Abstracts

There are very few reports of periictal MR brain abnormalities. Reversible local changes on T2 and DWI/ADC have usually been described. Isolated post-contrast enhancement is rare. MR abnormalities may be initially misinterpreted as indicating the presence of a tumor or infection. We review a case of partial epilepsy, presenting with leptomeningeal contrast enhancement on MRI. A patient with known symptomatic partial epilepsy was brought to the hospital by his family for left-sided weakness and altered consciousness for one day. He had a history of lung cancer with metastasis to the left occipital region for which he had previously undergone surgical resection. The following day he was back to his baseline clinical state. MR brain was obtained on admission. No changes were seen on FLAIR, T2 or T1 images except for an old resected left occipital lesion. DWI and ADC did not show abnormalities. Right temporoparietal leptomeningeal contrast enhancement was seen following gadolinium administration. EEG showed interictal right temporal epileptiform discharges, in the same region as the MRI contrast enhancement, but not over the resected left occipital region. CSF chemistry, cytology, Lyme antibodies, HIV and herpes PCR, ACE titer, fungal and AFB cultures were negative. CT scan of the chest, abdomen and pelvis, and whole-body PET did not show tumor recurrence. Nine days later, before planned biopsy, repeat MR brain demonstrated resolution of the contrast enhancement. Periictal contrast changes without other MR abnormalities are rare, but should be considered in patients with epilepsy, despite a history of cancer, to avoid unnecessary biopsy or surgery. Concordant epileptiform discharges on EEG can provide supportive evidence of an epileptic etiology for transient MR abnormalities.