RESOLUTION OF CALVARIAL HYPEROSTOSIS IN AFRICAN LION CUBS (PANTHERA LEO LEO) AFTER VITAMIN A SUPPLEMENTATION.

Two female (FL 1, FL 2) and one male (ML) 11-wk-old, intact, captive African lion cubs (Panthera leo leo) were presented with a history of mild vestibular signs. Initial serum vitamin A concentrations were low (140 nmol/L) for ML. Calvarial hyperostosis was confirmed using computed tomography (CT) of the head and cervical vertebrae in each cub. CT measurements were adapted in relation to the skull width. ML showed the most pronounced thickening of the tentorium cerebelli and occipital bone, represented by a tentorium cerebelli to skull width ratio (TCR) of 0.08 (FL 1: 0.06, FL 2: 0.05) and a basisphenoid to skull width ratio (BBR) of 0.07 (FL 1: 0.06, FL 2: 0.04). Magnetic resonance imaging (MRI) revealed cerebellar herniation and cervical intramedullary T2-weighted hyperintensity from C1, extending caudally for at least two cervical vertebrae in all cubs. Treatment was initiated with subcutaneous vitamin A supplementation and feeding of whole carcasses. Improvement in ataxia was noticed 3 wk later. Follow-up CT and MRI examinations were performed in ML after 3 and 8 mon. The affected bones appeared slightly less thickened and TCR and BBR had decreased to 0.05 after 3 mon. The cerebellum remained mildly herniated, accompanied by amelioration of cervical T2w hyperintensities. After 8 mon, evaluation and diagnostic imaging revealed further improvement regarding the neurologic status and measurements (TCR 0.05, BBR 0.04) despite persistence of a subtle cerebellar herniation. In conclusion, bone remodeling and improvement in clinical signs may be achievable in young lion cubs presented with calvarial hyperostosis and may be attributable to high-dose vitamin A supplementation.

Meningoencephalocele and supernumerary ectopic limb arising from the occipital bone in a Jacob sheep lamb.

This report describes the clinical, computed tomography, and magnetic resonance imaging findings for a Jacob sheep lamb diagnosed with meningoencephalocele and supernumerary ectopic limb. Key clinical message: This case demonstrates the utility of tomographic imaging in diagnosing congenital malformations in sheep and can be used to assess the extent of the lesion. This may help to determine any viable treatment, or, as in the case presented here, determine that the extent of the lesion precludes surgical intervention.

Méningoencéphalocèle et membre ectopique surnuméraire provenant de l'os occipital chez un agneau Jacob. Ce rapport décrit les résultats cliniques, de tomodensitométrie et d'imagerie par résonance magnétique d'un agneau de Jacob chez qui on a diagnostiqué une méningoencéphalocèle et un membre ectopique surnuméraire.Message clinique clé :Ce cas démontre l'utilité de l'imagerie tomographique dans le diagnostic des malformations congénitales chez le mouton et peut être utilisée pour évaluer l'étendue de la lésion. Cela peut aider à déterminer tout traitement viable ou, comme dans le cas présenté ici, à déterminer que l'étendue de la lésion exclut une intervention chirurgicale.(Traduit par Dr Serge Messier).

MRI diagnosis of spontaneous intraventricular tension-pneumocephalus in a 10-month-old male Saarloos Wolfdog.

A 10-month-old male Saarloos Wolfdog was presented with a history of multiple neurologic deficits that had acutely progressed. Neurologic examination findings localized signs to the cerebrum and brainstem. Magnetic resonance imaging revealed markedly enlarged and gas-filled lateral ventricles with a mass effect leading to cerebellar herniation. A right-sided defect of the cribriform plate with a dysplastic ethmoturbinate was identified as the inlet of air and origin of the intraventricular tension pneumocephalus. Surgical findings were consistent with a ruptured, congenital, nasal meningocele.

Comparison of high-field MRI and multidetector CT for grading Chiari-like malformation and syringomyelia in Cavalier King Charles Spaniels.

