Department of clinical sciences, Faculty of veterinary medicine, Université de Montréal, Saint-Hyacinthe, QC, J2S 2M2, Canada.
Department of pathology and microbiology, Faculty of veterinary medicine, Université de Montréal, Saint-Hyacinthe, QC, J2S 2M2, Canada.
BMC Vet Res. 2024 Jun 19;20(1):263. doi: 10.1186/s12917-024-04127-3.
Neurological inherited disorders are rare in domestic animals. Cerebellar cortical degeneration remains amongst the most common of these disorders. The condition is defined as the premature loss of fully differentiated cerebellar components due to genetic or metabolic defects. It has been studied in dogs and cats, and various genetic defects and diagnostic tests (including magnetic resonance imaging (MRI)) have been refined in these species. Cases in cats remain rare and mostly individual, and few diagnostic criteria, other than post-mortem exam, have been evaluated in reports with multiple cases. Here, we report three feline cases of cerebellar cortical degeneration with detailed clinical, diagnostic imaging and post-mortem findings.
The three cases were directly (siblings, case #1 and #2) or indirectly related (same farm, case #3) and showed early-onset of the disease, with clinical signs including cerebellar ataxia and tremors. Brain MRI was highly suggestive of cerebellar cortical degeneration on all three cases. The relative cerebrospinal fluid (CSF) space, relative cerebellum size, brainstem: cerebellum area ratio, and cerebellum: total brain area ratio, were measured and compared to a control group of cats and reference cut-offs for dogs in the literature. For the relative cerebellum size and cerebellum: total brain area ratio, all affected cases had a lower value than the control group. For the relative CSF space and brainstem: cerebellum area ratio, the more affected cases (#2 and #3) had higher values than the control group, while the least affected case (#3) had values within the ranges of the control group, but a progression was visible over time. Post-mortem examination confirmed the diagnosis of cerebellar cortical degeneration, with marked to complete loss of Purkinje cells and associated granular layer depletion and proliferation of Bergmann glia. One case also had Wallerian-like degeneration in the spinal cord, suggestive of spinocerebellar degeneration.
Our report further supports a potential genetic component for the disease in cats. For the MRI examination, the relative cerebellum size and cerebellum: total brain area ratio seem promising, but further studies are needed to establish specific feline cut-offs. Post-mortem evaluation of the cerebellum remains the gold standard for the final diagnosis.
神经遗传性疾病在宠物中较为罕见。小脑皮质变性是此类疾病中最常见的一种。该疾病是指由于遗传或代谢缺陷，完全分化的小脑成分过早丧失。在犬和猫中对其进行了研究，并且在这些物种中已经对各种遗传缺陷和诊断测试（包括磁共振成像（MRI））进行了改进。猫科动物的病例仍然很少且多为个体病例，并且在具有多个病例的报告中，除了尸检之外，很少有诊断标准得到评估。在这里，我们报告了三例具有详细临床，诊断成像和死后发现的猫小脑皮质变性病例。
这三个病例直接（兄弟姐妹，病例#1和#2）或间接（同一农场，病例#3）相关，并且具有疾病的早期发作，临床症状包括小脑共济失调和震颤。脑部 MRI 在所有三个病例中均高度提示小脑皮质变性。相对脑脊髓液（CSF）空间，相对小脑大小，脑干：小脑区域比以及小脑：大脑总区域比，均进行了测量，并与猫的对照组和文献中犬的参考截止值进行了比较。对于相对小脑大小和小脑：大脑总区域比，所有受影响的病例的值均低于对照组。对于相对 CSF 空间和脑干：小脑区域比，受影响更严重的病例（#2 和#3）的值高于对照组，而受影响最小的病例（#3）的值在对照组范围内，但随着时间的推移，可见到进展。尸检证实了小脑皮质变性的诊断，出现明显至完全丧失浦肯野细胞以及相关的颗粒层耗竭和伯格曼神经胶质增生。一例脊髓中还出现了华勒氏样变性，提示脊髓小脑变性。
我们的报告进一步支持了猫科动物小脑皮质变性的潜在遗传因素。对于 MRI 检查，相对小脑大小和小脑：大脑总区域比似乎很有前途，但是需要进一步的研究来建立特定的猫科动物截止值。对小脑进行死后评估仍然是最终诊断的金标准。
