Imaging Fetal Spine Malformations in the Context of In Utero Surgery.

This review covers the embryology, definition, and diagnosis of open spinal dysraphism with a focus on fetal ultrasound and MR imaging findings. Differentiating open versus closed spinal dysraphic defects on fetal imaging will also be discussed. Current fetal surgery practices and imaging findings in the context of fetal surgery are also reviewed.

Value of pre- and postnatal magnetic resonance imaging in the evaluation of congenital central nervous system anomalies.

Fetal MRI and neonatal MRI of the central nervous system (CNS) are complementary tools that can help to accurately counsel and direct the management of children with anomalies of the central nervous system. Postnatal MRI can add to fetal MRI by allowing for monitoring of changes in the severity of disease, better delineation of a suspected prenatal anomaly, evaluation for secondary pathologies related to the primary diagnosis, and surgical management direction. In this review we discuss the roles of fetal and neonatal MRI in the diagnosis and treatment of congenital anomalies of the CNS through a series of case examples and how both are important in patient management.

Extradural decompression versus duraplasty in Chiari malformation type I with syrinx: outcomes on scoliosis from the Park-Reeves Syringomyelia Research Consortium.

OBJECTIVE: Scoliosis is common in patients with Chiari malformation type I (CM-I)-associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression. METHODS: A large multicenter retrospective and prospective registry of 1257 pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for patients with scoliosis who underwent PFD with or without duraplasty. RESULTS: In total, 422 patients who underwent PFD had a clinical diagnosis of scoliosis. Of these patients, 346 underwent duraplasty, 51 received extradural decompression alone, and 25 were excluded because no data were available on the type of PFD. The mean clinical follow-up was 2.6 years. Overall, there was no difference in subsequent occurrence of fusion or proportion of patients with curve progression between those with and those without a duraplasty. However, after controlling for age, sex, preoperative curve magnitude, syrinx length, syrinx width, and holocord syrinx, extradural decompression was associated with curve progression > 10°, but not increased occurrence of fusion. Older age at PFD and larger preoperative curve magnitude were independently associated with subsequent occurrence of fusion. Greater syrinx reduction after PFD of either type was associated with decreased occurrence of fusion. CONCLUSIONS: In patients with CM-I, syrinx, and scoliosis undergoing PFD, there was no difference in subsequent occurrence of surgical correction of scoliosis between those receiving a duraplasty and those with an extradural decompression. However, after controlling for preoperative factors including age, syrinx characteristics, and curve magnitude, patients treated with duraplasty were less likely to have curve progression than patients treated with extradural decompression. Further study is needed to evaluate the role of duraplasty in curve stabilization after PFD.

Occipital-Cervical Fusion and Ventral Decompression in the Surgical Management of Chiari-1 Malformation and Syringomyelia: Analysis of Data From the Park-Reeves Syringomyelia Research Consortium.

BACKGROUND: Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology. OBJECTIVE: To examine factors influencing the use of OCF and OCF/VD in a multicenter cohort of pediatric CM-1 and SM subjects treated with PFD. METHODS: The Park-Reeves Syringomyelia Research Consortium registry was used to examine 637 subjects with cerebellar tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and at least 1 yr of follow-up after their index PFD. Comparisons were made between subjects who received PFD alone and those with PFD + OCF or PFD + OCF/VD. RESULTS: All 637 patients underwent PFD, 505 (79.2%) with and 132 (20.8%) without duraplasty. A total of 12 subjects went on to have OCF at some point in their management (PFD + OCF), whereas 4 had OCF and VD (PFD + OCF/VD). Of those with complete data, a history of platybasia (3/10, P = .011), Klippel-Feil (2/10, P = .015), and basilar invagination (3/12, P < .001) were increased within the OCF group, whereas only basilar invagination (1/4, P < .001) was increased in the OCF/VD group. Clivo-axial angle (CXA) was significantly lower for both OCF (128.8 ± 15.3°, P = .008) and OCF/VD (115.0 ± 11.6°, P = .025) groups when compared to PFD-only group (145.3 ± 12.7°). pB-C2 did not differ among groups. CONCLUSION: Although PFD alone is adequate for treating the vast majority of CM-1/SM patients, OCF or OCF/VD may be occasionally utilized. Cranial base and spine pathologies and CXA may provide insight into the need for OCF and/or OCF/VD.

