Endoscopic ultrasonic aspiration of posterior fossa abscess in Dandy-Walker malformation: case report.

BACKGROUND: Dandy-Walker malformation (DWM) is a posterior fossa malformation characterized by a huge posterior fossa cyst in communication with the fourth ventricle. Hydrocephalus is associated with more than 80% of cases and is usually treated by shunting. Despite infection being a common complication of the shunt, abscess formation within the cyst was reported only once. CASE REPORT: A neonate affected by DWM developed a posterior fossa abscess following a shunt infection. The purulent collection was refractory to standard treatment (antibiotics and burr hole drainage); therefore, an endoscopic approach was performed in order to remove the purulent collection under direct vision. This material was aspirated with the help of an endoscopic ultrasonic aspirator. The outcome was favorable, with a resolution of infection and re-implantation of the ventriculo-peritoneal shunt. Surprisingly, post-operative radiological examination showed substantial modification of the anatomy of the posterior fossa with disappearing of the Dandy-Walker cyst. To the best of our knowledge, this is the first documented report of a true Dandy-Walker malformation that modified its anatomical appearance over time. DISCUSSION AND CONCLUSION: Endoscopic aspiration of intracranial purulent collection should be considered a valid option to manage complicated cases. An endoscopic ultrasonic aspirator may make the procedure more effective and faster.

Occipital encephalocele associated with Dandy-Walker malformation: a case-based review.

INTRODUCTION: Occipital encephalocele is a brain malformation that has been remotely associated with Dandy-Walker; only case reports and very small series have been published so far; therefore, their behavior and management are still under investigation. The goal of the present case-based review is to provide a summary of the state of the art in this association. METHODS AND RESULTS: The pertinent literature has been reviewed, and an exemplary case has been reported (an 11-month-old female with Dandy-Walker malformation and occipital encephalocele). So far, 33 cases have been described, with a mean age at surgery of 5, 1 day). The majority of the cases tend to present with hydrocephalus. There are no specific surgery approaches or global consensus about this association. The management possibly relies on surgery with shunt or encephalocele excision but without a dedicated protocol yet. CONCLUSIONS: The clinical research on occipital encephalocele in association with Dandy-Walker malformation is just at the beginning. New targets and wide-ranging clinical trials are needed to get an optimal management protocol.

An incidental finding of Dandy-Walker malformation.

ABSTRACT: Dandy-Walker malformation is a rare congenital anomaly affecting the posterior fossa, occurring in one in 30,000 births. Its hallmark characteristics include hypoplasia of the vermis, dilation of the fourth ventricle, and an enlarged posterior fossa. This case study describes a finding of Dandy-Walker malformation during a workup of encephalopathy in a patient on veno-venous extracorporeal membrane oxygenation for acute respiratory distress syndrome.

Dandy-Walker malformation and syringomyelia: a rare association.

PURPOSE: Dandy-Walker malformation is a rare condition due to imperforation of the Blake's pouch during intrauterine brain development, usually leading to early severe hydrocephalus. The association with holocord syringomyelia is rare, and from the Gardner's first report in 1957, only 23 cases have been described, mostly from autopsy series and pre-MRI period. Besides a worsening of clinical picture, its occurrence generates some concern about the best surgical treatment that varies widely among the literature reports. METHODS: An 11-year-old girl with Dandy-Walker malformation presented with a holocord syrinx due to the herniation of the lower pole of the posterior fossa cyst through the foramen magnum. RESULTS: After an unsuccessful shunt revision, she underwent a cystoperitoneal shunt with regression of the syrinx and of neurological symptoms at the 12-month follow-up. CONCLUSIONS: Previous literature about pathogenesis, treatment, and follow-up is discussed and summarized.

The outcome of cochlear implantation among children with genetic syndromes.

OBJECTIVE: To assess the outcome and efficacy of cochlear implantation in children with genetic syndromes. METHOD: Study design: case-control study. SETTING: A cochlear implantation tertiary referral center. PATIENTS: All pediatric cochlear implantation recipients with Waardenburg syndrome, Usher syndrome, Dandy-Walker syndrome, or albinism. A control group was appropriately matched to the syndromic group with regard to age at implantation and duration of device use. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Subjects' auditory abilities, speech intelligibility, and pure tone thresholds were compared between the syndromic and non-syndromic group. RESULTS: A total of 25 subjects (13 syndromic and 12 non-syndromic) participated in the study. Neither auditory ability nor speech intelligibility scores differed significantly by group. The final PTA of both the groups showed normal-to-mild hearing loss: 26 dB HL in the syndromic group and 23 dB HL for the control group. CONCLUSIONS: Cochlear implant recipients with genetic syndromes achieved similar levels auditory perception and speech intelligibility as their peers with a genetic syndrome. The presence of any of the genetic syndromes described herein should not be a contraindication to cochlear implant provision, as it would have a positive impact on the patients' sensory perception and lifestyle.

