We report the case of a 69-year-old man with a 7-month history of severe progressive supranuclear gaze palsy associated with mild cognitive decline and sleep disturbances, but not parkinsonism. After a period spent consulting a range of different specialists, the appearance of brachial myoclonus prompted his referral to a movement disorders specialist. Duodenum biopsy confirmed the suspicion of neuro-Whipple disease. Antibiotic therapy was started but the delay in the diagnosis proved fatal to this patient. This noteworthy case shows unusual neurological features of a rare but treatable disease, often misdiagnosed as progressive supranuclear palsy.