Successful recovery from cardiac arrest due to atlantoaxial subluxation in Down syndrome: a case report

INTRODUCTION

Down syndrome is the most common chromosomal abnormality associated with intellectual impairments. Unexpected deaths are common with this disease. There are certain difficulties in clarifying the cause of death because the manifestations may be quite diverse and involve many organ systems. Atlantoaxial subluxation is a dangerous complication of Down syndrome, as it may lead to cervical cord-medullary compression.

CASE PRESENTATION

Herein, we present a case of Down syndrome in a patient who completely recovered from cardiac arrest due to atlantoaxial subluxation. The neck was immobilized during post-cardiac arrest care, and the patient underwent surgery after 14 days. The patient could walk independently and was discharged 3 months later. At the last follow-up 5 years after surgery, the patient's general condition was good.

DISCUSSION

Physicians should be aware that atlantoaxial instability can cause cardiac arrest in patients with genetic syndromes.

Paediatric syndromic scoliosis: proceedings of the half-day course at the 57th annual meeting of the Scoliosis Research Society

There are some syndromes that present with unique manifestations pertaining to the spinal column. A good working understanding of these common syndromes is useful for the spinal deformity surgeons and related healthcare providers. This review attempts to encompass these unique features and discuss them in three broad groups: hypermobility syndromes, muscle pathology-related syndromes, and syndromes related to poor bone quality. This review explores the features of these syndromes underpinning the aspects of surgical and medical management. This review represents the proceedings of the Paediatric Half-Day Course at the 57th Annual Meeting of the Scoliosis Research Society.

Surgical strategies in the management of atlantoaxial dislocation in Down syndrome

Aims

To study the clinicoradiological features and treatment outcomes of atlantoaxial dislocation (AAD) in Down syndrome.

Settings and Design

Retrospective case series.

Subjects and Methods

A retrospective chart and radiology review of 9 Down syndrome patients with AAD managed at our center from 2007 to 2018.

Statistical Analysis Used

Chi-squared/Fisher's exact test.

Results

There were 4 males and 5 females (n = 9). The median age was 14 years (interquartile range [IQR]: 7-15.5). 77.7% (7/9) of patients had severe spasticity (Nurick Grades 4 and 5). The median duration of symptoms was 9 months (IQR: 5-39). The AAD was reducible in all (n = 9) cases. Eight (88.8%) patients had os odontoideum. The mean atlantodental interval (ADI) was 8.5 mm (±2.9). T2W cord hyperintensity was seen in 66.6% (6/9). Posterior C1-2 transarticular fixation was done in 8 and occipitocervical fusion in 1 patient. Follow-up of more than 6 months (7-57 months) was available in 8/9 (88.9%) patients. There was a significant improvement in spasticity (n = 8, mean Nurick Grade 1.7 (±1.1), P = 0.003). Follow-up radiographs (n = 8) showed good reduction and fusion. A preoperative bedbound patient with poor respiratory reserve expired at 10 months following surgery. There were no other complications.

Conclusions

Posterior surgical approach for AAD in Down syndrome resulted in good alignment and fusion, with excellent clinical improvement. Patients with elevated PCO2 are poor surgical candidates and require home ventilation facility.

Congenital atlanto-occipital dislocation in a patient with Down syndrome: a case report

Down syndrome, also known as trisomy 21, is associated with congenital cervical spine abnormalities, including atlantoaxial instability with or without os odontoideum, atlanto-occipital instability, and hypoplasia of the atlas. Herein, we report a case of Down syndrome complicated by congenital atlanto-occipital dislocation. The patient presented with severe cervical myelopathy at 13 years of age after a 10-year follow-up. Radiography and computed tomography revealed os odontoideum protruding into the foramen magnum and congenital anterior atlanto-occipital dislocation. Additionally, a bifurcated internal occipital crest with a thinned central portion of the occipital bone was noted. Magnetic resonance imaging revealed kyphotic alignment of the spinal cord with severe compression at the foramen magnum level. As the neurological impairment was partially improved by halo vest immobilization, we performed in situ O-C2 fusion with an iliac autograft and decompression of the foramen magnum and posterior arch of C1. An improvement was observed immediately after surgery. Two years after surgery, radiography and computed tomography showed solid O-C2 segment fusion. The accumulation of similar cases is essential for determining the prognosis or optimal treatment for this rare congenital condition.

