Stereotaxic Surgical Approach to Microinject the Caudal Brainstem and Upper Cervical Spinal Cord via the Cisterna Magna in Mice.

Stereotaxic surgery to target brain sites in mice is commonly guided by skull landmarks. Access is then obtained via burr holes drilled through the skull. This standard approach can be challenging for targets in the caudal brainstem and upper cervical cord due to specific anatomical challenges as these sites are remote from skull landmarks, leading to imprecision. Here we outline an alternative stereotaxic approach via the cisterna magna that has been used to target discrete regions of interest in the caudal brainstem and upper cervical cord. The cisterna magna extends from the occipital bone to the atlas (i.e., the second vertebral bone), is filled with cerebrospinal fluid, and is covered by dura mater. This approach provides a reproducible route of access to select central nervous system (CNS) structures that are otherwise hard to reach due to anatomical barriers. Furthermore, it allows for direct visualization of brainstem landmarks in close proximity to the target sites, increasing accuracy when delivering small injection volumes to restricted regions of interest in the caudal brainstem and upper cervical cord. Finally, this approach provides an opportunity to avoid the cerebellum, which can be important for motor and sensorimotor studies.

An Uncommon Case of Neuroenteric Cyst Located at the Lateral Cerebellomedullary Cistern.

We present the case of a 42-year-old woman with a 5-week history of headache, progressive dysphagia, dysphonia, and hoarseness. A brain magnetic resonance imaging revealed an extra-axial cyst of the left lateral cerebellomedullary cistern. The subsequent histopathologic examination diagnosed a neuroenteric cyst. This case sheds light on the pivotal role of histologic identification of neuroenteric cyst, which could be crucial for further diagnostic investigations, especially in pediatric patients.

Adult cerebellopontine angle ependymoma presenting as an isolated cisternal mass: A case report.

INTRODUCTION: Ependymomas represent approximately 2%-8% of all primary intracranial brain tumors. The occurrence of extra-axial posterior fossa ependymomas in adults is rare. CASE AND OUTCOMES: We report a case of extra-axial cerebellopontine (CP) angle ependymoma in an adult patient, managed through gross total resection (GTR) and adjuvant radiotherapy. At her one-year postoperative visit, the patient remained clinically stable without any symptoms or focal neurological deficit and a follow up MRI showed no evidence of tumor recurrence. DISCUSSION: Only six cases of adult cerebellopontine angle ependymomas have been reported in the English literature, with the left side affected more commonly. Including this case, the mean age of the reported cases of adult extra-axial CP angle ependymoma is 44.14 years (range 22-66 years). Men accounted for five out of seven cases (71.4%). Maximal surgical resection is the mainstay of treatment in extra-axial CP angle ependymomas. Among seven reported cases, five received GTR and two had subtotal resection (STR). Patients were followed an average of 13.6 months (range 2-30 months) and only two patients with STR died during the follow-up period (6 weeks and 2 months after surgery). Six of the seven reported cases (including this one) received adjuvant radiotherapy. CONCLUSION: Although rare, extra-axial CP angle ependymomas should be considered as a differential diagnosis to other lesions of the CPA. Radical resection, whenever possible, is usually associated with a good outcome. Adjuvant radiotherapy remains an optional treatment with an unknown impact on overall and progression-free survival.

Three-dimensional volumetric study with VOCAL in normal and abnormal posterior fossa fetuses.

Purpose: The aim of this study was to compare volumetric parameters in the abnormal and normal posterior fossa using the Virtual Organ Computer-aided AnaLysis (VOCAL™) technique to determine whether fetuses with an abnormal posterior fossa have different volumes.Methods: A prospective study was conducted on 17 fetuses with an abnormal posterior fossa including, Dandy Walker malformation (DWM) (n = 6), vermian hypoplasia (VH) (n = 3), mega cisterna magna (MCM) (n = 8), and 99 healthy control fetuses from 20 to 34 weeks' gestation. Measurement of the fetal cisterna magna and cerebellar volume was performed in the standard transcerebellar plane through the VOCAL™ method. To establish the correlation of volumes with gestational age, polynomial regression analysis was performed. For comparison between groups, univariate ANCOVA was performed using gestational age as a covariate. The reliability was analyzed by the intraclass correlation coefficient (ICC).Results: Cerebellar volume and cisterna magna volume were correlated with gestational age. Posterior fossa volume was significantly larger in DWM (p < .0001) and MCM (p < .0001) in comparison to the control group. In VH group, cisterna magna volume does not seem to expand (p = .298). Cerebellar volume does not seem to change in subgroups when the influence of gestational age is discarded (p = .09). The ratio of cerebellar volume to the cisterna magna volume decreases significantly in abnormal fetuses (p < .0001). Good intraobserver and interobserver reliabilities were found for both cerebellum and cisterna magna measurements.Conclusions: Volume analysis may have a role in discrimination of different posterior fossa pathologies.

