Clinical and MRI findings of hemorrhagic infarcts in two cats with positive outcomes

Abstract

Case series summary: A 1.5-year-old male neutered domestic shorthair cat presented with an acute onset of lethargy and difficulty jumping. Prior medical history included a restrictive perimembranous ventricular septal defect and mild mitral regurgitation. Neurologic examination showed left hemiparesis and absent menace in the left eye. MRI revealed a lesion in the right frontal lobe and caudate nucleus with intralesional hemorrhage and restricted diffusion consistent with hemorrhagic infarct. A 6-year-old male neutered domestic shorthair cat presented with three neurologic episodes over 3 months, one consisting of circling to the right, absent menace in the right eye and right-sided postural reaction deficits, and the other two consisting of vestibular signs. MRI revealed a chronic hemorrhagic infarct of the left caudate nucleus. Both cats demonstrated favorable recovery, with cat 2 experiencing a fourth event 9 months after MRI.

Relevance and novel information: This case series details the first two cases of feline hemorrhagic infarct with ante-mortem diagnosis, MRI findings and recovery with a good long-term outcome. Hemorrhagic infarcts, uncommonly reported in companion animals, are a subtype of stroke involving hemorrhage resulting from reperfusion or collateral circulation into an ischemic area of brain tissue. This report discusses typical MRI findings in humans, including differentiation from intracerebral hemorrhage, and the potential role of comorbidities on the development and outcome of hemorrhagic infarcts in cats.

Keywords: Hemorrhagic infarct; MRI; brain; cerebral hemorrhage; hemorrhagic transformation; stroke.

Figure 1

Hemorrhagic infarct (arrows) within the right frontal lobe and caudate nucleus of cat 1. Left caudate nucleus (asterisk) is identified for anatomic reference. (a) Transverse T2-weighted fast-spin echo (T2W) image reveals a hyperintense lesion with a central area of isointensity (arrowhead). (b) Transverse T2*-weighted angiography image shows a large susceptibility artifact consistent with hemorrhage. (c) Transverse T1-weighted fast-spin echo (T1W) image shows the lesion is primarily isointense but with foci of hyperintensity (arrowhead). The lesion is mild to moderately, heterogeneously contrast enhancing with a faint ring enhancement pattern on (d) T1W post-contrast imaging. The lesion is hyperintense on (e) diffusion-weighted imaging with (f) reduced apparent diffusion coefficient values indicating restricted diffusion typical of an infarct

Figure 2

Chronic hemorrhagic infarct (arrows) within the left caudate nucleus, which is smaller than the right caudate nucleus (asterisk) and associated with an enlarged left lateral ventricle (arrowheads). (a) Transverse T2-weighted fast-spin echo and (b) fluid-attenuated inversion recovery images reveal a lesion that is primarily isointense with a hyperintense rim. (c) Transverse T2*-weighted angiography image shows a susceptibility artifact consistent with hemorrhage. (d) The lesion demonstrates moderate contrast enhancement on T1-weighted fast-spin echo post-contrast imaging. The lesion is not visible on (e) diffusion-weighted imaging or (f) apparent diffusion coefficient map