Penderis J, McConnell JF, Calvin J.
THIAMINE (as thiamine pyrophosphate) is important in carbohydrate and amino acid metabolism, forming an essential component of 2-oxoacid dehydrogenases (includ- ing pyruvate dehydrogenase and branched chain oxoacid dehydrogenase) and transketolase. Thiamine deficiency causes a progressive encephalopathy in human beings and animals, and experimental and natural neuropathological studies have revealed selective vulnerability is most likely due to focal energy derangement, lactic acidosis, and/or the release of glutamate (Hazell and others 1998). In carnivores, the predominant neuropathology is bilaterally symmetrical petechial haemorrhages, which consistently affect the caudal colliculi and variably involve the lateral geniculate, medial vestibular, oculomotor, habenular and other brainstem nuclei and periaqueductal grey matter (Jubb and others 1956, Loew and others 1970, Read and others 1977, Read and Harrington 1986, Okada and others 1987, Studdert and Labuc 1991). The magnetic resonance imaging (MRI) features in human patients correlate closely with the neuropathological findings (Suzuki and others 1996), and include symmetrical hyper- intense diencephalic and midbrain lesions on T2-weighted images (Victor 1990, Galluci and others 1990, Watson and others 2003, Weidauer and others 2003). The MRI features have been reported in one dog (Garosi and others 2003), but not in cats. In the dog, MRI changes were present in the red nuclei, caudal, colliculi, vestibular nuclei and cerebellar nodulus, but not the lateral geniculate or facial nuclei. This short communication describes the MRI findings in a cat with thiamine deficiency.