Schizencephaly in Hereditary Hemorrhagic Telangiectasia

Abstract

Background and purpose: The presence of malformations of cortical development in patients with hereditary hemorrhagic telangiectasia has been reported on previous occasions. We evaluated a sample of adults with hereditary hemorrhagic telangiectasia for the presence of malformations of cortical development, spatial coincidence of malformations of cortical development and AVMs, and the coincidence of brain and pulmonary AVMs.

Materials and methods: A total of 141 patients 18 years of age or older who were referred to the Augusta University hereditary hemorrhagic telangiectasia clinic and underwent brain MR imaging between January 19, 2018, and December 3, 2020, were identified. MR imaging examinations were reviewed retrospectively by 2 experienced neuroradiologists, and the presence of malformations of cortical development and AVMs was confirmed by consensus. Demographic and clinical information was collected for each case, including age, sex, hereditary hemorrhagic telangiectasia status by the Curacao Criteria, mutation type, presence of malformations of cortical development, presence of brain AVMs, presence of pulmonary AVMs, and a history of seizures or learning disabilities.

Results: Five of 141 (3.5%) patients with hereditary hemorrhagic telangiectasia had malformations of cortical development. Two of the 5 patients with polymicrogyria also had closed-lip schizencephaly. One of the patients had a porencephalic cavity partially lined with heterotopic GM. The incidence of spatially coincident polymicrogyria and brain AVMs was 40% (2/5 cases). Of the patients with hereditary hemorrhagic telangiectasia and malformations of cortical development, 4/5 (80%) had pulmonary AVMs and 2/5 (40%) had brain AVMs.

Conclusions: To our knowledge, we are the first group to report the presence of schizencephaly in patients with hereditary hemorrhagic telangiectasia. The presence of schizencephaly and porencephaly lends support to the hypothesis of regional in utero cerebral hypoxic events as the etiology of malformations of cortical development in hereditary hemorrhagic telangiectasia.

FIG 1.

A 26-year-old woman with HHT. Sagittal 3D fast-spoiled gradient recalled imaging demonstrates polymicrogyria involving the right posterior cingulate gyrus (A, yellow arrow). There is an abnormal GM-lined cleft between the calcarine sulcus and the occipital horn of the right lateral ventricle consistent with schizencephaly (A, red arrow). Coronal T1 image shows polymicrogyria (B, yellow arrow) and schizencephaly (B, red arrow).

FIG 2.

A 20-year-old man with HHT. 3D volume T1 images demonstrate a closed-lip schizencephaly projecting through the right inferior parietal lobe that extends to the lateral margin of the right lateral ventricle at the junction of the posterior body and atrium (A, red arrow). There is polymicrogyria involving the adjacent frontal and parietal cortex (A, yellow arrow). Coronal T1 image shows polymicrogyria (B, yellow arrow) and schizencephaly (B, red arrow).

FIG 3.

An 80-year-old man with HHT. Axial T2 FLAIR image shows porencephaly with surrounding gliosis (A, yellow circle) and an AVM in the left superior temporal gyrus (A, red arrow). Coronal volume T1 image shows porencephaly (B, yellow circle) partially lined by polymicrogyria (B, red arrow). Axial T2 FSE image shows flow voids associated with a small AVM (C, red arrow).

FIG 4.

An 18-year-old man with HHT. Coronal 3D T1 postcontrast imaging shows right parietal polymicrogyria (A, yellow arrows), an AVM (A, yellow circle), and a small AVM (A, red arrow). Axial T1 image shows left parietal occipital polymicrogyria (B, red arrows).

FIG 5.

A 28-year-old man with HHT. Axial T2 FSE image shows polymicrogyria in the left superior frontal gyrus (yellow circle).