Retrocerebellar Cyst Research Articles

Оценка влияния ретроцеребеллярных кист головного мозга на ликворную систему как критерий годности к летной работе

Retrocerebellar cysts of the brain represent the aspect that is important for determination of fitness for flight. The study was aimed to assess their impact on the pilot performance by conducting comparative analysis of MRI data of the first-year cadets and experienced pilots. We assessed the prevalence of retrocerebellar cysts among cadets and pilots, conducted non-contrast brain MRI, and compared the major academic and physical performance indicators, along with the results of professional psychological screen. The prevalence of retrocerebellar cysts among first-year cadets was 8.2%. High prevalence of asymptomatic retrocerebellar cysts among experienced pilots was revealed (two cases out of five). The intergroup comparison of indicators makes it possible to draw a conclusion about probable minor impact of such changes on fitness for flight. Further research is required to clarify the mechanisms underlying the impact of retrocerebellar cysts on the pilot performance and develop appropriate guidelines for medical boards.

Retrocerebellar Ependymal Cyst Presenting with Obstructive Hydrocephalus in an Infant

AbstractIntracranial ependymal cysts (ECs) are rare benign lesions. They are frequently asymptomatic and arise in the supratentorial regions. Retrocerebellar ECs is a rare location. We present a case of 3-months-old infant who developed obstructive hydrocephalus, bulging fontanel, and macrocephaly secondary to a retrocerebellar EC. Magnetic resonance imaging (MRI) showed a large retrocerebellar cyst that compressed the cerebellum and the brainstem, producing fourth ventricle outlet obstruction and supratentorial hydrocephalus. Microsurgical fenestration of the cyst to the obex of the fourth ventricle and a cystic wall biopsy were performed. The procedure improved supratentorial hydrocephalus, as well as the patient's clinical condition. A histopathological study confirmed the diagnosis of an EC.As far as we know, after a thorough review of the literature, this is the first reported case of retrocerebellar EC. It is a rare cause of hydrocephalus due to outlet obstruction of the fourth ventricle. Treatment of the cause itself was shown to be effective.

Corpus callosum metrics predict severity of visuospatial and neuromotor dysfunctions in ARID1B mutations with Coffin-Siris syndrome.

ARID1B mutations in Coffin-Siris syndrome are a cause of intellectual disability (0.5-1%), with various degrees of autism and agenesis of the corpus callosum (10%). Little is known regarding the cognitive and motor consequences of ARID1B mutations in humans and no link has been made between corpus callosum anomalies and visuospatial and neuromotor dysfunctions. We have investigated the visuospatial and neuromotor phenotype in eight patients with ARID1B mutations. A paramedian sagittal section of the brain MRI was selected, and corpus callosum was measured in anteroposterior length, genu and trunk width. Spearman's rank order coefficients were used to explore correlations between visuospatial and social cognitive variables and dimensions of the corpus callosum. A significant correlation between genu width size and visual cognition was observed. Retrocerebellar cysts were associated with corpus callosum anomalies. Here, we show that corpus callosum anomalies caused in ARID1B mutations may be predictive of the visuospatial and motor phenotype in Coffin-Siris syndrome.

«A case of a pharmacoresistant tachyarrhythmia associated with Arnold-Chiari malformation»

Introduction: Arnold-Chiari malformation is a group of congenital malformations of the hindbrain. Common symptoms include cephalgia, vestibular, cerebral and cochlear disorders We present a case of pharmacoresistant tachyarrhythmia associated with Arnold-Chiari malformation.Case Description: A 49-year-old female patient had an Arnold-Chiari malformation (ACM), syringomyelia, a retrocerebellar cyst and a 6 year history of tachyarrhythmia. Heart rhythm normalized after Chiari decompression.Conclusion: ACM can lead to heart rhythm disorders.