Chiari-like malformation (CM) and syringomyelia (SM) are common illnesses that can cause debilitating neuropathic pain in Cavalier King Charles spaniels (CKCS). The current imaging modality to screen CKCS for CM/SM is MRI of the brain and cervical spine. Magnetic resonance imaging provides good soft tissue detail and contrast of the cerebellum and cervical spinal cord. Computed tomography (CT) is another cross-sectional imaging technique that facilitates brain and neck evaluation; however, soft tissue resolution does not match that of MRI. Computed tomography benefits include identification of concurrent craniocervical junction anomalies (atlantooccipital overlap) and shorter imaging/anesthesia times with the ability to use only sedation. The aim of this retrospective, method comparison study is to assess the utility of multidetector CT for screening CM and SM in CKCS as compared to high-field MRI. Three groups of observers with different levels of experience graded CM and SM based on the British Veterinary Association/Kennel Club CM/SM classification criteria. Thirty CKCS underwent multidetector CT and 3 Tesla MRI studies. Computed tomography and MRI studies were reviewed at different timepoints to minimize bias. Computed tomography has lower Cohen's Kappa agreement for each observer group compared to MRI. The intraclass correlation coefficient averaging CM and SM for all groups was excellent using MRI, while CT was poor for SM and moderate for cerebellar herniation. Greater observer experience resulted in a higher agreement for CT and MRI. Magnetic resonance imaging should remain the standard for screening of CM and SM as CT can result in misclassification and greater disagreement.

Surgical correction of a meningoencephalocele in a thoroughbred filly.

OBJECTIVE: To describe the surgical correction of a closed meningoencephalocele in a thoroughbred filly. STUDY DESIGN: Case report. ANIMAL: One thoroughbred filly, 1.5 months old at the time of surgery. METHODS: A meningoencephalocele was identified at birth and diagnosed with radiography and MRI. The abnormal tissue was excised and submitted for histopathology, the dura was closed, and the defect in the skull was corrected with a titanium mesh. RESULTS: Histopathology confirmed the presence of neural parenchyma consisting of neurons and glial cells. The filly remained without neurologic deficits 7 months after surgery. CONCLUSION: Surgical correction of a meningoencephalocele was performed and considered successful, with no long-term neurologic deficits postoperatively. CLINICAL SIGNIFICANCE: Given the paucity of neural tube defect cases in the equine population, no surgical corrective techniques have been reported in the literature. This Case Report describes the first successful surgical treatment of a meningoencephalocele in a horse.

Clinical Features, Imaging Characteristics, and Long-term Outcome of Dogs with Cranial Meningocele or Meningoencephalocele.

BACKGROUND: The term meningoencephalocele (MEC) describes a herniation of cerebral tissue and meninges through a defect in the cranium, whereas a meningocele (MC) is a herniation of the meninges alone. HYPOTHESIS/OBJECTIVES: To describe the clinical features, magnetic resonance imaging (MRI) characteristics, and outcomes of dogs with cranial MC and MEC. ANIMALS: Twenty-two client-owned dogs diagnosed with cranial MC or MEC. METHODS: Multicentric retrospective descriptive study. Clinical records of 13 institutions were reviewed. Signalment, clinical history, neurologic findings and MRI characteristics as well as treatment and outcome were recorded and evaluated. RESULTS: Most affected dogs were presented at a young age (median, 6.5 months; range, 1 month - 8 years). The most common presenting complaints were seizures and behavioral abnormalities. Intranasal MEC was more common than parietal MC. Magnetic resonance imaging identified meningeal enhancement of the protruded tissue in 77% of the cases. Porencephaly was seen in all cases with parietal MC. Cerebrospinal fluid (CSF) analysis identified mild abnormalities in 4 of 11 cases. Surgery was not performed in any affected dog. Seventeen patients were treated medically, and seizures were adequately controlled with anti-epileptic drugs in 10 dogs. Dogs with intranasal MEC and mild neurologic signs had a fair prognosis with medical treatment. CONCLUSION AND CLINICAL IMPORTANCE: Although uncommon, MC and MEC should be considered as a differential diagnosis in young dogs presenting with seizures or alterations in behavior. Medical treatment is a valid option with a fair prognosis when the neurologic signs are mild.

A case of cranium bifidum with meningocele in Ayrshire calf.