Imaging in the presence of meroanencephaly.

Meroanencephaly occurs when there is an incomplete open median calvarial defect. This condition, which is in the spectrum of anencephaly, results in ectopic brain without skin covering and a normal foramen magnum. We present a rare case of a female fetus with meroanencephaly referred to our institution at 24 weeks and imaged with both prenatal ultrasound and MRI, demonstrating an open neural tube defect in the high parietal area and lack of visualization of the supratentorial ventricular system. Postnatal the child survived and went on to require antibiotic therapy and closure of the defect without cerebral spinal fluid diversion but demonstrates severe permanent neurologic deficits.

Complications in Children with Ehlers-Danlos Syndrome Following Spine Surgery: Analysis of the Pediatric National Surgery Quality Improvement Program Database.

BACKGROUND: Ehlers-Danlos syndrome (EDS) is a group of rare congenital disorders of connective tissue that result in tissue fragility and joint hyperextensibility. Owing to its rarity, outcomes of pediatric spine surgery in patients with EDS are poorly characterized. Although it has been suggested that complication rates are high, few studies have characterized these complications. METHODS: Pediatric National Surgery Quality Improvement Program data from 2012-2016 were analyzed. Patients with EDS undergoing spine surgery were identified along with patients without EDS undergoing the same surgeries using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes. RESULTS: Of 369,176 total patients, 279 were determined to have EDS. Of these, 56 patients underwent spine surgery; 46% were male and 54% were female (P = 0.108). Mean age at surgery was 11.59 years (P = 0.888) with a range of 1.77-17.33 years. The most common procedure was arthrodesis (n = 37). There were no differences in unplanned reoperations (n = 4, P = 0.119), wound infections or disruptions (n = 2, P = 0.670), or overall complications (n = 25, P = 0.751). Blood transfusions were required in 41% of patients with EDS, but this was not significant compared with patients without EDS undergoing the same procedures (n = 23, P = 0.580). The total amount of blood transfused (P = 0.508), length of hospital stay (P = 0.396), and total operative time (P = 0.357) were not different from control subjects. CONCLUSIONS: Pediatric patients with EDS do not appear to be at a higher risk of bleeding or other complications during spine surgery as reported in past case series. This is the largest retrospective review of its kind that has been performed in this patient population.

Prenatal and postnatal MRI findings in open spinal dysraphism following intrauterine repair via open versus fetoscopic surgical techniques.

PURPOSE: The purpose of the study is to examine MRI findings of the brain and spine on prenatal and postnatal MRI following intrauterine repair of open spinal dysraphism (OSD) by open hysterotomy and fetoscopic approaches. MATERIALS AND METHODS: This study is a single-center HIPAA-compliant and IRB-approved retrospective analysis of fetal MRIs with open spinal dysraphism from January 2011 through December 2018 that underwent subsequent prenatal repair of OSD. RESULTS: Sixty-two patients met inclusion criteria: 47 underwent open repair, and 15 underwent fetoscopic repair, with an average gestational age of 22.6 ± 1.4 weeks at initial MRI. On postnatal MRI, spinal cord syrinx was seen in 34% (16/47) of patients undergoing open versus 33.3% (5/15) undergoing fetoscopic repair (P = 0.96). Postnatally, there was no significant difference in hindbrain herniation between the open versus fetoscopic repair groups (P = 0.28). Lateral ventricular size was significantly larger in the open (20.9 ± 6.7 mm) versus the fetoscopic repair (16.1 ± 4.9 mm) group (P = 0.01). CONCLUSION: Though lateral ventricular size in the open repair group was larger than the fetoscopic repair group, this can likely be explained by initial selection criteria used for fetoscopic repair. Other postoperative imaging parameters on postnatal MRI were not significantly different between the two groups.

