Prevalence and natural history of arachnoid cysts in children

Dual-trajectory Approach for Simultaneous Cyst Fenestration and Endoscopic Third Ventriculostomy for Treatment of a Complex Third Ventricular Arachnoid Cyst

Objectives: We present a case of a multiloculated third ventricular arachnoid cyst to describe a novel technique for definitive management of these lesions via direct endoscopic fenestration and CSF diversion utilizing separate trajectories that offers superior visualization and avoids forniceal injury.

Methods and Results: We present a case of a 33-year-old woman with progressive headache and worsened vision, a known history of a multiloculated third-ventricular arachnoid cyst, and imaging findings consistent with cyst expansion and worsened obstructive hydrocephalus. We then describe the dual-trajectory approach for simultaneous cyst fenestration and endoscopic third ventriculostomy that ultimately resulted in successful treatment of her cyst and hydrocephalus.

Conclusions: Dual-trajectory endoscopic approach utilizing double burr holes should be considered when addressing lesions of the third ventricle causing obstructive hydrocephalus.

Image diagnosis: arachnoid cyst

A 14-year-old boy presented with 3 months of generalized headache that had increased in intensity and frequency with associated light-headedness. Primary arachnoid cysts result from developmental abnormalities; more rare secondary cysts develop as a result of head injury, meningitis, tumors, or as a complication of brain surgery.

[Epidemiology and classification of arachnoid cysts in children]

The prevalence of arachnoid cysts in children is 1-3%. They are more frequent in boys. They can be located intracranially or in the spine. Intracranial cysts are classified as supratentorial, infratentorial, and supra-infratentorial (tentorial notch). Supratentorial are divided into middle cranial fossa, convexity, inter-hemisferic, sellar region, and intraventricular. Infratentorial are classified into supracerebellar, infracerebellar, hemispheric, clivus, and cerebellopontine angle. Finally spinal arachnoid cysts are classified taking into account whether they are extra- or intradural, and nerve root involvement.

Incidental findings on brain and spine imaging in children

In recent years, the utilization of diagnostic imaging of the brain and spine in children has increased dramatically, leading to a corresponding increase in the detection of incidental findings of the central nervous system. Patients with unexpected findings on imaging are often referred for subspecialty evaluation. Even with rational use of diagnostic imaging and subspecialty consultation, the diagnostic process will always generate unexpected findings that must be explained and managed. Familiarity with the most common findings that are discovered incidentally on diagnostic imaging of the brain and spine will assist the pediatrician in providing counseling to families and in making recommendations in conjunction with a neurosurgeon, when needed, regarding additional treatments and prognosis.

Minimally invasive pediatric neurosurgery

Advances in technology have facilitated the development of minimally invasive neurosurgical options for the treatment of pediatric neurological disease. This review seeks to familiarize pediatric neurologists with some of the techniques of minimally invasive pediatric neurosurgery, focusing on treatments for hydrocephalus, arachnoid cysts, intracranial mass lesions, and craniosynostosis.

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.

Symptomatic foramen of Magendie arachnoid cyst in an elderly patient

Background:

Arachnoid cysts (ACs) are congenital anomalies of the central nervous system and arise in virtually all locations where the arachnoid membrane exists. Posterior fossa ACs are considered to develop in the posterior aspect of the rhombencephalic roof plate and do not communicate freely with the fourth ventricle or perimedullary subarachnoid space. Although posterior fossa ACs have been reported a number of times, ACs arising from the foramen of Magendie are very rare.

Case Description:

We report here on a 76-year-old female who presented with progressive gait disturbance. Magnetic resonance imaging of the head showed a large AC in the foramen of Magendie that was compressing the inferior vermis and medial aspects of the cerebellar hemisphere without causing hydrocephalus. Neurological examination revealed cerebellar ataxia without Romberg's sign. A nearly total excision of the cyst was safely performed via a median suboccipital approach. The patient's postoperative course was excellent and her neurological recovery was remarkable.

Conclusion:

Most cases of ACs located in the foramen of Magendie are reported in children, and it is extremely rare to observe such ACs in the elderly. In fact, to our knowledge, a symptomatic foramen Magendie AC has never been reported previously in an elderly person. Our results indicate that proper surgical intervention can yield highly positive outcomes in such cases.

[«De novo» development of a suprasellar arachnoid cyst]

Intracranial arachnoid cysts are fluid-filled cavities that arise within the cranial arachnoid, representing approximately 1%-2% of all intracranial lesions among the paediatric population. We present the case of a 2-year-old boy who presented with instability and episodes of ocular deviation. A computed tomography scan (CT scan) and magnetic resonance imaging (MRI) of the brain revealed a suprasellar cyst and obstructive hydrocephalus. At birth a transfontanellar ultrasound was normal. The cyst underwent endoscopic fenestration with complete remission of symptoms. In the review of the literature, we found only 6 previous cases of an intracranial arachnoid cyst whose origin was not clearly congenital or traumatic, and ours is the second case of a suprasellar arachnoid cyst to arise de novo. The clinical features, imaging characteristics and treatment of the previously reported cases are discussed.

