Autoimmune Limbic Encephalitis

Abstract

Limbic encephalitis is a rare but increasingly recognized disorder. The sudden onset of symptoms such as confusion, cognitive impairment, irritability, depression, hallucinations, is one of
the main characteristics. It is an inflammatory disease involving
the temporal lobes, which explains the frequency of seizures.
We report the case of a 27-year-old man, presenting hyperosmolar syndrome (owing to new onset diabetes mellitus), acute
confusional state and sudden onset of seizures. Several diagnostic hypotheses were raised: infectious meningoencephalitis,
autoimmune encephalitis, and metabolic encephalopathy. Despite treatment (antibiotics, correction of hyperosmolar state
and anticonvulsant therapy), continuous cognitive deterioration
and seizures persisted. We raised the hypothesis of an autoimmune limbic encephalitis by anti-GAD antibodies and treated
with human immunoglobulin. There was a dramatic improvement, corroborating the diagnosis (along with imaging findings). Although difficult to diagnose, limbic encephalitis should
be considered when studying acute confusional states with
psychiatric symptoms and seizures. Clinical suspicion and early
treatment are essential for therapeutic success.