Syringomyelia caused by an arachnoid web in a patient with shunted Dandy-Walker malformation.

INTRODUCTION: Dandy-Walker malformation (DWM) is a congenital brain anomaly characterized by dysgenesis of the cerebellar vermis and the presence of a posterior fossa cyst. The association of syringomyelia with DWM is extremely rare. CASE REPORT: A 10-year-old patient who was diagnosed with DWM in infancy presented with progressive scoliosis and fecal incontinence. He had been treated with cystoventriculoperitoneal shunting with a Y-connection during infancy, which was followed by a revision 6 years later. During the revision surgery, intraventricular bleeding occurred and was managed conservatively. Imaging studies for the current visit revealed syringomyelia along the cervicothoracic spinal cord and a membranous structure around the cervicomedullary junction. Phase-contrast cine magnetic resonance imaging (MRI) revealed disturbed cerebrospinal fluid (CSF) flow across the membrane. We excised the arachnoid web that was tethering the brainstem and blocking CSF flow. Postoperatively, the patient experienced symptom relief, and the follow-up imaging study demonstrated a dramatic decrease in the size of the syringomyelia. DISCUSSION: We suggest that syrinx formation in this patient was possibly caused by disturbed CSF flow and tethering of the brainstem. CONCLUSION: We experienced an unusual case of DWM with syringomyelia which was caused by an arachnoid web blocking CSF flow and tethering the brainstem. The arachnoid web seems to be formed by previous bleeding which occurred at the time of shunt revision. After excision of the arachnoid web, the patient showed good outcome.

Congenital Melanocytic Nevus Syndrome: A Case Series. / Síndrome del nevus melanocítico congénito. Serie de casos.

Congenital melanocytic nevus syndrome (CMNS) is the result of an abnormal proliferation of melanocytes in the skin and central nervous system caused by progenitor-cell mutations during embryonic development. Mutations in the NRAS gene have been detected in many of these cells. We present 5 cases of giant congenital melanocytic nevus, 3 of them associated with CMNS; NRAS gene mutation was studied in these 3 patients. Until a few years ago, surgery was the treatment of choice, but the results have proved unsatisfactory because aggressive interventions do not improve cosmetic appearance and only minimally reduce the risk of malignant change. In 2013, trametinib was approved for use in advanced melanoma associated with NRAS mutations. This drug, which acts on the intracellular RAS/RAF/MEK/pERK/MAPK cascade, could be useful in pediatric patients with CMNS. A better understanding of this disease will facilitate the development of new strategies.

[Intravenous Sedation and Repeated "the Same Day General Anesthesia" for a School-age Boy with Dandy-Walker Syndrome and Dentinogenesis].

Dandy-Walker syndrome (DWS) is characterized by perfect or partial defect of the cerebellum vermis and cystic dilatation of the posterior fossa communicating with the fourth ventricle. Common clinical signs are mental retardation, cerebellar ataxia, and those of increased intracranial pressure (ICP). Associated congenital anomalies are craniofacial, cardiac, renal, and skeletal abnormalities. We experienced a case of intravenous sedation and six times of "the same day" general anesthesia for a school-aged boy (10-13 years old) with DWS and hypodentinogenesis. The patient underwent an examination and dental treatments. We had to pay attention to airway management tracheal tube selection and control of ICP. In addition, we should prevent tooth injuries through mishaps during tracheal intubations, since all-tooth-hypoplasia with fragile dental crowns was strongly suggested in this case. Detailed postoperative care is also required for general anesthesia afflicted with DWS.

Challenges and outcome of cranial neuroendoscopic surgery in a resource constrained developing African country.

