Cranial cavity filled with cerebrospinal fluid in an otter (Lontra longicaudis) - case report / Cavitação craniana preenchida por fluido cerebroespinhal em lontra (Lontra longicaudis) - relato de caso

Computed tomography of the head of an otter with a history of incoordination, visual deficits, and seizures was performed. Intracranial images revealed a large non-enhancing fluid attenuating cystic lesion in the left frontoparietal region communicating with the left lateral ventricle and subarachnoid space. These findings are consistent with a congenital brain cavity filled by cerebrospinal fluid, with porencephaly being the most probable diagnosis based on the clinical and tomographic findings. The authors highlight the rarity of such a cystic lesion in wild animals, with this being the first report in otters.(AU)

Realizou-se o exame tomográfico do crânio de uma lontra com histórico de incoordenação, déficit visual e convulsões. Imagens intracranianas revelaram grande lesão cística não captante de contraste em região frontoparietal esquerda, apresentando comunicação com o ventrículo lateral esquerdo e espaço subaracnoidea. Esses achados foram consistentes com cavitação cerebral congênita preenchida por fluido cerebroespinhal, sendo porencefalia o diagnóstico de maior probabilidade com base nos achados clínicos e tomográficos. Destaca-se a raridade dessa condição em animais silvestres, sendo este o primeiro relato em lontras.(AU)

Porencephaly and Periventricular Encephalitis in a 4-month-old Puppy: Detection of Canine Parvovirus Type 2 and Potential Role in Brain Lesions.

A 4-month-old puppy died after showing intracranial signs a few days after a suspected viral enteritis. Grossly, the right cerebral hemisphere had a large irregular cavity external to the internal capsule. Histopathological examination revealed a cystic lesion in the right hemisphere and non-suppurative inflammation of the diencephalon and periaqueductal nervous tissue. Porencephaly associated with periventricular non-suppurative encephalitis was diagnosed. A nested polymerase chain reaction (PCR) identified the presence of parvovirus DNA in the brain and real-time PCR typed this as canine parvovirus (CPV) type 2a. Immunohistochemistry revealed the presence of CPV antigen in the cytoplasm of scattered cells in the subependymal layers and choroid plexus epithelium. The porencephaly was not associated with inflammatory lesions or CPV antigen and was considered to have preceded the neurological signs. In contrast, the detection of CPV antigen in the subependymal layers and choroid plexus epithelium supported the association of this virus with the periventricular encephalitis.

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.

Porencephaly in a fennec fox (Vulpes zerda).

A postmortem examination revealed a large brain cavity in the right cerebral hemisphere of a 9-year-old male fennec (Vulpes zerda). The cavity was filled with cerebrospinal fluid and extended to the right lateral ventricle. Swelling and displacement of the right hippocampal area were also observed. Histologic examination revealed no evidence of previous infarct lesions, hemorrhage, inflammation or invasive tumor cells. Observation of the defective part suggested a local circulatory disorder during the fetal stage, although the cause was not detected. No neurological symptoms that could enable a provisional diagnosis were observed during the course of his life. This is the first report of asymptomatic porencephaly in a fennec fox.

Porencephaly in dogs and cats: relationships between magnetic resonance imaging (MRI) features and hippocampal atrophy.

Porencephaly is the congenital cerebral defect and a rare malformation and described few MRI reports in veterinary medicine. MRI features of porencephaly are recognized the coexistence with the unilateral/bilateral hippocampal atrophy, caused by the seizure symptoms in human medicine. We studied 2 dogs and 1 cat with congenital porencephaly to characterize the clinical signs and MRI, and to discuss the associated MRI with hippocampal atrophy. The main clinical sign was the seizure symptoms, and all had hippocampal atrophy at the lesion side or the larger defect side. There is association between hippocampal atrophy or the cyst volume and the severe of clinical signs, and it is suggested that porencephaly coexists with hippocampal atrophy as well as humans in this study.

[Porencephaly in a female Greater Swiss Mountain Dog]. / Porenzephalie bei einer Großen Schweizer Sennenhündin.

A 15-month-old female Greater Swiss Mountain Dog was presented after an epileptic episode. In addition, the owner had noticed a recent marked change in the animal's behaviour. Because of the progressive nature of the neurological signs, a magnetic resonance imaging scan of the brain was performed and porencephaly in the parietal lobe of the right hemisphere was diagnosed. The dog was euthanized and submitted for pathology. Because of the histopathological findings and the history of a craniocerebral injury whilst a puppy, a traumatic genesis of this rare cystic lesion is discussed.