An Unusual Case of Limbic Encephalitis Caused by Whipple Disease.

Whipple disease (WD), a multisystemic infectious disorder caused by Tropheryma whipplei (T. whipplei), typically presents with gastrointestinal (GI) symptoms such as abdominal pain, diarrhea, GI bleeding, and weight loss. Uncommonly, it can also involve the central nervous system (CNS) and may present with a range of symptoms, including personality changes, dementia, and rhombencephalitis. Prompt antibiotic treatment and careful follow-up are crucial for favorable patient outcomes and a reduction in morbidity and mortality. In this case, we describe a 46-year-old male with primary CNS-WD and discuss the symptomatic manifestations, diagnostic findings, differential diagnosis, and management. This patient initially presented with arthritic complaints and, over a five-year period, developed progressive neurocognitive symptoms, including anxiety, panic attacks, retrograde amnesia, personality changes, aphasia, anhedonia, dysarthria, and rapidly progressive dementia. Magnetic resonance imaging (MRI) revealed symmetric T2 fluid-attenuated inversion recovery (FLAIR) hyperintensities in the bilateral medial temporal lobes, hippocampi, and hypothalamus. A lumbar puncture (LP) showed mild pleocytosis and elevated protein, with no autoimmune or paraneoplastic causes. Temporal lobe biopsy revealed rod-like structures, and T. whipplei DNA was confirmed by polymerase chain reaction (PCR). This case underscores the importance of maintaining a high index of suspicion for WD in patients presenting with atypical symptoms with rapidly progressive dementia, as early detection and management are key to circumventing irreversible neurological damage and death.