BACKGROUND: Congenital cranial bone defects predispose to herniation of meninges, sometimes with brain tissue involvement, to form a cerebrospinal fluid (CSF)-filled cyst in the head. Such defects mainly results from focal failure of neural tube closure during fetal development and has been reported in various species of domestic mammals. CASE PRESENTATION: A one week old Ayrshire calf with a fluctuant swelling on parieto-occipital region of the head was referred to the faculty. The calf was always lying on lateral recumbency and exhibited resistance to deep palpation around the swelling and neck flexion. Embedded to the midline of the dorso-caudal surface of the cyst's wall was a hard longitudinally oriented structure. The case was diagnosed as meningocele by means of radiographic examination. As the likelihood to full recovery was greatly reduced due to the negative impact already meted on brain tissue by intracranial pressure, the calf was euthanized on grounds of animal welfare and the diagnosis confirmed by anatomopathological findings which also revealed a circular bone defect in parieto-occipital region of the skull vault and a flattened bony structure embedded to the cyst's wall. CONCLUSION: Anatomopathological findings confirmed the diagnosis as cranial bifidum with meningocele at the parieto-occipital region of the skull vault. The presence of a bony structure embedded to the wall of meningeal sac was rather unusual and could not be sufficiently explained. It was however thought to, most likely, represent a part of interparietal bone that failed to get incorporated into squamous part of occipital bone as a result of the defect. The report also highlights challenges that work against timely delivery of urgent veterinary interventions in rural set ups of Africa and rest of the developing world, often leaving veterinarians with animal welfare consideration as main determinant of intervention measures.

Two cases of meningocele and meningoencephalocele in Jeju native pigs.

BACKGROUND: Meningocele and meningoencephalocele of the skull are congenital deformities. Various species, such as pigs, dogs, and cats, are susceptible to congenital meningocele and meningoencephalocele and the incidence is higher in large white and landrace pigs. CASE PRESENTATION: In this study, swelling was observed in the fontanel areas of the median planes of the skull cap in two female piglets of the same litter. Gross clinical examination, neurological examination, computed tomography (CT), and magnetic resonance imaging (MRI) were conducted on the symptomatic piglets. The gross clinical and neurological examinations revealed no specific findings, except for the swellings. According to the CT results, the length of the defect on the sagittal section of the skull was 4.7 mm in case 1 and 20.62 mm in case 2. Connected flow between the skull swellings and the cerebrospinal fluid (CSF) of the lateral ventricles was observed, and partial herniation was identified in case 2. On MRI, CSF with high T2 signals was identified in the arachnoid spaces between the cerebrum and the cerebellum in the two cases, which is consistent with intracranial hypertension. The size of the swelling formed in the parietal bones was 1.6 × 1.1 × 1.8 cm(3) (case 1) and 1.2 × 1.38 × 1.7 cm(3) (case 2). The increase in intracranial pressure was more obvious in case 2 than in case 1, and was accompanied by posterior displacements of the mesencephalon and cerebellum. CONCLUSIONS: Case 1 was diagnosed as meningocele resulting from meningeal herniation and case 2 was diagnosed as meningoencephalocele caused by brain tissue herniation.

Magnetic resonance imaging characteristics of equine head disorders: 84 cases (2000-2013).

The equine head is an anatomically complex area, therefore advanced tomographic imaging techniques, such as computed tomography or magnetic resonance imaging (MRI), are often required for diagnosis and treatment planning. The purpose of this multicenter retrospective study was to describe MRI characteristics for a large sample of horses with head disorders. Horses imaged over a period of 13 years were recruited. Eighty-four horses met the inclusion criteria, having neurological (n = 65), sinonasal (n = 14), and soft tissue (n = 5) disorders. Magnetic resonance imaging accurately depicted the anatomy and allowed identification of the primary lesion and associated changes. There were good correlations between MRI findings and intraoperative or postmortem results. Magnetic resonance imaging showed the exact localization of the lesions, their size, and relation to surrounding structures. However, in the neurological group, there were 45 horses with no MRI abnormalities, 29 of which had a history of recurrent seizures, related to cryptogenic epilepsy. Magnetic resonance imaging was otherwise a valuable diagnostic tool, and can be used for studying a broad range of head disorders using either low-field or high-field magnets.

Low-field MRI and multislice CT for the detection of cerebellar (foramen magnum) herniation in Cavalier King Charles Spaniels.

