symptoms, although genetic testing was negative for the GAA repeat expansion in one patient of the family. The GAA repeat expansion in the frataxin gene was shown in all of the family members except in a young female patient. MRI revealed arachnoid cysts in two patients; MRI was consistent with both cavum septum pellucidum-cavum vergae and nodular signal intensity increase in one patient. EMG showed demyelinating sensorimotor polyneuropathy in another patient. The GAA expansion-negative 11-year-old female patient had mental-motor retardation, epilepsy, and ataxia. None of the patients had significant cardiac symptoms. Description of FRDA families with different ethnic backgrounds may assist in identifying possible phenotypic and genetic features of the disease. Furthermore, the genetic heterogeneity observed in this family draws attention to the difficulty of genetic counseling in an inbred population and to the need for genotyping all affected members before delivering comprehensive genetic counseling.

Two Hundred Thirty-Six Children With Developmental Hydrocephalus: Causes and Clinical Consequences

Few systematic assessments of developmental forms of hydrocephalus exist. We reviewed magnetic resonance images (MRIs) and clinical records of patients with infancy-onset hydrocephalus. Among 411 infants, 236 had hydrocephalus with no recognizable extrinsic cause. These children were assigned to 1 of 5 subtypes and compared on the basis of clinical characteristics and developmental and surgical outcomes. At an average age of 5.3 years, 72% of children were walking independently and 87% could eat by mouth; in addition, 18% had epilepsy. Distinct patterns of associated malformations and syndromes were observed within each subtype. On average, children with aqueductal obstruction, cysts, and encephaloceles had worse clinical outcomes than those with other forms of developmental hydrocephalus. Overall, 53% of surgically treated patients experienced at least 1 shunt failure, but hydrocephalus associated with posterior fossa crowding required fewer shunt revisions. We conclude that each subtype of developmental hydrocephalus is associated with distinct clinical characteristics, syndromology, and outcomes, suggesting differences in underlying mechanisms.

Surgical Decompression of Arachnoid Cysts Leads to Improved Quality of Life: A Prospective Study

BACKGROUND

There is no previous prospective study on the outcome of surgical decompression of intracranial arachnoid cysts (AC).

OBJECTIVE

To investigate if surgical fenestration for AC leads to change in patients' health-related quality of life.

METHODS

Prospective study including 76 adult patients operated for AC. Patients responded to Short Form-36 and Glasgow Benefit Inventory quality of life questionnaires, and to visual analogue scales, assessing headache and dizziness pre- and postoperatively. Patient scores were compared with those of a large sample of healthy individuals.

RESULTS

Preoperatively, 84.2% of the patients experienced headache and 70.1% dizziness. Mean pre- versus postoperative Visual Analogue Scale scores for headache and dizziness dropped from 45.6 to 25.7 and from 35.2 to 12.2, respectively. Preoperative Short Form-36 scores were significantly below age norms in all subscales, but improved after surgery into normal range in 7 out of 8 subscales for middle-aged and older patients. Younger patients' scores remained lower than age norm in 6 out of 8 subscales. A significant postoperative improvement was seen in 3 out of 4 Glasgow Benefit Inventory subscales. Improvement in headache and/or dizziness, but not preoperative cyst size or reduction in cyst volume, correlated with improvement in 6 out of 8 Short Form-36 subscales and 3 out of 4 Glasgow Benefit Inventory subscales. Only 1 patient experienced a severe complication causing permanent invalidity.

CONCLUSION

Surgery for AC can be performed with a fairly low risk of complications and yields significant improvement in quality of life correlated to postoperative improvement in headache and dizziness. These findings may justify a more liberal approach to surgical treatment for AC.

Exploring predictors of surgery and comparing operative treatment approaches for pediatric intracranial arachnoid cysts: a case series of 83 patients

OBJECT

Although intracranial arachnoid cysts are a common incidental finding on pediatric brain imaging, only a subset of patients require surgery for them. For the minority who undergo surgery, the comparative effectiveness of various surgical approaches is debated. The authors explored predictors of surgery and compared operative techniques for pediatric patients with an intracranial arachnoid cyst seen at a tertiary care center.