Neonatal Halter Traction for Severe Cervical Spine Deformity: A Technical Case Report With 2-Year Follow-up

BACKGROUND AND IMPORTANCE

Although rare, severe congenital cervical spine deformity can present with limited treatment options and potentially catastrophic outcomes. The use of halter traction for cervical deformity correction in children has been well described, but it has not been previously reported in the management of neonates.

CLINICAL PRESENTATION

A baby girl born at full-term gestation presented with generalized hypotonia, bilateral club feet, and significant right upper extremity weakness. Imaging demonstrated a severe congenital swan-neck deformity with spinal cord compression. Halter traction was initiated in the neonatal intensive care unit with subsequent neurological and radiographic improvement. After 7 days, traction was discontinued and she was placed in a custom-fitted cervico-thoracic orthosis. At 2 years of follow-up, she remains neurologically stable with maintained cervical alignment.

CONCLUSION

Halter traction followed by external bracing is technically possible in the neonatal period. For children with severe cervical congenital deformity, this technique can reduce spinal cord compression, provide significant deformity correction, and delay the need for definitive operative spinal stabilization.

Reference values of four measures of craniocervical stability using upright dynamic magnetic resonance imaging

PURPOSE

To establish reference ranges for four most commonly used diagnostic measures of craniocervical instability (CCI) in three cervical sagittal positions. This necessitated development of a reliable measurement protocol using upright, dynamic MRI (udMRI), to determine differences in the extent of motion between positions, and whether age and sex correlate with these measures.

MATERIALS AND METHODS

Deidentified udMRIs of 50 adults, referred for reasons other than CCI, were captured at three positions (maximal flexion, maximal extension and neutral). Images were analyzed, providing measures of basion-axial interval, basion-axial angle, basion-dens interval (BDI) and the Grabb-Oakes line (GOL) for all three positions (12 measures per participant). All measures were independently recorded by a radiologist and neurosurgeon to determine their reliability. Descriptive statistics, correlations, paired and independent t-tests were used. Mean (± 2 SD) identified the reference range for all four measures at each craniocervical position.

RESULTS

The revised measurement protocol produced inter-rater reliability indices of 0.69-0.97 (moderate-excellent). Fifty adults' (50% male; mean age 41.2 years (± 9.7)) reference ranges for all twelve measures were reported. Except for the BDI and GOL when moving between neutral and full flexion, significant extents of movement were identified between the three craniocervical positions for all four measures (p ≤ 0.005). Only a minor effect of age was found.

CONCLUSIONS

This is the first study to provide a rigorous standardized protocol for four diagnostic measures of CCI. Reference ranges are established at mid and ends of sagittal cervical range corresponding to where exacerbations of signs and symptoms are commonly reported.

Dissection of mendelian predisposition and complex genetic architecture of craniovertebral junction malformation

The craniovertebral junction (CVJ) is an anatomically complex region of the axial skeleton that provides protection of the brainstem and the upper cervical spinal cord. Structural malformation of the CVJ gives rise to life-threatening neurological deficits, such as quadriplegia and dyspnea. Unfortunately, genetic studies on human subjects with CVJ malformation are limited and the pathogenesis remains largely elusive. In this study, we recruited 93 individuals with CVJ malformation and performed exome sequencing. Manual interpretation of the data identified three pathogenic variants in genes associated with Mendelian diseases, including CSNK2A1, MSX2, and DDX3X. In addition, the contribution of copy number variations (CNVs) to CVJ malformation was investigated and three pathogenic CNVs were identified in three affected individuals. To further dissect the complex mutational architecture of CVJ malformation, we performed a gene-based rare variant association analysis utilizing 4371 in-house exomes as control. Rare variants in LGI4 (carrier rate = 3.26%, p = 3.3 × 10^-5) and BEST1 (carrier rate = 5.43%, p = 5.77 × 10^-6) were identified to be associated with CVJ malformation. Furthermore, gene set analyses revealed that extracellular matrix- and RHO GTPase-associated biological pathways were found to be involved in the etiology of CVJ malformation. Overall, we comprehensively dissected the genetic underpinnings of CVJ malformation and identified several novel disease-associated genes and biological pathways.

