Tofey J. Leon, Elizabeth N. Kuhn, Anastasia A. Arynchyna, Burkely P. Smith, R. Shane Tubbs, James M. Johnston, Jeffrey P. Blount, Curtis J. Rozzelle, W. Jerry Oakes and Brandon G. Rocque
There are sparse published data on the natural history of “benign” Chiari I malformation (CM-I)—i.e., Chiari with minimal or no symptoms at presentation and no imaging evidence of syrinx, hydrocephalus, or spinal cord signal abnormality. The purpose of this study was to review a large cohort of children with benign CM-I and to determine whether these children become symptomatic and require surgical treatment.
Patients were identified from institutional outpatient records using International Classification of Diseases, 9th Revision, diagnosis codes for CM-I from 1996 to 2016. After review of the medical records, patients were excluded if they 1) did not have a diagnosis of CM-I, 2) were not evaluated by a neurosurgeon, 3) had previously undergone posterior fossa decompression, or 4) had imaging evidence of syringomyelia at their first appointment. To include only patients with benign Chiari (without syrinx or classic Chiari symptoms that could prompt immediate intervention), any patient who underwent decompression within 9 months of initial evaluation was excluded. After a detailed chart review, patients were excluded if they had classical Chiari malformation symptoms at presentation. The authors then determined what changes in the clinical picture prompted surgical treatment. Patients were excluded from the multivariate logistic regression analysis if they had missing data such as race and insurance; however, these patients were included in the overall survival analysis.
A total of 427 patients were included for analysis with a median follow-up duration of 25.5 months (range 0.17–179.1 months) after initial evaluation. Fifteen patients had surgery at a median time of 21.0 months (range 11.3–139.3 months) after initial evaluation. The most common indications for surgery were tussive headache in 5 (33.3%), syringomyelia in 5 (33.3%), and nontussive headache in 5 (33.3%). Using the Kaplan-Meier method, rate of freedom from posterior fossa decompression was 95.8%, 94.1%, and 93.1% at 3, 5, and 10 years, respectively.
Among a large cohort of patients with benign CM-I, progression of imaging abnormalities or symptoms that warrant surgical treatment is infrequent. Therefore, these patients should be managed conservatively. However, clinical follow-up of such individuals is justified, as there is a low, but nonzero, rate of new symptom or syringomyelia development. Future analyses will determine whether imaging or clinical features present at initial evaluation are associated with progression and future need for treatment.
Daxa M. Patel, R. Shane Tubbs, Gigi Pate, James M. Johnston Jr. and Jeffrey P. Blount
Surveillance imaging of the cerebral ventricles can be valuable in following up children with shunt-treated hydrocephalus. There also, however, has been recent increased awareness and concern over the potential risk associated with imaging-related radiation exposure in children. Magnetic resonance imaging represents an imaging alternative that does not use ionizing radiation; however, its practical utility has been limited due to the near-uniform requirement for sedation or general anesthesia in children. Magnetic resonance imaging without sedation is often futile because of the movement artifact produced by the nonsedated pediatric patient. Some studies have demonstrated the feasibility of using fast-sequence MRI (fsMRI), but the reported experiences are limited. The authors have incorporated fsMRI into their routine shunt surveillance imaging paradigms and report here a 5-year experience with this modality.
The authors initially started using fsMRI for routine surveillance in a single clinic in 2008 and have gradually increased their institutional utilization of this modality as experience has accumulated and protocols have been refined. Imaging sequences obtained for each child include an axial T2-weighted half-Fourier acquisition single-shot turbo spin-echo (HASTE), coronal T2-weighted HASTE, and sagittal T2-weighted HASTE images. The authors conducted a retrospective chart and imaging review. They rated each fsMR image according to 5 visibility parameters: 1) ventricle size, 2) ventricle configuration, 3) presence or absence of transependymal flow, 4) presence or absence of motion artifact, and 5) visualization of the ventricular catheter. Each parameter was graded as 1 (present) or 0 (absent). Thus, the maximum value assigned to each scan could be 5 and the minimum value assigned to each scan could be 0. Interrater reliability between pairs of observers was calculated using the Kendall's tau-b and intraclass coefficients.
