Martina Scharitzer MD, Abstract Co-Author: Nothing to Disclose

Christina M Plank MD, Presenter: Nothing to Disclose

Christoph Baumgartner MD, Abstract Co-Author: Nothing to Disclose

Daniela Prayer DSc, Abstract Co-Author: Nothing to Disclose

Chronic limbic encephalitis, usually associated with cancer as a paraneoplastic syndrome, may rarely occur without evidence of underlying malignancy. We present MR imaging and clinical workup in six patients with nonparaneoplastic, non-herpetic limbic encephalitis

Between 1999 and 2006, six patients (four women and two men; mean age 52.5 yrs; range 21-64 yrs) presented with symptoms of hippocampal dysfunction (memory deficits, changing mental status, temporal lobe epilepsy). Extensive clinical, laboratory and whole-body imaging work-up did not reveal underlying malignancy

MR imaging (19 investigations), performed on a 1.5 and 3 T superconducting system showed bilateral T1-weighted hypointense and T2-weighted and on the FLAIR sequence hyperintense signals in the hippocampi and amygdalae of all patients. Changes were symmetrical in two and asymmetrical in four cases. Diffusion-weighted source images (performed in 11 examinations) revealed mild hyperintense areas in the gyrus cinguli in two examinations. Postcontrast images showed no significant enhancement of the corresponding areas. Long-term follow-up MRI demonstrated complete resolution of the previous hippocampal T2 signal in two patients followed by hippocampal atrophy, partial resolution of abnormalities in two patients and progression in one patient with lethal course

In patients with clinical symptoms of hippocampal dysfunction without signs of acute illness and MR pattern of limbic involvement, chronic limbic encephalitis must be considered radiologically, even in absence of a malignant disease. The potential clinical improvement with new immunotherapy concepts in these patients emphasizes the importance of a correct diagnosis

In patients with MR pattern of limbic involvement, chronic limbic encephalitis must be considered radiologically, even in absence of a malignant disease.

Scharitzer, M, Plank, C, Baumgartner, C, Prayer, D, MRI Imaging in Nonneoplastic Limbic Encephalitis.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4437272.html