The Association Between Radiographic and MRI Cervical Spine Parameters in Patients With Down Syndrome

Introduction

Many patients with Down syndrome (DS) develop upper cervical spine instability that may lead to spinal cord injury. The purpose of this study was to investigate the association between the spinal cord compression in MRI and the occipto-cervical instability evident on plain radiographs in a Japanese population.

Methods

A retrospective analysis of cervical spine radiographs and MRI acquired from patients with DS was performed. Radiographic evaluation included measuring the atlanto-dental interval (ADI) and space available for the cord. The basion axial interval (BAI) and Weisel-Rothman (WR) measurements were taken to quantify occipto-axial (OA) and atlanto-occipital (AO) instability. These parameters were collected in patients both with (positive) and without (negative) spinal cord compression evident on MR imaging in a neutral position and the values were compared. In addition, we investigated the association between spinal cord compression and previously defined abnormal values with logistic regression analysis (abnormal values: ADI>6mm, SAC<14mm, BAI<-12mm or >5mm in neutral position).

Results

There were 17 patients in the positive group and 52 patients in the negative group. WR was 7.4 mm±6.0 in positive group and 8.6 mm±4.8 in negative group (p=0.31) in neutral position, 3.9 mm±5.4 and 6.3±5.0 (p=0.06) in flexion, and 7.0 mm±6.8 and 7.2 mm±4.8 (p=0.75) in extension, respectively. The difference in WR between flexion and extension was 3.1 mm ± 4.6 and 0.9 mm ± 3.8, respectively (p=0.15). All other parameters showed significant differences between the two groups excluding BAI in extension (p<0.05). In addition, abnormal values that significantly correlated with cord compression were ADI (odds ratio 42.3 p<0.01 95% CI 4.16-430.0) and SAC (odds ratio 31.90 p=0.013 95% CI 2.06-494.0).

Conclusions

These data suggest that OA and AA instability measured with ADI, SAC, and BAI are significantly associated with spinal cord compression in MRI; whereas instability measured with WR and DWR is not. In addition, the previously defined abnormal thresholds for the ADI and SAC can be used for screening the Japanese population.

Otolaryngologic Disease in Down syndrome

As the most common human chromosomal abnormality, Trisomy 21 is a condition that many otolaryngologists and likely all pediatric otolaryngologists will encounter during their careers. There are several considerations regarding airway obstruction, otologic conditions, anesthetic implications, and endocrine disorders that will impact the treatment of these patients. Further, there is increasing literature supporting the use of early instrumental assessment of swallowing, drug-induced sleep endoscopy at the time of first surgical intervention for sleep apnea, consideration of concurrent upper and lower airway evaluation, and early otologic management including potential surgical hearing rehabilitation.

Safety analysis and complications of condylar screws in a single-surgeon series of 250 occipitocervical fusions

Objective

Condylar screw fixation is a rescue technique and an alternative to the conventional configuration of occipitocervical fusion. Condylar screws are utilized when previous surgical bone removal along the supraocciput has occurred which makes anchoring of a traditional barplate technically difficult or impossible. However, the challenging dissection of C0-1 necessary for condylar screw fixation and the concerns about possible complications have, thus far, prevented the acquisition of large surgical series utilizing occipital condylar screws. In the largest case series to date, this paper aims to evaluate the safety profile and complications of condylar screw fixation for occipitocervical fusion.

Methods

A retrospective safety and complication-based analysis of occipitocervical fusion via condylar screws fixation was performed.

Results

A total of 250 patients underwent occipitocervical fusions using 500 condylar screws between September 2012 and September 2018. No condylar screw pullouts, or vertebral artery impingements were observed in this series. The sacrifice of condylar veins during the dissection at C0-1 did not cause any venous stroke. Hypotrophic condyles were found in 36.4% (91 of the 250) cases and did not prevent the insertion of condylar screws. Two transient hypoglossal deficits occurred at the beginning of this surgical series and were followed by recovery a few months later. Corrective strategies were effective in preventing further hypoglossal injuries.

