Improvement of obstructive sleep apneas caused by hydrocephalus associated with Chiari malformation Type II following surgery

The utility of poly(somno)graphy in evaluating children with Chiari malformation type II before and after surgical intervention: a case series

BACKGROUND

Children with Chiari Malformation type II (CM-II) have an increased risk of sleep apnoea. The aim of the study was to describe the management of patients with CM-II in relation to sleep apnoea syndrome, clinical symptoms and magnetic resonance imaging (MRI) findings.

CASE SERIES PRESENTATION

The paper reports 8 consecutive patients with CM-II followed between September 2013 and April 2017. The prevalence of sleep apnoea syndrome was high with 6 out of 8 patients having mild-to-severe sleep apnoea. Patients with severe sleep apnoea syndrome (3 patients) were treated with upper airway surgery and/or noninvasive ventilation.

CONCLUSION

Our findings highlight the importance of respiratory polygraphy in the management of patients with CM-ΙΙ. Poly(somno)graphy is recommended in the follow-up care of children with CM-II.

Respiratory arrest after posterior fossa decompression in patients with Chiari malformations: An overview

Background

Chiari malformation type 1 (CM1) is a structural abnormality in the skull and cerebellum, causing cerebellar tonsils to shift downward. Decompression of the posterior fossa is a common surgical method to relieve symptoms and prevent neurological deterioration. After posterior fossa decompression (PFD), individuals with CM1 were more likely to have respiratory arrest. Here, we present, for the first time, a comprehensive overview of the potential risk factors and causes of respiratory arrest following PFD.

Methods

A review of the literature highlighting the risk factors for postoperative respiratory arrest in CM1 patients was conducted in the databases of PubMed, Medline, and Google Scholar.

Results

Patients with syringomyelia and CM1 are at increased risk for respiratory arrest due to a number of factors, including impaired respiratory mechanics, central respiratory center dysfunction from edema or ischemia, intraoperative brain stem ischemia, and delayed gastric emptying from autonomic dysfunction. Occipitalization of the first cervical vertebra, basilar impression, and fusion of C2-C3 are all risk factors for respiratory arrest.

Conclusion

Implications for CM1 patient care and prospects for further investigation of postoperative respiratory arrest's causes and risk factors were discussed.

The efficacy of neurosurgical intervention on sleep-disordered breathing in pediatric patients with Chiari malformation type I

OBJECTIVE

Chiari malformation type I (CM-I) involves the herniation of the cerebellar tonsils through the foramen magnum. CM-I is associated with both obstructive sleep apnea (OSA) and central sleep apnea (CSA) in children. The primary management of symptomatic CM-I remains surgical decompression. There is, however, a paucity of data evaluating the efficacy of decompression surgery on outcomes related to sleep-disordered breathing (SDB). The objective of this study was to evaluate SDB outcomes, specifically the need for respiratory support following decompression in pediatric patients with CM-I.

METHODS

This was a retrospective chart review of all children diagnosed with CM-I when younger than 18 years of age who had polysomnography (PSG) studies pre- and postsurgery, between January 2008 and October 2018 at the Hospital for Sick Children in Toronto. Patient demographics, symptoms, PSG data, ongoing respiratory support, and surgical notes were recorded. Differences in PSG studies obtained pre- and postsurgery were compared using the Wilcoxon test for paired samples.