Horizontal Tonic Conjugate Gaze Deviation in a 4-Week-Old Infant: What Can the Eyes (of the Parents) Tell?

A 4-week-old healthy infant failed to make eye contact when approached from the left. When evaluated by us at the age of 11 weeks, left tonic conjugate gaze deviation was noted. Brain MRI showed a left frontotemporal large tension arachnoid cyst causing right falcial herniation. During the insertion of an Ommaya reservoir, hemosiderin was found to be coating the inner wall of the cyst, which may indicate that the asymptomatic cyst evolved to a tension cyst due to spontaneous hemorrhage. Surgical decompression resulted in complete restoration of the horizontal gaze and considerable reduction in the size of the cyst. After 3 months a cystoperitoneal shunt was placed due to increased intracranial pressure secondary to impaired drainage of the cyst. Since then the infant has done well, with normal developmental and neurological examination during his last follow-up at the age of 5 years. Although gaze central ocular motor control is still underdeveloped and chaotic eye movements are present during early infancy, the present case report reminds us that a thorough examination of eye movements should not be overlooked during neurodevelopmental evaluation.

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.

Ventricular endoscopy in the pediatric population: review of indications

INTRODUCTION

Neuroendoscopy has greatly impacted pediatric neurosurgery over the past few decades. Improved optics and microsurgical tools have allowed neuroendoscopes to be used for a multitude of neurosurgical procedures.

DISCUSSION

In this review article, we present the breadth of intraventricular neuroendoscopic procedures for the treatment of conditions ranging from hydrocephalus and brain tumors to congenital cysts and other pathologies. We critically discuss treatment indications and reported success rates for neuroendoscopic procedures. We also present novel approaches, technical nuances, and variations from recently published literature and as practiced in the authors' institution.

Extensive middle cranial fossa arachnoid cysts and different clinical presentation in two patients

Arachnoid cysts (ACs), particularly suprasellar cysts, cause a wide spectrum of endocrine disorders. Herein, we report two patients diagnosed with an extensive AC in the middle cranial fossa while being investigated for etiologies of precocious puberty and short stature. One of them required surgery due to his pubertal disorders associated with compression effects of cyst. After surgery, his puberty progression was regressed within one year. On the other hand, surgery was not planned for the second patient considering of his cranial imaging findings and the extremely low incidence of growth hormone (GH) deficiency caused by middle fossa AC (MFAC). We started treatment with recombinant human GH and no complication was found during treatment follow-up. Endocrine disorders associated with MFACs are extremely rare. By presenting with these two cases, we aimed to remain our fellow physcians that ACs can be possibly cause of endocrine disorders. Clinicians should be careful evaluating endocrine disorders because real cause may not be cyst itself but masked by it.

Suprasellar arachnoid cyst after subdural haemorrhage in an infant. A case based update

INTRODUCTION

Brain arachnoid cysts (AC) are congenital or acquired malformations. Their prevalence in children ranges between 0.2 and 2.3% of the studied populations. Few reported studies exist where AC appears after a subdural haemorrhage.

METHODS

We present one case of a symptomatic suprasellar AC after post-traumatic subdural haemorrhage in an infant.

RESULTS

After endoscopic ventriculocystostomy, the child quickly improved and the cyst reduced in size. The child was monitored for 22 months and his neurocognitive development remained normal.

CONCLUSION

Our case led us to the hypothesis that the inflammatory process due to subdural haemorrhage may locally result in arachnoiditis, and thus to the creation of a neomembrane, and eventually to cyst formation. This is also the case with the development of post-traumatic spinal AC.

Sequencing of a patient with balanced chromosome abnormalities and neurodevelopmental disease identifies disruption of multiple high risk loci by structural variation

Balanced chromosome abnormalities (BCAs) occur at a high frequency in healthy and diseased individuals, but cost-efficient strategies to identify BCAs and evaluate whether they contribute to a phenotype have not yet become widespread. Here we apply genome-wide mate-pair library sequencing to characterize structural variation in a patient with unclear neurodevelopmental disease (NDD) and complex de novo BCAs at the karyotype level. Nucleotide-level characterization of the clinically described BCA breakpoints revealed disruption of at least three NDD candidate genes (LINC00299, NUP205, PSMD14) that gave rise to abnormal mRNAs and could be assumed as disease-causing. However, unbiased genome-wide analysis of the sequencing data for cryptic structural variation was key to reveal an additional submicroscopic inversion that truncates the schizophrenia- and bipolar disorder-associated brain transcription factor ZNF804A as an equally likely NDD-driving gene. Deep sequencing of fluorescent-sorted wild-type and derivative chromosomes confirmed the clinically undetected BCA. Moreover, deep sequencing further validated a high accuracy of mate-pair library sequencing to detect structural variants larger than 10 kB, proposing that this approach is powerful for clinical-grade genome-wide structural variant detection. Our study supports previous evidence for a role of ZNF804A in NDD and highlights the need for a more comprehensive assessment of structural variation in karyotypically abnormal individuals and patients with neurocognitive disease to avoid diagnostic deception.

