New insights in cerebral findings associated with fetal myelomeningocele: a retrospective cohort study in a single tertiary centre

Abstract

Objective To investigate cerebral anomalies other than Chiari type 2 malformation in fetuses with myelomeningocele (MMC). Design A retrospective cohort study in a single tertiary centre. Setting A review of associated cerebral anomalies in cases with prenatal diagnosis of myelomeningocele. Population Seventy cases of fetal myelomeningocele. Methods Ultrasound and MRI images were blindly reviewed. Postnatal imaging and results of the postmortem results were also reviewed. The association between cerebral anomalies and the following ultrasound findings was measured: level of the defect, ventriculomegaly, microcephaly and fetal talipes. Main outcome measures A microcephaly was observed in 32/70 cases (46%) and a ventriculomegaly was observed in 39/70 cases (56%). Other cerebral anomalies were diagnosed in 47/70 (67%). Results Other cerebral anomalies were represented by 42/70 cases with abnormal CC (60%), 8/70 cases with perinodular heterotopia (PNH; 11%), 2/70 cases with abnormal gyration (3%). MRI performed only in fetal surgery cases confirmed the ulltrasound findings in all cases and provided additional findings in two cases (PNH). Risk ratios of fetal cerebral anomalies associated with MMC did not reach significance for microcephaly, ventriculomegaly, talipes or the level of the defect There was an overall good correlation between pre-and postnatal findings with a Kappa value of 0.79 [95% CI 0.57-1] and 82% agreement. Conclusion Fetal brain anomalies other than Chiari type 2 malformation are frequently observed in fetuses with myelomeningocele, predominantly represented by CC anomalies. Whether these associated cerebral anomalies have an impact on selecting cases eligible for fetal surgery needs further evaluation.

Incidence and patterns of abnormal corpus callosum in fetuses with isolated spina bifida aperta

“…On the contrary, a small prenatal study, though not in fetuses with SBA, reported a thickened CC as a single abnormal finding in the second trimester, which later becoming normal during the third trimester 29 . We documented a thickened body part of the CC in our cohort, which is in line with the recent publication of Maurice et al 30 . In that study, 18.6% (13/70) of the prenatal cohort of spina bifida fetuses had a thickened CC (>97th centile); although, the authors did not state in which part the CC becomes thickened.…”

“…In that study, 18.6% (13/70) of the prenatal cohort of spina bifida fetuses had a thickened CC (>97th centile); although, the authors did not state in which part the CC becomes thickened. In the same study, the authors described a stretched CC in almost 1/10 of their cases (5/70); however, we did not study this feature because of the absence of a clear definition for “stretched.” 30 The thickened appearance of the CC in spina bifida fetuses might change with advancing GA, as the feature was not reported in postnatal studies 14–17 . In this respect, it would be interesting to look at later images or even better to longitudinally follow‐up cases, both in the third trimester and in postnatal life.…”

Cranial findings detected by second‐trimester ultrasound in fetuses with myelomeningocele: a systematic review

“…In the same publication, the authors also reported abnormalities of cortical development. This comprised perinodular heterotopia (PNH) and abnormal gyral patterning, which were seen in 11 and 3% of MMC cases, respectively 34 …”

“…The incidence of ventriculomegaly, defined as lateral ventricular size of ≥10 mm, ranged from 45 to 89% of cases ( Figure 3). 24,[26][27][28][29][30][31][32]34,35 Of those, mild-to-moderate and severe ventriculomegaly were documented in 85 and 15%, respectively. 26 Regarding the shape of the lateral ventricles, an abnormal ultrasound finding was identified in the occipital horns: the normal round shape of the structure was substituted by an abnormal angulated/pointed contour 36,37 (Figure 3).…”

“…This comprised perinodular heterotopia (PNH) and abnormal gyral patterning, which were seen in 11 and 3% of MMC cases, respectively. 34 A total of ten studies reported the incidence of ventriculomegaly in the second trimester. The incidence of ventriculomegaly, defined as lateral ventricular size of ≥10 mm, ranged from 45 to 89% of cases ( Figure 3).…”