METHODS

The authors reviewed records of pediatric patients with an intracranial arachnoid cyst. For each patient, data on baseline characteristics, the method of intervention, and surgical outcomes for the initial surgery were extracted, and cyst size at diagnosis was calculated (anteroposterior × craniocaudal × mediolateral). Baseline variables were analyzed as predictors of surgery by using logistic regression modeling, excluding patients whose surgery was not related to cyst size (i.e., those with obstructive hydrocephalus secondary to the cyst compressing a narrow CSF flow pathway or cyst rupture/hemorrhage). Data collected regarding surgical outcomes were analyzed descriptively.

RESULTS

Among 83 pediatric patients with an intracranial arachnoid cyst seen over a 25-year period (1989-2013), 27 (33%) underwent surgery; all had at least 1 cyst-attributed symptom/finding. In the multivariate model, age at presentation and cyst size at diagnosis were independent predictors of surgery. Cyst size had greater predictive value; specifically, the area under the curve for the receiver-operating-characteristic curve was 0.89 (95% CI 0.82-0.97), with an ideal cutoff point of ≥ 68 cm(3). This cutoff point had 100% sensitivity (95% CI 79%-100%), 75% specificity (95% CI 61%-85%), a 53% positive predictive value (95% CI 36%-70%), and a 100% negative predictive value (95% CI 91%-100%); the positive likelihood ratio was 4.0 (95% CI 2.5-6.3), and the negative likelihood ratio was 0 (95% CI 0-0.3). Although the multivariate model excluded 7 patients who underwent surgery (based on prespecified criteria), excluding these 7 cases did not change the overall findings, as shown in a sensitivity analysis that included all the cases. Descriptive results regarding surgical outcomes did not indicate any salient differences among the surgical techniques (endoscopic fenestration, cystoperitoneal shunting, or craniotomy-based procedures) in terms of symptom resolution within 6 months, need for reoperation to date, cyst-size change from before the operation, morbidity, or mortality.

CONCLUSIONS

The results of these exploratory analyses suggest that pediatric patients with an intracranial arachnoid cyst are more likely to undergo surgery if the cyst is large, compresses a narrow CSF flow pathway to cause hydrocephalus, or has ruptured/hemorrhaged. There were no salient differences among the 3 surgical techniques for several clinically important outcomes. A prospective multicenter study is required to enable more robust analyses, which could ultimately provide a decision-making framework for surgical indications and clarify any differences in the comparative effectiveness of surgical approaches to treating pediatric intracranial arachnoid cysts.

Outcome of 12 antenatally diagnosed fetal arachnoid cysts: case series and review of the literature

OBJECTIVES

To investigate the natural history, associated abnormalities and outcome of 12 fetuses with arachnoid cyst diagnosed antenatally by ultrasound and magnetic resonance imaging and to compare the outcome with cases in the literature.

METHODS

A retrospective study of all cases of antenatally detected fetal arachnoid cysts was performed in patients referred to a tertiary unit between 2007 and 2013. Associated abnormalities, pregnancy outcome and postnatal follow-up were analyzed. All papers about prenatally diagnosed arachnoid cysts, of the last 30 years, were evaluated (search terms in Pubmed: "prenatal diagnosis", "Arachnoid Cysts").

RESULTS

Fetal arachnoid cysts were diagnosed in 12 fetuses, 9 were females. The mean gestational age of diagnosis was 28 1/7 (range 19 1/7-34 2/7 weeks). A total of 9 cases were supratentorial, 3 were located in the posterior fossa. In 10 cases a fetal MRI was performed which confirmed brain compression in 4 out of 5 supratentorial arachnoid cyst. MRI did not reveal other malformations nor signs of nodular heterotopia. Only one fetus presented with additional major anomalies (bilateral ventricumomegaly of >20 mm and rhombencephalosynapsis) leading to a termination of pregnancy. Two neonates underwent endoscopic fenestration of the arachnoid cyst in the first week of life with no additional intervention in childhood. All but one (10/11) had a favorable postnatal outcome. This child suffered from visual impairment at autism was diagnosed at the age of 5. One child had a surgical correction of strabismus later in childhood. In one child the infratentorial arachnoid cyst regressed spontaneously on ultrasound and MRI in the postnatal period.