Developmental Retrocerebellar Cysts: A New Classification for Neuroendoscopic Management and Systematic Review

Posterior fossa cystic malformations are diversely classified with considerable overlap without therapeutic relevance. These cysts posterior to the cerebellum, presenting in children younger than 5 years, are labeled developmental retrocerebellar cysts (DRCCs) under a new classification in relation to neuroendoscopy. DRCC was categorized as type 0 for asymptomatic enlarged cistern magna and was not treated. Among symptomatic cases, cysts with a compressed fourth ventricle were labeled type 1, whereas cysts in continuity with the fourth ventricle were termed type 2. They were further categorized as subtype B if hydrocephalus was greater relative to the cyst, or otherwise as subtype A. The literature was reviewed according to PRISMA guidelines. There were 13 children aged 3-48 months. Type 1A DRCC was noted in 5 patients, with onset before 6 months, 4 of whom (80%) had intracranial hypertension. All underwent suboccipital endoscopic deroofing and cisternostomy (SEDC), a new technique. Type 1B DRCC was seen in 2 patients, with onset at 8-9 months, who underwent endoscopic third ventriculostomy (ETV)+ endoscopic ventriculocystostomy (EVC). Type 2A DRCC was observed in 4 patients, with onset at 5-47 months, who underwent SEDC. Type 2B DRCC was noted in 2 patients, with onset 6-8 months, who underwent ETV. With a mean follow-up of 32months, all showed clinicoradiologic improvement. The application of our classification to other studies showed ETV/EVC to be successful in only 67% of type 1A DRCC and 72% of type 2A DRCC, compared with 100% efficacy of SEDC in our series. This is probably the first ever endoscopic classification of pediatric posterior fossa cyts, elucidating pathophysiology, presentation, and treatment. Patients with type 1 DRCC present early because of extraneous compression. Among patients with type 2 DRCC, posterior fossa compliance determines the degree of hydrocephalus. The newly described SEDC seems more appropriate for types 1A and 2A DRCC. ETV is adequate in type 2B DRCC and effective with EVC in type1B.

The cerebellar “tilted telephone receiver sign” enables prenatal diagnosis of PHACES syndrome

To describe a unique posterior fossa neuroimaging characteristic of prenatal PHACES syndrome (PS): unilateral cerebellar hypoplasia (UCH) and ipsilateral posterior fossa (PF) cyst communicating with an asymmetrically distended 4th ventricle. The registries of seven prenatal diagnosis centers were searched for cases with PF findings and a postnatal diagnosis of PS. All records were evaluated for ultrasound and MRI findings and the postnatal outcome. PS was diagnosed after birth according to the consensus statement on diagnostic criteria for PS from 2009. The imaging findings of the PS fetuses were compared to a group of consecutive cases with fetal UCH, whose postnatal diagnosis was not PS. The PS group included 10 fetuses. All were referred due to UCH accompanied by an ipsilateral retrocerebellar cyst. All pregnancies resulted in livebirths, all newborns had a large segmental facial hemangioma. In all PS fetuses the affected cerebellar hemisphere was upwardly displaced by an ipsilateral PF cyst communicating with an asymmetrically distended 4th ventricle. An upwardly rotated and deviated vermis merged with the contralateral cerebellar peduncles forming an elongated oblique connection between the cerebellar hemispheres, resulting in a unique cerebellar shape, "a tilted telephone receiver sign" (TTRS), on the coronal plane through the upper vermis.The non-PS group included 11 fetuses with UCH: clastic cerebellar lesions (8) and a unilateral PF arachnoid cyst (3). The TTRS was not depicted in any of them (p<0.0005). The cerebellar TTRS is a specific fetal imaging feature of PHACES syndrome enabling its prenatal diagnosis.

English

INTRODUCTION: The Dandy–Walker malformation was first described in 1887 by Sutton and was further characterized by Dandy and Blackfan in 1914 and Taggart and Walker in 1942 1, 2. True Dandy–Walker malformation [DWM]consists of cerebellar vermis hypoplasia, posterior fossa enlargement with elevation of the torcula and an enlarged 4th ventricle extending posteriorly as a retrocerebellar cyst. Other malformations with less severe cerebellar vermis hypoplasia and generally smaller posterior fossa fluid collections were categorized as ‘‘Dandy–Walker variants’’. We herein report a case of Dandy Walker Variant who presented in an unusual manner.

