Management of Sleep Apnea in Children with Chiari I Malformation: A Retrospective Study.

INTRODUCTION: The literature indicates that decompression of Chiari I malformations (CM-1) may resolve symptoms of sleep apnea. This study aims to identify the incidence of obstructive sleep apnea (OSA), central sleep apnea (CSA), and mixed sleep apnea in a cohort of pediatric CM-1 patients treated at our institution. We also assessed apnea-hypopnea index and symptomatology before and after surgery to investigate if Chiari decompression is a viable treatment for sleep apnea in CM-1 patients. Improvement relative to ENT surgical intervention was also considered. METHODS: We identified 75 patients who underwent polysomnography (PSG) from our database of 465 CM-1 patients. Sleep apnea diagnosis was based on the sleep physician's overall interpretation of the PSG. Symptomatology pre- and post-surgery was analyzed. RESULTS: Of the 75 CM-1 patients that underwent PSG, 23 were diagnosed with sleep apnea. Sixteen had OSA, 6 had CSA, and 1 had mixed apnea. Twelve OSA patients received ENT intervention. Eight improved and 2 further improved after Chiari decompression. Of the 4 patients that did not improve, one of those later improved following Chiari decompression. Of the 6 CSA patients, 2 underwent Chiari decompression, but only one improved. The mixed apnea patient underwent several ENT interventions that did not relieve symptoms but improved following Chiari decompression. DISCUSSION/CONCLUSIONS: Based on our results, sleep apnea in CM-1 patients may be obstructive, central, or mixed and is likely multifactorial. A multidisciplinary approach to the management of these patients is important, including neurosurgery, otolaryngology, and sleep medicine. Future prospective studies will lend further insight into this condition and its management.

Natural history of Chiari I malformation in children: a retrospective analysis.

PURPOSE: While there are increasing numbers of studies published regarding Chiari I malformation (CM1) in children, most of these focus on surgical indications, technique, and outcomes. Few studies examine the natural history of CM1 once the decision is made to treat a patient conservatively. In this study, we seek to determine the percentage of pediatric patients who undergo surgery for CM1, both after initial consultation and in a delayed fashion, the natural history of CM1 after a decision to pursue non-operative management, and attempt to identify patient factors that may predict development of new or worsening CM1 symptoms. METHODS: From our database of 465 pediatric patients with CM1, we identified those who were seen for initial consultation from July 1, 2011, to June 30, 2016. We examined rates of surgical intervention, types of surgical intervention, age, gender, and presence or absence of headache and syrinx, and looked carefully at the patients who had new or worsening symptoms prompting delayed surgical intervention. RESULTS: We identified 226 patients meeting inclusion criteria. Overall, 15% of patients had surgery, the majority being Chiari decompression. Just over half of these patients had surgery within 6 months of initial consultation. Of those with delayed surgery, only 4 patients had new symptoms/syrinx and 1 patient had symptom progression. The other patients had various reasons for surgical delay not related to symptom development or progression. There were no obvious commonalities among these 5 patients that could predict progression prospectively. All patients who had surgery did so within 2 years of initial consultation. CONCLUSION: Overall, the natural history of asymptomatic CM1 is benign. Patients treated non-operatively are unlikely to progress. If they do progress, this is likely to occur within 2 years of initial consultation. There were no factors identified in this study that predicted new or worsening symptoms over time.

Effects of growth hormone therapy in pediatric patients with growth hormone deficiency and Chiari I malformation: a retrospective study.

PURPOSE: The safety and efficacy of growth hormone replacement therapy (GHRT) on pediatric patients with growth hormone deficiency (GHD) and Chiari I malformation (CIM) are not well investigated within the current body of literature. With no clear indication of the effects of GHRT on CIM disease progression, we sought to determine the effect of GHRT on tonsillar herniation and progression of CIM symptomatology. METHODS: From a previously established database of 465 patients with radiologically confirmed CIM defined as > 5 mm of tonsillar descent on head magnetic resonance imaging (MRI), we identified 20 patients who also had GHD. Using the imaging analysis software package, ANALYZE, the degree of change in tonsillar herniation was documented between initial and final MRI measurements. The radiologic and clinical changes over time were examined via a proportional odds model, Student's t test, Mann-Whitney test, or a mixed model corresponding to the outcomes measured either on an ordinal scale or on a quantitative scale. RESULTS: Incidence of GHD in our CIM population was 4.3%. There was no significant effect of GHRT on the degree of tonsillar herniation in patients with GHD and CIM. No patient became symptomatic, developed syringomyelia, or required surgical intervention for CIM. CONCLUSION: Based on our findings with a larger sample size, along with recent reports, the incidence of patients with CIM and GHD we reported (0.86-5%) is likely more indicative of the actual incidence of GHD and CIM than the prior findings within the literature (9.1-20%). We also suggest that GHRT does not significantly affect CIM morphology or symptomatology. Therefore, neurosurgeons should have no hesitation clearing these patients for GHRT.

