Clinical, MRI, and histopathological findings of congenital focal diplomyelia at the level of L4 in a female crossbred calf

Abstract

Background This case report describes the clinical signs of a calf with focal diplomyelia at the level of the fourth lumbar vertebra. Magnetic resonance imaging (MRI) images and histological findings of the affected spinal cord are included in this case report. This case differs from previously reported cases in terms of localization and minimal extent of the congenital anomaly, clinical symptoms and findings during further examinations. Case presentation The calf was presented to the Farm Animal Health clinic, Faculty of Veterinary Medicine, Utrecht University, with an abnormal, stiff, ‘bunny-hop’ gait of the pelvic limbs. Prominent clinical findings included general proprioceptive ataxia with paraparesis, pathological spinal reflexes of the pelvic limbs and pollakiuria. MRI revealed a focal dilated central canal, and mid-sagittal T2 hyperintense band in the dorsal part of the spinal cord at the level of the third to fourth lumbar vertebra. By means of histology, the calf was diagnosed with focal diplomyelia at the level of the fourth lumbar vertebra, a rare congenital malformation of the spinal cord. The calf tested positive for Schmallenberg virus antibodies, however this is not considered to be part of the pathogenesis of the diplomyelia. Conclusions This case report adds value to future clinical practice, as it provides a clear description of focal diplomyelia as a previously unreported lesion and details its diagnosis using advanced imaging and histology. This type of lesion should be included in the differential diagnoses when a calf is presented with a general proprioceptive ataxia of the hind limbs. In particular, a ‘bunny-hop’ gait of the pelvic limbs is thought to be a specific clinical symptom of diplomyelia. This case report is of clinical and scientific importance as it demonstrates the possibility of a focal microscopic diplomyelia, which would not be evident by gross examination alone, as a cause of hind-limb ataxia. The aetiology of diplomyelia in calves remains unclear.

Case Report: Complex Congenital Brain Anomaly in a BBxHF Calf–Clinical Signs, Magnetic Resonance Imaging, and Pathological Findings

“…Serological tests for both BVDV antigen and antibodies were performed, and antibodies for BVDV were found at 40 days of age. The presence of antibodies can be explained through either colostrum-derived antibodies (transient infection or vaccination of the dam), a transient infection of the calf, or an intra-uterine infection between 75 and 170 days of gestation ( 7 ). The farm this calf originated from employed vaccination prevention strategies for BVDV for over 25 years and bovids that have been vaccinated can develop titers which can lead to the detection of these maternal antibodies in their calves.…”

“…Several bovine congenital anomalies related to viral infections, such as exencephaly, hydrocephalus, meningoencephaloceles, and diplomyelia have been characterized post-mortem ( 2 , 4 – 6 ). Magnetic resonance imaging (MRI) is the preferred diagnostic imaging modality to visualize and evaluate structures of the CNS and has been used to detect CNS anomalies in bovids ( 6 , 7 ). The normal MRI neuroanatomy of calves has been described in Schmid et al ( 8 ).…”

Congenital syringohydromyelia in a crossbred (Holstein-Friesian × Japanese Black) beef calf

“…Therefore, syringohydromyelia is used as an umbrella term of hydromyelia and syringomyelia [1,19]. Hydromyelia, syringomyelia, and syringohydromyelia frequently occur together with skeletal deformities [6,13], arthrogryposis [9], Arnold-Chiari malformations [3], and other myelodysplasias such as diplomyelia, diastematomyelia, hypoplasia, and aplasia [4,7,8,10,11,13,[15][16][17][21][22][23]. Hydromyelia, syringomyelia, and syringohydromyelia have previously been reported in Holstein, Japanese Black, Charolais, Brown Swiss, Tudanca, Simmental, and Brahman-crossed calves [1, 2, 4, 7-11, 15-17, 21].…”

“…In addition to MRI scans [7,13,16,23], ultrasonographic diagnosis of syringohydromyelia, diplomyelia, and hypoplasia from intervertebral spaces have been reported [21,22]. We attempted to initially diagnose the calf by ultrasonography prior to CT and MRI scans.…”

“…To date, calves exhibiting a hopping gait with hydromyelia, or syringohydromyelia, have shown involvement of the lumbar or lumbosacral spinal cord [2][3][4]8]. Hopping gait, however, has also been reported in calves with diplomyelia, syringomyelia, myelodysplasia, hypoplasia, or aplasia, with involvement of the L1-S2 spinal segments [1,4,8,23]; this is considered to occur due to a malfunction of the central pattern generator network of the pelvic limbs within the lumbar intumescence [4]. The most focally affected area in calves with a hopping gait is the L5 spinal segment [8].…”