CONCLUSIONS

The majority of arachnoid cysts in this series are of benign origin and remain stable. Based on the current series and the review of the literature, in the absence of other associated anomalies and when the karyotype is normal, the postnatal overall and neurological outcome is favorable. Large suprasellar arachnoid cysts however, may cause visual impairment and endocrinological disturbances. Rarely associated cerebral or cerebellar malformations are present. Modern postnatal management of suprasellar arachnoid cyst consists of endoscopic cystoventriculostomy.

Visual evoked potentials in a diagnosis of a visual pathway dysfunction of a child with an arachnoid cyst

Purpose

The aim of this case report was to demonstrate the usefulness of the flash visual evoked potentials in monitoring the effects of intracranial hypertension in a preterm-born child with a congenital arachnoid cyst.

Methods and results

At baseline, abnormalities were found in the right eye: exotropia and lack of foveal fixation. Visual acuity was not achieved. Pupillary responses were normal in both eyes. There was no evidence of nystagmus. Flash visual evoked potentials were normal and equal in both eyes. When repeated one year later the signal had deteriorated in both eyes; the peak times of N2 and P2 had increased. The increased VEP latencies were the only ocular signs noted. After referral to neurosurgery, intracranial hypertension was found and a shunt was performed.

Conclusions

Flash visual evoked potentials may be a valuable test in monitoring patients with arachnoid cysts.

Infantile hydrocephalus: a review of epidemiology, classification and causes

Hydrocephalus is a common but complex condition caused by physical or functional obstruction of CSF flow that leads to progressive ventricular dilatation. Though hydrocephalus was recently estimated to affect 1.1 in 1000 infants, there have been few systematic assessments of the causes of hydrocephalus in this age group, which makes it a challenging condition to approach as a scientist or as a clinician. Here, we review contemporary literature on the epidemiology, classification and pathogenesis of infantile hydrocephalus. We describe the major environmental and genetic causes of hydrocephalus, with the goal of providing a framework to assess infants with hydrocephalus and guide future research.

Diverse arachnoid cyst morphology indicates different pathophysiological origins

BACKGROUND

There are few, limited, and to some extent contradictory, reports on the cellular and subcellular morphology of arachnoid cysts. In the literature cyst membranes are described as similar to, or as vastly different from, normal arachnoid membranes.

METHODS

This paper reports electron microscopic analyses of symptomatic cysts from 24 patients (12 males and 12 females; age 10-79), that underwent fenestration surgery. Fourteen cysts were located in the middle cranial fossa (temporal), one in the interpeduncular cistern, five in the posterior fossa, and four were overlying the frontal cortex.

RESULTS

Microscopic findings confirmed the diverse nature of this clinical condition. Twelve cyst walls resembled normal arachnoid, four had a conspicuous core of dense fibrous tissue with a simple epithelial lining, and the remaining aberrant cysts exhibited non-arachnoid luminal epithelia with plentiful microvilli and/or cilia, and also nervous tissue components in the wall. The possible identity and origin of various cyst types are discussed. We hypothesize that cysts are formed mostly at an early stage of embryonic development, as a teratological event.

CONCLUSIONS

Cysts with various epithelial linings and extracellular components most likely have different barrier properties and fluid turnover characteristics. Further studies are needed to elucidate relations between cyst morphology, fluid composition, pathogenesis, and clinical behaviour including growth rate and relapse tendency.

Benign extracerebral fluid collection in infancy as a risk factor for the development of de novo intracranial arachnoid cysts

OBJECT

Intracranial arachnoid cysts are a relatively common benign intracranial pathology, accounting for as many as 0.75%-1% of nontraumatic CNS lesions. Although it has already been demonstrated that rupture of arachnoid cysts may lead to subdural hematomas/hygromas, no study to date has investigated benign extracerebral collection in infancy as a possible predisposing factor for further development of arachnoid cysts.

METHODS

The authors performed a retrospective imaging and chart review of macrocephalic infants 12 months old or younger who were referred to neurosurgical care at OSF St. Francis Medical Center from 2003 to 2010, and who were diagnosed with benign extracerebral fluid collection in infancy on thin-slice (1-mm) head CT scans. Special attention was given to the investigation of risk factors for further development of de novo arachnoid cysts. Several epidemiological factors in the infants and mothers were analyzed, including gestational age at delivery, mode of delivery, mother's age at delivery, delivery complications, birth weight, age of macrocephaly development, degree of macrocephaly, family history of macrocephaly, prenatal and postnatal history of infection, fontanel status, presence of papilledema, previous history of head trauma, and smoking status. Imaging characteristics of the initial scans, such as location of subdural collection (frontal vs frontoparietal and frontotemporal) and presence of ventriculomegaly, were also evaluated. For those patients in whom arachnoid cysts were identified on subsequent CT scans, the size and location of the cysts were also analyzed.

