Cases report: MRI findings of asymptomatically familial subependymal heterotopia with filamin A gene abnormality

Abstract

Subependymal heterotopia (SEH) is a rare neuronal migration disorder consisting of gray matter nodules along the lateral ventricular walls and is often associated with other brain malformations. Despite most SEH cases showing epilepsy during their lifetimes, very few patients with asymptomatically familial SEH tend to cause misdiagnosis or missed diagnosis. We present four familial SEH cases without any positive symptoms and medical history, including two fetuses, who were diagnosed by MRI and confirmed by genetic testing with mutation of filamin A. This report emphasizes the role of MRI in the recognition of SEH at an early age of gestation and in asymptomatically familial SEH. MRI provides a fast, repeatable, reliable, and cheap choice for detecting and screening familial SEH.

Keywords: asymptomatic; case report; filamin A; magnetic resonance imaging; subependymal heterotopia.

FIGURE 1

Fetal brain MRI at two fetuses of the pregnant woman. Fetus 1 (A–D), scanning at 27 + 1 weeks of gestation with bilateral subependymal heterotopia (SEH). Axial (1A, 1B) and coronal (1C) fetal MRI images show that bilateral ventricles are not dilated, ependyma is irregular, and multiple abnormal signal nodules can be seen. The T2-weighted sequence shows nodules in the ventricular wall similar to gray matter signals (black arrows). Fetal sonogram (D) Axial image, obtained at 26 weeks of gestation through the cerebellar level, shows the widened posterior cranial fossa (yellow measurement arrow); Fetus 2 (a–d), scanning at 25 + 2 weeks of gestation with bilateral SEH. Axial (1a, 1b) and coronal (1c) T2-weighted sequences at the level of the lateral ventricles show nodules in the ventricular wall similar to gray matter signals (black arrows). Fetal sonogram (1d) Axial image, obtained at 24 weeks of gestation through the double top diameter layer, shows the narrowing of the transparent compartment cavity (yellow measurement arrow).

FIGURE 2

Adult brain MRI images of the pregnant woman and her mother. The pregnant woman (A,B): T2-weighted sequence performed at the age of 35 years showed multiple foci of heterotopic gray matter outlining the walls of both lateral ventricles; this is consistent with the diagnosis of subependymal gray matter heterotopia (black arrows); The pregnant woman’s mother (a,b): T2-weighted sequence performed at 67 years of age showing multiple foci of heterotopic gray matter outlining both lateral ventricles walls (black arrows).