Reversal of hindbrain herniation after maternal-fetal surgery for myelomeningocele subsequently impacts on brain stem function.

Danzer E, Finkel RS, Rintoul NE, Bebbington MW, Schwartz ES, Zarnow DM, Adzick NS, Johnson MP. (2009) Reversal of hindbrain herniation after maternal-fetal surgery for myelomeningocele subsequently impacts on brain stem function. Neuropediatrics. 2008 Dec;39(6):359-62.

The Center for Fetal Diagnosis and Treatment, The Children's Hospital of Philadelphia and The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.

The aim of our study was to delineate whether the reversal of hindbrain herniation (HH) following fetal myelomeningocele (fMMC) closure subsequently reduces the incidence and severity of HH-associated brainstem dysfunction (BSD). Prior to the NIH-sponsored Management of Myelomeningocele Study (MOMS) trial, 54 children underwent fMMC closure at our institution. Forty-eight (89%) families participated in a structured survey focusing on HH-associated BSD (e.g., apnea, neurogenic dysphagia [ND], gastro-esophageal reflux disease [GERD], neuro-ophthalmologic disturbances [NOD]). Median age at follow-up was 72 months (range: 46-98). Fifty-percent required shunting. HH-related symptoms were completely absent in 15 (63%) non-shunted and 10 (42%) shunted children (P=0.15). No HH-related death occurred and none developed severe persistent cyanotic apnea. ND was reported in 2 (8%) non-shunted and 9 (38%) shunted infants (P=0.03). Mild GERD (medically managed) developed in 2 (8%) without and 6 (25%) with shunt placement (P=0.24). NOD was found in 6 (25%) and 13 (54%) of non-shunted and shunted children, respectively (P=0.07). The majority of fMMC children developed no or only mild BSD at follow-up. Our data support the hypothesis that neurodevelopmental deficits associated with MMC are at least partially acquired and that reversal of HH following fMMC surgery may help to reduce the incidence and severity of BSD.

PMID: 19569004

Anatomical progression of the Chiari II malformation.

Ruge JR, Masciopinto J, Storrs BB, McLone DG. Anatomical progression of the Chiari II malformation. Childs Nervous System. 1992 Mar;8(2):86-91.

To evaluate whether anatomic change of the relationship of the Chiari II malformation and the cranial base was occurring, 22 children with meningomyelocele had serial MRI scans reviewed. A ratio (B/A) was established between the distance from the foramen magnum to the caudalmost portion of herniated cerebellum (B) and the diameter of the foramen magnum (A) and this ratio was compared on serial MRI scans. Eighteen children had an increase in the B/A ratio, two children had a decrease, and two had no change. This indicates that continuous anatomic change of the Chiari II malformation and the skull base is occurring. Clinical deterioration in the older child may be explained by a combination of compressive and traction forces due to this change.


PMID: 1591752