Intracranial arachnoidal cysts

Quadrigeminal cistern arachnoid cyst as a probable cause of hemifacial spasm

Arachnoid cysts arising in the quadrigeminal cistern (ACQCs) are uncommon. A 68-year-old woman presented with an unsteady gait, facial spasm, and cerebellar ataxia. Non-contrast head computed tomography showed a cystic mass centered in the quadrigeminal cistern accompanying ventriculomegaly. On MRI, the cyst appeared hypointense on T1- and hyperintense on T2-weighted sequence. There was no restricted diffusion on diffusion-weighted imaging. The cerebral aqueduct was obstructed and the prepontine cistern was narrowed. The left vertebral artery (VA) coursed adjacent to the facial nerve at its origin. The patient underwent neuroendoscopic fenestration of the posterior wall of the third ventricle and ventral wall of the ACQC. Postoperatively, the patient's symptoms resolved. MRI showed a considerable reduction in the ACQC and expansion of the prepontine cistern, whereas the relationship between the left VA and the proximal segment of the facial nerve did not change. We assumed that the pre-existing close relationship between the VA and facial nerve might have been aggravated by the anterior displacement of the brainstem, thus causing the facial spasm.

Quadrigeminal arachnoid cyst with perinatal encephalocele

INTRODUCTION

Quadrigeminal arachnoid cyst (QAC) associated with encephalocele is rare; and while some treatments have been developed in recent years, no definite therapeutic approach for QAC has been established. Endoscopic treatment for arachnoid cyst is gaining popularity because it is relatively less invasive to the normal brain tissues.

CASE PRESENTATION

The patient, a 4-year-old girl, presented with QAC associated with congenital occipital encephalocele. At the age of 1 month, repair of the perinatal encephalocele had been performed at another institute. An asymptomatic arachnoid cyst remained in the posterior fossa, which was closely monitored with follow up. At age 4 years, the patient started to complain of headache, which gradually increased in both strength and frequency. Magnetic resonance imaging (MRI) revealed cerebellar compression due to cyst enlargement. We performed neuroendoscopic cyst fenestration with an occipital bone approach. Post-operative MRI showed reduced size of the cyst, and the headache dramatically improved and resolved.

DISCUSSION

The standard treatment of QAC is still controversial; however, our successful use of endoscopic fenestration toward the third ventricle indicates its efficacy and safety. QACs have been classified into 3 types based on their expansion mechanisms; our case might suggest another possible mechanism of QAC development.

CONCLUSION

In our case, endoscopic cyst fenestration was successful for QAC with perinatal encephalocele. However, long-term follow-up and analysis of similar cases are needed to determine its effectiveness.

Simultaneous bone remodeling and surgical decompression of large Sylvian arachnoid cyst

The most common location for intracranial arachnoid cysts is the region of the Sylvian fissure, where they can be found in 49% of cases. Management of these cysts is still quite controversial. We present our surgical technique for the treatment of large Sylvian fissure arachnoid cysts which involves cyst decompression and simultaneous calvarial remodeling. After decreasing cyst size, remodeling of the frontal, temporal, and parietal bones follows. The cyst itself is treated with a cystoperitoneal shunt. In immediate postoperative period, correction of the deformity is observed. The cyst volume is reduced immediately after surgery, and adequate adaptation of the bone is achieved. Our surgical procedure for simultaneous bone remodeling and cyst decompression is a fast, simple, and effective treatment option for patients with large Sylvian fissure arachnoid cysts associated with significant cranial disfigurement. We consider cranial remodeling in case of large arachnoid cyst important not just because of the cosmetic result but also for reducing remaining intracranial space filled with cerebrospinal fluid. It may be an important factor to reduce the risk of intracystic and subdural hemorrhage. It is a widely applicable procedure that does not require special tools and expensive equipment, and yet it can help avoid multiple surgeries and complications tied to them.

