✓ The authors describe the cases of three children in whom atlantoaxial instability was caused by os odontoideum, all requiring surgical fixation. Although C1–2 rod/cantilever constructs involving C-2 pedicle screws and C1–2 transarticular screws have been widely applied in adults, only C1–2 transarticular screw fixation has been reported in children. Both of these constructs potentially place the vertebral artery (VA) at risk because of the variable location of the transverse foramen. Atlantoaxial fixation with C-2 translaminar screws has recently been reported in adult cases in which the risk of VA injury was reduced. The authors report the successful results of rigid atlantoaxial fixation in three children in whom bilateral crossing C-2 translaminar screws were placed, and they discuss the possible advantages of this technique in the pediatric population.
Jeffrey R. Leonard and Neill M. Wright
Amrita Hari-Raj, Lauren Q. Malthaner, Junxin Shi, Jeffrey R. Leonard, and Julie C. Leonard
CSF shunt placement is the primary therapy for hydrocephalus; however, shunt malfunctions remain common and lead to neurological deficits if missed. There is a lack of literature characterizing the epidemiology of children with possible shunt malfunctions presenting to United States emergency departments (EDs).
A retrospective study was conducted of the 2006–2017 National Emergency Department Sample. The data were queried using an exhaustive list of Current Procedural Terminology and International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision codes representing children with hydrocephalus diagnoses, diagnostic imaging for shunt malfunctions, and shunt-related surgical revision procedures.
In 2017, there were an estimated 16,376 ED visits for suspected shunt malfunction. Children were more commonly male (57.9%), ages 0–4 years (42.2%), and publicly insured (55.8%). Many did not undergo diagnostic imaging (37.2%), and of those who did, most underwent head CT scans (43.7%). Between 2006 and 2017, pediatric ED visits for suspected shunt malfunction increased 18% (95% CI 12.1–23.8). The use of MRI increased substantially (178.0%, 95% CI 176.9–179.2). Visits resulting in discharge home from the ED increased by 76.3% (95% CI 73.1–79.4), and those involving no surgical intervention increased by 32.9% (95% CI 29.2–36.6).
Between 2006 and 2017, ED visits for children to rule out shunt malfunction increased, yet there was a decline in surgical intervention and an increase in discharges home from the ED. Possible contributing factors include improved clinical criteria for shunt evaluation, alternative CSF diversion techniques, changing indications for shunt placement, and increased use of advanced imaging in the ED.
Report of 6 cases
Manish N. Shah, Jeffrey R. Leonard, and Arie Perry
Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a rare, recently described WHO Grade I neoplasm. The authors report 6 examples of RGNT arising primarily from the cerebellar vermis. All the patients were female, and the mean age of presentation was 24.8 years. The original diagnoses included pilocytic astrocytoma, ependymoma, cerebellar dysembryoplastic neuroepithelial tumor (DNT), and oligodendroglioma. The cases showed classic pathological characteristics, although in 2 cases the lesions included DNT-like “floating neurons” involving Purkinje cells, a feature which has not been previously reported to the authors' knowledge. The clinical outcome was excellent with no recurrences after complete resection. These cases expand the known clinical and histological spectrum of this rare tumor type. Given the lack of fourth ventricle involvement in most of these cases, the authors suggest revising the name to RGNT of the posterior fossa.
Nicholas Theodore and Harold L. Rekate
Ivan Stoev, Alexander K. Powers, Joan A. Puglisi, Rebecca Munro, and Jeffrey R. Leonard
The sacroiliac (SI) joint can be a pain generator in 13%–27% of cases of back pain in adults. These numbers are largely unknown for the pediatric population. In children and especially girls, development of the pelvic girdle makes the SI joint prone to misalignment. Young athletes sustain repeated stress on their SI joints, and sometimes even minor trauma can result in lasting pain that mimics radiculopathy. The authors present a series of 48 pediatric patients who were evaluated for low-back pain and were found to have SI joint misalignment as the cause of their symptoms. They were treated with a simple maneuver described in this paper that realigned their SI joint and provided significant improvement of symptoms.
