Magnetic resonance imaging findings and clinical characteristics in mild malformation of cortical development with oligodendroglial hyperplasia and epilepsy in a predominantly adult cohort

Abstract

Objective We aimed to better characterize the magnetic resonance imaging (MRI) findings of mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE), a rare clinicopathological entity associated with pharmacoresistance recently described in patients with frontal lobe epilepsy. Methods We studied 12 patients who underwent epilepsy surgery and whose surgical specimens showed histopathological findings of MOGHE, characterized by preserved cortical lamination, blurred gray–white matter interface due to increased number of oligodendrocytes, and heterotopic neurons in the white matter. The age at MRI evaluation ranged from 11 to 58 years, except for one 4.5‐year‐old patient. Results Following a detailed MRI analysis using an in‐house protocol, we found abnormalities in all cases. The lesion was circumscribed in the frontal lobe in six (50%) and in the temporal lobe in three (25%) patients. In the remaining three patients (25%), the lesion was multilobar (frontotemporal and temporoparieto‐occipital). Cortical thickening was mild in all patients, except in the 4.5‐year‐old patient, who had pronounced cortical thickening and white matter blurring. We also identified cortical/subcortical hyperintense T2/fluid‐attenuated inversion recovery signal associated with gray/white matter blurring in all but one patient. When present, cleft cortical dimple, and deep sulci aided in localizing the lesion. Overall, the MRI findings were like those in focal cortical dysplasia (FCD) Type IIa. Surgical outcome was excellent in five patients (Engel Class I in 25% and II in 17%). The remaining seven patients (58%) had worthwhile seizure reduction (Engle Class III). Incomplete lesion resection was significantly associated with worse outcomes. Significance MRI findings associated with MOGHE are similar to those described in FCD Type IIa. Although more frequent in the frontal lobe, MOGHE also occurred in the temporal lobe or involved multiple lobes. Multilobar or extensive MOGHE MRI lesions are associated with less favorable surgical outcomes. Because this is a rare condition, multicenter studies are necessary to characterize MOGHE further.

Multilobar unilateral hypoplasia with emphasis on the posterior quadrant and severe epilepsy in children with FCD ILAE Type 1A

“…A neuroimaging transition from an immature type with the diagnostic fingerprint of an increased subcortical laminar signal on T2 and FLAIR images to a mature type with a more unspecific appearance or even MRI negativity 9 was not seen in our study cohort, when serial MRI were available for re‐evaluation. Cortical thickening, cortical dimples, or deep sulci, as frequently described in MOGHE, were also not seen in our cohort 62 . Instead, hypoplasia of the white matter of the affected regions is a consistent finding in MUHSEC, yet not in MOGHE 9,62 …”

“…Cortical thickening, cortical dimples, or deep sulci, as frequently described in MOGHE, were also not seen in our cohort 62 . Instead, hypoplasia of the white matter of the affected regions is a consistent finding in MUHSEC, yet not in MOGHE 9,62 …”

“…Cortical thickening, cortical dimples, or deep sulci, as frequently described in MOGHE, were also not seen in our cohort. 62 Instead, hypoplasia of the white matter of the affected regions is a consistent finding in MUHSEC, yet not in MOGHE. 9,62 The association of MOGHE with brain somatic variants of the SLC35A2 gene is most striking and will help to clarify these diagnostic challenges in the near future.…”

“…62 Instead, hypoplasia of the white matter of the affected regions is a consistent finding in MUHSEC, yet not in MOGHE. 9,62 The association of MOGHE with brain somatic variants of the SLC35A2 gene is most striking and will help to clarify these diagnostic challenges in the near future. 12 It also emphasizes the importance of an integrated clinicopathological and genetic classification scheme in the era of modern medicine and targeted drug-treatment options.…”

Histopathological Correlations of Qualitative and Quantitative Temporopolar MRI Analyses in Patients With Hippocampal Sclerosis

“…Nonvolumetric sequences were analyzed first with T1 inversion recovery, followed by T1, T2, FLAIR, and SWI sequences. The evaluation corresponded to visual analysis of 12 parameters based on previously described criteria (25,26). We paid particular attention to the presence of blurring and atrophy of the ipsilateral temporal pole, which are reported to occur in 28-66% of patients with TLE-HS (12,27,28).…”