BACKGROUND: Cranial neuroendoscopy has been safely applied to the surgical treatment of different lesions of the brain in our center since its introduction in September 2009. This article summarizes our experience with neuroendoscopy, highlighting the salient challenges and outcome. METHODS: A single institution, retrospective analysis of prospectively acquired cases over a 2.5-year period (September 2010 to February 2013). Challenges experienced during the course of patient care as well as complications and outcomes were recorded and analyzed using SPSS (SPSS Inc. Chicago IL, USA) version 17. Tests of statistical significance were set at 95% level. RESULTS: Of the 291 cranial procedures performed during the study period, 37 (12.7%) were neuroendoscopic interventions. Patients were between the ages of 0.25 years and 25 years with a mean of 5.7 ± 1.5 years (95% confidence interval (CI)). Aqueductal stenosis was the most common indication for endoscopic intervention in 22 (59.5%) patients. Endoscopic third ventriculostomy was the most commonly performed neuroendoscopic procedure in 21 patients (56.7%). Major challenges experienced were patient dependent in 28 ± 1.0 patients (95% CL), learning curve related in 21 ± 0.4 patients, and poor endoscopy support infrastructure in 15 ± 0.5 patients. Complications were significantly more common in the first 6 months of neuroendoscopy (χ2= 7.57, df = 1, P< 0.05). Overall, 30 (81.1%) patients in our study experienced a positive outcome. The permanent morbidity and mortality rates in our series were 2.7% and 8.5%, respectively. CONCLUSION: Highlighted are the myriad obstacles which interface the successful set up of neuroendoscopy service especially in resource-constrained settings. Endoscopic procedures become safer with experience and complications reduce significantly after a steep learning curve.

Dandy-Walker syndrome with severe velopharyngeal dysfunction: a contraindication for Le Fort I surgery?

Dandy-Walker syndrome is a rare congenital brain deformation. Most symptoms are related with fourth ventricle and skull base malformations. Quite often, symptoms develop from infancy or progress rapidly. Cerebellar dysfunction, lack of muscle coordination, and skull deformities involving eye movement might be present. There are several Dandy-Walker syndrome complex types. We present a 23-year-old patient who had a severe dentofacial deformity with mandibular prognathism and extremely undeveloped maxillary bone resulting in palatopharyngeal and velopharyngeal dysfunction with complete lack of soft palate function resulting in increased speech tone and volume. Performing Le Fort I osteotomy in this case is greatly controversial and might result in even greater loss of function or even its total lack. Velopharyngeal complex is very important, and every surgeon should consider its value while planning Le Fort I osteotomies.

Reduction cranioplasty for macrocephaly caused by giant occipital cystic lesion.

Reduction cranioplasty for macrocephaly improves patients' quality of life both functionally and aesthetically. However, it is indicated for only a small number of patients because of the risks of complications. Thus, it is rarely performed, and not many reports have been published. In Dandy-Walker syndrome, there is often a posterior fossa cyst continuous with the fourth ventricle. We report here a case of scaphocephalic macrocephaly because of such a cystic lesion. The patient underwent a single-stage surgery with plication of the cyst wall and posterior reduction cranioplasty. This procedure achieved good results.

Central brain herniation in shunted Dandy Walker cyst.

INTRODUCTION: Dandy-Walker Syndrome (DWS) is a constellation of congenital anomalies of the central nervous system consisting of cerebellar vermis hypoplasia or agenesis, cystic dilatation of the fourth ventricle, enlarged posterior fossa, and a high tentorium. Hydrocephalus is a common occurrence in DWS and its treatment varies between shunting-ventriculoperitoneal or cystoperitoneal or both, endoscopic cyst fenestration, and third ventriculostomy. Chronic cerebral herniation is a known complication of treatment in DWS; however, we present an unusual case of central brain herniation. CASE REPORT: A 2 year old boy with shunted DWS presented with status epilepticus. Initial CT brain scan showed no increase in ventricle or cyst size; however, tapping the shunt reservoir did not yield any CSF prompting a shunt revision. Postoperatively, he was very slow to wake and subsequently experienced an episode of fixed pupils and extensor posturing. MRI brain demonstrated severe herniation of both thalami through the tentorium. CONCLUSION: This child had chronic central brain herniation (CCBH) secondary to the shunting of his cyst. To our knowledge, this is the first case of CCBH following treatment of DW cyst.

The Management of Hydrocephalus in Midline Posterior Fossa Cystic Collections: Surgical Outcome From a Retrospective Single-Center Case Series of 54 Consecutive Pediatric Patients.

