Transient focal abnormalities of neuroimaging studies during focal status epilepticus.

We report transient changes in computed tomography (CT) and magnetic resonance imaging (MRI) scans in a patient with focal status epilepticus, referred to us with a tentative diagnosis of neoplasm based on CT and angiographic findings. EEG seizures originated independently from each temporal-occipital area, predominantly from the right. Previous EEGs had shown almost exclusively right temporo-occipital epileptogenic activity. MRI showed increased signal intensity, and CT showed decreased right hemisphere attenuation without enhancement. One month later, there was resolution of the radiological and clinical abnormalities. The transient CT and MRI changes probably represented focal cerebral edema, developing during focal status epilepticus. Lack of change in the left hemisphere probably reflected the quantitative difference in epileptic activity. Clues to the diagnosis of focal edema due to status include: (1) changes on electrical and imaging studies that correlate anatomically with the clinical status, and (2) resolution of abnormalities with appropriate seizure control. In patients with suspected seizure disorders, electrical and clinical data should be correlated before interpretation is made of focal lesions seen by neuroimaging techniques.