RESULTS

A total of 15 children with 15 interventions met inclusion criteria with pre- and postsurgery PSG studies and were considered for statistical analysis. Of the 15 subjects included for analysis, preoperative OSA was present in 2 (13.3%), CSA in 5 (33.3%), mixed SDB (both OSA and CSA) in 4 (26.7%), and no significant SDB in 4 (26.7%). Postoperatively, OSA was present in 3 (20.0%), CSA in 4 (26.7%), mixed SDB in 0 (0%), and no significant SDB in 8 (53.3%). The presence of severe OSA decreased from 4/15 (26.7%) to 2/15 (13.3%) postoperatively, and severe CSA decreased from 5/15 (33.3%) to 2/15 (13.3%) postoperatively. Following decompression surgery, 7/15 subjects (46.7%) required positive airway pressure for management of their SDB. Overall, significant improvements were observed in a number of respiratory parameters following decompression including the following: the total apnea-hypopnea index (AHI) (17.5 ± 48.2 vs 6.1 ± 32.7 events/hour; p = 0.001), obstructive AHI (2.1 ± 16.1 vs 1.0 ± 6.6 events/hour; p = 0.005), central AHI (6.3 ± 48.9 vs 2.7 ± 33.0 events/hour; p = 0.005), and the desaturation index (16.7 ± 49.6 vs 3.8 ± 25.3; p = 0.001).

CONCLUSIONS

Although decompression surgery led to a significant reduction in obstructive and central events, many children continued to have persistent SDB and required additional positive airway pressure therapy. This information is important and relevant for anticipatory guidance around decompression surgery and the necessity for respiratory support for the management of SDB in pediatric patients with CM-I.

A rare case of difficult airway management in a Klippel-Feil syndrome pediatric patient with osseous torticollis undergone orthopedic surgery : Difficult airway in pediatric patient with torticollis

Background

Orthopedic surgery for cervical torticollis poses potential threat to airway management both in tracheal intubation and extubation. Klippel-Feil syndrome (KFS) is a complex syndrome of osseous and visceral anomalies. The anatomical characteristics of KFS might have significant implications for airway management.

Case presentation

This is a rare case of an 8-year-old boy presenting with osseous torticollis, congenital occipito-atlantal deformity, congenital basilar invagination and KFS undergone elective torticollis correction surgery. Though with difficulty, tracheal intubation was successfully performed. Extubation failed twice on postoperative day 2 and 10, and required tracheostomy. Based on radiological findings, we speculated that prolonged airway edema accounted for the main reason of the failed extubation, the hypertrophic tonsil and occipito-cervical fusion resulted in reduced oropharyngeal space and limited cervical range of motion. Moreover, the Chiari malformation and KFS complicated the airway condition and lead to prolonged airway obstruction. The tracheostomy casing was removed 1 month later.

Conclusions

Cautions should be taken in extubation of pediatric patients undergone major osseous torticollis surgery. Reintubation should be prepared in case of failed extubation. Severe post-operative airway edema, complicated with hypertrophic tonsil, the structural abnormalities in the oropharyngeal cavity, and occipito-cervical deformities constituted the decreased oropharyngeal space and resulted in failed extubation. For severe airway compromise and prolonged intubation, tracheostomy should be considered.

Care management and contemporary challenges in spina bifida: a practice preference survey of the American Society of Pediatric Neurosurgeons

OBJECTIVE

Neurosurgical management preferences related to myelomeningocele (MMC) care demonstrate significant variability. The authors sought to evaluate variability in practice patterns across a group of senior pediatric neurosurgeons. The purpose of this study was to identify the extent of variability and of consensus with regard to neurosurgical management of MMC and associated hydrocephalus, Chiari II malformation, and tethered spinal cord.

METHODS

A 43-question survey was distributed electronically to the members of the American Society of Pediatric Neurosurgeons (ASPN). The survey covered domains such as clinic case volume, newborn management, hydrocephalus management, transition to adulthood, clinical indications for shunt revision, Chiari II malformation decompression (C2MD), and tethered cord release (TCR). Ninety responses were received from 200 active ASPN members, for an overall response rate of 45%.

