First occurrence of Arnold Chiari type II malformation and associated abnormalities in a Gir calf produced in vitro from Brazil - case report

H.S Toma,L.F.C Cunha Filho,C.D.M Toma,S.F.N Pertile,L.S Cabral,T.C.P Munhoz,J.V.P Barreto,A.M Amude,A.M Carvalho

doi:10.1590/1678-4162-12351

Abstract

ABSTRACT This study characterized the clinical, radiological, ultrasound, and necroscopic findings of a case of Arnold-Chiari type II malformation in a Gir breed calf from Brazil. The animal was hospitalized at sixty days of age, in permanent sternal recumbency, cutaneous appendix at the 4th lumbar vertebra and kyphoscoliosis of the caudal and lumbosacral thoracic spine. Radiographic examination of the spine and skull revealed spina bifida and suspected occipital hypoplasia. Upon examination of myelography with an injection of lumbar and atlantooccipital contrast, it was possible to visualize the meningocele at the 4th lumbar vertebra region and findings at the rhombencephalon level of increased regional pressure with failure to fill the contrast in the posterior fossa, in the presence of clear demarcation of the circumvolutions of the cerebral cortex and the subarachnoid space of the cervical spinal cord. Ultrasonographic examination of the cerebellum showed an insinuation of the cerebellar worm through the foramen magnum. The animal did not show changes in complete blood count, biochemical series, and cerebrospinal fluid and was negative for Pestivirus. There was a worsening of the clinical conditions and the animal died. This malformation of unknown etiology must be studied as a differential diagnosis of the nervous system disorders.

Highlights

Arnold-Chiari malformation is a very rare anomaly characterized by occipital bone hypoplasia and rhombencephalon complications such as herniation of the cerebellar vermis and caudal brain stem through the foramen magnum (Cho and Leipold, 1977)
John Cleland made the first description of a congenital malformation of the brain and cerebellum with herniation through the foramen magnum in 1833, and only in 1891, Hans Von Chiari characterized the malformation, which was named by Júlio Arnold in 1894 as Arnold-Chiari malformation (Aranda et al, 2011)
Herniation of the cerebellum through the foramen magnum was observed in ultrasound of the atlantooccipital joint

Summary

Introduction

Arnold-Chiari malformation is a very rare anomaly characterized by occipital bone hypoplasia and rhombencephalon complications such as herniation of the cerebellar vermis and caudal brain stem through the foramen magnum (Cho and Leipold, 1977). In calves, it is bilateral, symmetrical, and may occur simultaneously to spina bifida, meningomyelocele, hydrocephalus, syringomyelia (Loughin, 2016), arthrogryposis, lumbar kyphoscoliosis and cleft lip (Gülbahar et al, 2005). The Arnold-Chiari malformation is the result of abnormal embryonic development of neural tissue and bone structures (Cho and Leipold, 1977; Madarame et al, 1993; Gülbahar et al, 2005), the malformation of the skull base, and the enlargement of the foramen magnum are common (LeClerc et al, 1997).

Objectives

Methods

Findings

Conclusion