Pediatric intracranial arachnoid cysts: comparative effectiveness of surgical treatment options

PURPOSE

A variety of surgical approaches for the treatment of pediatric intracranial arachnoid cysts exist. In an effort to identify the optimal surgical treatment for this disorder, we developed a decision analytic model to evaluate outcomes of four surgical approaches in children. These included open craniotomy for cyst excision, open craniotomy for cyst fenestration, endoscopic cyst fenestration, and cystoperitoneal shunting.

METHODS

Pooled data were used to create evidence tables, from which we calculated incidence, relative risks, and summary outcomes in quality-adjusted life years (QALYs) for the four surgical treatments. Our study incorporated data up to 5 years postsurgery.

RESULTS

We analyzed 1,324 cases from 36 case series. There were no significant differences in outcome among the four surgical strategies. The QALYs (maximum of 5) for surgical approaches resulted in a range from 4.79 (for open craniotomy and excision) to 4.92 (for endoscopic fenestration).

CONCLUSIONS

Overall quality of life is comparable between patients undergoing open craniotomy for cyst excision or fenestration, endoscopic fenestration, and cystoperitoneal shunting up to 5 years after surgery. While each approach offers unique advantages and disadvantages, an individualized treatment strategy should be employed in the setting of surgical outcome equipoise.

Main congenital cerebral anomalies: how prenatal imaging aids counseling

The purpose of this article is to discuss some common cerebral lesions that may be detected during prenatal screening: corpus callosum dysgenesis, absent septum pellucidum, localized parenchymal ischemic-hemorrhagic lesions, megacisterna magna, Blake's pouch cyst, posterior fossa arachnoid cyst and Dandy-Walker malformation. For each cerebral defect, the main imaging findings are reminded, certain differential diagnoses are discussed and prenatal diagnostic accuracy is analyzed with emphasis on uncertainties encountered during analysis of ultrasound or magnetic resonance images. Detecting cerebral lesions in fetuses requires rapid counseling by neuropediatricians. Keeping in mind that the prenatal diagnostic accuracy is not 100%, the neuropediatricians have to answer the parents' questions regarding the outcome of the unborn child as well as the risk of recurrence for future pregnancies. This article is based on the authors' large experience in both prenatal imaging and neurocounseling. The frequently asked questions are set up. Answers are provided, underscoring the importance of an appropriate description of the cerebral defect, and therefore the pivotal role of prenatal imaging. However, prenatal neurocounseling remains challenging and the parents must be aware of uncertainties regarding both diagnostic accuracy and prognostic evaluation.

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.

Adult symptomatic and growing arachnoid cyst successfully treated by ventriculocystostomy: a new insight on adult arachnoid cyst history

BACKGROUND

Adult arachnoid cysts are known to be stable and asymptomatic but their history remains undefined.

CASE DESCRIPTION

The authors report the case of an 81-year-old woman with progressive hemiplegia and aphasia. CT scan revealed a voluminous left frontotemporal arachnoid cyst with a major mass effect on the midline and contralateral blocked hydrocephalus. Endoscopic ventriculocystostomy was performed with a spectacular neurological improvement.

DISCUSSION AND CONCLUSIONS

Symptomatic adult arachnoid cysts are extremely rare. To our knowledge, no similar clinical case of a growing arachnoid cyst in elderly patients has yet been reported in the literature. The mechanisms of cyst enlargement and decompensation still remain undefined and debated. The possibility of adult arachnoid cyst growth has to be considered in clinical practice. Endoscopic ventriculocystostomy is as effective as in paediatric cases.

Management of subdural hygromas associated with arachnoid cysts

OBJECT

Arachnoid cysts may occasionally be associated with subdural hygromas. The management of these concurrent findings is controversial.

METHODS

The authors reviewed their experience with arachnoid cysts and identified 8 patients with intracranial arachnoid cysts and an associated subdural hygroma. The medical records and images for these patients were also examined.

RESULTS

In total, 8 patients presented with concurrent subdural hygroma and arachnoid cyst. Of these 8 patients, 6 presented with headaches and 4 had nausea and vomiting. Six patients had a history of trauma. One patient was treated surgically at the time of initial presentation, and 7 patients were managed without surgery. All patients experienced complete resolution of their presenting signs and symptoms.

CONCLUSIONS

Subdural hygroma may lead to symptomatic presentation for otherwise asymptomatic arachnoid cysts. The natural course of cyst-associated subdural hygromas, even when symptomatic, is generally benign, and symptom resolution can be expected in most cases. The authors suggest that symptomatic hygroma is not an absolute indication for surgical treatment and that expectant management can result in good outcomes in many cases.

Institutional experience of endoscopic suprasellar arachnoid cyst fenestration

INTRODUCTION

Suprasellar arachnoid cysts can differ from other arachnoid cysts in several ways, making a separate analysis of these cysts worthwhile. Herein, we present the outcome and perform volumetric analysis of six children with suprasellar arachnoid cysts treated with endoscopic ventriculocystocisternostomy in order to evaluate the long-term outcomes.