RESULTS

The authors identified 44 children with benign extracerebral fluid collection in infancy. From this group, over a mean follow-up of 13 months (range 6-13 months), 18 children developed intracranial arachnoid cysts (a 40.9% incidence of de novo development of arachnoid cysts), with 27.8% presenting with bilateral cysts. In the multiple logistic regression analysis, infants who presented with an extracerebral collection restricted to the bilateral frontal region were more likely to develop intracranial arachnoid cysts (p = 0.035) than those with collections involving the frontotemporal and frontoparietal regions (odds ratio [OR] = 5.73). Additionally, children with benign extracerebral fluid collections and plagiocephaly were more likely to develop intracranial arachnoid cysts (p = 0.043) than those without plagiocephaly (OR = 4.96).

CONCLUSIONS

This is the first report in the neurosurgical literature demonstrating that benign extracerebral fluid collections in infancy may constitute a significant risk factor for development of de novo arachnoid cysts. These findings support a 2-hit hypothesis for the development of arachnoid cysts, in which the combination of an embryological defect in arachnoid development followed by a second event leading to impairment of CSF fluid absorption in early childhood could lead to abnormal CSF dynamics and the consequent expansion of fluid collections in the intraarachnoid spaces.

The effectiveness of neuroendoscopic versus non-neuroendoscopic procedures in the treatment of lateral ventricular cysts: a retrospective medical record review study

Background

The aim of this study was to assess the effectiveness of neuroendoscopy compared with non-neuroendoscopic procedures for treating patients with arachnoid membrane cysts in the lateral ventricles.

Methods

The medical records of 28 patients with arachnoid membrane cysts in the lateral ventricles who were treated with neuroendoscopy and 39 such patients treated with non-neuroendoscopic techniques using classic treatment procedures were reviewed. The neuroendoscopic approach combined craniotomy, corticectomy, lesion resection and cyst ventriculostomy or cyst cisternostomy to restore normal cerebrospinal fluid circulation. The non-neuroendoscopic techniques included craniotomy, corticectomy, and lesion resection performed under a microscope. Clinical outcomes of symptoms and cyst size change on imaging were compared between the two treatment groups during follow-up (range: 1–5 years).

Results

Patients in the neuroendoscopy group had significantly less blood loss (P < 0.001) and shorter operative time (P < 0.001), better marked improvement in symptoms (64.3% vs. 5.1%, respectively), and a higher total resection rate (92.9% vs. 66.7%; P = 0.011) compared with the patients in the non-neuroendoscopy group. In the neuroendoscopy group there was no cyst recurrence whereas in the non-neuroendoscopy group 8 (20.5%) patients had cyst recurrence. However, all patients in the neuroendoscopy group had postoperative transient fever and 8 (28.6%) patients had subdural fluid accumulation which was treated and subsequently resolved during follow-up. These symptoms did not occur in the non-neuroendoscopy group.

Conclusion

We found that neuroendoscopic therapy for arachnoid cysts in the lateral ventricles was more efficacious than non-neuroendoscopic methods. Our results indicate that neuroendoscopy may produce better clinical outcomes than non-neuroendoscopic procedures in treating patients with arachnoid cysts in the lateral ventricles.

Moyamoya disease with mesial temporal sclerosis

The combination of moyamoya syndrome and symptomatic mesial temporal sclerosis (MTS) has not previously been reported. The authors present the case of a 5-year-old boy with symptomatic MTS who developed progressive moyamoya syndrome. This combination of progressive moyamoya and a structural seizure focus presented a unique clinical problem, with the natural history of MTS predicting a high likelihood of needing resection in the future, which could be challenging following any type of moyamoya-related revascularization surgery. In anticipation of this problem, the patient underwent resection of the right inferior and mesial temporal lobe followed by right pial synangiosis as a 1-day combined operation. Postoperatively he recovered well without any neurological deficits and had an uneventful hospital stay. This case of moyamoya is unique in its association with MTS, and for the simultaneous operations for pial synangiosis and temporal lobectomy, highlighting the importance of surgical planning in patients with dual pathological processes.

