Faculty Bibliography

The authors describe the internal cranial expansion (ICE) procedure, a surgical technique that was used to treat two chronically shunt-treated children who presented with medically and surgically refractory intracranial hypertension despite the presence of functioning cerebrospinal fluid shunt systems. The ICE procedure was used as a means to increase intracranial volume without sacrificing calvarial rigidity. Intracranial volume was increased by 5% in one case and 10% in the other. Both patients have returned to their neurological and functional baselines, and they are free of symptoms related to intracranial hypertension.

OBJECT/OBJECTIVE:Atlantoaxial and occipitocervical instability in children have traditionally been treated with posterior bone and wire fusion and external halo orthoses. Recently, successful outcomes have been achieved using rigid internal fixation, particularly C1-2 transarticular screws. The authors describe flow diagrams created to help clinicians determine which method of internal fixation to use in complex anatomical circumstances when bilateral transarticular screw placement is not possible. METHODS:The records of children who underwent either atlantoaxial or occipitocervical fixation with rigid internal fixation over an 11-year period were retrospectively reviewed to define flow diagrams used to determine treatment protocols. RESULTS:Among the 95 patients identified who underwent atlantoaxial or occipitocervical fixation, the craniocervical anatomy in 25 patients (six atlantoaxial and 19 occipitocervical fixations [26%]) required alternative methods of internal fixation. Types of screw fixation included loop or rod constructs anchored by combinations of C1-2 transarticular screws (15 constructs), C-1 lateral mass screws (11), C-2 pars screws (24), C-2 translaminar screws (one), and subaxial lateral mass screws (six). The mean age of the patients (15 boys and 10 girls) was 9.8 years (range 1.3-17 years). All 22 patients with greater than 3-month follow-up duration achieved solid bone fusion and maintained stable constructs on radiographic studies. Clinical improvement was seen in all patients who had preoperative symptoms. CONCLUSIONS:Novel flow diagrams are suggested to help guide selection of rigid internal fixation constructs when performing pediatric C1-2 and occipitocervical stabilizations. Use of these flow diagrams has led to successful fusion in 25 pediatric patients with difficult anatomy requiring less common constructs.

This article addresses the key features, presentation, and current management of pediatric patients who have Chiari I and Chiari II malformations. It further discusses syringohydromyelia and scoliosis as they relate to pediatric Chiari malformations.

OBJECTIVE: Lack of human leukocyte antigens and costimulatory molecules have been suggested as mechanisms by which human malignant gliomas avoid immune recognition and elimination. METHODS: Using quantitative multiparameter flow cytometric analysis, tumor cells from patients with glioblastoma multiforme (n = 18) were examined ex vivo for the expression of human leukocyte antigen Class I and II molecules and the costimulatory molecules B7-1 and B7-2. They were compared with reactive astrocytes from peritumoral brain metastases (n = 7), and astrocytes removed during nontumor surgery (n = 5). RESULTS: In contrast to the vast majority of solid peripheral human tumors, these results demonstrate that glioblastoma multiforme frequently express both human leukocyte antigen Class I and II molecules. Like most solid peripheral tumors, glioblastoma multiforme tumor cells express few or no B7 costimulatory molecules. Functional assays using heterogeneous ex vivo tumor preparations or pure populations of ex vivo tumor cells and microglia obtained using fluorescence-activated cell sorting indicate that CD4+ T-cells are activated by tumor cells only in the presence of exogenous B7 costimulation (provided by addition of soluble agonist anti-CD28 monoclonal antibody). CONCLUSION: Thus, in contrast to many solid peripheral tumors, failure to present tumor antigens is not a likely impediment to immunotherapeutic strategies against malignant gliomas. Rather, immunotherapeutic strategies need to overcome low levels of B7 costimulation

The authors describe the case of a patient with an enhancing, intramedullary cervical spinal cord lesion and associated syrinx. Biopsy sampling of the cervical lesion was performed, and the histological findings were consistent with a demyelinating process supporting the diagnosis of multiple sclerosis (MS). Syrinx formation associated with demyelinating disease has only been described in isolated cases, almost exclusively in Japanese patients with MS. A 22-year-old woman of Caribbean descent presented with a subacute, progressive myelopathy including symptoms of pain and weakness in all extremities, bladder incontinence, and the inability to ambulate. Magnetic resonance imaging of the brain and spinal cord demonstrated an enlarged cervical cord with enhancement and central cavitation consistent with a syrinx. The patient underwent a C3-7 laminoplasty and placement of a dural graft for cord decompression as well as fenestration of the central syrinx. Biopsy sampling of the lesion was performed, and the histopathological analysis, in conjunction with subsequent laboratory and diagnostic testing, supported the diagnosis of demyelinating disease. After treatment with a course of high-dose dexamethasone and inpatient rehabilitation therapy, the patient demonstrated significant clinical improvement. Spinal cord involvement is not uncommon in patients with demyelinating disease; however, enhancing lesions associated with extensive tissue loss and syrinx formation have rarely been reported. For the consulting neurological surgeon, demyelinating disease should be included in the differential diagnosis of such lesions given the level of complexity and risk to the patient associated with open biopsy of the spinal cord.

