Seronegative limbic encephalitis: case report, literature review and proposed treatment algorithm

Non-infective, antibody-negative limbic encephalitis presents a diagnostic and therapeutic challenge. The treatment aims to minimise the functionally devastating and irreversible cognitive impairment. An illustrative case history and review of the literature are presented and a management algorithm proposed. Limbic encephalitis (LE) typically presents with amnesia, behavioural disturbance, psychiatric symptoms, seizures and altered consciousness. Although the aetiology was historically considered paraneoplastic, LE may also result from autoimmune processes, independent of malignancy. New central nervous system targets are being identified and our appreciation of the associated clinical phenotypes is evolving rapidly. With this improved understanding, specific treatment protocols are emerging. Despite these developments, patients with LE without the characteristic antibodies still present a considerable clinical challenge. We present a case history and review the treatment and management options for antibody-negative LE. A 65-year-old female personal assistant presented with 3 months of confusion and disorientation. Her family reported that she showed increasing depression, general malaise and fatigue. Her work performance had deteriorated as she had become increasingly forgetful, repetitive, anxious and irritable. Treatment in the community for a urinary tract infection had no discernible benefit. She had previously been treated for postnatal depression, but had been otherwise well. Her friends and relatives described her premorbid personality as cheerful, health-conscious, hard-working and well organised with good memory and social skills. She was a non-smoker and she drank one bottle of wine a week. On examination, she appeared anxious and had a coarse resting tremor. The reflexes were brisk but the plantars were flexor. The Addenbrookes' cognitive examination (ACE-R), although difficult to perform early in her presentation, was 69/100, with normal fluency and language, but poor attention and …