Putamina involvement in Wernicke encephalopathy induced by Janus Kinase 2 inhibitor

The aim of the study was to report a case of Wernicke encephalopathy (WE) due to fedratinib (Janus Kinase 2 inhibitor) treatment with atypical neuroimaging findings. We present a detailed report of the case and literature review. A 68-year-old woman under treatment with fedratinib (investigational JAK2 inhibitor) developed memory impairment, diplopia, and ataxia compatible with WE. Brain magnetic resonance imaging showed extensive lesions involving medial thalami, periaqueductal gray, caudate nuclei, and putamina. Thiamine supplementation provided clinical recovery and radiological improvement of the lesions described. Basal ganglia lesions have been previously described in children with this disease, but this is rarely found in adults. Clinical trials including fedratinib have been recently discontinued, and its involvement in pathogenesis of WE may be related to thiamine-transporter inhibition. Our case represents an example of drug-related WE, with a rare radiological pattern. Precocious diagnosis and treatment are essential to prevent irreversible brain injury.