Recent advances and trends in epilepsy imaging: pathogenesis and pathophysiology

Uncontrolled epilepsy is a serious, common, neurological disorder leading to social and psychological problems, as well as increased morbidity and mortality. Neuroimaging studies have the potential to provide information on pathophysiologic mechanisms and underlying etiologies, as well as supporting clinical localization for potential surgical therapy. Magnetic resonance imaging (MRI) scanning has shown that patients with a history of complex or prolonged febrile seizures are at increased risk for the development of hippocampal injury and mesial temporal sclerosis. Animal models support this finding. In patients with familial partial seizures, mesial temporal sclerosis may be found whether family members have seizures or not, suggesting multifactorial inheritance. Positron emission tomography (PET) with specific neuroreceptor ligands has shown decreased serotonin and benzodiazepine receptor binding, even when structural MRI is normal. These studies have limited clinical value but suggest potential epileptogenic mechanisms. Imaging evaluation in epilepsy should be performed in an orderly sequence, guided by clinical and electroencephalographic data.