Conclusions

This surgical series suggests that the use of condylar screws fixation is a relatively safe and reliable option for OC fusion in both adult and pediatric patients. Methodical dissection of anatomical landmarks, intraoperative imaging, and neurophysiologic monitoring allowed the safe execution of the largest series of condylar screws reported to date. Separate contributions will follow in the future to provide details about the long-term clinical outcome of this series.

Evaluation of Pain in Adults With Childhood-Onset Disabilities and Communication Difficulties

Adults with childhood-onset disabilities, particularly those with central nervous system impairment, commonly experience pain. Because many such individuals have difficulties in communication, caregivers and medical professionals must identify and interpret non-verbal behaviors as indicators of pain. This process is challenging and can lead to poor outcomes through delayed or incorrect diagnosis and treatment. Most research in the evaluation of pain in individuals with neurologic impairment has focused on the pediatric population, and evidence-based guidelines do not exist for adults. The purpose of this paper is to review current recommendations for pain assessment in adults with communication impairment. This approach includes guidance for history-taking, pharmacologic review, physical examination, and the judicious use of laboratory and imaging tests. Finally, we discuss adult-specific diagnoses to consider when evaluating pain in adults with childhood-onset disabilities and communication difficulties.

Repeat Pediatric Trisomy 21 Radiographic Exam: Does Atlantoaxial Instability Develop Over Time?

BACKGROUND

Atlantoaxial instability (AAI) is common in pediatric patients with Trisomy 21 and can lead to spinal cord injury during sports, trauma, or anesthetized neck manipulation. Children with Trisomy 21 therefore commonly undergo radiographic cervical spine screening, but recommendations on age and timing vary. The purpose of this study was to determine if instability develops over time.

METHODS

We performed a retrospective review for all pediatric Trisomy 21 patients receiving at least 2 cervical spine radiographic series between 2008 and 2020 at our institution. Atlantodens interval (ADI) and space available for the cord at C1 (SAC) were measured; bony abnormalities such as os odontoidium, and age and time between radiographs were noted. AAI was determined by ADI ≥6 mm or SAC ≤14 mm based on our groups' prior study. Those who developed instability were compared with those who did not.

RESULTS

A total of 437 cervical spine radiographic series from 192 patients were evaluated, with 160 included. Mean age at first radiograph was 7.4±4.4 years, average ADI was 3.1 mm (±1.2), and SAC was 18.1 mm (±2.6). The average time between first and last radiographs was 4.3 years (±1.8), with average final ADI 3.2 mm (±1.4) and SAC 18.9 mm (±2.9). Seven patients (4%) had instability: 4 were unstable on their initial studies and 3 (1.6%) on subsequent imaging. Os odontoideum was found in 5 (71%) unstable spines and 3 (2%) stable spines (P<0.0001); only 1 patient that became unstable on subsequent radiograph did not have an os. There was no specific age cut-off or surveillance time period after which one could be determined no longer at risk.

CONCLUSIONS

Trisomy 21 patients have a 4.4% overall rate of AAI in our series with a 1.6% rate of progression to instability over ∼4 years. Given this nearly 1 in 23 risk of instability, we recommend initial surveillance radiograph for all children over 3 years with Trisomy 21; repeat asymptomatic surveillance should continue in those with os odontoideum given their high instability risk.

LEVEL OF EVIDENCE

Level II-diagnostic study.

Refractory Syncope and Presyncope Associated with Atlantoaxial Instability: Preliminary Evidence of Improvement Following Surgical Stabilization

BACKGROUND

The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a higher than expected incidence of AAI in hereditary connective tissue disorders. We demonstrate a strong association of AAI with manifestations of dysautonomia, in particular syncope and lightheadedness, and make preliminary observations as to the salutary effect of surgical stabilization of the atlantoaxial motion segment.

METHODS

In an institutional review board-approved retrospective study, 20 subjects (16 women, 4 men) with hereditary connective tissue disorders had AAI diagnosed by computed tomography. Subjects underwent realignment (reduction), stabilization, and fusion of the C1-C2 motion segment. All subjects completed preoperative and postoperative questionnaires in which they were asked about performance, function, and autonomic symptoms, including lightheadedness, presyncope, and syncope.

