Correlation between Incomplete Hippocampal Inversions (IHI) with Incidence of Seizure Based on MRI Findings: A Systematic Review

Abstract

Introduction:Incomplete Hippocampal Inversions (IHI) is considered as leading cause of several neurological complications including epilepsy. <br/>This paper provides a systematic literature review about the possible causative role of incomplete hippocampal inversions in patient with epilepsy based on findings of Magnetic Resonance Imaging (MRI). <br/>Materials and Methods: The incomplete inversion of hippocampus with MRI imaging in patient with epilepsy was searched in PubMed and Scopuswith the following search strategy ((incomplete hippocampal inversion or hippocampal malrotations)) and epilepsy) and (magnetic resonance imaging or MRI). Then, data including the number of patients, and concluded results were extracted and compared between the groups. <br/>All types of articles including case series, clinical trials and cohort studies in English language with no time limitation were included. <br/>All searches, selection of articles and the data extraction were performed by two independent reviewers. <br/>Results: Only 11 papers met the inclusion criteria. Data were extracted and compared between two groups of patients and healthy controls. Results of this review showed that among 854 healthy controls and 1402 patients with verified temporal lobe epilepsy or hippocampal abnormalities, 59 cases with Hippocampal Malrotation (HIMAL) were in control groups, and 165 cases were in patients with epilepsy. <br/>Conclusions: The results showed that incomplete hippocampal inversion can be considered as an important cause of seizure. But still, studies with large sample size and equal number of cases and controls should be conducted to strongly confirm this association.