A retrospective review of the electronic records identified 48 patients who were referred with primary complaints of low-back pain and were determined to have SI joint misalignment during bedside examination maneuvers described here. Three patients did not have a record of their response to treatment and were excluded. Patients were evaluated by a physical therapist and had the realignment procedure performed on the day of initial consultation. The authors collected data regarding the immediate effect of the procedure, as well as the duration of pain relief at follow-up visits.
Eighty percent of patients experienced dramatic improvement in symptoms that had a lasting effect after the initial treatment. The majority of them were given a home exercise program, and only 2 of the 36 patients who experienced significant relief had to be treated again. Fifty-three percent of all patients had immediate and complete resolution of symptoms. Three of the 48 patients had missing data from the medical records and were excluded from computations.
Back pain is multifactorial, and the authors' data demonstrate the potential importance of SI joint pathology. Although the technique described here for treatment of misaligned SI joints in the pediatric patients is not effective in all, the authors have observed significant improvement in 80% of cases. Often it is difficult to determine the exact cause of back pain, but when the SI joint is suspected as the primary pathology, the authors have described a simple and effective bedside treatment that should be attempted prior to the initiation of further testing and surgery.
Donncha F. O'Brien, Tae-Sung Park, Joan A. Puglisi, David R. Collins, Eric C. Leuthardt, and Jeffrey R. Leonard
A retrospective study was performed to determine the following: 1) whether children who walk independently after selective dorsal rhizotomy (SDR) undergo fewer subsequent orthopedic operations than those who walk with assistance; and 2) the effect of age at SDR on the rate of orthopedic operations.
The cases of 158 children with spastic diplegia who were 2 to 14 years of age when they underwent SDR were followed over a 5- to 9-year period. Patients were grouped by age at the time of SDR as follows: 2 to 3 years (Group 1), 4 to 7 years (Group 2), and 8 to 14 years (Group 3). Follow-up data showed that children in all age groups who walked independently after SDR underwent fewer orthopedic operations than did children who walked with assistance. Overall rates of orthopedic surgery 5 to 9 years after SDR at last follow up were 24% for independent walkers and 51% for assisted walkers. Two-way categorical analysis (age group by ambulation) yielded a highly significant effect of ambulation (p = 0.0003). Children in Group 1 needed the fewest orthopedic operations at follow-up evaluation. In the older age groups (Groups 2 and 3), those who walked independently at the time of SDR underwent fewer orthopedic operations after SDR than did walkers who required assistance (p = 0.01).
These data are of value in advising parents about the likelihood of orthopedic surgery based on the child's gait status both at the time of SDR and at follow-up evaluation. Orthopedic surgery is more likely in patients destined to be nonambulators.
Ammar H. Hawasli, Thomas L. Beaumont, Timothy W. Vogel, Albert S. Woo, and Jeffrey R. Leonard
Acalvaria is a rare congenital malformation characterized by an absence of skin and skull. The authors describe a newborn at an estimated 38 weeks gestational age who was delivered via cesarean section from a 32-year-old mother. Upon delivery, the child was noted to have a frontal encephalocele and an absence of calvaria including skull and skin overlying the brain. A thin membrane representing dura mater was overlying the cortical tissue. After multiple craniofacial operations, including repair of the encephalocele and application of cultured keratinocytes over the rostral defect, the patient demonstrated significant closure of the calvarial defect and was alive at an age of more than 17 months with near-average development.
Case report and review of the literature
William W. Ashley Jr., Prithvi Narayan, Tae Sung Park, Pang-hsien Tu, Arie Perry, and Jeffrey R. Leonard
✓Juvenile xanthogranuloma (JXG) is a specialized form of non—Langerhans cell histiocyte proliferation that occurs in children. The majority of cases present as a solitary cutaneous lesion with a predilection for the head and neck region; however, isolated lesions occasionally have been identified in the central nervous system. The cutaneous forms of JXG usually follow a benign course. Other physicians have reported surgery as the first line of treatment in symptomatic patients with accessible lesions. Adjuvant therapies may be indicated for multicentric or surgically inaccessible lesions. The authors describe an unusual case of isolated intraparenchymal JXG in an asymptomatic child with no cutaneous manifestations and provide a review of the literature.