Endoscopic approach for quadrigeminal cistern arachnoid cyst

Objectives Quadrigeminal cistern arachnoid cysts (QCACs), which are usually asymptomatic and may be accidental findings during radiological evaluation, are rare, comprising 5-10% of all intracranial arachnoid cysts (ACs). We report a series of eight patients with QCACs treated with neuroendoscopic intervention and try to discuss the different endoscopic approaches according to the different types of QCACs. Materials and methods Between October 2007 and January 2013, eight patients affected by QCACs were endoscopically treated. All the endoscopic procedures were completed uneventfully (infratentorial approaches in four cases and supratentorial approaches in four cases), which included ventriculocystostomy in seven cases (lateral ventriculocystostomy in one case, third ventricle cystostomy in five cases and both in one case), endoscopic third ventriculostomy in three cases and cystocisternostomy in one case. Results Five patients achieved complete cure after the endoscopic procedure alone; nevertheless, in none of the patients did the cyst totally collapse following the endoscopic procedure during follow-up. The number of episodes decreased significantly even after cessation of all medications and headache disappeared in one patient and the two patients who had unsteady gait together with visual complaints showed remarkable improvement. Conclusion QCAC is one kind of pineal region ACs and it is advisable to plan the operative approach before the endoscopic procedure according to the different types of pineal region ACs. Pineal region ACs and the associated hydrocephalus can be successfully treated with simple, minimally invasive endoscopic procedure.

Stricter indications are recommended for fenestration surgery in intracranial arachnoid cysts of children

PURPOSE

The indication of surgical treatment for intracranial arachnoid cysts (ACs) is a controversial issue. In this study, we reviewed surgical outcomes of intracranial ACs that were treated with endoscopic fenestration or microscopic fenestration, which are currently standard practices for surgical treatment of AC. In addition, we also evaluated the validity of current surgical indications.

METHODS

We analyzed pediatric patients under 18 years of age who underwent surgical management for intracranial AC between January 2000 and December 2011. Patients with a follow-up period of less than 1 year were excluded. A total of 75 patients were enrolled in this study. These patients were assessed by subjective symptoms and by a clinician's objective evaluation. The radiological assessment of AC after surgery was also evaluated.

RESULTS

The median age of patients at the initial operation was 5 years. The median follow-up period was 38 months. The goal of surgery was achieved in 28% (21/75) of patients. The radiological alteration of AC after initial fenestration surgery was diverse. The results of the clinical and radiological assessments did not always coincide. A total of 35 complications occurred in 28 patients. Subdural fluid collection was the most common unexpected radiological complication.

CONCLUSIONS

Our study showed that the fenestration procedure for AC produced unsatisfactory clinical improvements compared to the relatively high complication rate. Therefore, surgical treatment for AC should be strictly limited to patients who have symptoms directly related to AC.

MRI of optic tract lesions: review and correlation with visual field defects

Visual field defects are a conglomerate of patterns of visual impairment derived from diseases affecting the optic nerve as it extends from the globe to the visual cortex. They are complex signs requiring perimetry or visual confrontation for delineation and are associated with diverse aetiologies. This review considers the chiasmatic and post-chiasmatic causes of visual disturbances, with an emphasis on magnetic resonance imaging (MRI) techniques. Newer MRI sequences are considered, such as diffusion-tensor imaging. MRI images are correlated with perimetric findings in order to demonstrate localization of lesions in the visual pathway. This may serve as a valuable reference tool to clinicians and radiologists in the early diagnostic process of differentiating causes of various visual field defects in daily practice.

Long-term results of cystoperitoneal shunt placement for the treatment of arachnoid cysts in children

OBJECT

The authors present a single-institution experience in shunt treatment for arachnoid cysts (ACs).

METHODS

Between January 2003 and January 2005, 62 patients with ACs underwent cystoperitoneal (CP) shunt placement at the authors' institution. All patients were evaluated with CT or MRI studies and had regular follow-up examinations.

RESULTS

Forty-six cysts (74%) were within the sylvian fissure, 8 (13%) were in the cerebral convexity, and 8 (13%) were infratentorial. A CP shunt was placed in all patients. Follow-up imaging studies showed that 59 (95%) of 62 ACs reduced in size during a mean postoperative follow-up period of 6.5 years (range 6-8 years). Although a CP shunt was effective in achieving early obliteration, shunt dependency occurred within the patient group (13%). Shunt revision for various reasons was performed in 16 patients (26%).

