Successful steroid treatment for probable non-paraneoplastic limbic encephalitis – case report
Limbic encephalitis (LE) was first described in the ‘60s as a clinical-pathological syndrome in adults. Non-infectious cases are usually a manifestation of paraneoplastic syndrome, related mostly to small-cell lung cancer. Infection-related LE is usually caused by herpes simplex virus (HSV). Non-paraneoplastic LE subtype (NPLE) accompanying autoimmune diseases with antibodies directed against cell membrane antigens were also described. Basing on clinical symptoms, MRI findings, absence of tumour and long-term follow-up, a still another group of NLPE patients without the abovementioned antibodies has been identified. Here, LE symptoms were not preceded by an acute infection. Temporal lobe epilepsy is a prominent symptom of this variant. NPLE is a potentially reversible LE variant. We report a 62-year-old man, with a two years’ history of memory loss, orientation and mood disorders and seizures. His brain MRI T2-weighted fluid-attenuated inversion recovery (FLAIR) scan revealed classic hyperintense foci within the temporal structures. He had no antibodies against onconeural antigens in serum. There was no evidence of a neoplasm. The entire clinical picture suggested a diagnosis of non-paraneoplastic limbic encephalitis. A course of steroids improved his clinical symptoms with significant resolution of radiological abnormalities. Lacking generally accepted diagnostic criteria of NPLE, we recommend a long-term follow-up with repeated neurological examination and oncological survey of patients presenting without evidence of a malignancy.