Os odontoideum is a common cause of atlantoaxial instability in the pediatric population. The authors present the cases of 2 patients whose initial clinical presentation and MR imaging findings were suggestive of an intramedullary neoplasm, but whose ultimate diagnosis was determined to be cervical spine instability and cord injury due to os odontoideum.
Paul R. Gigante, Neil A. Feldstein and Richard C. E. Anderson
Paul Klimo Jr., Richard C. E. Anderson and Douglas L. Brockmeyer
✓Two cases of a previously undescribed cervical spinal anomaly distinct from cervical spondylolysis are presented. The authors report the first detailed description of a congenital vertebral anomaly characterized by multilevel cervical spondylolysis, sagittal deformity, and spinal cord compression. The sine qua non of the condition is a lack of communication between the anterior and posterior columns of the cervical spinal canal, which may occur over several vertebral levels. A kyphotic deformity of the anterior column occurs, whereas the posterior column may have relatively normal alignment. The underlying biomechanical stresses caused by the anterior–posterior column disconnection result in spinal instability and progressive kyphotic deformity, often to a profound degree. Two children, 2 and 3 years of age, presented with congenital multilevel disconnection and myelopathy. In the first stage of treatment, each underwent an anterior decompression, reduction, and reconstruction of the involved segments. This was followed by posterior stabilization and fusion as a separate procedure. In both patients, the myelopathy improved and a solid, circumferential fusion was achieved. The authors’ success in treating these patients indicates that management of these conditions can be based on the principles of deformity correction, spinal cord decompression, and combined anterior–posterior arthrodesis.
Benjamin C. Kennedy, Michael B. Cloney, Richard C. E. Anderson and Neil A. Feldstein
Choroid plexus papillomas (CPPs) are rare neoplasms, often found in the atrium of the lateral ventricle of infants, and cause overproduction hydrocephalus. The extensive vascularity and medially located blood supply of these tumors, coupled with the young age of the patients, can make prevention of blood loss challenging. Preoperative embolization has been advocated to reduce blood loss and prevent the need for transfusion, but this mandates radiation exposure and the additional risks of vessel injury and stroke. For these reasons, the authors present their experience using the superior parietal lobule approach to CPPs of the atrium without adjunct therapy.
A retrospective review was conducted of all children who presented to Columbia University/Morgan Stanley Children's Hospital of New York with a CPP in the atrium of the lateral ventricle and who underwent surgery using a superior parietal lobule approach without preoperative embolization.
Nine children were included, with a median age of 7 months. There were no perioperative complications or new neurological deficits. All patients had intraoperative blood loss of less than 100 ml, with a mean minimum hematocrit of 26.9% (range 19.6%–36.2%). No patients required a blood transfusion. The median follow-up was 39 months, during which time no patient demonstrated residual or recurrent tumor on MRI, nor did any have an increase in ventricular size or require CSF diversion.
The superior parietal lobule approach is safe and effective for very young children with CPPs in the atrium of the lateral ventricle. The results suggest that preoperative embolization is not essential to avoid transfusion or achieve overall good outcomes in these patients. This management strategy avoids radiation exposure and the additional risks associated with embolization.
Todd C. Hankinson, Elizabeth J. Fontana, Richard C. E. Anderson and Neil A. Feldstein
The traditional reasons for surgical intervention in children with single-suture craniosynostosis (SSC) are cosmetic improvement and the avoidance/treatment of intracranial hypertension, which has been thought to contribute to neurocognitive deficits. Despite considerable work on the topic, the exact prevalence of intracranial hypertension in the population of patients with SSC is unknown, although it appears to be present in only a minority. Additionally, recent neuropsychological and anatomical literature suggests that the subtle neurocognitive deficits identified in children with a history of SSC may not result from external compression. They may instead reflect an underlying developmental condition that includes disordered primary CNS development and early suture fusion. This implies that current surgical techniques are unlikely to prevent neurocognitive deficits in patients with SSC. As such, the most common indication for surgical treatment in SSC is cosmetic, and most patients benefit from considerable subjective cosmetic normalization following surgery. Pediatric craniofacial surgeons have not, however, agreed upon objective means to assess postoperative cranial morphological improvement. We should therefore endeavor to agree upon objective craniometric tools for the assessment of operative outcomes, allowing us to accurately compare the various surgical techniques that are currently available.