RESULTS

All patients with AAI reported lightheadedness, and 15 had refractory syncope or presyncope despite maximal medical management and physical therapy. Postoperatively, subjects reported a statistically significant improvement in lightheadedness (P = 0.003), presyncope (P = 0.006), and syncope (P = 0.03), and in the frequency (P < 0.05) of other symptoms related to autonomic function, such as nausea, exercise intolerance, palpitations, tremors, heat intolerance, gastroesophageal reflux, and sleep apnea.

CONCLUSIONS

This study draws attention to the potential for AAI to present with syncope or presyncope that is refractory to medical management, and for surgical stabilization of AAI to lead to improvement of these and other autonomic symptoms.

Evaluation of 2011 AAP cervical spine screening guidelines for children with Down Syndrome

PURPOSE

Atlantoaxial instability (AAI) has a higher incidence rate among individuals with Down syndrome (DS) than the non-DS population. In 2011, the American Academy of Pediatrics (AAP) updated its AAI screening guidelines for children with DS from radiographic screening to radiographs only if there are clinical symptoms suggestive of cervical spine pathology. An assessment of whether this alteration has been associated with an increase in AAI-associated spinal cord injury has not been undertaken.

METHODS

We provide the first neurosurgical review of a large experience implementing the 2011 AAP guidelines. We reviewed the courses of patients with DS seen at the Sie Center for Down Syndrome at Children's Hospital Colorado who were evaluated for cervical spine disease and determined whether screening radiographic imaging could have led to earlier diagnosis or prevented development of neurological deficits. We also report an illustrative case of a 5-year-old female with Down syndrome who presented with instability after normal screening radiographs per the pre-2011 guidelines.

RESULTS

The clinical experience of the Sie Center demonstrates that even when limiting imaging to patients who show signs or symptoms of spine pathology, the vast majority of x-rays are negative. Our exemplary patient presented to the emergency department for neck pain without a history of significant trauma. She was diagnosed and treated for atlantoaxial subluxation associated with os odontoideum.

CONCLUSION

Routine radiographic screening may not be sufficiently predictive of DS individuals at risk to develop AAI. This experience supports the appositeness of the de-escalation of care asserted by the guidelines.

Rare Presentation: A Report of 2 Identical Cases with Thoracic Compressive Myelopathy in Down Syndrome

BACKGROUND

Atlantoaxial instability, a common finding in patients with Down syndrome (DS), is attributed to laxity of ligamentous structures. Cervical spondylosis identified in these patients has a pathogenesis of ligament laxity and early degeneration compared with the normal population. No cases have been reported showing affection of thoracic or lower levels.

CASE DESCRIPTION

Two adults with DS presented with progressive spastic paraparesis with hypertrophy of ligamentum flavum at the lower thoracic level, causing canal stenosis and myelopathy. Degenerative changes were seen in the entire spine. Both patients improved with canal decompression.

CONCLUSIONS

Degenerative changes of the spine occur earlier in DS, probably due to increased movements across the vertebrae owing to laxity in the ligaments. Routine workup of patients with DS presenting in their adult lives should keep in mind the affection of lower spinal levels. Early identification of thoracic myelopathy and lumbar canal stenosis gives a chance of cure.

An Updated Algorithm for Radiographic Screening of Upper Cervical Instability in Patients With Down Syndrome

STUDY DESIGN

Retrospective evaluation of cervical spine images from 2006-2012 for the purposes of "screening" children with Down syndrome for instability.

OBJECTIVE

To determine whether a full series of cervical spine images including flexion/extension lateral (FEL) radiographs was needed to avoid missing upper cervical instability.

SUMMARY OF BACKGROUND DATA

The best algorithm, measurements, and criteria for screening children with Down syndrome for upper cervical instability are controversial. Many authors have recommended obtaining flexion and extension views. We noted that patients who require surgical stabilization due to myelopathy or cord compression typically have grossly abnormal radiographic measurements on the neutral upright lateral (NUL) cervical spine radiograph.