Is Cisterna Magna Width a Useful First-Trimester Marker of Aneuploidy?

OBJECTIVE: To assess whether the cisterna magna (CM) width measured in first-trimester fetuses is a useful marker for aneuploidy detection. METHODS: This was a prospective study in 2 different cohorts in a tertiary referral center. The first cohort comprised 913 fetuses from the general pregnancy population during the period 2012-2016 and was used to construct the CM reference ranges applying the λ-µ-σ (LMS) method. The second cohort included 714 high-risk fetuses undergoing chorionic villus sampling during the period 2012-2016. Mean detection rates using the 95th percentile for CM width observed in chromosomal anomaly groups were compared with those obtained in chromosomally normal fetuses. RESULTS: The 50th percentile for CM ranged from 1.66 to 2.75 mm when crown-rump length (CRL) increased from 45 to 84 mm. Among high-risk fetuses, the following chromosomal anomalies were diagnosed in 125 (17%) fetuses: trisomy 21 (n = 63), trisomy 18 or 13 (n = 21), monosomy X (n = 9), submicroscopic anomalies (n = 11), and other anomalies (n = 22). The mean CM width for euploid fetuses was 2.4 mm (1.13 multiples of the median, MoM). While CM width was significantly increased in trisomy 21 (mean 2.7 mm; 1.23 MoM; p > 0.05), no differences were found in the other anomaly groups. Among the 63 fetuses with trisomy 21, a CM width above the 99th percentile was observed in 23 fetuses (37%). CONCLUSIONS: The new reference range for CM width at 11-13 weeks of gestation did not differ from previous studies. In first-trimester fetuses with trisomy 21, CM width appears to be increased, although its value as an ultrasound marker is limited, because of its detection rate of 37%.

Lymphatic outflow of cerebrospinal fluid is reduced in glioma.

Glioblastoma is a malignant brain tumor with mean overall survival of less than 15 months. Blood vessel leakage and peritumoral edema lead to increased intracranial pressure and augment neurological deficits which profoundly decrease the quality of life of glioblastoma patients. It is unknown how the dynamics of cerebrospinal fluid (CSF) turnover are affected during this process. By monitoring the transport of CSF tracers to the systemic blood circulation after infusion into the cisterna magna, we demonstrate that the outflow of CSF is dramatically reduced in glioma-bearing mice. Using a combination of magnetic resonance imaging (MRI) and near-infrared (NIR) imaging, we found that the circulation of CSF tracers was hindered after cisterna magna injection with reduced signals along the exiting cranial nerves and downstream lymph nodes, which represent the major CSF outflow route in mice. Due to blockage of the normal routes of CSF bulk flow within and from the cranial cavity, CSF tracers were redirected into the spinal space. In some mice, impaired CSF clearance from the cranium was compensated by a lymphatic outflow from the sacral spine.

Efficacy of cyst-cisternal shunt for refractory cyst regrowth of cystic vestibular schwannomas.

Vestibular schwannomas (VSs) are generally benign and slow-growing tumors, and microsurgical resection is the commonly recommended treatment. Some reports suggested that inserting a cystoperitoneal shunt was effective for treatment of cystic VSs; however, there was no report of a cyst-cisternal shunt which diverts cyst fluid into cistern. We report a case of cystic VS with repeated cyst regrowth within weeks after repeated surgeries. We prevented further recurrence using cyst-cisternal shunt. This technique may be a new treatment option for refractory cyst regrowth of cystic VSs.

The Clinical and Molecular Characteristics of Molybdenum Cofactor Deficiency Due to MOCS2 Mutations.

BACKGROUND: We explored the clinical and molecular characteristics of molybdenum cofactor deficiency due to MOCS2 muations. METHODS: We summarize the genetic and clinical findings of previously reported patients with a MOCS2 mutation. We also present a new patient with novel neuroradiological findings associated with molybdenum cofactor deficiency due to a novel homozygous variant in the 5' untranslated region of the MOCS2 gene. RESULTS: The study population comprised 35 patients with a MOCS2 gene mutation. All reported children had delayed motor milestones. The major initial symptom was seizures in neonatal period. Facial dysmorphism was present in 61% of the patients. Only one patient had ectopia lentis. Agenesis of the corpus callosum and an associated interhemispheric cyst in our case are novel neuroradiological findings. CONCLUSIONS: The occurrence of neonatal seizures and feeding difficulties can be the first clinical signs of molybdenum cofactor deficiency. Although there is no effective therapy for this condition, early diagnosis and genetic analysis of these lethal disorders facilitate adequate genetic counseling.