Quantitative proteomics comparison of arachnoid cyst fluid and cerebrospinal fluid collected perioperatively from arachnoid cyst patients

BACKGROUND

There is little knowledge concerning the content and the mechanisms of filling of arachnoid cysts. The aim of this study was to compare the protein content of arachnoid cysts and cerebrospinal fluid by quantitative proteomics to increase the understanding of arachnoid cysts.

METHODS

Arachnoid cyst fluid and cerebrospinal fluid from five patients were analyzed by quantitative proteomics in two separate experiments.In a label-free experiment arachnoid cyst fluid and cerebrospinal fluid samples from individual patients were trypsin digested and analyzed by Orbitrap mass spectrometry in a label-free manner followed by data analysis using the Progenesis software.In the second proteomics experiment, a patient sample pooling strategy was followed by MARS-14 immunodepletion of high abundant proteins, trypsin digestion, iTRAQ labelling, and peptide separation by mix-phase chromatography followed by Orbitrap mass spectrometry analysis. The results from these analyzes were compared to previously published mRNA microarray data obtained from arachnoid membranes.

RESULTS

We quantified 348 proteins by the label-free individual patient approach and 1425 proteins in the iTRAQ experiment using a pool from five patients of arachnoid cyst fluid and cerebrospinal fluid. This is by far the largest number of arachnoid cyst fluid proteins ever identified, and the first large-scale quantitative comparison between the protein content of arachnoid cyst fluid and cerebrospinal fluid from the same patients at the same time. Consistently in both experiment, we found 22 proteins with significantly increased abundance in arachnoid cysts compared to cerebrospinal fluid and 24 proteins with significantly decreased abundance. We did not observe any molecular weight gradient over the arachnoid cyst membrane. Of the 46 proteins we identified as differentially abundant in our study, 45 were also detected from the mRNA expression level study. None of them were previously reported as differentially expressed. We did not quantify any of the proteins corresponding to gene products from the ten genes previously reported as differentially abundant between arachnoid cysts and control arachnoid membranes.

CONCLUSIONS

From our experiments, the protein content of arachnoid cyst fluid and cerebrospinal fluid appears to be similar. There were, however, proteins that were significantly differentially abundant between arachnoid cyst fluid and cerebrospinal fluid. This could reflect the possibility that these proteins are affected by the filling mechanism of arachnoid cysts or are shed from the membranes into arachnoid cyst fluid. Our results do not support the proposed filling mechanisms of oncotic pressure or valves.

Cluster headache and arachnoid cyst

Background

Cluster headache is a primary headache by definition not caused by any known underlying structural pathology. However, symptomatic cases have been described, e.g. tumours, particularly pituitary adenomas, malformations, and infections/inflammations. The evaluation of cluster headache is an issue unresolved.

Case description

We present a case of a 43-year-old patient who presented with a 2-month history of side-locked attacks of pain located in the left orbit. He satisfied the revised International Classification of Headache Disorders criteria for cluster headache. His medical and family histories were unremarkable. There was no history of headache. A diagnosis of cluster headache was made. The patient responded to symptomatic treatment. Computer tomography and enhanced magnetic resonance imaging after 1 month displayed a supra- and intrasellar arachnoid cyst with mass effect on adjacent structures. After operation, the headache attacks resolved completely.

Discussion and evaluation

Although we cannot exclude an unintentional comorbidity, in our opinion, the co-occurrence of an arachnoid cyst with mass effect with unilateral headache, in a hitherto headache-free man, points toward the fact that in this case the CH was caused or triggered by the AC. The headache attacks resolved completely after the operation and the patient also remained headache free at the follow-up. The response of the headache to sumatriptan and other typical CH medications does not exclude a secondary form. Symptomatic CHs responsive to this therapy have been described. Associated cranial lesions such as tumours have been reported in CH patients and the attacks may be clinically indistinguishable from the primary form.

Conclusions

Neuroimaging, preferably contrast-enhanced magnetic resonance imaging should always be considered in patients with cluster headache despite normal neurological examination. Late-onset cluster headache represents a condition that requires careful evaluation. Supra- and intrasellar arachnoid cyst can present as cluster headache.