Regarding limbic encephalitis (LE),
1. Usually presents with long term memory impairment
2. MRI typically shows high signal on T2 and FLAI in the limbic region
3. The most common underlying malignancy is small cell lung cancer (SCLC)
4. PET is useful in diagnosing underlying occult malignancy
Answers: F, T, T, T,
Notes: LE usually presents with short term memory impairment, seizures, confusion and psychiatric symptoms. Brain stem may also be involved. LE can be paraneoplastic or non-paraneoplastic. SCLC is the most common cause; other causes include testicular cancer, ca breast, teratoma, HL, thymoma. Although LE can be idiopathic, underlying malignancy should be searched.
Reference:
Rutherford GC et al. Imaging in the investigation of paraneoplastic syndromes. Clinical Radiology Volume 62, Issue 11, November 2007, Pages 1021-1035