Non-dysraphic intramedullary lipoma of the craniocervical region in an adult: Case report.

Intradural spinal lipomas with intracranial extension are very rare and are typically diagnosed in childhood. Radical surgical excision usually causes a high rate of morbidity because of the firm adherence between the lipoma and neural tissues. In this report, we present a case of craniocervical intradural intramedullary lipoma in an adult patient. The patient underwent surgery with excision of the mass, leaving a sheet of lipoma on the tumor bed.

Differential Diagnoses and Their Implications of Dandy-Walker Malformation or Isolated Cisterna Magna, a Case Study: Baby V.

We explore the outcome of a fetus with a posterior fossa abnormality thought to be a Dandy-Walker malformation based on prenatal ultrasound imaging. The infant was later diagnosed by magnetic resonance imaging (MRI) as having an isolated cisterna magna. When assessing brain abnormalities, there is increased accuracy of prenatal MRI versus prenatal ultrasound. Accurate diagnosis of an infant is paramount so that an inheritance pattern, risk of recurrence, involvement of other systems, and a prognosis can be determined. Communicating with the family and supporting them with the correct information is then enhanced. It should be standard protocol to obtain a fetal MRI if an abnormal prenatal ultrasound of the brain is detected. Further research is needed to assess the accuracy of using MRI versus ultrasonography prenatally to diagnose posterior brain abnormalities.

Standardized Method for Intra-Cisterna Magna Delivery Under Fluoroscopic Guidance in Nonhuman Primates.

Intrathecal delivery of adeno-associated virus vectors and other therapeutics are currently being evaluated for the treatment of central nervous system sequelae of lysosomal storage diseases, motor neuron diseases, and neurodegenerative diseases. As products transition from preclinical to clinical studies, a standardized and clinically relevant method of intrathecal delivery is increasingly germane. Here, we describe a method of intrathecal delivery via suboccipital puncture into the cisterna magna under fluoroscopic guidance in nonhuman primates. This procedure is suitable for use in good laboratory practice compliant studies, has an excellent safety profile, and is highly similar to the procedure currently being explored for use in humans.

Ventriculocisternal Shunt Redivivus: Third Ventricle-Cisterna Magna Intradural Shunt: A Technical Note and Case Report.

OBJECTIVE: To present a hitherto unreported modification of the classic Torkildsen procedure: passing a catheter intracranially, between the third ventricle and cisterna magna. METHODS: We applied our technique to a 56-year-old man who presented to our department for treatment of a pineal region mass. RESULTS: The patient was placed in sitting position and the mass was gross totally removed through a supracerebellar infratentorial approach. After the completion of the tumor resection, the patency of the cerebral aqueduct was checked, but the permeability was doubtful. During the same procedure, a shunt was inserted, under direct microsurgical control, into the third ventricle and passed over the cerebellar surface into the cisterna magna. The postoperative course was uneventful, and the patient was discharged from our unit with no neurological deficits and able to carry on with his day-to-day life. CONCLUSIONS: Our case illustrates that ventriculocisternal shunting can successfully be used in selected cases. The variation we describe can be a valuable surgical strategy in patients with pineal region masses, in whom a supracerebellar infratentorial route is used and in whom uncertainty exists regarding the patency of the sylvian aqueduct.

Prenatal diagnosis of hydrancephaly and enlarged cerebellum and cisterna magna in a fetus with thanatophoric dysplasia type II and a review of prenatal diagnosis of brain anomalies associated with thanatophoric dysplasia.

OBJECTIVE: We present prenatal diagnosis of hydrancephaly and enlarged cerebellum and cisterna magna in a fetus with thanatophoric dysplasia type II (TD2) and a review of prenatal diagnosis of brain anomalies associated with TD. CASE REPORT: A 33-year-old woman was referred for genetic counseling at 25 weeks of gestation because of fetal ultrasound abnormalities. Prenatal ultrasound at 14 weeks of gestation revealed an increased nuchal translucency (NT) and hydrocephalus. Level II ultrasound examination at 25 weeks of gestation revealed hydrancephaly, macrocephaly, a cloverleaf skull, frontal bossing, enlarged cerebellum and cisterna magna, a narrow chest, small ribs, short straight limbs. Amniocentesis revealed a karyotype of 46,XX. FGFR3 mutation analysis using the DNA extracted from uncultured amniocytes revealed a genotype of WT/c.1948A>G (p.Lys650Glu). The result was consistent with a K650E mutation in FGFR3 and TD2. The pregnancy was subsequently terminated. CONCLUSION: Fetuses with TD2 may present increased NT, early onset hydrocephalus, enlarged cerebellum and cisterna magna, and hydrancephaly on prenatal ultrasound.