BACKGROUND: Cavalier King Charles Spaniels (CKCS) have a high prevalence of Chiari-like malformation (CM). Herniation of the cerebellum into the foramen magnum is a key diagnostic feature for CM. Midsagittal MR images are the preferred technique for visualizing cerebellar herniation (CH). OBJECTIVE: To investigate whether CT can be used to diagnose CH. ANIMALS: Fifteen client-owned CKCS dogs referred for investigation of the brain and cranial cervical spine on MRI and CT. METHODS: Two reviewers retrospectively analyzed midsagittal T1WSE and T2WSE MR images and midsagittal pre- and postcontrast 2D multiplanar reformatted CT images from each dog for the presence of CH. And, if present, the length (mm, CHL) of the herniation was measured. The results were analyzed statistically. RESULTS: There was no significant difference between the different observers and techniques for the detection of CH and measurement of CHL. Overall, the CHL was longer on the CT images. CONCLUSION AND CLINICAL IMPORTANCE: Both techniques are useful for detecting CH and measuring CHL. Because CHL does not have a known direct impact on the clinical presentation of CM, CT can be used as a diagnostic tool in a routine clinical practice for CM in CKCS when MRI is not available. We emphasize that MRI is the standard screening technique in CKCS for breeding purposes to detect the presence of CM and SM and, at the current time, CT cannot replace MRI.

Imaging diagnosis--meningoencephalitis secondary to suppurative rhinitis and meningoencephalocele infection in a dog.

Nasal encephaloceles (meningoceles or meningoencephaloceles) are rare and not reported to be infected or coupled with a facial deformity in dogs. This report describes an older dog with acute worsening of seizures due to suppurative meningoencephalitis with coexisting suppurative rhinitis and infection of a meningoencephalocele. Additionally, the dog had a facial deformity for at least 5 years. The results of necropsy, computed tomography, and postmortem magnetic resonance imaging are compared. The development of nasal encephaloceles is discussed, including the potential role of early trauma, and whether separation of neural ectoderm from the surface ectoderm is part of the pathogenesis.

Surgical treatment of a meningoencephalocele in a cat.

OBJECTIVE: To report the clinical signs, imaging findings and surgical treatment of a meningoencephalocele in a cat. STUDY DESIGN: Case report. ANIMAL: Domestic shorthaired cat, 4 months old. METHODS: A parietal meningoencephalocele was identified and characterized by magnetic resonance and computed tomography (CT) imaging. The abnormal tissue was excised and submitted for histopathology, and the meningeal and skull defects were reconstructed. RESULTS: The cat made a full recovery and the episodes of aggression, restlessness and apparent discomfort that occurred before surgery ceased after surgical treatment. The cat was clinically normal 1 year postoperatively. CONCLUSION: Surgical management of meningoencephalocele in cats may be a viable treatment option.

MRI of secondary cervical syringomyelia in four cats.

This report describes the use of magnetic resonance imaging (MRI) to diagnose cervical syringomyelia in 4 cats. MRI revealed enlargement of the lateral ventricle in all the cats. Of the 4 cases, MRI revealed herniation of the cerebellum in 3 cats, an isolated fourth ventricle in 1 cat, severe hydrocephalus in 2 cats and brain masses in 1 cat. In this report, the cervical syringomyelia in these cats may have been due to formation of a secondary syrinx (enlargement of the central canal) as a result of blockage of flow in the outlet of the fourth ventricle caused by FIP encephalomyelitis or secondary cerebellar tonsillar herniation caused by increased intracranial pressure due to intracranial masses or may have been due to caudal compression of the cerebellum caused by increased intracranial pressure due to hydrocephalus.

Comparison of cerebral cranium volumes between cavalier King Charles spaniels with Chiari-like malformation, small breed dogs and Labradors.

OBJECTIVES: To ascertain whether cavalier King Charles spaniels (CKCSs) have a proportionately smaller caudal fossa compared with other small dogs and with Labradors. To evaluate if cerebellar herniation in CKCS correlates with caudal fossa volume. METHODS: In this retrospective study, three-dimensional images were created from magnetic resonance imaging brain series of 117 dogs (split into three groups: CKCS, Labradors and small breeds) from which the volumes of the fossae and brain parenchyma were calculated. These volumes were transformed into percentages of total cranial cavity and parenchyma volumes, respectively. The percentages were statistically compared among the groups. The percentage of herniated cerebellum in the CKCS was compared using linear regression with the caudal fossa and parenchyma percentages. RESULTS: Cavalier King Charles spaniels had a proportionately smaller caudal fossa compared with Labradors (P=0.002) but not to small breeds (P=0.103). Their caudal fossa parenchyma was proportionately the same volume as Labradors (P=0.976) but greater than small breeds (P=0.005). No relationship was found for the per cent of cerebellum herniated. CLINICAL SIGNIFICANCE: The results support mesoderm insufficiency or craniosynostosis as the pathogenesis of Chiari-like malformation (CM) in CKCS. It presents evidence for overcrowding of the caudal fossa due to a mismatch of brain parenchyma and fossa volumes as to why CKCS and not other small dogs are affected.

