Parietal lobe epilepsy.

ABSTRACT

When symptoms such as lateralized paresthesias or pain occur prominently and early in partial seizures, parietal lobe seizure origin should be suspected. Most patients with parietal lobe seizures, however, have no symptoms or signs suggesting the parietal lobe. In the absence of detectable epileptogenic lesions, these patients without clinical seizure characteristics suggesting parietal lobe origin can present with misleading findings, resulting in erroneous localization, which can, in turn, lead to ineffective surgical intervention (23,25). Although ictal SPECT might provide vital evidence of parietal lobe seizure origin (25), as noted previously, this technology also can produce misleading data in some patients (52). Even when parietal lobe seizure origin is suspected, in the absence of a structural lesion, documenting this with invasive monitoring can be difficult. The parietal lobes, like the frontal lobes, are large, diffuse structures, and the potential for sampling error is high (19). Spread patterns are unpredictable and can result in false localization (23). Even with extensive and repetitive invasive studies, localization can prove elusive (53). No well-documented series of patients with non-lesional parietal lobe epilepsy in the modern literature who have been cured by surgery have been reported as a result of a combination of the rarity of the condition, the lack of correct recognition, as well as the difficulty of localization. Patients with medically intractable parietal lobe seizures, however, can experience excellent surgical results (23,24). Postoperative parietal lobe symptoms and signs, even when extreme, are usually not enduring (patient 3). One of our patients, however, did develop a chronic pain syndrome (48).