OBJECT/OBJECTIVE:Currently, no diagnostic or procedural standards exist for clearing the cervical spine in children after trauma. The establishment of protocols has been shown to reduce the time required to accomplish clearance and reduce the number of missed injuries. The purpose of this study was to determine if reeducation and initiation of a new protocol based on the National Emergency X-Radiography Utilization Study criteria could safely increase the number of pediatric cervical spines cleared by nonneurosurgical personnel. METHODS:The authors collected and reviewed data regarding cervical spine clearance in children (age range 0-18 years) who presented to the emergency department at Primary Children's Medical Center in Salt Lake City, Utah, between 2001 and 2006 after sustaining significant trauma. Radiographic and clinical methods of clearing the cervical spine, as well as the type and management of injuries, were determined for two periods: Period I (January 2001-December 2003) and Period II (January 2004-February 2006). Between 2001 and 2003, 95% of 936 cervical spines were cleared by the neurosurgical service. Twenty-one ligamentous injuries (2.2%) and 12 fracture/dislocations (1.3%) were detected, and five patients (0.5%) required operative stabilization. Since January 2004, 585 (62.4%) of 937 cervical spines have been cleared by nonneurosurgical personnel. Twelve ligamentous injuries (1.3%) and 14 fracture/dislocations (1.5%) were identified, and four patients (0.4%) required operative stabilization. No late injuries were detected in either time period. CONCLUSIONS:The protocol outlined in the paper has been effective in detecting cervical spine injuries in children after trauma and has increased the number of cervical spines cleared by nonneurosurgical personnel by nearly 60%. Reeducation with the establishment of protocols can safely facilitate clearance of the cervical spine after trauma by nonneurosurgical personnel.

OBJECT/OBJECTIVE:Despite decades of surgical experience, the long-term consequences of occipitocervical (OC) and atlantoaxial (C1-2) fusions in children are unknown. The purpose of this study was to determine the long-term effects of these fusions on growth and alignment of the maturing cervical spine. METHODS:A retrospective chart review was conducted for patients 6 years of age or younger (mean 4.7 years, range 1.7-6.8 years) who underwent OC or C1-2 fusion at the Primary Children's Medical Center at the University of Utah within the last 10 years. Immediate postoperative plain radiographs and computed tomography (CT) scans were compared with the most recent plain and dynamic radiographs to assess changes in spinal growth and alignment. Seventeen children met entry criteria for the study. All patients had fusion documented on follow-up radiography or CT scans. At a mean follow up of 28 months, there were no cases of sagittal malalignment (kyphotic or swan-neck deformity), subaxial instability (osteophyte formation or subluxation), or unintended fusion of adjacent levels. The lordotic curvature of the cervical spine increased from a mean of 15 degrees postoperatively to 27 degrees at follow up (p = 0.06). A mean of 34% of the vertical growth of the cervical spine occurred within the fusion segment. When data were analyzed pertaining to a subgroup of five patients who underwent follow-up periods for longer than 48 months (mean 50.2 months, range 48-54 months), similar results were seen. CONCLUSIONS:Preliminary follow-up results indicate that, compared with older children, children 6 years of age or younger undergoing OC or C1-2 fusion are not at an increased risk of spinal deformity or subaxial instability. Longer follow-up periods, during which measurements of the spinal canal are taken, will be necessary to determine precisely how children's spines grow and remodel after an upper cervical spine fusion.

The management of childhood spasticity requires a multidisciplinary effort. With input from pediatricians, physical and occupational therapists, neurologists, orthotists, orthopedic surgeons, neurological surgeons, and other healthcare personnel, effective treatment for spasticity can be initiated and maintained that can lead to meaningful improvements in quality of life for vast numbers of children. Neurosurgical treatment of spasticity will continue to evolve and be refined as procedures and techniques are appropriately evaluated with reliable and validated outcome measures.

Abnormal head morphology is common among infants and often leads parents to ask their pediatricians for guidance. While the vast majority of such children development and prevent adverse neurobehavioral sequelae secondary to increased intracranial pressure or impaired cerebral growth. The coordination of a multidisciplinary team in the setting of a center experienced in the management of craniosynostosis will assure the best possible results for each patient.