RESULTS

The majority (58%) of respondents closed 5-15 new cases of open MMC per year. Nearly all (98%) respondents perform back closure within 48 hours of birth, with the majority imbricating the placode and striving for a 3- to 4-layer closure. The most consistent indications for surgical intervention in early hydrocephalus were CSF leak from the back (92%), progressive ventricular enlargement (89%), and brainstem symptoms, including apnea/bradycardia (81%), stridor (81%), and dysphagia (81%). Eighty percent of respondents indicated that spina bifida care is delivered through multidisciplinary clinics, with neurosurgery, orthopedic surgery, urology, physical therapy, and social work as the most common disciplines included. One-third of clinics see both pediatric and adult patients, one-third offer a formal transition program to adult care, and one-third have no transition program. The vast majority of respondents offer prenatal counseling (95%), referral for in utero closure (66%), and endoscopic third ventriculostomy/choroid plexus cauterization (72%). Respondents were more willing to perform shunt revision for symptoms alone than for image changes alone. An asymptomatic broken shunt without ventricular enlargement produced responses evenly divided between observation, intervention, and further investigation. Operative shunt exploration was always performed before C2MD by 56% of respondents and performed sometimes by 40% of respondents. Symptoms of brainstem dysfunction were the strongest clinical triggers reported for C2MD, while declines in urinary continence, leg strength or sensation, or ambulation were the most consistent thresholds for TCR.

CONCLUSIONS

Significant disparities exist surrounding key areas of decision making regarding treatment for patients with MMC, though there are central areas of agreement among ASPN members. Additionally, there is significant variation in the clinical management of chronic hydrocephalus, C2MD, and TCR, underscoring the need for further research into these specific areas.

Role of sleep study in children with Chiari malformation and sleep disordered breathing

PURPOSE

Chiari malformation incorporate numerous forms of congenital or acquired cerebellar herniation through the foramen magnum. This may lead to brain stem, high spinal cord and cranial nerve compression resulting in obstructive and central apneas. This review highlights he high prevalence of sleep-disordered breathing in this population and the importance of refering these patients for sleep studies as part of their workup.

METHODS

A review of the literature was performed through a PubMed and EMBASE search of original articles and reviews using the key words "chiari" "chiari malformation" "hindbrain herniation" "sleep disordered breathing" "obstructive sleep apnea" "central sleep apnea" "sleep study" and "foramen magnum decompression".

DISCUSSION

We highlight the pathophysiology of sleep disordered breathing in patients with Chiari malformation, how it can be diagnosed and what the treatment options are.

CONCLUSIONS

Sleep-disordered breathing is highly prevalent in patients with CM1. Clinicians caring for these patients should be aware of this and prioritise sleep diagnostic testing to allow for early diagnosis and management particularly in the presence of neurological symptoms and specific brain MRI pointers.

Audiological evaluation in children affected by myelomeningocele

PURPOSE

The aim of the present study is to evaluate the auditory system in children affected by myelomeningocele and comparing the results with clinical neurological conditions.

MATERIALS AND METHODS

Forty-three children, aged between 7 and 26 years, affected by myelomeningocele were investigated by means of subjective tonal audiometry and objective impedance audiometry (tympanometry and acoustic stapedial reflex).

RESULTS

Audiological evaluation showed an alteration in 32 patients (74%%). Nine patients presented a mild hearing loss: bilateral in six cases (three sensorineural, one mixed, and two conductive) and unilateral in three cases (two mixed and one conductive). One patient had moderate unilateral conductive deafness and, finally another one severe unilateral sensorineural. Almost all patients with deafness were affected by myelomeningocele and Chiari II. Stapedial-cochlear reflex investigation showed an alteration in 30 patients (70%): 9 of these also showed deafness while the remaining 21 was normal hearing. In these 30 patients, we demonstrated the presence of myelomeningocele, hydrocephalus, and Chiari II malformation in 21 subjects (70%).

CONCLUSION

Otoneurological evaluation is important in myelomeningocele not only at the birth but also in the follow-up. It could have an important prognostic role for neurological impairment.