CONCLUSIONS

Shunt placement is a safe and effective surgical treatment for symptomatic ACs in children, although efforts should be made to decrease complications in the procedure.

[Management of arachnoid cysts of the middle cranial fossa accompanied by subdural effusions]

Subdural effusions are uncommon but known complications of arachnoid cysts of the middle cranial fossa. They mainly occur after minor head traumas in young patients. Here, we report eight cases of arachnoid cyst of the middle cranial fossa associated with subdural hematoma in five cases and hygroma in three cases. Major symptoms are signs of raised intracranial pressure. CT scan and MRI showed the cyst and the subdural effusion. An excellent therapeutic result was achieved with evacuation of the subdural fluid via burr holes in the five cases of subdural hematoma while in the two cases of hygroma a subduro-peritoneal shunt was necessary. In the last case, a temporal craniotomy was performed with evacuation of the hygroma and fenestration of the cyst. We suggest treating only the complicating event in the case of a subdural hematoma via burr holes evacuation. Whereas, in the case of hygroma we think that craniotomy with fenestration of the cyst or the use of a subdural shunt are more often needed.

Endoscopic treatment of suprasellar arachnoid cysts in children

OBJECT

Suprasellar arachnoid cysts (SACs) are rare, comprising approximately 10% of all intracranial arachnoid cysts. Although neuroendoscopic management is emerging as a safe effective alternative to microsurgery, the type of endoscopic surgery whether ventriculocystostomy (VC) or ventriculocystocisternostomy (VCC) is still controversial. This study evaluates the role of endoscopy in the treatment of SACs in children. It compares VC and VCC to determine which procedure is superior in the long term.

METHODS

Twenty-five children (14 boys and 11 girls; mean age 26 months) with symptomatic SACs associated with hydrocephalus are the subject of this study. According to the surgical procedure adopted, patients were divided into 2 groups. Patients in Group A (11 patients) underwent VC with a mean follow-up of 55 months, and those in Group B (14 patients) underwent VCC with a mean follow-up of 64.7 months.

RESULTS

Both procedures proved to be effective clinically and radiologically. The incidence of improvement of hydrocephalus-related symptoms was 63.6% in Group A compared with 85.7% in Group B. Improvement in cyst size and hydrocephalus after VC was 81.8% and 63.6%, respectively, compared with 100% and 85.7%, respectively, after VCC. There were no deaths or permanent morbidity, and no patient was left with a permanent shunt. Recurrence occurred in 3 cases after VC (27.3%), whereas no recurrence (0%) was encountered after VCC. At a second endoscopic procedure, the fenestration was found to be closed in all 3 recurrent cases.

CONCLUSIONS

An endoscopic procedure is recommended in the treatment of SACs in children because it is simple, effective, minimally invasive, and associated with low morbidity and mortality rates. Both procedures, VC and VCC, proved to be almost equally effective clinically and radiologically. Nevertheless, because of the statistically significant difference between the incidence of recurrence after VC and VCC during long-term follow-up, the author concludes that VCC should be considered as the procedure of choice in the treatment of these cases. The important finding of reclosure of the VC fenestration in the recurrent cases underscores the significance of performing cystocisternostomy at initial surgery to guard against cyst recurrence.

Neuroendoscopic treatment of arachnoid cysts of the quadrigeminal cistern: a series of 14 cases

OBJECT

In this paper, the authors' goal was to evaluate the role of neuroendoscopy in the treatment of arachnoid cysts of the quadrigeminal cistern.

METHODS

Between March 1995 and February 2008, 14 patients affected by arachnoid cysts of the quadrigeminal cistern were treated endoscopically. The cysts were classified according to their anatomical and radiological appearance. The most frequent form (Type I) extended infratentorially and supratentorially with a dumbbell shape. Type II cysts were confined to the infratentorial space and were associated with the most severe and acute form of hydrocephalus. Type III cysts presented a significant asymmetric expansion toward the temporal fossa. Ten patients underwent an endoscopic procedure as primary treatment and 4 as an alternative to shunt revision. In 6 cases, the first endoscopic procedure was ventriculocystostomy (VC) together with endoscopic third ventriculostomy (ETV). In the other 8 cases, the first endoscopic procedure was VC alone.