Not all ventriculomegaly is created equal: diagnostic overview of fetal, neonatal and pediatric ventriculomegaly.

Fetal ventriculomegaly refers to a condition in which there is enlargement of the ventricular spaces, typically on prenatal ultrasound. It can be associated with other CNS or extra-CNS abnormalities, and this relationship is crucial to understand as it affects overall neonatal outcome. Isolated ventriculomegaly has been described in the literature with variable clinical outcome. Typically, outcome is based on the etiology and degree of ventriculomegaly. When associated with a pathologic condition, ventriculomegaly can be a result of hydrocephalus. While initial diagnosis is usually made on prenatal ultrasound, fetal magnetic resonance imaging is preferred to further elucidate any associated CNS malformations. In this paper, the authors aim to provide a comprehensive review of the diagnosis, associated etiologies, prognosis, and treatment options related to fetal, neonatal, and pediatric ventriculomegaly and hydrocephalus. In addition, preliminary data is provided from our institutional cohort of patients with a prenatal diagnosis of ventriculomegaly followed through the perinatal period.

Growing up with spina bifida: bridging the gaps in the transition of care from childhood to adulthood.

Spina bifida is the most common nonchromosomal birth defect, resulting in permanent disability of multiple organ systems, yet compatible with long-term survival. Important advances across various disciplines have now improved survival among the spina bifida population. Although the majority of individuals living with spina bifida are now adults, there are few publications in the neurosurgical literature regarding the care of adults with spina bifida, associated medical conditions, surgical interventions, and long-term complications. The major goals for transitioning adult patients with spina bifida are preservation of function and promotion of independence as well as general overall health. Nevertheless, many gaps exist in our knowledge and understanding of the complex needs of this aging patient population. The goal of this paper was to provide a comprehensive updated review of the literature regarding the challenges and considerations involved in the transitional care to adulthood for patients with spina bifida. Unique to this review, the authors provide a first-hand personal communication and interview with an adult patient with spina bifida that discusses many of these challenges with transition.

Myelomeningocele Versus Myelocele on Fetal MR Images: Are There Differences in Brain Findings?

OBJECTIVE: The purpose of this study was to examine differences between patients with myelomeningocele and those with myelocele with respect to brain imaging findings at fetal MRI. MATERIALS AND METHODS: A single-center retrospective analysis was performed of fetal MRI examinations revealing open spinal dysraphism from 2004 through 2016 with available diagnostic postnatal spinal MR images in conjunction with neurosurgical follow-up findings. Images were reviewed by two board-certified fellowship-trained pediatric neuroradiologists. Relevant clinical data were recorded. RESULTS: The study included 119 fetal MRI examinations of patients with open spinal dysraphism. Myeloceles were found in 29.4% (35/119) of these examinations and myelomeningoceles in the others. All (35/35) myeloceles showed grade 3 (severe) Chiari II malformations. Only 73.8% (62/84) of myelomeningoceles showed grade 3 Chiari II malformation. Clinically significant spinal kyphosis was found in 5.0% (6/119) of fetuses, and all of these fetuses had grade 3 Chiari II malformations. The size of the spinal dysraphic defect had significant positive correlation with lateral (p < 0.0001) and third (p = 0.006) ventricular size. Mean volume of the myelomeningocele sac was significantly different among Chiari II grades and inversely proportional to Chiari II grade (p = 0.0009). CONCLUSION: Larger spinal dysraphic defects correlated with increased ventricular size at fetal MRI. All of the fetuses with myelocele or kyphosis had severe Chiari II malformations. Larger myelomeningocele sac size was associated with lower grade of Chiari II malformation, suggesting that myelomeningocele sac formation may be protective against hindbrain herniation.

Routine surveillance imaging following mild traumatic brain injury with intracranial hemorrhage may not be necessary.

