Diagnosis and management of Whipple's disease of the brain.

Whipple's disease of the brain is one of the most challenging neurological diagnoses. "Is it Whipple's disease?" is a frequent question, but rarely is the answer yes. The neurological manifestations do not help to distinguish primary from secondary Whipple's disease of the brain, and although MR brain scanning with gadolinium is mandatory, it can be normal and any abnormalities are non-specific. There must be a comprehensive search for multisystem involvement such as raised inflammatory markers, lymphadenopathy or malabsorption; biopsy of lymph node or duodenum may be necessary. PCR and DNA sequencing for Tropheryma whipplei on lymphocytes from blood and cerebrospinal fluid is essential. Treatment is as difficult as the diagnosis-there are no randomised controlled trials.