Abstracts

When patients present with partial status epilepticus (SE), they often require extensive diagnostic investigation to determine the cause. Along with serum and CSF laboratory studies, MRI is used to help visualize the underlying brain pathology. While it is a very useful tool, MRI can be difficult to interpret in the setting of SE. The difficulty arises from the MRI changes produced by the seizure itself, which can mimic other pathologies. The following is a case series of 7 patients presenting with SE who had MRI findings from seizures that were initially read as either stroke, encephalitis, or tumor. A chart review was performed on 7 patients who presented at University Hospitals of Cleveland with EEG-verified SE who were initially thought to have stroke, infection, or tumor as a result of an abnormal initial MRI. Patients were chosen for this case series only if they were known to have had subsequent imaging and/or biopsy that suggested there was no underlying pathology other than transient MRI changes from the seizures. The results were analyzed by comparing the official radiology reports from the sequential imaging studies and, when available, biopsy results. : Three of the patients presented with focal neurological deficits and diffusion-weighted (DWI) MRI findings that were initially read as infarctions. They were later determined to be seizing and were treated accordingly. One patient had been incorrectly diagnosed with a right MCA stroke at an outside hospital and had not received any treatment for seizures for two days prior to transfer. No vascular occlusions were detected in any of the patients initially, though one later developed a small venous thrombosis. All three resolved both clinically and radiographically. The DWI lesions in all three cases have since been attributed to seizures rather than stroke.
: The other four patients presented with SE from the onset, and were found to have bright lesions on T2 and associated edema. Two of them also had leptomeningeal contrast enhancement. Lumbar puncture was negative for inflammation, viral PCR, and cytology. One patient with a remote history of nodular blastoma then had extensive cancer screening that included a brain biopsy. Another patient, HIV positive, also had a brain biopsy. All tests were negative for encephalitis and tumor. In all cases, the patients resolved both clinically and radiographically. Seizures can produce transient MRI changes in the brain that mimic stroke, encephalitis, and tumor. Encephalitis and tumor require careful investigation, and must be ruled out prior to ascribing such abnormalities to seizures alone. DWI is often thought to be specific to stroke, which can lead to delay in recognition and treatment of seizures.