Soft tissue density within the foramen magnum, a predictor for surgical intervention in pediatric patients with Chiari malformation type I.

OBJECTIVE: Chiari malformation type I (CMI) is diagnosed as herniation of the cerebellar tonsils by at least 5 mm below the foramen magnum. However, the degree of tonsillar herniation is a poor predictor of the need for decompression surgery. Exploration for an alternative morphological predictor for surgical intervention could provide greater insight into the development of an appropriate treatment plan for these patients. To investigate this issue, the authors calculated the soft tissue density within the foramen magnum as a measure of impaction of the cerebellar tonsils. Soft tissue density within the foramen magnum and degree of tonsillar herniation were then assessed for their correlation with the need for surgical intervention. METHODS: The authors conducted a retrospective, longitudinal chart review of pediatric patients with CMI. Those who had undergone surgical intervention were considered symptomatic and those who had been treated conservatively, as asymptomatic. Soft tissue density was found by dividing the soft tissue occupancy of the foramen magnum (brainstem and cerebellar tonsils) by the total area of the bony foramen magnum. The predictive value of these two measurements for the need of surgery was determined. RESULTS: Of the 465 patients seen for CMI at the authors' institution between July 1, 2011, and May 31, 2017, 80 underwent surgical intervention and 385 were asymptomatic. The average tissue density was significantly greater in the surgical group than in the asymptomatic group (83.3% and 78.6%, respectively, p < 0.0001). The average tonsillar descent for surgical patients was 10.8 mm compared to 9.8 mm for asymptomatic patients (p = 0.140). The point-biserial correlation coefficient was assessed, and soft tissue density was found to positively correlate with the need for surgical intervention (rpb = 0.199, p = 0.0001), whereas tonsillar herniation did not correlate with the need for surgery (rpb = 0.083, p = 0.115). Additionally, the degree of tonsillar herniation did not correlate with soft tissue density (r = 0.09), indicating that soft tissue density is an independent morphological parameter. CONCLUSIONS: The study findings suggest that the need for surgical intervention in CMI patients is positively correlated with increasing soft tissue density within the foramen magnum, whereas the degree of tonsillar herniation did not show a correlation with the need for surgical intervention. Additionally, soft tissue density is a factor independent of the degree of tonsillar herniation. Further investigation of tissue density within the foramen magnum is needed in the hope of discovering a clinically applicable parameter that would indicate a need for surgical intervention in patients with CMI.

Management of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation in a child with autism: case report.

The authors report an unusual case of an odontoid synchondrosis fracture causing chronic translational anterior atlanto-axial subluxation and present a discussion of the unique management of this case. Traumatic translational anterior atlanto-axial subluxation is a rare manifestation within pediatrics. Patients with preexisting abnormalities in ligamentous or bony structures may present with unusual symptomatology, which could result in delay of treatment. A 6-year-old male patient with autism who presented with acute respiratory arrest was noted to have an odontoid synchondrosis fracture and severe anterior translational atlanto-axial subluxation. Initial attempts at reduction with halo traction were tried for first-line treatment. However, because of concern regarding possible inadvertent worsening of the impingement, the presence of comorbid macrocephaly, and possible instability with only C1-2 fusion, a posterior C1 laminectomy was performed. Further release of the C1-2 complex and odontoid peg from extensive fibrous tissue allowed for complete reduction. Acute injuries of the C1-2 complex may not present as expected, and the presence of pain is not a reliable symptom. Halo traction is an appropriate initial treatment, but some patients may require surgical realignment and stabilization.