The prominent retrocerebellar cerebrospinal fluid (CSF) space can be frequently encountered on paediatric neuroimaging studies. In cases involving abnormal vermian development where imaging does not align with the established criteria of Dandy-Walker malformation (DWM), the term \"Dandy-Walker variant or continuum\" has been historically employed to describe the aberrant posterior fossa development. Instead, the emphasis is on a more elaborate description of the findings in the posterior fossa. Moreover, combining the findings in the supratentorial brain can occasionally predict certain neurogenetic disorders that mimic Dandy-Walker phenotype. The present review demonstrates and differentiates the imaging features of various entities that result in an enlarged retrocerebellar CSF space, such as inferior vermian hypoplasia (IVH) and several neurogenetic conditions.

Congenital melanocytic naevus (CMN) syndrome, previously termed neurocutaneous melanosis, is a rare disease caused by postzygotic mosaic mutations occurring during embryogenesis in precursors of melanocytes. The severity of neurological manifestations in CMN patients is related to central nervous system abnormalities found at magnetic resonance imaging. The association between CMN and Dandy-Walker malformation (DWM) has been described in the literature, but recent advances in imaging and genetics lead to diagnostic criteria revision. In this paper, we aim to re-evaluate the proposed association by reviewing the available literature and present a patient with CMN and a large posterior fossa cyst.

BACKGROUND: Chromosome 13q deletion syndrome shows variable clinical features related to the different potential breakpoints in chromosome 13q. The severely malformed phenotype is known to be associated with the deletion of a critical region in 13q32. However, esophageal atresia is a rare symptom and the relevant region is unknown. Thus, determining the association between accurate breakpoints and new clinical features is essential.
METHODS: A 28-year-old Japanese primigravid woman was referred for fetal growth restriction, absence of a gastric bubble, cerebellar hypoplasia, overlapping fingers, and polyhydramnios at 31 weeks gestation. At 38 + 0 weeks, she delivered a 1774 g female infant. The infant presented with isolated esophageal atresia (Gross type A), Dandy-Walker malformation, right microphthalmia, left coloboma, overlapping fingers, pleurocentrum in the thoracic vertebrae, reduced anogenital distance, and hearing loss. Her karyotype was diagnosed as 46,XX,del(13)(q32.1-qter) by amniocentesis, but array comparative genomic hybridization after birth revealed the deletion of 13q31.3-qter. At 48 days after birth, the infant underwent surgery for esophageal atresia and was later discharged from the hospital at 7 months of age.
CONCLUSIONS: This case report and the literature reviews supports the previous findings on the pathological roles of haploinsufficiency of the ZIC2/ZIC5 in Dandy-Walker malformation and the EFBN2 haploinsufficiency in eye malformation and hearing loss. Furthermore, the possible involvement of IRS2, COLA1, and COLA2 in eye malformation were identified. This is the first case of 13q deletion syndrome with esophageal atresia (Gross A), but it may be a symptom of VATER/VACTER association (vertebral defects, anorectal malformations, cardiac defects, tracheoesophageal fistula with or without esophageal atresia, renal malformations, and limb defects), as in the previous cases. These symptoms might also be associated with EFBN2 haploinsufficiency, although further research is required.

Keratitis-ichthyosis-deafness syndrome is a rare genetic disease presenting with cutaneous, ocular, and otic defects. This comprehensive review provides insight into the clinical presentations, highlighting the cutaneous manifestations including histopathology and treatment options.

BACKGROUND: Dandy-Walker syndrome (DWS) is a group of brain malformations which occasionally accompanied by psychotic symptoms. The co-occurrence of DWS and epilepsy in children is quite rare.
METHODS: We reported a 14-year-old male who presented with a 8-month history of inconsistent upper limb tremor and accidental seizure. The MRI showed the typical alterations of DWS: cystic dilatation of the fourth ventricle, vermian hypoplasia, enlarged posterior fossa. He received the ventriculoperitoneal shunting (VPS) placement for hydrocephalus and had a symptom-free period for 8 days. Then he experienced a recurrence of involuntary upper limb tremor and behavior disturbance after decreasing the pressure of cerebrospinal fluid (CSF) from 150 to 130 mm Hg. After being treated with Olanzapine 10 mg/d, Clonazepam 3 mg/qn and Valproate acid (VPA) 500 mg/bid for nearly a month, his mental status and psychotic symptoms fluctuated. A search of Pub Med showed little report of hydrocephalus and DWS comorbidity with seizure and psychosis. Here we presented the whole process of a rare disease from the very beginning with all his symptoms, examinations and treatments.
CONCLUSIONS: VPS placement surgery at an earlier stage may be an effective way to avoid inevitable brain damage so as to improve the clinical outcomes for patients with DWS. Continued treatment with regard to DWS condition may include shunt placement, but it mainly focus on developmental concerns, with occupational and physical therapy along with ongoing supportive psychotherapy to improve the coping skills and quality of life.