PATIENTS AND METHODS

Operative and postoperative data were retrospectively reviewed for six patients harboring suprasellar arachnoid cysts. Imaging was then used to follow success of surgical intervention.

RESULTS

Six patients with suprasellar arachnoid cysts underwent ventriculocystocisternostomy. Presenting symptoms were headaches in three patients, developmental delay in another, and an incidental finding in the remaining patients. All patients had enlarged lateral and third ventricles on initial imaging. Average age at presentation was 145.7 months (65.4-250.2). Follow-up was an average of 46.5 months (3-84). The average cyst size was 153.96 cm(3) (42.98-369.20) preoperatively and an average of 39.92 cm(3) (3.20-101.47) at follow-up.

CONCLUSIONS

Based on our experience, suprasellar arachnoid cyst treatment with ventriculocystocisternostomy is an adequate surgical intervention. Suprasellar and third ventricular size does respond to the surgical intervention at long-term follow-up.

Incidental findings in children with blunt head trauma evaluated with cranial CT scans

OBJECTIVE

Cranial computed tomography (CT) scans are frequently obtained in the evaluation of blunt head trauma in children. These scans may detect unexpected incidental findings. The objectives of this study were to determine the prevalence and significance of incidental findings on cranial CT scans in children evaluated for blunt head trauma.

METHODS

This was a secondary analysis of a multicenter study of pediatric blunt head trauma. Patients <18 years of age with blunt head trauma were eligible, with those undergoing cranial CT scan included in this substudy. Patients with coagulopathies, ventricular shunts, known previous brain surgery or abnormalities were excluded. We abstracted radiology reports for nontraumatic findings. We reviewed and categorized findings by their clinical urgency.

RESULTS

Of the 43,904 head-injured children enrolled in the parent study, 15,831 underwent CT scans, and these latter patients serve as the study cohort. On 670 of these scans, nontraumatic findings were identified, with 16 excluded due to previously known abnormalities or surgeries. The remaining 654 represent a 4% prevalence of incidental findings. Of these, 195 (30%), representing 1% of the overall sample, warranted immediate intervention or outpatient follow-up.

CONCLUSIONS

A small but important number of children evaluated with CT scans after blunt head trauma had incidental findings. Physicians who order cranial CTs must be prepared to interpret incidental findings, communicate with families, and ensure appropriate follow-up. There are ethical implications and potential health impacts of informing patients about incidental findings.

Distribution of cerebellar tonsil position: implications for understanding Chiari malformation

OBJECT

Prior attempts to define normal cerebellar tonsil position have been limited by small numbers of patients precluding analysis of normal distribution by age group. The authors' objective in the present study was to analyze cerebellar tonsil location in every age range.

METHODS

Two thousand four hundred patients were randomly selected from a database of 62,533 consecutive patients undergoing MRI and were organized into 8 age groups. Magnetic resonance images were directly examined for tonsil location, morphology, and other features. Patients with a history or imaging findings of posterior fossa abnormalities unrelated to Chiari malformation (CM) were excluded from analysis. The caudal extent of the cerebellar tonsils was measured at the midsagittal and lowest parasagittal positions.

RESULTS

The mean tonsil height decreased slightly with advancing age into young adulthood and increased with advancing age in the adult age range. An increasing age in the adult age range was associated with a decreased likelihood of a tonsil position 5 mm or more below the foramen magnum (p = 0.0004). In general, the lowest tonsil position in each age group was normally distributed. Patients with pegged morphology were more likely to have a tonsil location at least 5 mm below the foramen magnum (85%), as compared with those having intermediate (38%) or rounded (2%) morphology (p < 0.0001). Female sex was associated with a lower mean tonsil position (p < 0.0001). Patients with a lower tonsil position also tended to have an asymmetrical tonsil position, usually lower on the right (p < 0.0001).

CONCLUSIONS

Cerebellar tonsil position follows an essentially normal distribution and varies significantly by age. This finding has implications for advancing our understanding of CM.

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.

De novo trisomy 20p characterized by array comparative genomic hybridization: report of a novel case and review of the literature

We report on a boy with speech delay, mental retardation, motor clumsiness, hyperactivity, dysmorphic facial features, brachytelephalangy and short stature. Electrocardiogram, echocardiography, renal ultrasound, electroencephalogram, fundoscopic exam and auditory brainstem responses were all normal. Brain magnetic resonance imaging showed a left temporal arachnoid cyst and a small pineal gland cyst. High resolution karyotype and FISH analysis detected a de novo duplication of the short arm of chromosome 20. A molecular characterization of the chromosomal anomaly was performed by array-CGH, confirming a 17.98 Mb duplication of the short arm of chromosome 20 associated with a small duplication on chromosome 3p, that was shown to be maternally inherited. This is one of the few cases of de novo trisomy 20p with extensive workup, characterization at molecular level and close follow-up from the neonatal period to age 30 months. We also compared the phenotype of our patient with that previously reported in literature, therefore contributing to better define the trisomy 20p syndrome and helping pediatricians and geneticists to better counsel families about the developmental prognosis of these children.