A prospective study on fetal posterior cranial fossa assessment for early detection of open spina bifida at 11-13 weeks.

The objective of this study was to test three measurements: brain stem (BS), intracranial translucency (IT) and brain stem to occipital bone distance (BSOB), as well as one landmark: cisterna magna (CM) visibility, for early diagnosis of open spina bifida (OSB) in a low risk population. A prospective observational study was undertaken in a university hospital. A sample of 1479 women consented to participate between 20 September 2013 and 30 June 2015. Measurements were performed from the mid-sagittal view, as is routinely used for nuchal thickness assessment. CM visibility was assessed qualitatively as the third anechoic band in the posterior cranial fossa (PCF). All pregnancies were screened with a combination of maternal serum alpha-fetoprotein and second trimester anomaly scan and followed until delivery. Predictive values were calculated for each marker. We were able to diagnose two OSB cases and highly suspect one Dandy-Walker malformation case at the first trimester scan by the observation of PCF. PCF characteristics of OSB cases were increased BS diameter, increased BS-BSOB ratio and non-visualization of the CM. All the markers demonstrated high sensitivity and specificity but CM visibility reached the highest positive predictive value. Due to relatively high false positive rates, PCF measurements could not reach a satisfactory performance to validate their clinical use as a single marker. CM visibility has the advantage of being a qualitative marker and reduces the need for sophisticated and time-consuming measurements. Intracranial translucency and BS-BSOB ratio measurements should be used when the CM visibility is absent or in doubt.

Non-visualization of choroid plexus of fourth ventricle as first-trimester predictor of posterior fossa anomalies and chromosomal defects.

OBJECTIVE: To assess non-visualization of the choroid plexus of the fourth ventricle (CP-4V) as a simple, qualitative and reproducible first-trimester ultrasound feature of the posterior fossa for the prediction of central nervous system (CNS) anomalies and chromosomal defects. METHODS: First-trimester three-dimensional ultrasound datasets of the fetal brain were obtained prospectively from 65 consecutive normal singletons and retrospectively from 27 fetuses identified as having an abnormal posterior fossa on first-trimester ultrasound examination, and randomly combined to form the final study group. The stored ultrasound volumes were analyzed offline by two accredited sonologists, who were not aware of the final diagnoses. The CP-4V was assessed by multiplanar navigation and classified as visible or non-visible in its normal position depending on whether or not the echogenic structure that separates the fourth ventricle from the cisterna magna was identified in both midsagittal and axial planes. Correlation with subsequent second-trimester ultrasound, fetal magnetic resonance imaging, or postmortem or postnatal findings was performed to determine the predictive value of the first-trimester findings. RESULTS: Among the 92 ultrasound datasets analyzed, 73 (79%) were acquired transabdominally and 19 (21%) transvaginally. The CP-4V was classified as visible in 64 cases and non-visible in 28 cases, with agreement between the two observers in both sagittal and axial planes in all but one case. Twelve of the 28 (43%) fetuses with non-visible CP-4V were subsequently diagnosed as having a CNS malformation (open spina bifida (n = 6), Dandy-Walker malformation (n = 2), Blake's pouch cyst (n = 2), cephalocele (n = 1) and megacisterna magna (n = 1)). In addition, 20 of these 28 (71%) fetuses had aneuploidy (trisomy 18 (n = 10), triploidy (n = 5), trisomy 13 (n = 3), Turner syndrome (n = 1) or trisomy 21 (n = 1)). There was only one false-positive case, in which the CP-4V was classified as absent in a normal fetus. CONCLUSIONS: Non-visualization of the CP-4V in the first trimester appears to be a strong marker of posterior fossa anomalies and chromosomal defects. Qualitative evaluation of this anatomic structure is simple, feasible and reproducible, and its routine assessment during the first-trimester scan may facilitate the early detection of CNS anomalies and associated fetal aneuploidy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

An optimized technique of endoscopic third ventriculocisternostomy (ETV) for children with occlusive hydrocephalus.

