[Limbic encephalitis--a diagnostic challenge]

The etiology of limbic encephalitis (LE) is often autoimmune. Autoimmune LE is often paraneoplastic and should be suspected in patients with subacute confusional states. Subgroups of LE require different treatment, and the prognosis is variable; making the correct diagnosis is therefore essential for a good outcome.

The article is based on the authors' clinical experience with these patients and a review of recent literature retrieved from PubMed with the key words limbic encephalitis, limbic inflammation, paraneoplastic encephalitis, limbic and cancer, ion channel antibodies and viral encephalitis. Two case reports illustrate important clinical points.

Patients with LE constitute a heterogenous group with neuropsychiatric features, seizures and amnesia as the main symptoms. An early diagnosis is essential to limit sequelae. Viral encephalitis and Wernicke-Korsakoff Syndrome are important differential diagnoses. Presence of an onconeural antibody in serum is a specific tumour marker that should be used for screening all patients for malignancy. Not all cases of LE are paraneoplastic; ion channel antibodies can be an important marker for good response to immunosuppressive therapy in this group.