Case report: simultaneous occurrence of multifocal cortical hypoplasia and degeneration in the cerebellum and systematic cerebrovascular intimal fibroelastosis in a calf

Abstract

The etiology of cerebellar hypoplasia is often uncertain in one litter or single animals. A spontaneous case of cerebellar cortical hypoplasia and degeneration with a topographic difference in the involvement of lesions is herein described in a 6-month-old female Japanese Shorthorn calf with a history of neurologic signs beginning at birth. The calf was euthanatized because of unfavorable prognosis. The most significant gross lesions were present in the cerebellum, where the cerebellar folia of the vermis and flocculonodular lobe were smaller in size than normal. Upon histopathologic examination of the cerebellum, the whole rostral vermis, some lobules of the caudal vermis, and the whole flocculonodular lobe displayed bilaterally symmetric cortical hypoplasia characterized by narrowing of the molecular layer, absence of Purkinje cells, and hypocellularity of the granular layer. Additional intracerebellar findings consisted of a varying degree of Purkinje cell loss leaving empty baskets in some folia of the well-developed lobules at the caudal vermis and the presence of areas displaying bilateral myelin deficiency in association with spongy vacuolar changes in the deep cerebellar nuclei. Other significant findings included an ischemic cell change of the cerebrocortical pyramidal neurons in the Sylvian gyrus of the left parietal lobe and systematic intimal fibroelastic hyperplasia similar to arterio(lo)sclerosis in the cerebral and cerebellar blood vessels. These histopathologic evidences raise one possibility that a putative chronic hypoxemia due to systematic cerebrovascular alteration might have been implicated in the development of multifocal cerebellar cortical hypoplasia and degeneration in this calf, though final affirmation of this notion should await further investigations of similar or identical cases.