RESULTS

In the 6 cases in which VC was performed with an ETV, the procedure was successful, and the patients did not require further surgery. Of the 8 cases in which the first endoscopic procedure performed was VC without ETV, 7 underwent reoperation. Four of these patients underwent endoscopic procedures (by reopening the obstructed VC and performing ETV or cystocisternostomy) 2, 4, 4, and 5 months later with final success in all cases. Three patients (all of whom were previously treated using ventriculo- or cystoperitoneal shunts) required shunt reimplantation (complete failure). Subdural collection developed in 1 case, which was managed by transient insertion of a subduroperitoneal shunt. Neurological and developmental outcomes were good except for 1 patient who did not show improvement in preoperative developmental delay. No transient or permanent morbidity or mortality was observed.

CONCLUSIONS

The analysis of this series suggests that arachnoid cysts of the quadrigeminal cistern and the associated hydrocephalus can be effectively treated by endoscopy; this approach allows the patient to be shunt independent in more than 78% of the cases. If endoscopy is used as first option, the success rate of endoscopic procedures observed in this series was 90%. Endoscopic third ventriculostomy should be associated with a VC to offer the highest success rate with a single procedure.

Arachnoid cyst resulting in sixth nerve palsy in a child

A 2 year old presented with incomitant esotropia and abduction deficit consistent with sixth nerve palsy. Neuroimaging revealed an arachnoid cyst on the left. Neurosurgical shunting followed by strabismus surgery relieved the abduction deficit and esotropia. An arachnoid cyst may be a rare cause of acquired sixth nerve palsy and strabismus in children.

Acetazolamide and corticosteroid therapy in complicated arachnoid cyst

CASE REPORT

We report on the successful conservative treatment of a child harbouring a right-temporal arachnoid cyst associated with bilateral hygroma.

TREATMENT

Medical treatment was by corticosteroids for several days and acetazolamide (15 mg/kg/die) for 10 months.

OUTCOME

Clinical symptoms and signs disappeared completely with partial resolution of the bilateral hygroma at MRI follow-up.

Microsurgical Keyhole Approach for Middle Fossa Arachnoid Cyst Fenestration

OBJECTIVE

The optimal surgical treatment for symptomatic temporal arachnoid cysts is controversial. Therapeutic options include cyst shunting, endoscopic fenestration, and craniotomy for fenestration. We reviewed the results for patients who were treated primarily with craniotomy and fenestration at our institution, to provide a baseline for comparisons of the efficacies of other treatment modalities.

METHODS

A retrospective review of data for 50 children who underwent keyhole craniotomy for fenestration of temporal arachnoid cysts between 1994 and 2001 was performed after institutional review board approval. During that period, the first-line treatment for all symptomatic middle fossa arachnoid cysts was microcraniotomy for fenestration. Microsurgical dissection to create communications between the cyst cavity and basal cisterns was the goal. All patient records were reviewed and numerous variables related to presentation, cyst size and classification, treatment, cyst resolution, symptom resolution, follow-up periods, and cyst outcomes were recorded.

RESULTS

Fifty temporal arachnoid cysts in 50 treated patients were identified. The average age at the time of surgery was 68 ± 57.2 months. The follow-up periods averaged 36 months. There were 34 male and 16 female patients in the series. Twenty-six cysts were on the left side. Indications for surgery included intractable headaches (45%), increasing cyst size (21%), seizures (25%), and hemiparesis (8%). The symptoms most likely to improve were hemiparesis (100%) and abducens nerve palsies. Headaches (67%) and seizure disorders (50%) were less likely to improve. Nine patients exhibited progressive increases in cyst size in serial imaging studies. Those patients were monitored for a mean of 40 ± 23 months before intervention. In the entire series, 82% of patients demonstrated decreases in cyst size in serial imaging studies. Of those patients, 18% demonstrated complete cyst effacement. Overall, 83% of patients with Grade II cysts and 75% of patients with Grade III cysts exhibited evidence of decreases in cyst size in long-term monitoring. Two patients required shunting after craniotomy (4%). Hospital stays averaged 3.4 days. Total surgical times averaged 115 minutes. No significant blood loss occurred (5–50 ml). Complications included spontaneously resolving pseudomeningocele (10%), transient Cranial Nerve III palsy (6%), cerebrospinal fluid leak (6%), subdural hematoma (4%), and wound infection (2%).

