Neuropathological analysis of an asymptomatic adult case with Dandy-Walker variant

Regional brain development in fetuses with Dandy-Walker malformation: A volumetric fetal brain magnetic resonance imaging study

Dandy-Walker malformation (DWM) is a common prenatally diagnosed cerebellar malformation, characterized by cystic dilatation of the fourth ventricle, upward rotation of the hypoplastic vermis, and posterior fossa enlargement with torcular elevation. DWM is associated with a broad spectrum of neurodevelopmental abnormalities such as cognitive, motor, and behavioral impairments, which cannot be explained solely by cerebellar malformations. Notably, the pathogenesis of these symptoms remains poorly understood. This study investigated whether fetal structural developmental abnormalities in DWM extended beyond the posterior fossa to the cerebrum even in fetuses without apparent cerebral anomalies. Post-acquisition volumetric fetal magnetic resonance imaging (MRI) analysis was performed in 12 fetuses with DWM and 14 control fetuses. Growth trajectories of the volumes of the cortical plate, subcortical parenchyma, cerebellar hemispheres, and vermis between 18 and 33 weeks of gestation were compared. The median (interquartile range) gestational ages at the time of MRI were 22.4 (19.4-24.0) and 23.9 (20.6-29.2) weeks in the DWM and control groups, respectively (p = 0.269). Eight of the 12 fetuses with DWM presented with associated cerebral anomalies, including hydrocephalus (n = 3), cerebral ventriculomegaly (n = 3), and complete (n = 2) and partial (n = 2) agenesis of the corpus callosum (ACC); 7 presented with extracerebral abnormalities. Chromosomal abnormalities were detected by microarray analysis in 4 of 11 fetuses with DWM, using amniocentesis. Volumetric analysis revealed that the cortical plate was significantly larger in fetuses with DWM than in controls (p = 0.040). Even without ACC, the subcortical parenchyma, whole cerebrum, cerebellar hemispheres, and whole brain were significantly larger in fetuses with DWM (n = 8) than in controls (p = 0.004, 0.025, 0.033, and 0.026, respectively). In conclusion, volumetric fetal MRI analysis demonstrated that the development of DWM extends throughout the brain during the fetal period, even without apparent cerebral anomalies.

Head Tilting Elicited by Head Turning in Three Dogs with Hypoplastic Cerebellar Nodulus and Ventral Uvula

The nodulus and ventral uvula (NU) of the cerebellum play a major role in vestibular function in humans and experimental animals; however, there is almost no information about NU function in the veterinary clinical literature. In this report, we describe three canine cases diagnosed with presumptive NU hypoplasia. Of them, one adult dog presented with cervical intervertebral disk disease, and two juvenile dogs presented with signs of central vestibular disease. Interestingly, an unusual and possibly overlooked neurological sign that we called “positioning head tilt” was observed in these dogs. The dogs were able to turn freely in any direction at will. The head was in a level position when static or when the dog walked in a straight line. However, the head was tilted to the opposite side when the dog turned. Veterinary clinicians should be aware of this neurological sign that has not been reported previously, and its application in lesion localization in dogs.

Neuropsychological Function in a Case of Dandy-Walker Variant in a 68-Year-Old Veteran

Dandy-Walker syndrome (DWS) is a congenital brain malformation that is characterized by partial or complete agenesis of the cerebellar vermis and cystic dilatation of the 4th ventricle that shifts ventrolaterally to displace the cerebellar hemispheres. This case is a 68-year-old male veteran with complaints of new-onset cognitive disorder who was found to have previously unsuspected DWS on head computed tomography. This is one of the first case studies to present complete neuropsychological test results in a veteran with DWS. Despite the level of abnormality on imaging, the veteran functioned well until onset of mild cognitive impairments in late adulthood.

Central diabetes insipidus, central hypothyroidism, renal tubular acidosis and dandy-walker syndrome: new associations

Dandy-Walker syndrome (DWS) is a rare brain malformation involving the cerebellum, and the fluid filled spaces around it, usually detected during the antenatal period or the early infancy. Clinically, it is characterized by mental retardation, developmental delay as well as cerebellar ataxia. It has been frequently associated with other conditions such as congenital heart diseases, primary hypothyroidism, and other disorders of the central nervous, gastrointestinal, genitourinary, and orthopedic systems. In this report, we describe a 3-month-old Saudi boy with the rare association of DWS with central diabetes insipidus, congenital central hypothyroidism, and type-2 renal tubular acidosis.