In this article, we present an optimized minimally invasive technique of ETV for children with occlusive hydrocephalus. The study comprises of 64 consecutive pediatric cases (34 boys and 30 girls aged from 1 month to 5 years) of occlusive hydrocephalus from various etiologies, which were treated with a modified technique of ETV. Mean clinical follow-up period after ETV was 24.2 ± 3.8 months. Application of the new technique made it possible to significantly reduce the length of the soft tissue incision for access, and the use of upgraded instruments allowed to perform a twist drill hole in the skull to less than half a usual size. Access to the brain and lateral ventricle was performed by blunt trephination of the dura without the need for significant corticectomy or coagulation, and yielded minimal damage to the brain, which is very important in patients of young age. Continued endoscopic control during the approach down to the lateral ventricle increases safety and decreases risk of injury, and can be performed in cases of pathologies affecting the anatomical relationships of the lateral and third ventricle. Mortality in our cohort was 0%, and there were no postoperative neurological, endocrinological, or infectious complications. Patency rates of the first ETV performed was 78%, with the remaining patients requiring additional surgical procedures for complicated settings. This new technique of minimally invasive ETV placement in pediatric patients is an effective and safe method to treat occlusive hydrocephalus and can be recommended for extensive clinical use.

Cisterna magna meningiomas without dural attachment: Report of two cases.

Meningiomas within the cisterna magna without dural attachment are extremely rare. To the best of our knowledge, only three cases of meningiomas within the cisterna magna have been reported in the literature. The authors present two cases of patient with the cisterna magna meningioma without dural attachment. (Case 1) A 36-year-old female presented with a 10-month history of numbness in the left hand. Magnetic resonance imaging (MRI) disclosed the presence of a contrast-enhanced tumor in the posterior fossa. A suboccipital craniectomy was performed, and the tumor located within the cisterna magna with no attachment to the dura. Diagnosis is made as clear cell meningioma. The postoperative course was uneventful, and a recurrence has not been observed for three years. (Case 2) A 58-year-old man presented with a well-circumscribed mass in the posterior fossa. At surgery, the tumor located within the cisterna magna with a connection to the right tenia. The tumor was totally removed without neurological deficits. At a 7-year follow-up, no evidence of a recurrence was observed. It is quite difficult to preoperatively diagnose as a cisterna magna meningioma without dural attachment. However, complete removal of the tumor should be achieved.

Familial aplasia cutis congenita associated with mega-cisterna magna.

Aplasia cutis congenita (ACC; MIM 107600) is a congenital skin disorder that manifests as localized absence of skin. Here we report a case of familial ACC and mega-cisterna magna. A female neonate was born with skin defects on the scalp. Brain magnetic resonance imaging demonstrated retrocerebellar space widening suggesting mega-cisterna magna. Her father also had a skin defect on the scalp at birth, and brain computed tomography of the father showed a cystic lesion over the right occipital lobe, similar to the patient's brain imaging. Karyotype 46,XX, t(6;18)(q23.2;q11.2) was identified on G-banded karyotype analysis of the patient and her father, after which whole exome sequencing was carried out, but this was thought to be a coincidental finding. This indicates that ACC may be associated with brain anomaly, although it is very rare.

[Megacisterna magna as incidental finding in a boy with ADHD]. / Megacisterna magna als toevalsbevinding bij een jongen met ADHD.

In this case report we describe how a 13-year-old boy with a complex development profile was diagnosed with adhd and who was also found to have a megacisterna magna, a posterior fossa anomaly in the Dandy-Walker continuum. We searched the literature for reports of other patients who had this (mild) brain anomaly along with psychiatric problems in general and attention problems in particular. Our search of the literature suggested a possible link between the two diagnostic entities.

The Results of the Surgical Treatment of Spontaneous Rhinorrhea via Craniotomy and the Contribution of CT Cisternography to the Detection of Exact Leakage Side of CSF.

AIM: To share the results of conventional surgery in rhinorrhea and the contribution of computerized tomography (CT) cisternography to determination of the site of cerebrospinal fluid (CSF) leak. MATERIAL AND METHODS: Twelve cases treated for spontaneous rhinorrhea were included in this study. All the cases underwent cranial CT and magnetic resonance imaging (MRI). CT cisternography was performed in four patients whose bone defect or leakage site could not be detected by CT and MRI. In order to repair the defect, either the galea or galea together with collagen matrix was used and the procedure was supported with fibrin glue. RESULTS: In the cases, postoperative rhinorrhea was seen in neither the early nor the late follow up period. We observed no complications related to CT cisternography or craniotomy. The leakage area was successfully detected with CT cisternography when the other methods failed. CONCLUSION: Bone defect can usually be shown by means of CT. However, when bone-defect cannot be shown or the dura in the defective area is intact, CT cisternography is useful to show the CSF leak. Conventional surgery was very succesful in the treatment of spontaneous rhinorrhea but it was cosmetically problematic. In the patients both treated with galea and galea together with collagen matrix, the repair of the defect was successful.