CONCLUSION

A microsurgical keyhole approach to arachnoid cyst fenestration is a safe effective method for treating middle fossa cysts. This procedure can be performed with minimal morbidity via a minicraniotomy. Compared with an endoscopic approach, better control of hemostasis can be obtained, because of the ability to use bipolar forceps and other standard instruments. The operative time and length of hospital stay were not excessively increased.

Posterior fossa arachnoid cysts can mimic Meniere’s disease

Arachnoid cysts constitute 1% of all intracranial space-occupying lesions. In the posterior fossa, they typically produce vague, nonspecific symptoms. However, a subset of these lesions can produce signs and symptoms indistinguishable from those of Meniere's disease. We discuss the clinical and laboratory features of 2 cases of posterior fossa arachnoid cysts mimicking Meniere's disease as well as the substantial resolution of symptoms in 1 patient after cysto-peritoneal shunt. Posterior fossa arachnoid cyst must be considered in the differential diagnosis of patients presenting with signs and symptoms of Meniere's disease.

Temporal lobe epilepsy associated with hippocampal sclerosis and a contralateral middle fossa arachnoid cyst

We report on a 13-year-old boy with temporal lobe epilepsy associated with left hippocampal sclerosis and a contralateral arachnoid cyst in the middle cranial fossa (ACMCF). Chronic intracranial recording from subdural grid electrodes showed the left medial temporal lobe to be the ictal onset zone. After left anterior temporal lobectomy with hippocampectomy, seizure control was improved. ACMCF was not considered the direct cause of epilepsy; instead the seizures were attributed to hippocampal sclerosis.

Endoscopic treatment of mesencephalic ependymal cysts: technical case report

OBJECTIVE

To evaluate the results of different neuroendoscopic surgical procedures for the treatment of mesencephalic ependymal cysts.

METHODS

The clinical records of five patients treated for symptomatic mesencephalic ependymal cysts were retrospectively studied. Two patients had been operated on using an endoscope-assisted microsurgical technique and three patients using a pure endoscopic procedure.

RESULTS

Adequate fenestration of the cysts was achieved in all of the patients. Two of the patients were symptom-free, and the other three had improved significantly after a mean follow-up duration of 14 months. There was no surgical morbidity.

CONCLUSION

Mesencephalic ependymal cysts can be treated adequately, resulting in a low morbidity rate, using neuroendoscopy or endoscope-assisted microsurgery. This specific surgical technique is presented.

Magnetic resonance imaging and computed tomography characteristics of intracranial intra-arachnoid cysts in 6 dogs

Magnetic resonance imaging (MRI) and computed tomographic imaging (CT) characteristics of intracranial intra-arachnoid cysts in six dogs are described. Of the six dogs, three were less than one year of age and 4 were males. Five of the six dogs weighed less than 11 kg. Five cysts were located in the quadrigeminal cistern. On CT images, the intracranial intra-arachnoid cysts had sharply defined margins, contained fluid isodense to CSF and did not enhance following i.v. administration of contrast. On MRI images, the intracranial intra-arachnoid cysts were extra-axial, contained fluid isointense with CSF and did not enhance following i.v. contrast. While spinal arachnoid cysts of dogs have been reported in the literature, other than the six dogs contained in this report, intracranial intra-arachnoid cysts have not to our knowledge been described in animals. These six dogs have a similar age, sex, history, clinical signs, CT and MRI findings to those reported in people with intracranial intra-arachnoid cysts.