Periventricular nodular heterotopia on prenatal ultrasound and magnetic resonance imaging

To describe the prenatal ultrasound and magnetic resonance imaging (MRI) findings suggestive of periventricular nodular heterotopia (PNH). This retrospective case series included fetuses referred to our institution for brain MRI between 2007 and 2012, which were diagnosed with PNH and confirmed by postnatal MRI or autopsy. The type of PNH, associated ventriculomegaly and associated malformations are reported. We included 11 fetuses (nine female, two male) with a mean gestational age at diagnosis of 31 (range, 23-34) weeks. PNH lesions were small and diffuse (n = 7), large and multiple (n = 1) or single (n = 3). A targeted ultrasound examination performed before fetal MRI missed the diagnosis in four cases (one diffuse and three single); a further ultrasound examination performed after MRI diagnosed PNH in two of these four cases. Ventriculomegaly was present in six cases (four unilateral and two bilateral). PNH appeared in all cases as nodules of intermediate echogenicity protruding into the ventricular lumen. In all cases of diffuse PNH, the frontal horns and bodies of the lateral ventricles appeared square in shape on coronal view, with irregular borders on axial view. Associated cerebral malformations were observed in seven cases and included corpus callosal agenesis (n = 4, with additional malformations in two) and retrocerebellar cyst (n = 3). Extracerebral malformations were also present in two cases. Maternal MRI was performed in five of the six cases of isolated small and diffuse PNH in female fetuses, and demonstrated PNH in two of these. PNH is underdiagnosed at prenatal ultrasound, even on targeted scans. Irregular ventricular borders on axial view and irregular square-shaped lateral ventricles on coronal view are suggestive of PNH at prenatal ultrasound.

Unilateral cerebellar hypoplasia and mesencephalic malformation in a Hanoverian foal

Neurological cases, especially in foals, are rare in the daily practical work. The most common causes are traumata and infectious diseases of the central nervous system (CNS). This case report provides further insights into the wide spectrum of possible neuropathological lesions by detailing a complex malformation with unilateral neurological signs that occurred later post natum. Thus, clinicians should also be aware of malformations in case of respective neurological patients. A Hanoverian foal was presented with progressive ataxia. General and blood examination revealed no further alterations. By neurologic examination, a unilateral hypermetria was diagnosed and a cysternography of the head was performed. A cerebellar malformation was assumed and the foal was euthanized due to poor prognosis. At necropsy, a unilateral absence of a cerebellar hemisphere and vermis accompanied by contralateral malformation of the mesencephalon was diagnosed. The missing areas of the right cerebellar hemisphere were replaced by a cystic formation. The left part of the mesencephalic lamina quadrigemina was reduced in size and the corpus callosum was hypoplastic. Additional microscopical findings were most obvious near the cyst formation and included angiofibrosis in remaining cerebellar and mesencephalic parenchyma and leptomeninges, heterotopia of cerebellar neurons, sclerosis in cerebellar cortex, focal proliferation of meningeal cells and mild mononuclear perivascular infiltrates. Occassional irregular neuronal arrangement in the mesencephalon was also present. Infectious agents such as Borna disease virus, rabies virus, and equine herpesvirus were not detected. Therefore, the complex malformation in this foal might have been caused by a destructive, possibly ischemic event, or could represent a sequel of a primary retrocerebellar cyst with accompanying compression of adjacent parenchyma.