Prevalence and natural history of arachnoid cysts in adults

Object

Arachnoid cysts are a frequent finding on intracranial imaging. The prevalence and natural history of these cysts in adults are not well defined.

Methods

We retrospectively reviewed the electronic medical records of a consecutive series of adults who underwent brain MRI over a 12-year interval to identify those with arachnoid cysts. The MRI studies were reviewed to confirm the diagnosis. For those patients with arachnoid cysts, we evaluated presenting symptoms, cyst size, and cyst location. Patients with more than 6 months' clinical and imaging follow-up were included in a natural history analysis.

Results

A total of 48,417 patients underwent brain MRI over the study period. Arachnoid cysts were identified in 661 patients (1.4%). Men had a higher prevalence than women (p < 0.0001). Multiple arachnoid cysts occurred in 30 patients. The most common locations were middle fossa (34%), retrocerebellar (33%), and convexity (14%). Middle fossa cysts were predominantly left-sided (70%, p < 0.001). Thirty-five patients were considered symptomatic and 24 underwent surgical treatment. Sellar and suprasellar cysts were more likely to be considered symptomatic (p < 0.0001). Middle fossa cysts were less likely to be considered symptomatic (p = 0.01. The criteria for natural history analysis were met in 203 patients with a total of 213 cysts. After a mean follow-up of 3.8 ± 2.8 years (for this subgroup), 5 cysts (2.3%) increased in size and 2 cysts decreased in size (0.9%). Only 2 patients developed new or worsening symptoms over the follow-up period.

Conclusions

Arachnoid cysts are a common incidental finding on intracranial imaging in all age groups. Although arachnoid cysts are symptomatic in a small number of patients, they are associated with a benign natural history for those presenting without symptoms.

Symptomatic thoracic arachnoid cyst with coexisting tick paralysis: case report and review of the literature

Tick paralysis is an uncommon phenomenon resulting from the release of a neurotoxin from the salivary glands of an engorged, gravid female tick about 5-7 days after attachment. The neurotoxin produces ascending weakness, mimicking other ascending paralytic processes. We present a case of a child presenting with weakness of the lower extremities and frequent falls who was found to have a compressive thoracic arachnoid cyst and a large distal syrinx. After surgical decompression, the patient made significant improvement in her leg strength, but quickly developed an ascending quadriparesis, followed by respiratory depression. Subsequent imaging and physical examination revealed an engorged tick embedded in her scalp. The tick was removed, and the patient made a rapid and complete clinical recovery. We present a unique case of concomitant tick paralysis and a symptomatic spinal intradural arachnoid cyst, and review the literature on tick paralysis.

Development of intracranial hypertension after surgical management of intracranial arachnoid cyst: report of three cases and review of the literature

OBJECTIVE

To describe three cases of delayed development of intracranial hypertension (IH) after surgical treatment of intracranial arachnoid cyst, including the pathogenesis of IH and a review of the literature.

METHODS

A retrospective and prospective analysis of three male patients (two 18 years old and one 45 years old) was performed. All patients underwent surgical intervention for symptomatic intracranial arachnoid cyst in the form of fenestration of the cyst and a cystoperitoneal shunt.

RESULTS

All three patients presented at a later stage with new-onset headaches after the initial management of arachnoid cyst. Magnetic resonance imaging and magnetic resonance venography ruled out any intracranial vascular pathology. Lumbar puncture and intracranial pressure monitoring showed increased intracranial pressure suggestive of idiopathic IH. To manage IH, intracranial pressure monitoring, cystoperitoneal shunt, ventriculoperitoneal shunt, and lumboperitoneal shunt were performed.

CONCLUSIONS

The pathogenesis of delayed development of IH in this clinical setting is not clearly elucidated. When intracranial arachnoid cysts are treated, the possibility of future development of IH should be borne in mind. Delayed presentation with headaches in patients after treatment of intracranial arachnoid cysts should raise the possibility of IH.

Preuntethering and postuntethering courses of syringomyelia associated with tethered spinal cord

BACKGROUND

There has been controversy regarding the management of syringomyelia associated with tethered spinal cord. Previous reports on the topic have included only a small number of patients, considered open/closed spinal dysraphism together, or had a short follow-up.

OBJECTIVE

To review a uniform group of patients with syringomyelia associated with tethered cord and treated mainly by untethering alone.

METHODS

Of the 135 patients operated on for closed spinal dysraphism between 2003 and 2008, 33 patients with preoperative syringomyelia were identified. The preoperative/postoperative clinical data and syrinx index (ratio of the syrinx area and the cord area) were retrospectively reviewed. The syrinx index of each patient was plotted as an individual graph to outline the temporal change of the syrinx before and after untethering surgery.

