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Two 1-day-old full-term female calves from different farms located in the Brazilian state of Rio Grande do Sul were unable to stand due to paresis of the pelvic limbs. Both calves had spina bifida on the spinal lumbar segment and were submitted to euthanasia due to poor prognosis. Postmortem examination revealed cerebellar herniation, caudal displacement of the brainstem, rostral deviation of the cranial nerves, caudal extension of occipital lobes, absence of dorsal lamina of lumbar vertebrae with exposed spinal cord, myelodysplasia, kyphosis, segmental spinal agenesis, renal fusion, muscular atrophy, and arthrogryposis. Histology highlighted myelodysplasia (syringomyelia and diplomyelia) and muscular atrophy. The reverse transcription-polymerase chain reactions for ruminant pestivirus were negative. Based on these lesions, the diagnosis of complex neural tube and skeletal malformations was made. A review of previous publications on calves diagnosed with these malformations, originally called Chiari or Arnold-Chiari malformations, revealed a wide range of nervous system and skeletal lesions. These variations amplified the uncertainty regarding whether all cases represent the same disorder and reinforced the importance of reconfiguring the terminology.

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Neuroectodermal developmental anomalies are reported rarely in cetaceans and central nervous system cysts are not described. We describe the gross, microscopical, histochemical and immunohistochemical features of a neuraxial myelencephalic cyst in a stranded neonatal Burmeister's porpoise (Phocoena spinipinnis). Grossly, a subdural, extra-axial, well-demarcated, yellow fluid-filled cystic structure (1.9 × 1.6 × 1 cm) expanded the left foramen of Luschka, the left caudolateral cerebellar recess and the left cranioventral myelencephalon. The cyst displaced the ipsilateral ventral paraflocculus and distended the underlying cranial nerves IX, X, XI and XII. Microscopically, the cystic structure was lined by a monolayer of low cuboidal to flattened epithelium supported by a thin fibrovascular matrix. Immunohistochemistry (IHC) revealed strong and diffuse expression of AE1/AE3 and focal positivity for vimentin. IHC for epithelial membrane antigen, glial fibrillary acid protein, synaptophysin and S100 was negative. Based on these findings, an extra-axial cyst of the choroid plexus of the fourth ventricle (CCPFV) was diagnosed. The pathological relevance of the CCPFV in this case is uncertain. The cause of death involved severe perinatal interspecific (shark) trauma. The present case provides the first evidence of a neuroepithelial cyst in cetacean species.

anomalias de desenvolvimento neuroectodérmicas são raramente relatadas em cetáceos e cistos do sistema nervoso central não são descritos. Descrevemos as características macroscópicas, microscópicas, histoquímicas e imuno-histoquímicas de um cisto mielencefálico neuroaxial em uma toninha de Burmeister neonatal encalhada (Phocoena spinipinnis). Grosso modo, uma estrutura cística amarela subdural, extra-axial, bem demarcada e cheia de líquido (1,9 × 1,6 × 1 cm) expandiu o forame esquerdo de Luschka, o recesso cerebelar caudolateral esquerdo e o mielencéfalo cranioventral esquerdo. O cisto deslocou o paraflóculo ventral ipsilateral e distendeu os nervos cranianos subjacentes IX, X, XI e XII. Microscopicamente, a estrutura cística foi revestida por uma monocamada de epitélio cubóide a achatado baixo, suportada por uma fina matriz fibrovascular. A imuno-histoquímica (IHC) revelou forte e difusa expressão de AE1 / AE3 e positividade focal para vimentina. O IHC para antígeno da membrana epitelial, proteína do ácido fibrilar glial, sinafofisina e S100 foi negativo. Com base nesses achados, foi diagnosticado um cisto extra-axial do plexo coróide do quarto ventrículo (CCPFV). A relevância patológica do CCPFV neste caso é incerta. A causa da morte envolveu traumatismo interespecífico (tubarão) perinatal grave. O presente caso fornece a primeira evidência de um cisto neuroepitelial em espécies de cetáceos. patologia cetáceo Anomalia congenita neuroectoderma

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Background: The nervous system is one of the most affected by congenital malformations. These can occur during neural tube formation or failed neurogenesis. Segmental spinal cord hypoplasia commonly involves two or three spinal segments in the thoracolumbar region. It is characterized by incomplete formation of the spinal cord and may also be followed by spine column malformations. Clinical signs usually include functional impairment of the hindlimbs. Diagnosis is based on history, clinical signs, age, radiographs and is confi rmed with necropsy and histopathological fi ndings. There is no treatment for this condition and the animals present low life quality. This paper aims to report the clinical, radiographic and histopathological aspects of multiple segmental spinal cord hypoplasia in a domestic cat. Case: A 52-days-old, female, Persian breed, domestic cat weighing 0.55 kg was treated presenting a history of pelvic limb paraplegia associated with urinary and fecal incontinence since birth. On clinical examination there were fl accid paraplegia of hind limbs associated with absence of proprioception, anal refl ex and tone and postural defi cits. Also, all spinal refl exes of pelvic limbs and deep and superfi cial pain were absent. There was no clinical history of muscular tremors, nystagmus, seizures or other central nervous system signs. The other animals of the litter showed...(AU)

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Background: The nervous system is one of the most affected by congenital malformations. These can occur during neural tube formation or failed neurogenesis. Segmental spinal cord hypoplasia commonly involves two or three spinal segments in the thoracolumbar region. It is characterized by incomplete formation of the spinal cord and may also be followed by spine column malformations. Clinical signs usually include functional impairment of the hindlimbs. Diagnosis is based on history, clinical signs, age, radiographs and is confi rmed with necropsy and histopathological fi ndings. There is no treatment for this condition and the animals present low life quality. This paper aims to report the clinical, radiographic and histopathological aspects of multiple segmental spinal cord hypoplasia in a domestic cat. Case: A 52-days-old, female, Persian breed, domestic cat weighing 0.55 kg was treated presenting a history of pelvic limb paraplegia associated with urinary and fecal incontinence since birth. On clinical examination there were fl accid paraplegia of hind limbs associated with absence of proprioception, anal refl ex and tone and postural defi cits. Also, all spinal refl exes of pelvic limbs and deep and superfi cial pain were absent. There was no clinical history of muscular tremors, nystagmus, seizures or other central nervous system signs. The other animals of the litter showed...

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Relata-se o caso de uma gata Siamês de seis meses de idade que desde o nascimento apresentava paraplegia espástica associada à incontinência fecal e urinária. No exame neurológico, exibia paralisia, analgesia, hiperreflexia e perda das reaçöes posturais nos membros posteriores. Radiografias simples e contrastadas (mielografia) da coluna vertebral toracolombar evidenciaram estreitamentos do canal vertebral na regiäo lombar e da medula espinhal, vértebras torácicas e lombares. Na necropsia e exame histopatológico, verificou-se hipoplasia segmentar caracterizada pelo afinamento localizado da medula espinhal em T4-T6 e L2-L3, depleçäo neuronal na substância cinzenta e filetes nervosos interligando as partes craniais e caudais, todos recobertos por dura mater íntegra e espessada. Essas alteraçöes permitiram concluir o diagnóstico de mielodisplasia segmentar múltipla.

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