Todd C. Hankinson, Eli Grunstein, Paul Gardner, Theodore J. Spinks and Richard C. E. Anderson
In rare cases, children with a Chiari malformation Type I (CM-I) suffer from concomitant, irreducible, ventral brainstem compression that may result in cranial neuropathies or brainstem dysfunction. In these circumstances, a 360° decompression supplemented by posterior stabilization and fusion is required. In this report, the authors present the first experience with using an endoscopic transnasal corridor to accomplish ventral decompression in children with CM-I that is complicated by ventral brainstem compression.
Two children presented with a combination of occipital headaches, swallowing dysfunction, myelopathy, and/or progressive scoliosis. Imaging studies demonstrated CM-I with severely retroflexed odontoid processes and ventral brainstem compression. Both patients underwent an endoscopic transnasal approach for ventral decompression, followed by posterior decompression, expansive duraplasty, and occipital-cervical fusion.
In both patients the endoscopic transnasal approach provided excellent ventral access to decompress the brainstem. When compared with the transoral approach, endoscopic transnasal access presents 4 potential advantages: 1) excellent prevertebral exposure in patients with small oral cavities; 2) a surgical corridor located above the hard palate to decompress rostral pathological entities more easily; 3) avoidance of the oral trauma and edema that follows oral retractor placement; and 4) avoidance of splitting the soft or hard palate in patients with oral-palatal dysfunction from ventral brainstem compression.
The endoscopic transnasal approach is atraumatic to the oral cavity, and offers a more superior region of exposure when compared with the standard transoral approach. Depending on their comfort level with endoscopic surgical techniques, pediatric neurosurgeons should consider this approach in children with pathological entities requiring ventral brainstem decompression.
Omar N. Syed, Todd C. Hankinson, William J. Mack, Neil A. Feldstein and Richard C. E. Anderson
Pediatric neurosurgeons frequently care for children with traumatic scalp and skull injury. Foreign objects are often observed on imaging and may influence the clinician's decision-making process. The authors report on 2 cases of poorly visualized hair beads that had become embedded into the skull during blunt trauma. In both cases, skull radiography and CT scanning demonstrated depressed, comminuted fractures with poorly demonstrated spherical radiolucencies in the overlying scalp. The nature of these objects was initially unclear, and they could have represented air that entered the scalp during trauma. In one case, scalp inspection demonstrated no evidence of the bead. In the other case, a second bead was observed at the site of scalp laceration. In both cases, the beads were surgically removed, the fractures were elevated, and the patients recovered uneventfully. Radiolucent fashion accessories, such as hair beads, may be difficult to appreciate on clinical examination and may masquerade as clinically insignificant air following cranial trauma. If they are not removed, these foreign bodies may pose the risk of an infection. Pediatric neurosurgeons should consider hair accessories in the differential diagnosis of foreign bodies that may produce skull fracture following blunt trauma.
Richard C. E. Anderson, Ronald G. Emerson, Kathryn C. Dowling and Neil A. Feldstein
Object. The optimal treatment for patients with symptoms related to Chiari I malformation remains controversial. Although a suboccipital decompression with duraplasty is most commonly performed, there may be a subset of patients who improve in response to bone decompression alone. In an initial attempt to identify such patients, we performed a continuous study of intraoperative brainstem auditory evoked potentials (BAEPs) in patients undergoing a standard decompression with duraplasty and compared conduction times at three different time points: 1) baseline while the patient is supine (before positioning); 2) immediately after opening of the bone and release of the atlantooccipital membrane (that is, the dural band); and 3) after opening of the dura mater.
Methods. Eleven children and young adults (mean age 9.8 years) with symptoms related to Chiari I malformation underwent suboccipital decompression and duraplasty with intraoperative monitoring of BAEPs and somatosensory evoked potentials (SSEPs). Six patients (55%) had associated syringomyelia.
At baseline, the I to V interpeak latency (IPL) for both sides (total 21 BAEPs) was 4.19 ± 0.22 msec (mean ± standard deviation). After complete bone decompression and before the dura mater was opened, the I to V IPL decreased to 4.03 ± 0.25 msec (p = 0.0005). When the dura was opened, however, no further decrease in the I to V IPL was detected (4.03 ± 0.25 msec; p = 0.6). The SSEPs remained stable throughout the procedure.
Conclusions. In children and young adults undergoing suboccipital decompression with duraplasty for Chiari I malformation, the vast majority of improvement in conduction through the brainstem occurs after bone decompression and division of the atlantooccipital membrane, rather than after opening of the dura. Additional studies are needed to establish whether the improvement seen with BAEP monitoring during bone decompression will predict long-term clinical improvement in these patients.