Inferior parietal lobule gyrations in refractory epilepsy.

Posterior parietal epilepsy can be difficult to identify due to complex clinical presentation and non-localisable electrophysiological findings. The inferior parietal lobule (IPL) exhibits normal gyral variation, and hidden among this are cases of refractory surgically remediable epilepsies. We present a case series of four patients with refractory parietal epilepsy in which IPL gyral variation was associated with dysplasia, confirmed histopathologically in three of the cases. All patients underwent extensive presurgical evaluation including 3T MRI-volumetric T1, FLAIR and T2 SPACE sequences. Awareness is essential as these cases can be easily missed. Interpretation of volumetric brain MRI on sagittal plane is important to identify these cases. With better awareness and understanding of foetal development of the sylvian fissure and operculisation, inferior parietal gyral refractory epilepsies may be more common than currently recognized.