METHODS

The atlanto-dental interval, space available for cord, and basion axial interval were measured on all films. The Weisel-Rothman measurement was made in the FEL series. Clinical outcome of those with abnormal measurements were reviewed. Sensitivity, specificity, and positive and negative predictive values of NUL and FEL radiographs for identifying clinically significant cervical spine instability were calculated.

RESULTS

A total of 240 cervical spine series in 213 patients with Down syndrome between the ages of 4 months and 25 years were reviewed. One hundred seventy-two children had an NUL view, and 88 of these patients also had FEL views. Only one of 88 patients was found to have an abnormal atlanto-dental interval (≥6 mm), space available for cord at C1 (≤14 mm), or basion axial interval (>12 mm) on an FEL series that did not have an abnormal measurement on the NUL radiograph. This patient had no evidence of cord compression or myelopathy.

CONCLUSIONS

Obtaining a single NUL radiograph is an efficient method for radiographic screening of cervical spine instability. Further evaluation may be required if abnormal measurements are identified on the NUL radiograph. We also propose new "normal" values for the common radiographic measurements used in assessing risk of cervical spine instability in patients with Down syndrome.

LEVEL OF EVIDENCE

Level IV.

Morphological classification of the tubercle of insertion of the transverse atlantal ligament: A computer tomography-based anatomical study of 200 subjects

BACKGROUND AND PURPOSE

The atlantal tubercle is the attachment point of the transverse atlantal ligament, the main stabilizer of the atlantoaxial complex. No system of classification of the tubercle exists in the literature. We aimed to develop a morphologically based classification system of the atlantal tubercle to aid clinicians who deal with craniocervical pathology.

MATERIALS AND METHODS

A retrospective review of computed tomography (CT) scans of the cervical spine was performed. The morphology of the atlantal tubercle was classified into four variants: rounded (classical), pointed, flattened, and hypoplastic. Age, presence, and morphological type were recorded.

RESULTS

A total of 200 CT scans were identified and reviewed. The tubercle was present bilaterally in all patients. Patients were equally distributed over various age ranges. The following morphological types were recorded: rounded (227/400; 56.8%), pointed (13/400; 3.3%), flattened (126; 31.5%), and hypoplastic (34/400; 8.5%). The same type was seen bilaterally in 68% (135/200) of patients. Morphological types appear equally on the right and left side of the atlas.

CONCLUSIONS

The first morphologically based classification system of the atlantal tubercle utilizing CT is presented. Morphology type, especially hypoplastic type, may confer an increased risk for subsequent need for posterior fusion.

Neuroimaging assessment in Down syndrome: a pictorial review

Down syndrome (DS), or trisomy 21, is the leading genetic cause of intellectual incapacity worldwide, with a reported incidence of about 1 in 1,000 to 1 in 1,100 live births. Besides the several commonly known physical features characteristic of this syndrome present at birth, DS may additionally affect every organ system. In addition, despite the large number of published papers concerning this syndrome, there is scarce literature focusing specifically in the typical neuroimaging features associated with this condition. The aim of this paper is to review and systematize the distinctive characteristics and abnormalities of the central nervous system, head and neck, and spine present in DS patients that should actively be searched for and evaluated by radiologists and/or neuroradiologists.

Outcomes of Surgical Correction of Atlantoaxial Instability in Patients with Down Syndrome: Systematic Review and Meta-Analysis

BACKGROUND

Atlantoaxial instability (AAI) is a common cause of neurologic dysfunction and pain in patients with Down syndrome (DS), frequently requiring instrumented fusion of the upper cervical spine. Despite this, optimal treatment strategy is controversial.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systemic Reviews and Meta-Analysis statement to identify patients with AAI and DS were treated with upper cervical spine fusion. Patient demographics, preoperative symptoms, fixation type, and outcome measures including complications, neurologic outcomes, and bony fusion status were gathered for patients in the included publications. Meta-analysis was performed to compare outcomes of different types of fixation constructs.