Cervical myelopathy due to chronic overshunting in a pediatric patient: case report and review of the literature

We present a rare cause of cervical myelopathy produced by an engorged suboccipital epidural venous plexus due to chronic cerebrospinal fluid (CSF) overdrainage. A 17-year-old boy with obstructive hydrocephalus due to a retrocerebellar cyst and secondary implantation of a ventricloperitoneal shunt (VP-shunt) presented with progressive spastic tetraparesis. MRI imaging revealed myelopathy due to significant compression of the cervical spinal cord by engorged epidural veins. Further assessment at a low-pressure setting revealed a broken shunt valve. The VP-shunt valve was changed with an additional anti-siphon device leading to a gradual increase of the intracranial pressure (ICP). After intensive physiotherapy, the patient showed slight clinical improvement. Follow-up imaging within nine days showed distinct regression of the dilated venous plexus at the cranial-cervical junction (CCJ) with the resolution of cord compression. Engorgement of the epidural venous plexus should always be considered in the differential diagnosis of myelopathy in long-term shunt patients even when classical clinical and radiological signs of overshunting are missing.

Microsurgical fenestration of retrocerebellar cysts as a treatment for syringomyelia

Abnormal posterior fossa cerebrospinal fluid (CSF) collections (PFC) are a constituent feature of several welldescribed disorders [1, 25]. These include retrocerebellar arachnoid cysts and the continuum of Dandy Walker pathology described by Barkovich and coworkers (including Dandy Walker malformation, Dandy Walker variant, and Blake’s pouch cyst) [4]. It is thought that similar to Chiari malformations, posterior fossa cysts adjacent to the foramen magnum can herniate and cause impaction of the foramen magnum. Although rare, such impaction may lead to secondary syringomyelia, probably secondary to obstruction of CSF flow between the posterior fossa and the cervical spinal subarachnoid space [2, 6, 9, 10, 15, 17, 19–21, 23, 24, 26–28]. We report our experience treating two children with PFC causing secondary syrinx and review the literature on this topic.

Growing Posterior Fossa Arachnoid Cyst Causing Tonsillar Herniation and Hydrocephalus

A25-YEAR-OLDWOMAN without any significantmedicalortraumatichistorypresented with a 1-month episodeofrecurrentandprogressive bioccipitalheadachesandnausea.At age18years,shehadbeeninvestigated foroccasionalbitemporalheadachein alocalclinic,anda11-cmretrocerebellarcysthadbeenincidentallydetectedonmagneticresonanceimaging (Figure, A). The lesion was consideredtobeofnosignificancewithregardtohersymptomsatthattimeand thus was left untreated. Neurologic examination findings were normal other than the presence of ataxia on the Romberg test. Fundus examination documented bilateral papilledema. Magnetic resonance imaging revealed a 45-cm retrocerebellar cyst compressing the cerebellum anteroinferiorly, resulting in tonsillar herniation and hydrocephalus (Figure, B and C). The patient underwent an urgentsuboccipitalcraniotomy.Intraoperatively, a bulging cyst containing a xanthochromic fluid was documented (Figure, D). Chemical analysis of the cyst fluid content revealed an elevated ferritin level of 21.4 ng/mL (to convert to picomoles per liter, multiply by 2.247), whereas the level of ferritin in the cerebrospinal fluid, which was independently collected from the cisterna magna, was normal at 6.8 ng/mL (12.0 is pathological). A wide resection of the cyst membranewasperformed,andthepathologicaldiagnosiswasconsistentwith an arachnoid cyst. The patient showed a full recovery after the operation. Follow-up magnetic resonance imaging confirmed shrinkage of the arachnoid cyst with resolution of the tonsillar herniation and hydrocephalus, and fundus examination confirmed the disappearance of bilateral papilledema 3 months after the operation. COMMENT Arachnoid cysts are incidentally detected in 2.6% of the pediatric population (aged 18 years). 1 Because progressive neurological signs secondary to growth of the lesion are rare, radiological follow-up and prophylactic surgery for asymptomatic arachnoid cysts are considered unnecessary. We are unaware of any published cases where both tonsillar herniation and hydrocephalus resulted from the growth of a posterior fossa arachnoid cyst. Examination of the ferritin concentration in the cerebrospinal fluid as a potential marker of previous subarachnoid bleeding showed a 3-fold elevation in the arachnoid cyst fluid compared with the cerebrospinal fluid in our case, which may reflect the preceding intracystic hemorrhage that can cause arachnoid cyst growth via an osmotic gradient. 2 The xanthochromic arachnoid cyst fluid in our case also seems to be suggestive of the previous intracystic bleeding.