William W. Ashley Jr., Robert C. McKinstry, Jeffrey R. Leonard, Matthew D. Smyth, Benjamin C. Lee, and Tae Sung Park
The authors examine the use of rapid-sequence magnetic resonance (rsMR) imaging to make the diagnosis of malfunctioning and/or infected shunts in patients with hydrocephalus. Computerized tomography (CT) scanning is usually used in this context because it rapidly acquires high-quality images, yet it exposes pediatric patients to particularly high levels of radiation. Standard MR imaging requires longer image acquisition time, is associated with movement artifact, and, in children, usually requires sedation. Standard MR imaging provides greater structural resolution, yet visualization of ventricular catheters is relatively poor.
The authors analyzed a series of 67 rsMR imaging examinations performed without sedation in pediatric patients with hydrocephalus whose mean age was 4 years at the time of the examination. The mean study duration was 22 minutes. Catheter visualization was good or excellent in more than 75% of studies reviewed, and image quality was good or excellent in more than 60% of studies reviewed. The authors analyzed cancer risk with a model used for atomic bomb survivors. Fifty percent of their patients with hydrocephalus had undergone more than four brain imaging studies (CT or MR imaging) in their lifetimes. For the many patients who had undergone more than 15 studies, the total estimated lifetime attributable cancer mortality risk was calculated to be at least 0.35%.
Rapid-sequence MR imaging yields reliable visualization of the ventricular catheter and offers superior anatomical detail while limiting radiation exposure. The authors' protocol is rapid and each image is acquired separately; therefore, motion artifact is reduced and the need for sedation is eliminated. They recommend the use of rsMR imaging for nonemergent evaluation of pediatric hydrocephalus.
Francesco T. Mangano, Jose A. Menendez, Tracy Habrock, Prithvi Narayan, Jeffrey R. Leonard, Tae Sung Park, and Matthew D. Smyth
The use of adjustable differential pressure valves has been recommended to improve ventriculoperitoneal (VP) shunt performance in selected patients; however, published data are scarce regarding their clinical reliability. Recently, the identification of a number of malfunctioning programmable valves during shunt revision surgery in children prompted a retrospective review of valve performance in this patient cohort.
The authors performed a retrospective chart analysis of 100 patients with programmable valve shunts and 89 patients with nonprogrammable valve shunts implanted at the St. Louis Children's Hospital between April 2002 and June 2004. They noted the cause of hydrocephalus, the type of shunt malfunction, and cerebrospinal fluid (CSF) protein levels. Regular clinical follow up ranged from 1 to 26 months, with a mean follow-up time of 9.75 months for patients with programmable valves and 10.4 months for patients with nonprogrammable valves.
Patient ages ranged from 2 weeks to 18 years. One hundred patients had 117 programmable valves implanted, and 35 of these patients (35%) underwent shunt revision because of malfunction. The programmable valve itself malfunctioned in nine patients who had undergone shunt revision (11.1%/year of follow up). The nonprogrammable valve group had no valve malfunctions. The overall VP shunt revision rate in the nonprogrammable valve group was 20.2%. No significant differences were identified when CSF protein levels and specific malfunction types were compared within the programmable valve and nonprogrammable valve groups.
In this study the authors demonstrated an annualized intrinsic programmable valve malfunction rate of 11.1%, whereas during the same period no intrinsic valve malfunctions were noted with nonprogrammable valve systems for similar causes of hydrocephalus. The CSF protein levels did not correlate with observed valve malfunction rates. Further evaluation in a prospective, randomized fashion will elucidate specific indications for programmable valve systems and better determine the reliability of these valves in the pediatric population.