Cavernous sinus syndrome secondary to intracranial lymphoma in a cat

Abstract

Cavernous sinus syndrome is characterised by internal and external ophthalmoplegia and sensory deficits over the head due to combined deficits of the three cranial nerves (CNs) responsible for the eye movements and pupil function (CN III, IV, VI) and at least one branch of the trigeminal nerve (CN V). It has rarely been described in cats and may occur secondarily to inflammatory, infectious or neoplastic lesions within the region of the cavernous sinus on the ventral aspect of the calvarium. This report describes the clinical and magnetic resonance imaging findings in a 14-year-old domestic shorthair cat with neurological deficits compatible with cavernous sinus syndrome caused by presumptive extranodal lymphoma. Treatment with chemotherapy resulted in clinical and imaging remission. Identification of the neurological deficits in cavernous sinus syndrome allows accurate neuroanatomical localisation in order to target diagnostic imaging studies.

Figure 1

Anisocoria in a 14-year-old domestic shorthair cat, with mydriasis in the right eye. In addition to the lesion affecting the right pupil, the affected right eye also demonstrated external ophthalmoplegia (paralysis of the extraocular muscles). The normal left eye was able to look straight ahead (a), deviate the gaze to the right (b) and deviate the gaze to the left (c), but in all instances the cat was unable to deviate the affected right eye

Figure 2

Post-contrast T1-weighted MR images before (a,b) and 6 weeks after (c,d) initiation of treatment with the University of Wisconsin–Madison lymphoma chemotherapy protocol in the sagittal (a,c) and transverse (b,d) planes. There is a contrast-enhancing mass lesion in the region of the pituitary gland (arrowed) in (a) and (b). In the post-treatment images (c,d) there is resolution of the mass lesion