Suspected pontine and extra‐pontine myelinolysis in a cat

Abstract

A 4.5‐year‐old neutered female domestic shorthair cat was presented with an acute onset of neurological signs suggestive of multifocal or diffuse intracranial lesions. MRI of the head revealed bilaterally symmetrical T2‐weighted hyperintensities in the pons and thalamus, suggestive of a metabolic or toxic aetiology. The pontine lesion on MRI resembled what in humans is known as the ‘trident sign’ reported in cases of pontine myelinolysis. Ancillary cerebrospinal fluid analysis revealed albuminocytologic dissociation and suspected myelin debris. No specific cause was identified, but the cat recovered over the next few weeks with only supportive therapy.

Diagnosis of post-attenuation neurological signs syndrome in a cat with refractory status epilepticus and clinical response to therapeutic plasma exchange

“…The bilateral symmetrical areas of increased T2 signal intensity in the lateral geniculate nuclei, tegmental reticular formation and pons appear particularly similar to those lesions previously reported in a suspect case of pontine and extrapontine myelinolysis in a cat. 10 Similar findings have also been described in a dog diagnosed with experimentally induced pontine myelinolysis 4 days after correction of the hypernatraemia and in a dog with experimentally induced hyponatraemia. 5,16 Pontine and extrapontine myelinolysis, referred to as osmotic demyelination syndrome (ODS), is associated with severe and acute neurological signs, and has been described as a fatal complication in humans after liver transplantation.…”

“…The bilateral changes in the pons mirror recently reported changes in suspected osmolar myelinolysis. 10 Additionally, concomitant postictal cortical brain oedema or early-stage laminar cortical necrosis were considered the most plausible cause of the occipital lobe bilateral T2W hyperintensities. The T1 hyperintensities at the lentiform nuclei were compatible with manganese deposition and were considered to be residual from the PSS.…”