BACKGROUND: Mild traumatic brain injury (mTBI) comprises the majority of pediatric traumatic brain injury. Children with mTBI even with traumatic intracranial hemorrhage (tICH) rarely experience a clinically significant neurologic decline (CSND). The utility of routine surveillance imaging in the pediatric population also remains controversial, especially owing to concerns about the risks of radiation exposure at a young age. This study aims to identify demographic or injury-related characteristics that may facilitate recognition of children at risk of progression with mTBI. METHODS: We performed a retrospective review of patients <16 years old with mTBI (GCS 13-15) and tICH admitted to a Level I pediatric trauma center between 2009 and 2014. Management of these patients was directed by the Cincinnati Children's Hospital Medical Center Minor Head Injury Algorithm. We reviewed each chart with emphasis on patient demographics, injury specific data, and radiographic or clinical progression. RESULTS: 154 patients met inclusion criteria with mean age of 4 [0-16]; 116 sustained an tICH and 38 patients had isolated skull fractures. Repeat neuroimaging was obtained in 68 patients (59%). Only 9 patients (13%) with tICH had radiographic progression, none of which resulted in CSND. In addition, 9 patients experienced CSND, leading to neurosurgical intervention in 6 patients. Notably, none of these patients had repeat imaging prior to their neurologic changes. Both CSND and need for intervention were significantly higher in patients with epidural hematomas than other types of tICH (19.2% vs. 1.1%, p = 0.002). Of 154 patients, 19 did not have documented follow-up, 135 were seen as outpatients and 65 (48%) had follow up neuroimaging. All patients who had surveillance imaging in the outpatient setting had stable or resolved tICH. CONCLUSION: Few children with mTBI and tICH experience clinical decline. Importantly, all patients that required neurosurgical intervention were identified by clinical changes rather than via repeat imaging. Our study suggests that in the vast majority of cases, clinical monitoring alone is safe and sufficient in patients in order to avoid exposure to repeat radiographic imaging. LEVEL OF EVIDENCE: Level III, prognostic and epidemiological.

Lessons learned from administration of high-dose methylprednisolone sodium succinate for acute pediatric spinal cord injuries.

OBJECTIVE Methylprednisolone sodium succinate (MPSS) has been studied as a pharmacological adjunct that may be given to patients with acute spinal cord injury (ASCI) to improve neurological recovery. MPSS treatment became the standard of care in adults despite a lack of evidence supporting clinical benefit. More recently, new guidelines from neurological surgeon groups recommended no longer using MPSS for ASCI, due to questionable clinical benefit and known complications. However, little information exists in the pediatric population regarding MPSS use in the setting of ASCI. The aim of this paper was to describe steroid use and side effects in patients with ASCI at the authors' Level 1 pediatric trauma center in order to inform other hospitals that may still use this therapy. METHODS A retrospective chart review was conducted to determine adherence in ordering and delivery according to the guideline of the authors' institution and to determine types and frequency of complications. Inclusion criteria included age < 17 years, blunt trauma, physician concern for ASCI, and admission for ≥ 24 hours or treatment with high-dose intravenous MPSS. Exclusion criteria included penetrating trauma, no documentation of ASCI, and incomplete medical records. Charts were reviewed for a predetermined list of complications. RESULTS A total of 602 patient charts were reviewed; 354 patients were included in the study. MPSS was administered in 59 cases. In 34 (57.5%) the order was placed correctly. In 13 (38.2%) of these 34 cases, MPSS was administered according to the recommended timeline protocol. Overall, only 13 (22%) of 59 patients received the therapy according to protocol with regard to accurate ordering and administration. Among the patients with ASCI, 20 (55.6%) of the 36 who received steroids had complications, which was a significantly higher rate than in those who did not receive steroids (8 [24.2%] of 33, p = 0.008). Among the patients without ASCI, 10 (43.5%) of the 23 who received steroids also experienced significantly more complications than patients who did not receive steroids (50 [19.1%] of 262, p = 0.006). CONCLUSIONS High-dose MPSS for ASCI was not delivered to pediatric patients according to protocol with a high degree of reliability. Patients receiving steroids for pediatric ASCI were significantly more likely to experience complications than patients not receiving steroids. The findings presented, including complications of steroid use, support removal of high-dose MPSS as a treatment option for pediatric ASCI.