Surgical options in the treatment of interhemispheric arachnoid cysts

BACKGROUND

Arachnoid cysts located within the interhemispheric fissure are a matter of discussion as to the surgical indication and the choice of the most appropriate surgical procedure. In fact, in spite of the large dimensions that they can reach, the clinical manifestations may remain subtle and apparently stable over the years. On the other hand, the larger utilization of prenatal ultrasound investigations has increased the number of lesions detected before they can provoke clinical manifestations. As far as surgery is concerned, two main options are available-an extrathecal shunting procedure or a direct approach to the lesion, with excision of its wall.

METHODS

In this report, we analyze the results obtained in 25 children harboring an interhemispheric arachnoid cyst, surgically treated in the period 1978 to 1994. Mean age at diagnosis was 18.8 months (10 days to 15 years). RESULTS The main clinical manifestations included macrocrania, mild to moderate signs of increased intracranial pressure, cranial bulging, developmental delay, and neurologic signs. In 14 cases, the diagnosis had been obtained prenatally. The cyst was located in one hemicranium in 16 cases, whereas it was on the midline, with bilateral extension, in the remaining 9 cases; in the latter cases, variable degrees of callosal agenesis were also observed. All 25 children were operated on. In 16 of them, the treatment consisted of a craniotomy with wide excision of the cyst lining and marsupialization into the subarachnoid spaces of the midline (and/or into the ventricular system). In 6 children, the surgical procedure was a cystoperitoneal (CP) shunt. The last 3 children of our series underwent craniotomy and cyst excision after having been treated by means of a ventriculoperitoneal shunt. At follow-up examination, 17 children are normal, and the remaining 8 disclose mild to moderate psychomotor retardation.

CONCLUSIONS

Although both craniotomy and CP shunt are associated with good results, the first surgical procedure offers the advantage of avoiding the insertion of a permanent cerebrospinal fluid shunt device and the known complications of this type of procedure.

Arachnoid cysts in adults: experience with internal shunts to the subdural compartment

Twelve patients (10 males, 2 females) with symptomatic arachnoid cysts of the middle cranial fossa (9 patients) or overlying the frontal cortex (3 patients) were included. Under local anesthesia, an internal shunt was implanted from the cyst to the subdural compartment. Postoperative computed tomography scans showed volume reduction in eight patients. Permanent clinical improvement was also seen in eight patients. In the remaining four, the improvement was only temporary or partial, necessitating additional surgery in three patients. Complications (two subdural hematomas, one subdural infusion), were observed in three patients, all with large cysts. The complications were treated without sequelae. Internal shunts may be tried in adults as the first treatment for this condition.

Supratentorial interhemispheric cysts associated with callosal agenesis: surgical treatment and outcome in 16 children

Cerebrospinal-fluid-filled interhemispheric cysts associated with callosal agenesis are relatively rare lesions, and have been subject to a varied and confusing terminology. From a pragmatic surgical point of view, we believe that the dorsal III ventricular cyst [35] and the giant interhemispheric cyst [23], although of different embryological origin, can be classified as one group. The most important condition that must be distinguished from interhemispheric cysts is the alobar form of holoprosencephaly. We describe the clinical symptomatology in 16 children who were surgically treated with a cysto-peritoneal shunt. The outcome, both neurologically and developmentally, was good in the large majority of cases, and compared favorably to similar cases in the older literature. It therefore seems reasonable, at the present state of knowledge and until further studies clarify the origin and natural history of these cysts, to treat them as early as possible in order to prevent gross developmental deficits.

Symptomatic, expansive middle cranial fossa arachnoid cyst treated by a cysto-peritoneal shunt. Case report and evaluation of treatment options

We report a symptomatic space-occupying arachnoid cyst in a 16-year-old boy. During the last two years, he was frequently absent from school because of headaches. Due to symptoms of nausea, fever and headache the patient was primarily referred to a surgical unit, where appendectomy was performed, revealing a normal appendix. Postoperatively, the patient complained of severe headache. Computed tomography (CT) of the head demonstrated a large left-sided middle cranial fossa arachnoid cyst. The patient was operated with insertion of a cysto-peritoneal shunt. A total regress of the clinical symptoms was seen at follow-up examination 3 months after shunting.