Clinical Neuroimaging Features and Outcome in Molybdenum Cofactor Deficiency

Molybdenum cofactor deficiency predominantly affects the central nervous system. There are limited data on long-term outcome or brain magnetic resonance imaging (MRI) features. We examined the clinical, brain MRI, biochemical, genetic, and electroencephalographic features and outcome in 8 children with a diagnosis of molybdenum cofactor deficiency observed in our institution over 10 years. Two modes of presentation were identified: early (classical) onset with predominantly epileptic encephalopathy in 6 neonates, and late (atypical) with global developmental impairment in 2 children. Children in both groups had varying degrees of motor, language, and visual impairment. There were no deaths. Brain MRI demonstrated cerebral infarction in all but one child in the atypical group. Distinctive features were best observed on early brain MRI: acute symmetrical involvement of the globus pallidi and subthalamic regions coexisting with older cerebral hemisphere infarction, chronic lesions suggestive of a prenatal insult, pontocerebellar hypoplasia with retrocerebellar cyst, and presence of a distinctive band at the cortical/subcortical white matter. Sequential imaging revealed progressive pontine atrophy and enlargement of retrocerebellar cyst. The brain MRI of one child with atypical presentation (verbal dyspraxia, lens dislocation) showed symmetrical cerebellar deep nuclei signal abnormality without cerebral infarction. Imaging pattern on early brain MRI (<1 week) may prompt the diagnosis, potentially allowing early treatment and disease modifications.

A novel method for stereotactic, endoscope-assisted transtentorial placement of a shunt catheter into symptomatic posterior fossa cysts

Posterior fossa cysts are usually divided into Dandy-Walker malformations, arachnoid cysts, and isolated and/or trapped fourth ventricles. Shunt placement is a mainstay treatment for decompression of these fluid collections when their expansion becomes symptomatic. Although several techniques to drain symptomatic posterior fossa cysts have been described, each method carries its own advantages and disadvantages. This article describes an alternative technique. In 10 patients, the authors used an alternative technique involving stereotactic and endoscopic methods to place a catheter in symptomatic posterior fossa cysts across the tentorium. Discussion of these cases is included, along with a review of various approaches to shunt placement in this region and recommendations regarding the proposed technique. No patient suffered intracranial hemorrhage related to the procedure and catheter implantation. All 3 patients who underwent placement of a new transtentorial cystoperitoneal shunt and a new ventriculoperitoneal shunt did not suffer any postoperative complication; a decrease in the size of their posterior fossa cysts was evident on CT scans obtained during the 1st postoperative day. Follow-up CT scans demonstrated either stable findings or further interval decrease in the size of their cysts. In 1 patient, the postoperative head CT demonstrated that the transtentorial catheter terminated posterior to the right parietal occipital region without entering the retrocerebellar cyst. This patient underwent a repeat operation for proximal shunt revision, resulting in an acceptable catheter implantation. The patient in Case 8 suffered from a shunt infection and subsequently underwent hardware removal and aqueductoplasty with stent placement. The patient in Case 9 demonstrated a slight increase in fourth ventricle size and was returned to the operating room. Exploration revealed a kink in the tubing connecting the distal limb of the Y connector to the valve. The Y connector was replaced with a T connector, and 1 week later, CT scans exhibited interval decompression of the ventricles. This patient later presented with cranial wound breakdown and an exposed shunt. His shunt hardware was removed and he was treated with antibiotics. He later underwent reimplantation of a lateral ventricular and transtentorial shunt and suffered no other complications during a 3-year follow-up period. The introduction of endoscopic and stereotactic techniques has expanded the available treatment possibilities for posterior fossa cysts.