BACKGROUND: Hydrocephalus frequently occurs with midline posterior fossa cystic collections. The classification of this heterogeneous group of developmental anomalies, including Dandy-Walker malformation, persisting Blake's pouch, retrocerebellar arachnoid cysts, and mega cisterna magna, is subject of debate. The absence of diagnostic criteria is confusing regarding the ideal management of PFCC-related hydrocephalus. OBJECTIVE: To decipher the surgical strategy for the treatment of children with PFCC-related hydrocephalus through a retrospective analysis of the surgical outcome driven by their clinical and radiological presentation. METHODS: This study enrolled patients operated of symptomatic PFCC-related hydrocephalus. Clinical and MRI features were examined, as well as the surgical outcome. Unbiased subgroup classification of the patients was performed with multiple component analysis as a function of imaging characteristics and hierarchical clustering on principal component. Outcome was assessed with binomial logistic regression and Kaplan-Meier analysis. RESULTS: Fifty-four patients were included between 2007 and 2021. Multiple component analysis suggested that cerebellar and vermian hypoplasia, vermian rotation, basal-tentorial angle, and fastigial angle were strongly correlated. Hierarchical clustering and the distribution of the patients in the bidimensional plot showed the clear segregation of 3 major clusters, which correlated with the radiological diagnosis ( P < .01). Binomial logistic regression and survival analysis showed that endoscopic third ventriculostomy was an effective treatment for patients with persisting Blake's pouch, while failing to control hydrocephalus in most of patients with Dandy-Walker malformation. CONCLUSION: Preoperative MRI in patients with PFCC-related hydrocephalus is essential to better define the diagnosis. The choice of treatment strategy notably relies on correct radiological diagnosis.

Prenatal diagnosis of 'isolated' Dandy-Walker malformation: imaging findings and prenatal counselling.

OBJECTIVE: The purpose of this article is to improve prenatal imaging diagnosis and counselling for cases of 'isolated' Dandy-Walker malformation (DWM) in the light of recent literature, which has demonstrated a potential good clinical and intellectual outcome of fetuses presenting with DWM characterised by partial vermian agenesis (identification of two fissures and three lobes) and absence of associated anatomical anomalies. METHODS: This is a retrospective observational study of six consecutive prenatal cystic posterior fossa malformations, diagnosed as DWM, encountered in a national reference centre for posterior fossa malformations over a 2-year period. RESULTS: In all cases, DWM was diagnosed as isolated (without any associated central nervous system or extra-central nervous system malformations and normal standard karyotype). Despite good-quality imaging, including fetal magnetic resonance imaging (MRI), prenatal analysis of the vermis was impossible because of limited identification of fissuration and lobulation. In three cases, a cytogenetic anomaly was found, including 6p subtelomeric deletion (n = 2) and partial 4 qter deletion associated with partial 7p trisomy (n = 1). One fetus with 6p deletion was terminated. In four of the five postnatal cases, MRI confirmed the diagnosis of DWM but provided only limited information for vermian analysis. In one case, postnatal MRI showed a large Blake's pouch cyst with rotated but complete vermis associated with a marked mass effect on the distal part of the tentorium. Of the four babies born with postnatal diagnosis of DWM, all required ventriculoperitoneal shunting because of early postnatal hydrocephalus. CONCLUSION: When fetal MRI is necessary to exclude additional cerebral lesions in the diagnosis of DWM, we highlight the inaccuracy of magnetic resonance for anatomical analysis of the vermis. We also emphasise the potential high incidence of subtelomeric anomalies in isolated DWM, especially 6p deletion. In the postnatal period, paediatricians should look for postnatal hydrocephalus even if the ventricular size is normal or slightly dilated on prenatal imaging.

Ascending transaqueductal cystoventriculoperitoneal shunting in Dandy-Walker malformation: technical note.

The optimal treatment for Dandy-Walker malformation is still controversial. Ventriculoperitoneal shunting, cystoperitoneal shunting or combinations are the most common surgical options in the management of this clinical entity. Endoscopic procedures like ventriculocystostomy, 3rd ventriculostomy or endoscopy-assisted shunt surgeries have become the focus of recent publications. We describe a new transcystic endoscopic technique, with the usage of a single ascending transaqueductal shunt catheter with additional holes, whereby both the posterior fossa cyst and supratentorial ventricular compartments are drained effectively. By using this new technique complications associated with combined shunting can be avoided. In addition, by equalizing the pressure within the supra- and infratentorial compartments, the upward or downward herniations associated with single-catheter shunting can be prevented.

Lateral ventricle pleomorphic xanthoastrocytoma concurrent with Dandy-Walker complex: A case report.