Congenital and Hereditary Diseases of the Spinal Cord.

Congenital anomalies of the spinal cord can pose a diagnostic dilemma to the radiologist. Several classification systems of these anomalies exist. Antenatal ultrasound and fetal magnetic resonance imaging is playing an increasingly important role in the early diagnosis and management of patients. Understanding the underlying anatomy as well as embryology of these disorders can be valuable in correctly identifying the type of spinal cord dysraphic defect. Hereditary spinal cord diseases are rare but can be devastating. When the onset is in adulthood, delay in diagnosis is common. Although the spine findings are nonspecific, some imaging features combined with brain imaging findings can be distinctive. Sometimes, the radiologist may be the first to raise the possibility of these disorders.

Differentiating Closed Versus Open Spinal Dysraphisms on Fetal MRI.

OBJECTIVE: The purpose of this study is to identify differences in findings between open and closed spinal dysraphisms seen on fetal MR images. MATERIALS AND METHODS: A single-institution retrospective analysis of fetal MR images for spinal dysraphism was performed. Postnatal images and clinical and operative reports were reviewed. RESULTS: Sixteen fetuses with postnatally confirmed closed spinal dysraphisms were included. Of these, 25% (4/16) had posterior fossa anomalies, 12.5% (2/16) had ventriculomegaly, and 37.5% (6/16) had OEIS (omphalocele, exstrophy, imperforate anus, and spinal defects) complex. Of 90 fetuses with postnatally confirmed open spinal dysraphism, 95.6% (86/90) had posterior fossa anomalies, 85.6% (77/90) had ventriculomegaly, and none had OEIS complex. Twenty fetuses with open spinal dysraphism were randomly selected to compare with fetuses with closed spinal dysraphisms. Continuity of the epidermal and subcutaneous tissues with the sac wall on fetal MR images was seen in 93.8% (15/16) of patients with closed spinal dysraphisms, as opposed to 5% (1/20) of patients with open spinal dysraphisms. The mean (± SD) sac wall thickness was less in open (0.7 ± 0.6 mm) than closed (2.9 ± 1.3 mm; p < 0.001) spinal dysraphism. None of the fetuses had T1-hyperintense fat within the defect. CONCLUSION: On fetal MR images, closed spinal dysraphisms tend to have a sac wall in continuity with the epidermal and subcutaneous tissues, a thicker sac wall, fewer posterior fossa anomalies, and high association with OEIS complex.

Prenatal and postnatal evaluation for syringomyelia in patients with spinal dysraphism.

OBJECT: Syringomyelia can be diagnosed in isolation but is more commonly found in the presence of craniocervical junction anomalies or spinal dysraphism. The origin of syringomyelia has been hypothesized to be either congenital or acquired. The purpose of this study was to determine the incidence of syringomyelia within the fetal and postnatal population with neural tube defects (NTDs). METHODS: A review was performed of the authors' fetal MRI database of pregnancies with imaging between March 2004 and November 2011 for evaluation of an intrauterine anomaly detected via prenatal ultrasonography. Those cases with an NTD were then selected and a chart review was performed of all prenatal and postnatal imaging as well as available clinical history. RESULTS: A total of 2362 fetal MRI examinations were performed, and 109 of these were patients with an NTD. Of the 2362 studies reviewed, 2 cases of fetal syringomyelia were identified. Both fetal syrinxes were identified in fetuses with CSF flow disturbances (1 case each of encephalocele and myelomeningocele). Both fetal MRI examinations were performed late in gestation, at 31 and 38 weeks, respectively. The patient with an encephalocele was excluded from the spinal NTD population; therefore a syrinx was identified in 0.08% (2/2362) of the entire population of fetuses who underwent MRI, or 0.9% (1/109) of fetuses with a spinal NTD. Sixty-three of the 109 patients with an NTD had postnatal clinical data available for review. Twenty-nine (46%) of 63 had a syrinx identified during the follow-up period. Of this group, 50 patients had an open NTD and 27 (54%) of 50 developed a syrinx. Among the patients with an open NTD who developed a syrinx, only 7% did not have or develop hydrocephalus, compared with 35% of the patients who did not develop a syrinx (p < 0.05). There were nonsignificantly more frequent shunt revisions among those patients who developed a syrinx, and a syrinx developed in all patients who required surgical Chiari malformation decompression or tethered cord release. The initial identification of a spinal cord syrinx varied greatly between patients, ranging from 38 weeks gestation to greater than 4 years of age. CONCLUSIONS: These data suggest that syringomyelia is not a congenital embryonic condition. A syrinx was not identified in fetuses who underwent imaging for other intrauterine anomalies. In the population of patients with NTDs who are known to be at high risk for developing syringomyelia, the pathology was only identified in 2 third-trimester fetuses or postnatally, typically in the presence of hydrocephalus, shunt placement, Chiari malformation decompression, or tethered cord release. The study supports the authors' hypothesis that a syrinx is an acquired lesion, most likely due to the effects of abnormal CSF flow.

