Parietal lobe epilepsy

Abstract

Patients with parietal lobe epilepsy (PLE) exhibit an electroclinical epilepsy syndrome that is rarely seen even at large epilepsy centers. Clinically, most patients with PLE exhibit a somatosensory aura that may include painful dysesthesias, though vertigo, aphasia, disturbances of one's body image also occur, when ictal propagation occurs from the parietal lobe to the supplementary motor area, hypermotor manifestations are noted. When temporolimbic propagation occurs, complex visual or auditory hallucinations and automatisms may appear. Scalp electroencephalogram (EEG) is often nonlocalizing. Ictal EEG is rarely localizing in PLE, and invasive EEG is often required for definitive localization and functional mapping. Recent advances in clinical neurophysiology during the evaluation of patients with refractory partial epilepsy include Ictal magnetic source imaging (MSI). Combined EEG and functional magnetic resonance imaging (EEG-fMRI) may be useful for patients with PLE to refine the localization in patients undergoing a presurgical evaluation. High-frequency oscillations (HFOs) are more concentrated inside the seizure onset zone (SOZ), indicating that they may be used as interictal scalp EEG biomarker for the SOZ. When medical therapy fails, resective epilepsy surgery can result in seizure freedom or significant reduction especially when a lesion is present.