RESULTS

Five patients showed symptom progression during the preoperative period, and 4 of the 5 had an additional magnetic resonance imaging before the operation that showed progression of the syringomyelia. Postoperatively, 31 of 32 patients (97%) who underwent postoperative follow-up imaging showed long-term stability or a decrease in the syrinx index. Four symptomatically stable patients showed a transient increase in the syrinx index during the initial postoperative 6 months, which later decreased spontaneously. In 1 patient with retethering, the syrinx index increased 6 months before the onset of new urinary symptoms.

CONCLUSION

Untethering alone may be sufficient for the management of syringomyelia associated with tethered cord. A transient increase in the syrinx index during the initial postoperative period may be observed without additional surgery if patients are symptomatically stable.

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.

Enlarging arachnoid cyst: a false alarm for infants

PURPOSE

The natural history of change in size of arachnoid cysts (ACs) is an unsettled issue. This leads to confusion in deciding treatment strategies of incidental, asymptomatic AC in children, since the risks and complications of surgery are not negligible. The aim of the present study was to elucidate the clinical significance of change in size of AC in young children.

METHODS

From 2000 to 2008, 86 patients younger than 5 years with AC documented on brain imaging were included. They were divided into four different age groups (group I: 0-0.5 year, group II: 0.5-1 year, group III: 1-3 years, group IV: 3-5 years). The temporal changes in size of the AC on consecutive ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI) of each patient were measured and plotted as individual graphs. Natural progression of AC size was assessed by evaluation of the pattern of each graph.

RESULTS

Seventeen patients showed enlargement of AC during follow-up; 14 patients were younger than 1 year. None of the patients in group IV showed enlargement during follow-up. Overall, 11 of the 17 patients with demonstrated AC enlargement were not operated on. In six patients, AC enlargement ceased, and spontaneous regression was observed in three patients. The remaining two untreated patients had shown asymptomatic increase in size at last follow-up. Statistical analysis revealed age at diagnosis to be the only significant factor affecting cyst enlargement.

CONCLUSION

Asymptomatic enlargement of AC in infants may not be an indication for surgical intervention. Close follow-up is a viable option for such children.

CT cisternography in intracranial symptomatic arachnoid cysts: classification and treatment

OBJECTIVES

The symptom and neuroimaging as indications for treating arachnoid cysts (ACs) are not adequate. Understanding the communication between cyst and subarachnoid space is helpful for decision-making. We took a dynamic study of ACs using CT cisternography (CTC) and proposed a classification of arachnoid cysts.

MATERIALS AND METHODS

Total 52 symptomatic patients with ACs were enrolled in this prospective study. CTC images were ordered, in all enrolled patients, at the 1, 3, 6, 12, 24 and 48 h after the intrathecal Omnipaque administration. Enhancement in cysts was measured quantitatively and was compared with neighboring subarachnoid spaces. All enrolled patients were allocated randomly in 2 groups. The CTC result was considered before treatment in one group (CTC group), while another group was surgically treated without considering CTC results (surgical group).

RESULTS

ACs in our study were classified into 3 types: complete (cyst filling time at 1 h), incomplete (filling time began at 3 h) and noncommunicating cysts (no or slight filling after 24 h). Twenty-two patients in CTC group with incomplete communicating, or noncommunicating cysts underwent surgeries. And other 6 patients with complete communicating cysts were closely observed. In CTC group, the symptom of all surgical patients was relieved, and 5 out of 6 observational patients showed clinical improvement or no deterioration during the follow-up. In surgical group, only 18 out of 24 patients showed clinical improvement after surgeries, and there were 6 patients showing no difference before and after surgeries in symptom and in imaging.

CONCLUSIONS

This classification based on dynamic CT cisternography is useful for the decision of surgical indication. Some symptomatic patients with complete communicating ACs may not need surgical intervention.

Multiloculated hydrocephalus: a review of current problems in classification and treatment

PURPOSE

Loculated hydrocephalus is a condition in which discrete fluid-filled compartments form in or in relation to the ventricular system of the brain. Both uni- and multiloculated variants exist, with marked differences in outcome. However, several competing and seemingly interchangeable nomenclatures exist, and none address the pathophysiological basis of the condition. To clarify current treatment options, we carried out a review of the literature.

METHODS

A protocol describing search strategy and inclusion criteria was prepared in advance, and a search of MEDLINE, the Cochrane Database of Systematic Reviews, and the U.S. NIH ClinicalTrials.gov database was carried out with the search terms: "multicystic," "multiloculated," "multicompartment," "uniloculated," and "loculated." All were used in conjunction with the search term "hydrocephalus."

RESULTS

A single study with a control group was found. Remaining reports are purely case series. Research efforts are hampered by unclear and seemingly interchangeable nomenclatures, which makes comparison between studies difficult. There is a paucity of studies of high methodological quality concerning choice of treatment. At the case series level, evidence is in favor of the neuroendoscopic approach.

CONCLUSIONS

In order to ensure a consistent nomenclature as well as to guide future research, we propose a new system of classification for loculated hydrocephalus. It acknowledges the differences between uniloculated and multiloculated hydrocephalus, and goes beyond a pure anatomical model. For future research, it enables us to clearly characterize subgroups, which is essential if we are to advance our understanding and level of care for this challenging group of patients.