RESULTS

Of the 1191 publications retrieved, 51 met inclusion criteria, yielding 137 patients. Six fixation strategies were identified: noninstrumented (n = 6), wiring (n = 77), wiring with rods (n = 14), screw fixation (n = 33), hook and rod fixation (n = 2), and screw and wire fixation (n = 5). Constructs with screws and rods had greater bony union (P = 0.003) and a lower rate of revision surgery (P = 0.047), loss of reduction or pseudoarthrosis (P = 0.009), halo utilization (P < 0.001), and early neurologic decline (P = 0.004) compared with wiring alone. Constructs with wires and rods had greater bony union (P = 0.036) than wiring alone.

CONCLUSIONS

Numerous fixation strategies exist for AAI in patients with DS. Using a combination of screws, rods, and wiring in appropriately selected patients may help reduce the high rate of surgical complications in these patients.

Anterior atlantoaxial subluxation with Down syndrome and arthritis: case report

Down syndrome (DS) occurs when an individual has a full or partial extra copy of chromosome 21 and is the most common of all malformation syndromes. Associating with numerous pathologies like anterior atlantoaxial subluxation (AAAS) which is an increase in the space between the anterior arch of the first cervical vertebra (C1) and the odontoid process of the second vertebra (C2), most of the time its asymptomatic, only 1-2% to all the 30% who may have the AAAS and DS develop clinical symptoms. In this occasion, we present the case of a patient with SD and Juvenile chronic arthritis (JCA) who has atlantoaxial subluxation of approximately 11mm, basilar impression and platybasia with severe medullary compression in 2 points, requiring surgical management by the Neurological Surgery Service in Bucaramanga-Colombia.

Dynamic MRI in the Evaluation of Atlantoaxial Stability in Pediatric Down Syndrome Patients

BACKGROUND/AIMS

Down syndrome is the most common inherited disorder. Some patients develop atlantoaxial instability. Existing screening guidelines were developed prior to availability of MRI. We present predictors for deficit using dynamic MRI of the craniocervical junction.

METHODS

A retrospective review of Down syndrome patients from 2001 to 2015 was carried out. Patients were considered symptomatic if they had clinical deficits or signal change on MRI. Measurements were taken at the atlantoaxial junction and structural abnormalities noted. Analysis was performed with SPSS.

RESULTS

A total of 36 patients were included. Patients averaged 93 months of age with a follow-up of 57 months. No asymptomatic patients developed myelopathy during follow-up. During dynamic imaging, symptomatic patients had greater changes in space available for the cord (SAC) (5.2 vs. 2.7 mm; p < 0.001) and atlantodental interval (ADI) (2.8 vs. 1.3 mm; p = 0.04). These patients were also more likely to have a bony anomaly (50 vs. 13%; p = 0.03).

CONCLUSION

This study characterizes the range of motion seen on dynamic MRI and provides parameters that can be used to distinguish patients at risk for neurologic injury. Changes greater than 3 mm in ADI or 5 mm in SAC during dynamic MRI or any bony abnormality warrants further investigation. Patients without these features may be able to avoid an unnecessary intervention.

Fatal atlantoaxial dislocation due to an odontoid synchondrosis fracture in a child with chromosome 9 abnormality: A case report

A 5-year-old boy with a chromosome-9 abnormality and multiple external and visceral malformations was found in cardiopulmonary arrest during a regular visit to the hospital; he did not respond to cardiopulmonary resuscitation and died. An odontoid process fracture and calcification and fibrosis of the muscles around the superior cervical vertebra were observed during the autopsy. Postmortem computed tomography revealed an anterior dislocation of the atlas; odontoid synchondrosis fracture; and delayed, incomplete bony fusion of the odontoid process relative to his age. The cause of his death was a superior spinal cord injury. The tissue surrounding the upper cervical spine presented with myositis ossificans, suggesting a prior injury. He experienced a minor traffic accident 3 months before his death. It was concluded that the odontoid synchondrosis fracture occurred during the accident based on the incomplete bony fusion and atlantoaxial instability, which were consistent with the findings of myositis ossificans. Delayed fatal dislocation may then have occurred under the influence of a minor external force. Odontoid process abnormalities and atlantoaxial instability are common in patients with trisomy 21 and other congenital diseases; however, the condition's association with chromosome-9 abnormalities has not been reported. In children with various chromosomal abnormalities, periodic assessment of instability and morphology of the cervical spine, and a lowered examination threshold for the children at risk, could prove useful in the prevention injuries leading to fatality, and provide additional information to rule out abuse.

