Ictal semiology in precuneus seizures: A systematic review

To evaluate the ictal semiology in seizures originating in the precuneus and to help guide seizure interpretation within the framework of presurgical evaluation.

This systematic review followed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and a Quality Assessment tool for Diagnostic Accuracy Studies (QUADAS2) based approach. We searched PubMed and Embase with keywords related to the precuneus, parietal or posterior epilepsy, video-EEG, and epilepsy surgery. Included studies report patients with seizures originating in the precuneus and video-EEG-based description of seizure symptoms. Screening and data extraction of all studies were performed by two independent reviewers. The summary of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Nine studies reporting 29 patients were included in the final analysis. The most common symptoms at the onset of seizures were vestibular symptoms, visual illusions and hallucinations, and body perception illusions. Motor symptoms were either elementary or complex motor phenomena that emerged during seizure propagation. However, the overall quality of evidence remained moderate or low.

This systematic review suggests typical seizure symptoms associated with precuneus seizures. However, it also shows a paucity of reports on precuneus seizures. Larger prospective studies with more detailed anatomo-electro-clinical data are needed to better understand seizures with precuneal origin within the entity of posterior cortex seizures.