Reply to the comment to the paper (CNS-09-0420) “The clinical spectrum of Blake’s pouch cyst: report of 6 illustrative cases” by Professor Charles Raybaud

Reply to the comment to the paper (CNS-09-0420) “The clinical spectrum of Blake’s pouch cyst: report of 6 illustrative cases” by Professor Charles Raybaud

Ventriculocystostomy and endoscopic third ventriculostomy/shunt placement in the management of hydrocephalus secondary to giant retrocerebellar cysts in infancy

Hydrocephalus secondary to giant retrocerebellar cysts in infancy is a challenging condition and many treatment options exist. The authors report on 3 consecutive cases involving infants under the age of 6 months treated successfully with ventriculocystostomy in combination with direct hydrocephalus treatment (endoscopic third ventriculostomy or shunt placement). They describe the operative procedure, the surgical morbidity, and outcome in each case and review the literature regarding surgical approaches to this condition.

Familial congenital unilateral cerebral ventriculomegaly: Delineation of a distinct genetic disorder

We identified two female siblings, derived from healthy first cousin parents, with congenital unilateral cerebral ventriculomegaly detected prenatally. Patient 1 underwent ventriculoperitoneal shunt operation at 1 week old, while Patient 2 was followed without surgical intervention. Both patients presented with mild developmental delay and hemiparesis contralateral to the involved hemisphere. Focal seizures were observed in Patient 1, whose neuroimaging revealed posterior insular polymicrogyria in the normal sized ventricle hemisphere and retrocerebellar cyst. Both siblings displayed near absence of white matter with marked thinning of the overlying cortex in the affected hemisphere and very thin corpus callosum. Investigations revealed no other system involvement and karyotyping was normal. Normal TORCH screening in subsequent pregnancies, normal parental coagulation profile and undetectable maternal autoantibodies suggested against the possible role of extrinsic factors as an etiological factor for unilateral ventriculomegaly. Parents had normal brain imaging findings. We suggest delineation of a distinct developmental brain defect, most likely of autosomal recessive inheritance.

There might be more to SPG4!

SPG4-related hereditary spastic paraplegia is associated with posterior fossa abnormalities that are part of the Dandy–Walker complex (DWC). Scuderi et al 1 share their finding of developmental posterior fossa anomalies...

Posterior fossa arachnoid cyst, tonsillar herniation, and syringomyelia in trichorhinophalangeal syndrome Type I

The authors report the case of a patient with Chiari malformation Type I (CM-I) and syringomyelia probably caused by a retrocerebellar arachnoid cyst. The patient's phenotype corresponded to trichorhinophalangeal syndrome Type I. The authors attributed the origin of both the retrocerebellar cyst and the abnormal posterior fossa to endochondral ossification anomalies that occur in this syndrome. The patient's spinal pain was most likely a result of the combination of CM-I and syringomyelia. To the best of the authors' knowledge, this is the first report on the association of CM-I and syringomyelia with a retrocerebellar arachnoid cyst occurring in a patient with trichorhinophalangeal syndrome Type I. The authors discuss the pathogenetic mechanisms involved in the production of tonsillar descent and syringomyelia in this patient, and review the current literature on related conditions that can result in this association.

Adams–Oliver syndrome: further evidence of an autosomal recessive variant

Adams-Oliver syndrome is characterized by aplasia cutis congenita and variable degrees of terminal transverse limb defects. Other associated anomalies were described in the syndrome. Most described cases follow an autosomal dominant pattern of inheritance. Sporadic and autosomal recessive cases, however, were reported. In this study, we report on three Egyptian patients with Adams-Oliver syndrome from three different families. The parents were normal and consanguineous in all three families. There was history of similarly affected sibs for two cases. These findings denote autosomal recessive inheritance. The reported cases had typical skull and limb anomalies with cutis marmorata telangiectatica congenita. We observed additional rare manifestations in the form of microcephaly, psychomotor retardation, epilepsy, eye anomalies and atrophic skin lesions. MRI of the brain in one of the studied cases revealed retrocerebellar cyst and mild asymmetrical cerebellar hypoplasia, which to our knowledge, were not previously reported in Adams-Oliver syndrome. The results of this study provide further evidence of clinical and genetic heterogeneity and support the presence of autosomal recessive variant of Adams-Oliver syndrome.