OBJECTIVE: To investigate the clinical characteristics, the neuroimaging features and associated anomalies observed in children affected by Dandy-Walker malformations (DWM) and variants (DWV) in a single tertiary hospital in Catania and compare our data to their existent in the literature.
METHODS: A retrospective case series using the medical records has been performed on 28 children diagnosed with DWM and DWV admitted to a single tertiary section of Pediatric Neurology, Department of Catania, Italy from January 2005 to January 2021. We reviewed the neuroimaging using the new diagnostic criteria of Klein et al. RESULTS: Associated anomalies were frequently reported. Among these, hydrocephalus was found in 13/28 (48%), and hydrocephalus plus corpus callosum anomalies in three children (10%). We described corpus callosum, cardiac and genitourinary anomalies in 2/28 (7%), 3/28 (10%), and 3/28 (10%), respectively. The most common clinical features were the developmental delay and epilepsy observed in 19/28 (67%) and in 9/28 (32%) of the cases. The first exam at the diagnosis was MRI in 17/28 patients, followed by transfontanellar ultrasound in 5/28, computed tomography in 4/28 and prenatal ultrasound in 2/28. To note, a child with DWM was affected by Down syndrome and one by congenital disorders of N-linked glycosylation (CDG-IId).
CONCLUSIONS: Children with DWV were more commonly observed than children with DWM. Hydrocephalus is an anomaly, frequently and equally reported in both DWM and DMV. Perinatal complications were frequent adverse events with severe respiratory distress and need for cardiopulmonary resuscitation. Cognitive involvement and epilepsy were the most common comorbidities. Single DWV is associated with a better developmental outcome.

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.
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.
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.

The Ritscher-Schinzel syndrome (RTSCS) is a rare condition with craniofacial, cardiac and fossa posterior abnormalities. RTSCS is subdivided into Ritscher-Schinzel syndrome 1 (RTSCS1) caused by pathogenic variants in coiled-coil domain-containing protein 22 (CCDC22), and Ritscher-Schinzel syndrome 2 (RTSCS2) caused by pathogenic variants in WASH complex subunit 5 (WASHC5). CCDC22 is inherited in an X-linked recessive manner while WASHC5 is inherited in an autosomal recessive manner. Only 17 individuals with a molecular diagnosis are reported. In the past, the diagnosis of RTSCS was solely based on the clinical findings, and minimal diagnostic criteria has been proposed for the syndrome: Cardiac malformations (other than isolated patent ductus arteriosis), fossa posterior malformations, and certain dysmorphic features. However, those criteria are not present in all patients. We aim to further delineate the spectrum of CDCC22 associated RTSCS and present a novel patient with epileptic encephalopathy due to a presumed disease causing CCDC22 missense variant inherited from a healthy mother and grandmother. An affected maternal uncle had passed away at the age of 12 months and was thus unavailable for genetic testing. The proband and the maternal uncle had the typical facial dysmorphism associated with RTSCS, and they closely resembled previously published RTSCS2 patients with a molecular diagnosis. This suggests that RTSCS1 and RTSCS2 patients have a similar facial gestalt. We also review the literature on RTSCS, we explore potential differences and similarities between CCDC22 and W ASHC5 associated RTSCS and discuss the minimal diagnostic criteria.

BACKGROUND: Dandy-Walker Syndrome (DWS) is a rare congenital brain malformation characterized by underdevelopment of cerebellar vermis and cystic enlargement of the fourth ventricle and enlargement of the posterior fossa. The cooccurrence of DWS and syringomyelia in adults is very rare.
METHODS: We report a man aged 19 years who presented with a 2-year history of tremor. Magnetic resonance imaging showed cystic dilation of the fourth ventricle, hypoplasia of the cerebellar vermis, and syringomyelia. Posterior fossa decompression and spinal cord ostomy were performed. Tremor was markedly improved and the fourth ventricular and the syringomyelia were reduced in size postoperatively.
CONCLUSIONS: Tremor can be a clinical manifestation in patients of DWS concomitant with syringomyelia in adults. Spinal cord ostomy combined with posterior fossa decompression may be an effective approach for alleviation of symptoms and syringomyelia.

OBJECTIVE: The clinical variability of Blake\'s pouch cysts (BPC) may range from asymptomatic via ataxia to sequelae of decompensated hydrocephalus. On the other hand, Dandy-Walker malformation (DWM) and cerebellar vermis hypoplasia generally correlate with less favorable neurologic development. The aim was to illustrate the potential of prenatal and postnatal neuroimaging to distinguish a BPC or persistent BP from other posterior fossa malformations.
METHODS: This pictorial review addresses the inconsistent nomenclature, clinical features, and magnetic resonance imaging (MRI) patterns of BPC and five differential diagnoses. The MRI findings of 11 patients, acquired at up to 3 T in 3 institutions, are demonstrated. Furthermore, the literature was searched for recent improvements in genetic and embryological background knowledge.
RESULTS: Posterior fossa malformations often resemble each other and may even be imitated by sequelae of hemorrhagic, ischemic or infectious disruptions, i.e. congenital anomalies of morphology despite normal developmental potential. Hydrocephalus is a typical, albeit not always congenital finding in BPC. It is frequently associated with cerebellar disruptions and DWM; however, it is also a rare complication of posterior fossa arachnoid cysts. A moderately elevated vermis needs follow-up to confirm persistent BP versus vermian hypoplasia or DWM. The fetal cerebellar tail, previously assumed to be specific for DWM, may be imitated in cases of persistent BP.
CONCLUSIONS: The accurate diagnosis of isolated BPC is not always straightforward, which is especially critical in the context of fetomaternal medicine. A detailed description of posterior fossa malformations is to be preferred over unspecific terminology.