Imaging the course of a hypoplastic cerebellum in a spina bifida newborn

INTRODUCTION

We report about a spina bifida patient with myelomeningocele at the lumbar level L5, extensive Chiari malformation type II with vermal herniation reaching to C6 with downward pontine shift, and a severe hypoplastic cerebellum. Chromosomal diagnostic tests showed no abnormalities.

CASE REPORT

The infant experienced severe central apneas successfully treated with oxygen therapy and caffeine medication; functional motor level was established at L5 with sparse anal sphincter function.

DISCUSSION

After surgical intervention (myelomeningocele repair and ventriculoperitoneal shunt placement), these abnormalities significantly improved on radiological imaging; the preoperative hypoplastic, almost undetectable, cerebellum developed to a fair sized cerebellum. Apneas disappeared over time and the patient showed further developmental improvement. Herein, we illustrate and discuss the changes of the cerebellar volume before and after neurosurgical intervention.

Apnea as an uncommon preoperative manifestation of medulla cavernous malformation: surgical treatment and literature review

OBJECTIVE

Apnea is not a common preoperative manifestation of medulla cavernous malformations (CMs). The role of surgical resection in patients suffering from apnea secondary to hemorrhage from medulla CMs requires further definition.

METHODS

Medical records and radiographs were reviewed retrospectively for four patients treated surgically for medulla CMs in our institution between 2008 and 2011. Recent outcomes for these patients were also evaluated. The modified Rankin Scale (mRS) was used to evaluate neurological function.

RESULTS

All four patients (3 male, 1 female; mean age: 41.3 years) suffered two or three hemorrhages with a preoperative mRS of five and, due to the loss of autonomous respiration and consciousness, underwent a preoperative tracheotomy for mechanical ventilation, which lasted an average of 4.5 days. Prior to surgery, all patients had recovered to the point of maintaining spontaneous breath and normal blood gas values with oxygen supplementation. Lesions were totally resected in all patients via the posterior suboccipital approach. Postoperative ventilation was continued in one patient for 1 day. The mean postoperative mRS score at discharge was 3.5, and all patients had improved from their previous scores. The tracheostomy was closed in three patients at 15, 16, and 35 days after surgery. After a mean follow-up of 34.7 months, the most recent mRS scores were 3, 2, 2, and 2; no recurrent hemorrhage was noted, and three patients lived independently.

CONCLUSION

In carefully selected patients with hemorrhage due to medulla CMs, favorable outcomes can be achieved even if apnea was a part of the preoperative clinical presentation. Surgery should be considered in these patients, particularly in those with repeated hemorrhages, and apnea should not be considered an absolute contraindication to surgery.

Primary and secondary management of the Chiari II malformation in children with myelomeningocele

OBJECT

Chiari malformation type II is almost exclusively found in patients with open spinal dysraphism. Etiology and pathophysiology are not yet completely understood, and management guidelines regarding the best follow-up and treatment of this pathological entity do not exist. In order to assess essential management aspects, literature and a series of secondary neurosurgical interventions in Chiari II patients have been reviewed.

METHODS

A literature review regarding etiology, diagnostics, pathophysiology, and management of Chiari malformation type II (CMII) and a retrospective evaluation of a series (2009-2012) of secondary interventions in Chiari II patients have been performed. Inclusion criteria were ICD for myelomeningocele with or without hydrocephalus and ICD for Chiari malformation and neurosurgical OR procedure. Evaluated parameters were: patient demographics, primary management, secondary neurosurgical operations (cranio-cervical decompression, shunt revision, myelolysis) as well as specific findings pre- and postoperatively. Essential results from literature review and patients' series are compiled in order to define management recommendations.

