Expanding the spectrum of congenital anomalies of the diencephalic–mesencephalic junction

Abstract

The spectrum of DMJ patterning defects is wide and may be associated with several brain malformations. Infratentorial brain structures should be carefully evaluated to better define the type of associated midbrain-hindbrain anomalies.

MR Imaging Diagnosis of Diencephalic-Mesencephalic Junction Dysplasia in Fetuses with Developmental Ventriculomegaly

“…On imaging, DMJ dysplasia is characterized by a poorly defined junction between the diencephalon and the mesencephalon and by a ventral cleft contiguous with the third ventricle, producing a characteristic butterfly-shaped contour of the midbrain on axial images. [1][2][3] Notably, MR imaging identified the butterfly sign and the abnormal relation between the midbrain and thalamic mass already at 20 -21 gestational weeks in 6 fetuses of this series. Nonetheless, if not carefully sought, this finding may be overlooked, especially in the early gestational weeks.…”

“…D iencephalic-mesencephalic junction (DMJ) dysplasia is a rare malformation characterized by a poorly defined junction between the diencephalon and the mesencephalon and associated with a characteristic butterfly-shaped contour of the midbrain on axial sections on MR imaging. [1][2][3] This condition is included in a larger spectrum of DMJ anomalies, comprising forms that are recognizable in the axial (type A-DMJ anomalies, including DMJ dysplasia) or sagittal planes (type B-DMJ anomalies). 3 DMJ anomalies may be variably associated with other brain malformations, including callosal abnormalities and supratentorial ventricular dilation.…”

“…[1][2][3] This condition is included in a larger spectrum of DMJ anomalies, comprising forms that are recognizable in the axial (type A-DMJ anomalies, including DMJ dysplasia) or sagittal planes (type B-DMJ anomalies). 3 DMJ anomalies may be variably associated with other brain malformations, including callosal abnormalities and supratentorial ventricular dilation. In the original report, massively enlarged lateral ventricles were appreciated in 2 patients with DMJ dysplasia.…”

“…1 Thereafter, partial aqueductal stenosis was identified in 1 patient with DMJ dysplasia and prenatal onset of severe ventriculomegaly, suggesting a mixed obstructive and malfor-mative cause of the hydrocephalus. 3 The prenatal imaging features of DMJ have not been reported. Moreover, the relationship between DMJ anomalies and early developmental hydrocephalus remains unclear.…”

The patient with mild diencephalic–mesencephalic junction dysplasia – Case report and review of literature

“…For the time being there have been published only few cases of DMJD patients [1,2,12,13] describing the possible correlations between the exact radiological imaging and clinical manifestations of the disorder. In a majority of cases, the neurological and general symptoms were rapidly accumulating in the first months after birth, but at the same time there was also a group of patients described by Severino et al [13] as type B DMJ pattern. The group was neurologically less impaired in comparison to patients classified as type A DMJ pattern ( Fig.…”