INTRODUCTION: Dandy-Walker complex and pleomorphic xanthoastrocytomas are both rare disease entities that typically manifest early in life and are associated with congenital etiological factors. Dandy-Walker complex is a cerebellar malformation associated with a series of anatomical changes. The disease onset is usually at birth or during infancy. Late onset in adulthood is uncommon. Pleomorphic xanthoastrocytoma is a rare WHO grade II astrocytic tumor affecting mainly young adults. Concomitant occurrence of Dandy-Walker complex and pleomorphic xanthoastrocytoma has not been previously reported. PATIENT CONCERNS AND DIAGNOSIS: A 30-year-old woman with a previous history of unconfirmed resected lateral ventricle meningioma presented with severe headache for 1 day. Imaging examination revealed a mass in the right lateral ventricle with heterogeneous signal patterns, changes in the posterior fossa corresponding to a Dandy-Walker variant, and mild hydrocephalus. INTERVENTIONS AND OUTCOMES: Surgical complete resection of the mass was achieved. postoperative histopathological examination confirmed WHO grade II pleomorphic xanthoastrocytoma. Three years postsurgery, ventriculoperitoneal shunt was performed due to worsening of hydrocephalus. The patient has since remained symptom-free. CONCLUSION: This is the first report of concomitant occurrence of Dandy-Walker complex and pleomorphic xanthoastrocytoma. The association of neurological congenital malformation with intracranial neoplasms may be multifactorial, with underlying role of genetic mutations or chromosome alterations.

CSF hydrothorax after ventriculoperitoneal shunt without catheter migration: a case report.

Ventriculoperitoneal (VP) shunting is the most common procedure performed for the management of hydrocephalus. VP shunt related complications remain a persistent problem in current clinical practice. Five-year-old female patient was admitted to our hospital with persistent dyspnea complaint. The patient was operated at the age of 3 months and a VP shunt established in a different clinic due to hydrocephalus associated with Dandy-Walker malformation. The patient's chest X-ray revealed right sided pleural effusion. Thorasentesis was performed and the effusion was drained with a chest tube. The discharged liquid was consistent with CSF. Scintigraphic radionuclide shunt analyses were performed and CSF passage from abdomen to chest and lower mediastinal region was determined in the late static images. The patient was operated and the incorporated ventriculoperitoneal shunt was removed. Hydrothorax was completely resolved after early postoperative stage. CSF hydrothorax especially without catheter migration is an unusual but potentially serious-clinical complication.

Giant occipital meningocele in an 8-year-old child with Dandy-Walker malformation.

INTRODUCTION: The possibility of an association between Dandy-Walker malformation and occipital meningocele is well-known. However, just an overall number of about 40 cases have been previously reported. Giant occipital meningocele has been described only in three newborns. Incidence, pathology, clinical presentation, and proper management of this association are still poorly defined. REPORT OF THE CASE: An 8-year-old boy with Dandy-Walker malformation and giant (25 cm in diameter) occipital meningocele is presented. This boy was born without any apparent occipital mass and harbored no other significant malformations including hydrocephalus. On admission, he was neurologically intact and the giant occipital mass presented partially calcified cyst walls. Treatment consisted of the excision of the occipital malformation, cranioplasty, and cysto-peritoneal shunt. Outcome was excellent. CONCLUSIONS: To the best of our knowledge, among the few reported patients with Dandy-Walker malformation associated to occipital meningocele, this is the oldest one and the one with the largest occipital meningocele; he is unique with calcified walls of the occipital meningocele and the only one who survived the repair of the giant malformation. In Dandy-Walker malformation, occipital meningocele may develop and grow regardless of hydrocephalus. Giant size may be reached and the cyst may become calcified. Surgical repair may warrant favorable outcome.

Hydrocephalus in Dandy-Walker malformation.

INTRODUCTION: Even if the first description of Dandy-Walker dates back 1887, difficulty in the establishment of correct diagnosis, especially concerning differential diagnosis with other types of posterior fossa CSF collection, still persists. Further confusion is added by the inclusion, in some classification, of different malformations with different prognosis and therapeutic strategy under the same label of "Dandy-Walker". METHODS: An extensive literature review concerning embryologic, etiologic, pathogenetic, clinical and neuroradiological aspects has been performed. Therapeutic options, prognosis and intellectual outcome are also reviewed. CONCLUSION: The correct interpretation of the modern neuroradiologic techniques, including CSF flow MR imaging, may help in identifying a "real" Dandy-Walker malformation. Among therapeutical strategies, single shunting (ventriculo-peritoneal or cyst-peritoneal shunts) appears effective in the control of both ventricle and cyst size. Endoscopic third ventriculostomy may be considered an acceptable alternative, especially in older children, with the aim to reduce the shunt-related problems. Prognosis and intellectual outcome mostly depend on the presence of associated malformations, the degree of vermian malformation and the adequate control of hydrocephalus.