RESULTS

Fifty patients (28 f, 22 m; mean age, 7.1 years (range, 0.5-26 years)) with myelomeningocele-associated Chiari malformation type II were operated on between 2009 and 2012. Twenty-four patients had syringomyelia and scoliosis each, and 12 suffered from both. Orthopedic surgery for scoliosis or kyphosis had been performed in 13 cases. Shunt revision was performed in 38 cases, myelolysis in 17, and decompression of the foramen magnum in 14 (28 %). After a mean follow-up of 1.9 years, syringomyelia decreased from 24 to 16 cases. There was a postoperative reduction of neck pain (one third), sensorimotor (two fifths), and cranial nerve deficits (one half). CSF flow at the foramen magnum did not change visibly after surgery. Ventricular size improved in about half of the patients. Slit-like ventricles were found in nine (6 pre-surgical) and enlarged ventricles in nine (23 pre-surgical). Complication rate was 6 % (3/50) per cases, and no patient died or deteriorated neurologically after surgery.

CONCLUSION

CMII-related management guidelines are not well defined, since clinical constellations and presentations are varying. Often associated findings are syringomyelia, hydrocephalus, and scoliosis, and symptomatic CMII may be triggered by more than one underlying condition. According to literature and clinical experience, management recommendations can be defined. The most important finding is that hydrocephalus is often involved in symptomatic CMII and must always be considered first in any symptomatic patient. Intrinsic brain stem dysfunctions cannot be treated surgically, and monitoring of vital functions is sometimes the only clinical means that can be offered to the patient. Knowledge of the complex background has led to improved follow-up programs for the affected children and thus also improved longtime survival.

The neurophysiological balance in Chiari type 1 malformation (CM1), tethered cord and related syndromes

The Chiari malformation (CM) is a syndrome embodied in heterogeneous groups of malformations, spanning from the more benign and known, the CM1, to more complex syndromes such as the rare association with the tethered cord, as spinal lipomas, and the CM2, associated to open spina bifida. The clinical picture may be well expressed and detected at birth or even during intrauterine life, as for CM2, but in the other cases they may run a rather subtle clinical course. The diagnosis of these syndromes is driven by clinical examination and MRI, and it usually requires a multidisciplinary approach in order to plan the therapeutic strategies, such as surgery. Among the diagnostic investigations, the imaging techniques represent the most useful, for their capabilities to detect subclinical lesions, such as syringomyielia and lipoma; the urological investigation is useful to evaluate the urogenital dysfunctions. The neurophysiological investigations represent a non invasive diagnostic procedure to investigate the peripheral nerve, the spinal cord, the brainstem functionalities and more higher brain functions; the nerve conduction studies and the cranial reflexes, the brainstem (BAEP) and the somatosensory (SEPs) evoked potentials (EPs), alone or in combination, can be used for the diagnosis, follow-up and intraoperative monitoring. The most useful diagnostic tools in CM1 are likely represented by the brainstem auditory evoked potentials (BAEPs) and the blink-reflex (BR), while the usefulness of SEPs is still doubtful and debated; in CM2 and tethered cord the neurophysiological techniques can be combined in different ways in order to make a functional balance and to answer specific questions. BAEPs and BR can be useful to investigate the brain stem functionality and SEP to evaluate whether the ascending sensory pathway to the cortex can be hampered at some level; the visual EPs are particularly useful to evaluate the integrity of posterior visual pathway and visual cortex in the case of associated hydrocephalus. In the tethered cord, both nerve conduction study and somatosensory evoked potentials (SEPs) are useful to evaluate motor and sensory dysfunction of the lombosacral roots and nerves and spinal cord for their capability to detect subclinical impairment of conduction along the sensory and motor pathway. Finally, last but not the least, the neurophysiological techniques are remarkably useful during surgery; the intraoperative monitoring (IOM) by means of electromyography and direct nerve stimulation and recordings are able to detect early nerve damage, minimize nerve lesions and optimise the surgical techniques. In the operated children with incomplete removal of lipoma and/or persistent tethering, the recordings of SEP and BAEP are useful to demonstrate a conduction deterioration along the ascending sensory pathway due to increasing tethering of the spinal cord due to somatic growth.