Outcome, reoperation, and complications in 99 consecutive children operated for tight or fatty filum.

OBJECTIVE: Recent studies have suggested that retethering in patients operated for a tight or fatty filum is higher than previously predicted. In this retrospective review, outcome, complications, and risk of reoperation for recurrent tethered cord syndrome (TCS) at our own institution were investigated. METHODS: The medical records of 100 consecutive children who underwent initial division of the filum terminale at Cincinnati Children's Hospital Medical Center (November 1995-May 2006) for a tight or fatty filum were reviewed. One patient was excluded due to previous spinal surgery at an outside institution. Presenting symptoms/signs, magnetic resonance imaging findings, complications, postoperative symptoms/signs, and need for reoperation were recorded. Mean follow-up for 97 of the 99 patients was 33 months; 80 were followed for 6 months or more and 68 were followed for 12 months or more. RESULTS: The most common presenting symptoms were bladder and/or bowel dysfunction, followed by gait abnormality, back pain, and spasticity. At last follow-up, 85 patients were improved or stable, whereas 12 patients had at least one symptom or sign that had worsened. Five children required a second operation for recurrent TCS. Mean time to reoperation was 58 months (range 22-73 months). Arachnoid adhesions accounted for the retethering in four of five patients. There were a total of 12 complications in 9 patients including 5 wound infections, 4 cerebrospinal fluid leaks, 1 pseudomeningocele, 1 stitch abscess, and 1 transient headache. CONCLUSIONS: Division of a tight or fatty filum, in this consecutive series of pediatric patients, resulted in improved or stable neurological symptoms in 88% of patients. However, the complication and reoperation rate for recurrent TCS were not insignificant. Future studies aimed at reducing complications and retethering in this population may be warranted.

Microlaparoscopic-assisted lumboperitoneal shunt in the lateral position for pseudotumor cerebri in a morbidly obese adolescent.

BACKGROUND: Pseudotumor cerebri or idiopathic intracranial hypertension is a known complication of morbid obesity that often requires neurosurgical intervention for worsening symptoms. Placement of a lumboperitoneal shunt (LPS) is one of the treatment options, but in a morbidly obese patient it can be technically challenging. We describe the use of 3-mm instrumentation for assistance in placing the peritoneal end of the shunt. CASE REPORT: A 16-year-old morbidly obese girl with a diagnosis of pseudotumor cerebri and decreasing visual acuity and contraction of her visual fields underwent lumboperitoneal shunt placement. Due to her body habitus secondary to her morbid obesity a microlaparoscopic-assisted approach was utilized for placement of the peritoneal end of the lumboperitoneal shunt. RESULTS: No operative or postoperative problems occurred, and she was discharged home with resolution of symptoms. Her visual acuity and fields had normalized at 3-month follow-up. CONCLUSION: Microlaparoscopic-assisted lumboperitoneal shunt placement in the lateral position is an efficient and safe method for the treatment of pseudotumor cerebri. It is a minimally invasive, simple, effective tool for placing the peritoneal catheter for LPS.