Inferior cerebellar hypoplasia resembling a Dandy-Walker-like malformation in purebred Eurasier dogs with familial non-progressive ataxia: a retrospective and prospective clinical cohort study

Cerebellar malformations can be inherited or caused by insults during cerebellar development. To date, only sporadic cases of cerebellar malformations have been reported in dogs, and the genetic background has remained obscure. Therefore, this study`s objective was to describe the clinical characteristics, imaging features and pedigree data of a familial cerebellar hypoplasia in purebred Eurasier dogs. A uniform cerebellar malformation characterized by consistent absence of the caudal portions of the cerebellar vermis and, to a lesser degree, the caudal portions of the cerebellar hemispheres in association with large retrocerebellar fluid accumulations was recognized in 14 closely related Eurasier dogs. Hydrocephalus was an additional feature in some dogs. All dogs displayed non-progressive ataxia, which had already been noted when the dogs were 5 – 6 weeks old. The severity of the ataxia varied between dogs, from mild truncal sway, subtle dysmetric gait, dysequilibrium and pelvic limb ataxia to severe cerebellar ataxia in puppies and episodic falling or rolling. Follow-up examinations in adult dogs showed improvement of the cerebellar ataxia and a still absent menace response. Epileptic seizures occurred in some dogs. The association of partial vermis agenesis with an enlarged fourth ventricle and an enlarged caudal (posterior) fossa resembled a Dandy-Walker-like malformation in some dogs. Pedigree analyses were consistent with autosomal recessive inheritance.

Blake's pouch cyst and Werdnig-Hoffmann disease: Report of a new association and review of the literature

Background:

We report a case of a neonate with proximal spinal muscular atrophy (SMA) type 1 (also known as Werdnig-Hoffmann disease or severe infantile acute SMA) associated with a Blake's pouch cyst; a malformation that is currently classified within the spectrum of Dandy-Walker complex. The association of the two conditions has not been previously reported in the English literature. A comprehensive review of the pertinent literature is presented.

Case Description:

A male neonate was noted to have paucity of movement of the four limbs with difficulty of breathing and poor feeding soon after birth. Respiratory distress with tachypnea, necessitated endotracheal intubation and mechanical ventilation. Pregnancy was uneventful except for decreased fetal movements reported by the mother during the third trimester. Neurological examination revealed generalized hypotonia with decreased muscle power of all limbs, nonelicitable deep tendon jerks, and occasional tongue fasciculations. Molecular genetic evaluation revealed a homozygous deletion of both exons 7 and 8 of the survival motor neuron 1 (SMN1) gene, and exon 5 of the neuronal apoptosis inhibitory protein (NAIP) gene on the long arm of chromosome 5 consistent with Werdnig-Hoffmann disease (SMA type 1). At the age of 5 months, a full anterior fontanelle and abnormal increase of the occipito-frontal circumference were noted. Computed tomographic (CT) scan and magnetic resonance imaging (MRI) of the brain revealed a tetraventricular hydrocephalus and features of Blake's pouch cyst of the fourth ventricle.

Conclusions:

This case represents a previously unreported association of Blake's pouch cyst and SMA type 1.

The Geneva brain collection

The University of Geneva brain collection was founded at the beginning of the 20th century. Today, it consists of 10,154 formaldehyde- or buffered formaldehyde-fixed brains obtained from the autopsies of the Department of Psychiatry and, since 1971, from the Department of Geriatrics. More than 100,000 paraffin-embedded blocks and 200,000 histological slides have also been collected since 1901. From the time of its creation, this collection has served as an important resource for pathological studies and clinicopathological correlations, primarily in the field of dementing illnesses and brain aging research. These materials have permitted a number of original neuropathological observations, such as the classification of Pick's disease by Constantinidis, or the description of dyshoric angiopathy and laminar sclerosis by Morel. The large number of cases, including some very rare conditions, provides a unique resource and an opportunity for worldwide collaborations.