De novo suprasellar arachnoid cyst: case report and review of the literature

PURPOSE

We present a case of a 4-year-old child who was incidentally found to have a suprasellar arachnoid cyst (SAC) after initial CT imaging at 6 weeks of age but who demonstrated no anomalies. This is only the sixth case of intracranial de novo ACs documented in the English literature and only the second case of SAC to arise de novo.

METHODS

Case review after an SAC was found on an MRI scan at 4 years of age which had not been present on a previous CT of the head.

RESULTS

Apparent de novo SAC formation in a healthy 4-year-old female without a history of intracranial infection, surgery or trauma.

CONCLUSION

The pathophysiology leading to the formation of the cyst might well be congenital, although there is some question as to how early in development the cysts are formed as our child was a 32-week GA preemie with an initial scan at 38 weeks GA. With the use of fast MRI scans instead of CT scans and the continued neuroimaging of premature infants, we can take a better look at the anatomy and better determine the timing of development of the SAC.

Endoscopic fenestrations for suprasellar arachnoid cysts

OBJECT

The endoscopic treatment of a suprasellar arachnoid cyst (SAC) consists mainly of ventriculocystostomy (VC) and ventriculocystocisternostomy (VCC). However, the most appropriate treatment for these cysts has not been fully determined yet. The authors report on the effectiveness of endoscopic VC for SACs communicating with the basal cisterns, which is demonstrated by preoperative CT cisternography.

METHODS

The authors retrospectively analyzed the surgical results of patients with an SAC treated using endoscopic fenestration. The patient charts were reviewed for demographic data, clinical presentations, surgical therapies, and clinical outcomes.

RESULTS

Six consecutive patients with SAC were surgically treated using endoscopic fenestration (VC or VCC) between March 2004 and February 2011. The mean age was 18.5 months (range 5 days to 37 months). Five patients were previously untreated, and 1 patient had previously undergone ventriculoperitoneal shunt placement. Five patients underwent preoperative CT cisternography, and communication between the SAC and the basal cisterns was demonstrated in 3 patients, very slight communication in 1, and no communication in 1. Four patients, including the 3 with communication between the SAC and basal cisterns, underwent VC. Two patients with very slight or no communication underwent VCC. In all patients the SAC decreased in size and hydrocephalus improved postoperatively. Five patients (3 treated with VC and 2 with VCC [83%]) have been stable without reoperation (mean follow-up 32.7 months). All 3 patients with an SAC communicating with the basal cisterns have been stable without reoperation following VC.

CONCLUSIONS

Preoperative cisternography may be useful for selecting the optimal endoscopic treatment method for SAC. If an SAC communicates with the basal cisterns, a VC could be an effective, safe, and simpler treatment option.

Chiari malformation Type I and syrinx in children undergoing magnetic resonance imaging

OBJECT

Chiari malformation Type I (CM-I) with an associated spinal syrinx is a common pediatric diagnosis. A better understanding of the relative age-related prevalence and MR imaging characteristics of these associated conditions may lead to improved treatment decisions.

METHODS

The authors performed a retrospective review of 14,116 consecutive individuals 18 years of age or younger who had undergone brain or cervical spine MR imaging at the University of Michigan between November 1997 and August 2008. In the patients with CM-I, demographic, clinical, and radiographic information was recorded.

RESULTS

Five hundred nine children (3.6%) with CM-I were identified. Among these patients, 23% also had a spinal cord syrinx, and 86% of the syringes were found in the cervical spine. The MR imaging prevalence of CM-I with a syrinx was 1.2% in girls and 0.5% in boys (p < 0.0001). The severity of impaired CSF flow at the foramen magnum was associated with the amount of tonsillar herniation (p < 0.0001) and conformation of the tonsils (p < 0.0001). Patients with CM-I were treated surgically in 35% of cases; these patients exhibited more severe tonsillar herniation (p < 0.0001) and impaired CSF flow (p < 0.0001) as compared with those who did not undergo surgery. On imaging, 32% of all the patients with CM-I were considered symptomatic by the treating physician. Patients were more likely to be considered symptomatic if they were female, had a syrinx, displayed abnormal tonsillar pulsations, or had a greater amount of tonsillar herniation.

CONCLUSIONS

In this study the authors describe the age-related prevalence and MR imaging characteristics of CM-I and its association with a syrinx and other abnormalities in a large group of children who underwent MR imaging for any indication. Syringes are more common in older children, in girls, and in patients with a greater degree of tonsillar descent and CSF flow impairment.

Technical considerations to prevent postoperative endocrine dysfunction after the fenestration of suprasellar arachnoid cyst

OBJECTIVE

The endocrine dysfunction after the operation for suprasellar arachnoid cysts is not rare. The careful operation to prevent structures can prevent this complication, but it is not enough and effective to prevent it. Authors present technical surgical considerations to prevent this complication with a review of our suprasellar arachnoid cyst patients who had postoperative endocrine dysfunction.

