Relapsing polychondritis is a generalised disorder characterised by recurrent inflammation of cartilaginous structures throughout the body, without recognised collagen disease or infectious disorders. Central nervous system involvement is rarely reported in this disorder. We describe the cases of two patients with relapsing polychondritis who presented with severe memory impairment and psychiatric features such as euphoria and hyperactive behaviours, leading to a diagnosis of non-herpetic limbic encephalitis.

Limbic encephalitis is caused by the herpes simplex virus (HSV) or by heterogeneous non-herpetic disorders (non-herpetic viruses, Hashimoto’s encephalopathy, central nervous system lupus, gliomatosis cerebri, intravascular malignant lymphomatosis, and paraneoplastic conditions). Clinical characteristics include cognitive dysfunction, severe memory impairment, seizures, depression, anxiety, and hallucinations. Magnetic resonance imaging (MRI) studies reveal selective unilateral or bilateral involvement of the limbic system, particularly the medial temporal lobe regions.

Our first patient was a 45 year old man referred to us because of subacute progressive mental confusion, euphoria, hyperactive behaviour, disorientation, and forgetfulness of recent episodes. He had a history of right sided conjunctivitis successfully treated with steroid and antibiotic ointment, shoulder stiffness, headache, low grade fever, and recent weight loss (6 kg).

On admission, the patient was disoriented, with an inappropriately jocular affect, disjointed speech, confabulation, attention deficits, and memory impairment including anterograde and 1 year retrograde amnesia. His Mini Mental Status Examination (MMSE) score was 11 (of a possible 30). He had no …