Neuropathological findings in Dandy Walker variant

OBJECTIVE

Dandy-Walker malformation is a congenital malformation that is characterized by hypoplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle and enlargement of the posterior fossa. The aim of the study is to describe the morphological and morphometric alterations of neurons (in various regions of the brain) in a case of Dandy-Walker Variant.

METHODS

By Golgi method and routine techniques, the alterations in the brain of a 23 years old case of Dandy-Walker Variant who died accidentally were studied. Furthermore, a detailed morphometric analysis of neuronal parameters and a statistical comparison with an age-matched control were applied.

RESULTS

In the cerebellum the morphological study, apart from gliosis, revealed reduction of the size of cell body and poverty of dendritic arborization with loss of dendritic branches and spines. In the cerebral cortex and the hippocampus the most prominent findings were the tortuous configuration of the apical dendrites of the pyramidal neurons, the focal swellings of the axons and the dendrites and significant gliosis.

CONCLUSION

Although the gross anatomical examination of the brain demonstrated only mild neurodevelopmental anomalies (except the key features of the syndrome), the microscopic examination revealed significant morphological alterations of neurons and dendrites.

The Dandy-Walker variant: a case series of 24 pediatric patients and evaluation of associated anomalies, incidence of hydrocephalus, and developmental outcomes

OBJECT

The Dandy-Walker complex is a continuum of aberrant development of the posterior fossa that has been associated with multiple congenital anomalies, radiographic abnormalities, and developmental delay. The Dandy-Walker variant (DWV) is a unique entity believed to represent a milder form of the complex, and is characterized by a specific constellation of radiographic findings. In this retrospective case series, the authors report the association of the DWV with other congenital anomalies, the associated radiographic findings linked with DWV, and the developmental outcome in this population.

METHODS

The charts and radiographs of 10 male and 14 female patients treated between 2000 and 2006 were examined. The patients' mean gestational age was 35.6 weeks (range 23-41 weeks), and the mean follow-up period was 5.1 years (range 1 month-15 years).

RESULTS

Three patients died. Associated anomalies included cardiac (41.7%), neurological (33.3%), gastrointestinal (20.8%), orthopedic (12.5%), and genitourinary (12.5%) abnormalities. Less common were pulmonary and psychiatric findings. Developmental delay was identified in 11 of the 21 patients for whom follow-up was available. Five of 6 patients with isolated DWV had a normal developmental course. Radiographic findings associated with DWV included corpus callosum dysgenesis in 20.8%, ventricular enlargement in 29%, and vermian rotation in 8.3%. Shunts were placed in 4 of 7 patients with ventriculomegaly. Using the two-tailed Pearson correlation, the authors determined that developmental outcome was solely affected by neurological deficits and that ventricular enlargement predicted the need for shunt placement.

CONCLUSIONS

The DWV was associated with both extra- and intracranial anomalies. Associated radiographic abnormalities including ventriculomegaly were observed. Hydrocephalus requiring cerebrospinal fluid diversion may be indicated. Isolated DWV was associated with a good developmental outcome.

[Late diagnosis of Dandy-Walker syndrome revealed by gait disorders in an elderly]

The Dandy-Walker syndrome is a rare malformation usually diagnosed during pregnancy or early in the course of life. We report a case in an elderly hospitalised for gait disorders and recurrent falls. Cerebral MRI revealed hydrocephalus and posterior fossa cyst. The patient improved after ventriculocisternostomia.

Dandy-Walker syndrome in adult mimicking myasthenia gravis

The Dandy-Walker syndrome (DWS) is a rare posterior fossa malformation. The DWS can occur associated with other brain or systemic malformations, but ocular abnormalities in this disease are rare and clinical findings mimicking myasthenia gravis have not been described to date. We report a 23-year-old woman who presented mild limitation of the ocular movements with progressive palpebral ptosis, which changed in intensity during the day. The investigation showed negative anti-acetylcholine receptor antibody, repetitive nerve stimulation and "Tensilon test", but the brain magnetic resonance image reveals DWS with hydrocephalus associated with calosal dysgenesis. The characteristic of disease, clinical manifestations and pathologic features, specially the clinical evaluation of ocular abnormalities in suspicion of DWS, including the MG in differential diagnosis are discussed.