Whipple disease is a chronic multisystem disorder caused by the bacterium Tropheryma whippeli. Between 70-80% of cases have positive CSF PCR. Whipple disease is most commonly seen in middle-aged white men, with a mean age at onset of 50 years. 5% of patients present with CNS symptoms.
Lesions tend to cluster in the thalami, hypothalamus, quadrigeminal plate, periaqueductal gray matter, and medial temporal lobes. These lesions are T2 hyperintense and display mild enhancement. The lesions usually do not restrict on diffusion sequences.