METHODS

From January 2002 to December 2009, eight patients who had suprasellar arachnoid cysts with visual impairment underwent surgery. The mean age was 57.1 years (range, 33-77). Preoperatively, their endocrine function was clinically normal, and laboratory hormonal levels were within normal ranges. Cyst fenestration was performed by craniotomy (n=6) or by a neuro-endoscopic procedure (n=2), and, simultaneously, along with a cyst wall biopsy.

RESULTS

The surgery was uneventful in all eight patients, and there were no neurological morbidities. However, in four patients, endocrine dysfunction occurred postoperatively. We compared these four patients (group A) to the other 4 patients without endocrine dysfunction (group B) with intraoperative findings and with the histopathological findings of the cyst wall biopsy. The group A patients had more abundant vasculature on the cystic wall than the group B patients according to both the intraoperative findings and the histopathological findings.

CONCLUSION

When performing a surgical cyst wall fenestration, surgeons should try to minimize the destruction of the cystic wall vasculature and not to make the fenestration at a site that contains many vascular striae.

The effectiveness of ventriculocystocisternostomy for suprasellar arachnoid cysts

OBJECT

The aim of this study was to report the long-term outcomes of patients receiving endoscopic ventriculocystocisternostomy (VCC) for suprasellar arachnoid cysts (SACs), and to analyze all published reports on outcomes of ventriculocystostomy (VC) versus VCC to compare the effectiveness of the 2 techniques.

METHODS

Eleven consecutive patients with previously untreated SACs were surgically treated using endoscopic VCC. Another 2 patients were treated with VCC following ventriculoperitoneal shunt placement. Clinical imaging data were recorded. An analysis was performed of all published patient outcomes following endoscopic VC or VCC for an SAC.

RESULTS

Developmental delay and progressive macrocephaly were the most common preoperative symptoms. At a mean clinical follow-up interval of 63 months, 10 of 11 patients undergoing primary VCC did not require reoperation. An analysis of the literature suggests that VCC may be more effective than VC. Of the 44 reported patients that underwent VC as a first treatment, 7 (16%) required reoperation, and 7 (8%) of 86 patients who underwent VCC as a first treatment required reoperation. When VC or VCC was performed following a prior surgical procedure, 4 of 11 patients undergoing VC had a treatment failure requiring reoperation. In contrast, only 2 of the 17 reported cases of VCC following a prior procedure required further treatment. The difference in reoperation rates following either primary or secondary VC was significantly higher than following primary or secondary VCC (p = 0.04).

CONCLUSIONS

The authors conclude that VCC is an effective and durable treatment for symptomatic SACs in most cases.

The endocrine spectrum of intracranial cysts in childhood and review of the literature

Intracranial cysts (ICC) may cause a wide spectrum of endocrinological disorders. We evaluated 27 patients who were diagnosed with ICC during investigation for neuroendocrine dysfunctions and reviewed the relevant literature. The types of ICC in the patients were arachnoid cysts (n = 13); Rathke cleft cysts (n = 7); pineal cysts (n = 5); an ependymal cyst (n = 1) and a cavum septum pellucidum cyst (n = 1). The neuroendocrine dysfunctions of the patients were obesity (n = 7), isolated growth hormone deficiency (n = 6), central precocious puberty (n = 6), multiple pituitary hormone deficiency (n = 3), central diabetes insipidus (n = 1), growth hormone deficiency and central precocious puberty (n = 1), obesity and galactorrhea (n = 1), obesity and hypogonadotropic hypogonadism (n = 1) and growth hormone neurosecretory dysfunction (n = 1). Only three patients, who had arachnoid cysts, showed neurologic symptomatology. Although three patients underwent surgery, no improvements in endocrinological dysfunctions were observed. ICC should be considered when evaluating patients with endocrinological problems and patients with coincidental ICC should be recommended for follow-up.

Neocortical and hippocampal volume loss in a human ciliopathy: A quantitative MRI study in Bardet-Biedl syndrome

Cilia are ubiquitous cell surface organelles with diverse roles from embryogenesis to adult life. The neurodevelopmental functions of the cilium are currently under investigation in animal systems, but relevance to human brain development remains uncertain. We present the first systematic investigation of structural neuroanatomy in a ciliopathy-Bardet-Biedl syndrome (BBS). Qualitative and quantitative aspects of brain structure were evaluated via magnetic resonance imaging in 10 patients with BBS (ages 14-28 years). In comparison to age and gender-matched healthy controls, BBS patients had significantly reduced total gray matter (GM) volume but no total white matter (WM) or cerebrospinal fluid volume changes. Voxel-based morphometric analysis indicated regional GM volume loss bilaterally in the anterior temporal lobes and in the medial orbitofrontal cortex, and WM volume loss in the right inferior longitudinal fasciculus. Region-of-interest measurements revealed reduced volume of the hippocampus. Two patients were found to have ventriculomegaly. Global GM reduction and regional volume reductions in the temporal lobe may underlie the learning disabilities and behavioral problems experienced by some patients with BBS. These findings are consistent with previous observations in mouse models of BBS, and further implicate the cilium in neurodevelopmental processes relevant to human cognitive function.