Last modified: 2018-09-09
Abstract
Introduction: Generalized epilepsy with focal lesion is prevalent in pediatric population. However, many lesional parietal lobe epilepsies show focal clinical semiology with non-lateralizing discharges.
We present a case of generalized epilepsy with epileptogenic zone over right parietal lobe documented by invasive monitoring. This case is unique as the invasive monitoring was based on MRI negative and PET positive focus on parietal convexity.
Methods: We evaluated an adolescent female who had refractory absences with eye flutter for two years. Following comprehensive evaluation, she underwent surgical evaluation to rule out focal epilepsy.
Case description: An adolescent female dancer presented with refractory daily absences, eye flutter and few generalized seizures. Video EEG revealed multiple ictal events with correlate of 3-4 Hz bi-frontal discharges. To rule out a focus (e.g., midline lesions) causing generalized epilepsy, she underwent surgical evaluation. Normal MRI prompted PET-CT which revealed right parietal hypometabolism. Resting state fMRI revealed right parietal hyperintensity. She underwent bilateral stereoEEG interrogation which confirmed the ictal onset over right parietal region. A right parietal corticectomy preserving post-central gyrus resulted in seizure freedom for last 6 months without deficit.
Conclusion: Parietal lobe epilepsy can present as generalized epilepsy and needs a thorough evaluation to confirm epileptogenicity in MRI negative cases. Bilateral EEG findings and non-lateralizing semiology can be explained by parietal neural networks with extensive connectivity. Presence of eye flutter in this case may suggest involvement of parietal eye field allegedly located in intra-parietal sulcus.