Impact of the cystic neural tube defects on fetal motor function in prenatal myelomeningocele repairs: A retrospective cohort study

Abstract

Objective: To determine the impact of the lesion type (cystic [myelomeningocele] or flat [myeloschisis]) on the fetal motor function (MF) in cases candidates for prenatal open neural tube defect (ONTD) repair. Methods: Retrospective cohort study of patients with ONTD who underwent prenatal repair at a single institution between 2011 and 2019. The lesion type and the measurements of the length and width of the lesions to calculate the surface of the ellipsoid lesion were performed using MR scans. Prenatal MF of the lower extremities was evaluated by ultrasound following a metameric distribution at the time of referral. Intact MF was defined as the observation of plantar flexion of the ankle. Logistic regression was performed to determine the predictive value of the type of lesion for having an intact MF at the time of referral.Results: 103 patients were included at 22.9 (19-25.4) weeks; 65% had cystic and 35% had flat lesions. At the time of referral, there was a higher proportion of cases with an intact MF in the presence of flat lesions (34/36; 94.4%) as compared to cystic lesion (48/67; 71.6%, p < 0.01). When adjusting for gestational age and anatomical level of the lesion, flat ONTD were 3.1 times more likely to be associated by intact motor function (CI%95 [2.1-4.6], p < 0.01) at the time of referral. Conclusion:Cystic ONTD are more likely to be associated with impaired MF at midgestation in candidates for prenatal ONTD repair. Key pointsWhat's already known about this topic? � The diagnosis of open neural tube defect is associated with motor and sensory deficit. Open neural tube defects can be divided into two phenotypes: cystic (myelomeningocele) and flat (myeloschisis) lesions.

Presurgery motor level assessment for prediction of motor level at birth in fetuses undergoing prenatal repair of open spina bifida: time to abandon anatomical level in counseling

“…The main effects of spinal open neural tube defects (NTDs) can be explained by two main factors: first, leakage of cerebrospinal fluid results in hindbrain herniation of the cerebellum and may lead to different degrees of ventriculomegaly and central nervous system malformations, known as Chiari-II malformations; second, direct injury of the neural tissue exposed to the amniotic cavity can cause impairment of motor function (second-hit hypothesis). Recently, a 'third-hit' hypothesis has been described, suggesting that traction of the neural placode and neural roots caused by fluid within the meningeal cyst in cases with myelomeningocele may also impair motor function [1][2][3] .…”

Length of hysterotomy for fetal spina bifida repair is associated with prematurity risk

“…18 For the latter, we considered characteristics that were earlier reported by others to impact gestational age at delivery or membrane rupture following prenatal SBA repair, that is, gestational age at operation, [19][20][21][22] parity, [19][20][21] and operative time. 19 Lesion characteristics such as lesion level and lesion type have also earlier been reported to affect operative time; 23,24 hence, we included these variables as well. We matched patients on a 1:1 basis, without replacement and within caliper technique.…”

Prenatal diagnosis and postnatal outcome of closed spinal dysraphism

“…Functional segmental motor function was determined by a detailed neurological evaluation in the first 48 h of life. Motor levels were defined by the lowest myotomes involved in active motor activity 7,36,37 . After discharge, the infants were followed up in our institution's multidisciplinary Spina Bifida Clinic.…”

“…Motor levels were defined by the lowest myotomes involved in active motor activity. 7,36,37 After discharge, the infants were followed up in our institution's multidisciplinary Spina Bifida Clinic. Neurogenic dysfunction of the bladder was defined as either overactive bladder, underactive bladder, or non-contractile detrusor as described by Weiss et al 38 The diagnosis is made by urodynamic studies combined with video fluoroscopy.…”