Surgical treatment of a canine intranasal meningoencephalocele.

OBJECTIVE: To report the clinical signs, diagnosis, and surgical treatment of an intranasal meningoencephalocele in a dog. STUDY DESIGN: Case report. ANIMAL: Female Border collie, 5 months old. METHODS: A right intranasal meningoencephalocele was identified by computed tomography and magnetic resonance imaging. RESULTS: The lesion was approached by a modified transfrontal craniotomy. Surgical closure of the defect at the level of the cribriform plate and removal of extruded brain tissue resulted in regression of lacrimation and coincided with absence of seizuring. Treatment with phenobarbital was gradually reduced and stopped at 7 months after surgery. At 28 months the dog remained free of seizures. CONCLUSION: Meningoencephalocele, although rare, can cause seizures in dogs and can be treated surgically. CLINICAL RELEVANCE: A transfrontal craniotomy with excision of the meningoencephalocele and closure of the defect can be an effective treatment for an intranasal meningoencephalocele in dogs.

[Two rare brain malformations in black and white German Holstein calves]. / Zwei seltene Gehirnmissbildungen bei schwarzbunten Kälbern der Rasse Deutsche Holstein.

Two black and white female German Holstein calves showed malformations of the cerebrum. The first calf exhibited a cystencephaly and the second calf a meningoencephalocele. The animals originated from two different dairy farms. Both calves were sired by two unrelated sires used in artificial insemination. The calf affected by cystencephaly was lacking the corpus callosum which may had been caused the cystencephaly. Exept for a pressure atrophy, the remaining parts of the brain were macroscopically and histologically inconspicious. Histological examination of the cerebrum, brain stem and cerebellum in the second calf did not reveal specific changes. A further finding in the second calf was a unilateral anophthalmia. Both animals were affected by additional defects in the spinal column including brachyuria, duplications and fusions of vertebral bodies and rips as well as malformations of the heart such as ventricular-septal defects. Only mild clinical symptoms could be observed in both calves. The calves were not inbred and further calves affected by the identical anomalies could not be ascertained at the farms where the calves were born. Chromosomal anomalies could not be detected after examination of metaphase spreads using light microscopy.

The relationship between clinical signs and brain herniation associated with rostrotentorial mass lesions in the dog.

Retrospective analysis of magnetic resonance imaging and clinical findings in a referral population of dogs was used to determine the relationship between rostrotentorial space-occupying lesions and the development of secondary neurological signs. Brain herniation was detected in 54/153 cases of uni-focal rostrotentorial space-occupying lesions; of these 30 had caudal transtentorial herniation (CTH) and 24 had both transtentorial and foramen magnum herniation (CTH/FMH). Masses associated with herniation were larger and situated more dorsally and caudally within the cranial vault. Clinical signs classically associated with CTH, e.g., oculomotor nerve palsy, were seen in only one case of isolated CTH and seven (14%) of all herniation cases. Deficits in caudal cranial nerve function were detectable in 39% of cases with FMH. We conclude that severe shifts in brain parenchyma can exist in the absence of detectable localising signs.

Ethmoidal encephalocoele associated with seizures in a puppy.

A six-month-old puppy was presented for investigation of a seizure disorder. Neurological examination indicated persistent cerebral dysfunction in the absence of any identifiable metabolic disorder and magnetic resonance imaging revealed extension of the rostral lobes of the cerebrum into the nasal cavity. Despite symptomatic treatment, the puppy continued to exhibit seizures and appeared distressed and so was euthanased. Postmortem examination confirmed the abnormal anatomy of the rostral part of the brain and absence of a cribriform plate. There was extensive grey and white matter degeneration plus intraparenchymal haemorrhage in the abnormal brain tissue. The findings are consistent with a diagnosis of ethmoldal encephalocoele--a condition that has not previously been reported in the dog.