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
Alfred T. Ogden, Neil A. Feldstein and Paul C. McCormick
Although there has been considerable experience with anterior approaches to ventral intradural, extramedullary, and pial-based spinal lesions, there is no information in the literature regarding the safety and feasibility of the resection of an intramedullary tumor via an anterior approach. The authors report on the gross-total resection of an intramedullary cervical pilocytic astrocytoma via a C-7 corpectomy and anterior myelotomy. The surgery proceeded without complication, and postoperatively the patient maintained the preoperative deficit of mild unilateral hand weakness but had no sensory deficits. Follow-up MR imaging at 6 months showed gross-total macroscopic resection. Selected intramedullary tumors can be safely removed via an anterior approach. This approach avoids the typical sensory dysfunction associated with posterior midline myelotomy.
Jason A. Ellis, Paul C. McCormick II, Neil A. Feldstein and Saadi Ghatan
Cystic lesions in the atrium (trigone) of the lateral ventricle may become symptomatic due to obstruction of physiological CSF circulation and/or from mass effect on adjacent structures. A minimally invasive approach that not only allows for straightforward access to multiple regions of the atrial cyst wall, but also enables direct inspection of the entire lateral ventricular system, has not been elaborated. In this paper the authors describe their experience with the endoscopic transoccipital horn approach for treating cystic lesions in the atrium of the lateral ventricle.
A retrospective review was performed of all patients who underwent endoscopic surgical treatment for cysts in the atrium of the lateral ventricle between 1999 and 2014.
The cohort consisted of 13 consecutive patients who presented with symptomatic lateral ventricular entrapment due to the presence of an atrial cyst. There were 9 male and 4 female patients, with a median age of 5 years. Headache was the most common complaint at presentation. The transoccipital horn approach facilitated successful cyst reduction and fenestration in all cases. Temporal and occipital horn entrapment was reversed in all cases, with reestablishment of a physiological CSF flow pattern throughout the ventricles. Hydrocephalus was also reversed in all patients presenting with this neuroimaging finding at presentation. No cyst or ventricular entrapment was noted to recur during a mean follow-up period of 36 months. No patient in the study cohort required repeat surgery or permanent CSF diversion postoperatively.
The endoscopic transoccipital horn approach represents a safe and effective treatment strategy for patients with symptomatic atrial cysts of the lateral ventricle. Using this minimally invasive technique, all poles of the lateral ventricular system can be visualized and the unobstructed flow of CSF can be confirmed after cyst resection obviating the need for additional diversion.
Jason A. Ellis, Juan C. Mejia Munne, Neil A. Feldstein and Philip M. Meyers
Sinus pericranii is an uncommon congenital cranial venous malformation that may become symptomatic in the pediatric population. Both dominant and accessory sinus pericranii, as determined by the intracranial venous drainage pattern, have been described. The dominant variety drain a significant proportion of the intracranial venous outflow while the accessory variety have minimal or no role in this. Classic teachings hold that dominant sinus pericranii should never be treated while accessory sinus pericranii may be safely obliterated. This determination of dominance is solely based on a qualitative assessment of standard venous phase catheter cerebral angiography, leaving some doubt regarding the actual safety of obliteration. In this paper the authors describe a simple and unique method for determining whether intracranial venous outflow may be compromised by sinus pericranii treatment. This involves performing catheter angiography while the lesion is temporarily obliterated by external compression. Analysis of intracranial venous outflow in this setting allows visualization of angiographic changes that will occur once the sinus pericranii is permanently obliterated. Thus, the safety of surgical intervention can be more fully appraised using this technique.
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.
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.