Limbic encephalitis with relapsing polychondritis: persistent white matter lesions and brain atrophy.

Relapsing polychondritis (RP) is a rare autoimmune disorder affecting cartilage. Limbic encephalitis is a rare central nervous system manifestation of RP. This current case report describes a 66-year-old Chinese male patient who complained of developing myoclonus in the left leg, ataxia and speech difficulties 3 weeks prior to hospital admission. The patient presented with cognitive impairment, sleep disorder and extrapyramidal symptoms. The patient was diagnosed with RP that affected auricular cartilage, which also manifested as limbic encephalitis. Magnetic resonance imaging showed bilateral temporal lobe lesions involving the hippocampi and basal ganglia. Signal abnormalities in the white matter persisted during the 15-month follow-up period after treatment with corticosteroids and intravenous immunoglobulin. Over the same period, the bilateral hippocampi showed significant atrophy.