Two hundred patients underwent fsMRI. No child required sedation. The average duration of examinations was approximately 3.37 minutes, and mean age of the patients was 5.7 years. Clinically useful images were attained in all cases. Overall quality of the fsMRI studies based on the 5 different visibility parameters showed that 169 images (84.5%) included 4 or 5 parameters (score ≥ 4) and had statistically significant excellent quality. The Kendall's tau-b for the overall fsMRI ratings was 0.82 (p = 0.002) and the intraclass coefficient was 0.87 (p < 0.0001).
In the present cohort of 200 patients, fsMRI studies were shown to have an excellent overall quality and a statistically significant high degree of interrater reliability. Consequently, the authors propose that fsMRI is a sufficiently effective modality that eliminates the need for sedation and the use of ionizing radiation and that it should supplant CT for routine surveillance imaging in hydrocephalic patients.
Joshua J. Chern, Mitchel Muhleman, R. Shane Tubbs, Joseph H. Miller, James M. Johnston, John C. Wellons III, Jeffrey P. Blount, W. Jerry Oakes and Curtis J. Rozzelle
Most children with spina bifida aperta have implanted CSF shunts. However, the efficacy of adding surveillance imaging to clinical evaluation during routine follow-up as a means to minimize the hazard of shunt failure has not been thoroughly studied.
A total of 396 clinic visits were made by patients with spina bifida aperta and shunt-treated hydrocephalus in a spina bifida specialty clinic during the calendar years 2008 and 2009 (initial clinic visit). All visits were preceded by a 6-month period during which no shunt evaluation of any kind was performed and were followed by a subsequent visit in the same clinic. At the initial clinic visit, 230 patients were evaluated by a neurosurgeon (clinical evaluation group), and 166 patients underwent previously scheduled surveillance CT scans in addition to clinical evaluation (surveillance imaging group). Subsequent unexpected events, defined as emergency department (ED) visits and caregiver-requested clinic visits, were reviewed. The time to an unexpected event and the likelihood of event occurrence in each of the 2 groups were compared using Cox proportional hazards survival analysis. The outcome and complications of shunt surgeries were also reviewed.
The clinical characteristics of the 2 groups were similar. In the clinical evaluation group, 2 patients underwent shunt revision based on clinical findings in the initial visit. In the subsequent follow-up period, there were 27 visits to the ED and 25 requested clinic visits that resulted in 12 shunt revisions. In the surveillance imaging group, 11 patients underwent shunt revision based on clinical and imaging findings in the initial visit. In the subsequent follow-up period, there were 15 visits to the ED and 9 requested clinic visits that resulted in 8 shunt revisions. Patients who underwent surveillance imaging on the day of initial clinic visit were less likely to have an unexpected event in the subsequent follow-up period (relative risk 0.579, p = 0.026). The likelihood of needing shunt revision and the morbidity of shunt malfunction was not significantly different between the 2 groups.
Surveillance imaging in children with spina bifida aperta and shunted hydrocephalus decreases the likelihood of ED visits and caregiver-requested clinic visits in the follow-up period, but based on this study, its effect on mortality and morbidity related to shunt malfunction was less clear.
Joshua J. Chern, Joseph H. Miller, R. Shane Tubbs, Thomas R. Whisenhunt, James M. Johnston, John C. Wellons III, Curtis J. Rozzelle, Jeffrey P. Blount and W. Jerry Oakes
A large volume of patients presented to a Level I pediatric trauma center during and after a recent tornado disaster. Injuries of the central and peripheral nervous systems and the medical responses of a pediatric neurosurgical team are reviewed.
The clinical courses of patients who suffered cranial, spinal, and peripheral nerve injuries due to the tornado storm are reported. The clinical actions taken by the neurosurgical team during and after the event are reviewed and the lessons learned are discussed.
The tornado storm system moved through the Tuscaloosa and Birmingham metropolitan areas on the early evening hours of April 27, 2011. Twenty-four patients received care from the neurosurgical team. A total of 11 cranial (including placement of an external ventricular drain), 2 spine, and 2 peripheral procedures were performed for the victims. Nine procedures were performed within the first 12 hours of the event, and an additional 6 surgeries were performed in the following 24 hours. Injuries of the peripheral nervous system often presented in a delayed fashion. Several key components were identified that enabled adequate neurosurgical care for a large influx of acute patients.
Massive casualties due to tornados are rare. A well-organized physician team working with the hospital administration may decrease the mortality and morbidity of such events.