Cervical instability in patients with Trisomy 21: The eternal gamble

Patients with Trisomy 21 are particularly at risk of cervical instability due to ligamentous laxity and osseous abnormalities. Up to 30% of Trisomy 21 patients are affected by atlanto-axial or atlanto-occipital instability, but only 1%-2% of cases are symptomatic. The radiologic assessment of cervical instability is not unanimously considered mandatory. The dynamic cervical spine radiograph is the most common screening tool for ruling out cervical spine instability in patients with Trisomy 21, and it is often requested before surgery. Several measurements have been investigated to assess the presence and degree of cervical instability; however, no conclusive recommendations have been forthcoming. In daily practice, many anesthesiologists may provide anesthesia via such means as laryngoscopy and tracheal intubation during surgery, without any radiological investigations before surgery. This review focuses on the diagnostic and prognostic measures available to evaluate the presence and degree of cervical instability in patients with Trisomy 21 and to propose practical recommendations to be applied in clinical practice.

The Outcomes of Posterior Arthrodesis for Atlantoaxial Subluxation in Down Syndrome Patients: A Meta-Analysis

STUDY DESIGN

This is a meta-analysis.

OBJECTIVE

To establish rates of (1) neurological complications, (2) bony-related complications, (3) complications delaying recovery, (4) reoperation, and (5) fatalities following posterior cervical arthrodesis in Down syndrome (DS) patients with atlantoaxial subluxation. To determine if presenting symptoms had any relationship to postoperative complications.

SUMMARY OF BACKGROUND DATA

Posterior arthrodesis is commonly utilized to correct cervical instability secondary to atlantoaxial instability in DS patients. However, there has never been a global evaluation of postoperative complications associated with posterior cervical spinal arthrodesis in DS patients.

METHODS

A comprehensive search of Medline/PubMed, EMBASE, and Ovid databases between January 1980 and July 2017 was utilized to identify DS patients with atlantoaxial subluxation who underwent posterior cervical arthrodesis. Data were sorted by neurological complications, complications delaying recovery, bony-related complications, reoperations, and fatalities. Patients were sorted into 2 groups based on presentation with or without neurological deficits.

RESULTS

Twelve studies met inclusion criteria, including 128 DS patients. Mean age was 13.8 years (range: 6.7-32.7 y; 47.8% male). Mean follow-up was 31.7 months (range: 14.9-77 mo). All patients underwent primary posterior cervical arthrodesis with an average of 2.5 vertebrae fused. A total of 39.6% of patients had bony-related complications [95% confidence interval (CI), 31.4%-48.5%], 23.3% had neurological deficits (95% CI, 16.6%-31.6%), and 26.4% experienced complications delaying recovery (95% CI, 19.4%-34.9%). The reoperation rate was 34.9% (95% CI, 25.5%-45.6%). The mortality rate was 3.9% (95% CI, 1.5%-9.7%). Neurological complications were 4-fold (P<0.05) and reoperation was 5.5-fold (P<0.05) more likely in patients presenting with neurological deficits compared with those without.

CONCLUSIONS

This study detailed global complication rates of posterior arthrodesis for DS patients, identifying bony-related complications and reoperations among the most common. Patients presenting with neurological symptoms and cervical instability have increased postoperative rates of neurological complications and reoperations than patients with instability alone. Further investigation into how postoperative complications effect patient independence is warranted.

Measurements in cervical vertebrae CT of pediatric cases: normal values

PURPOSE

This study aims to determine the normal limits of atlanto-dental interval (ADI), basion-dens interval (BDI), basion-cartilaginous dens interval (BCDI), and prevertebral soft tissue thickness (PVSTT) according to age groups for normal pediatric cases.

MATERIALS AND METHODS

CT images of 256 pediatric patients aged between 1 and 15 years were retrospectively evaluated. ADI, BDI, BCDI and PVSTT measurements were performed.

RESULTS

Upper normal limit (UNL) values for ADI were 2.65-4.8 mm. UNL values for PVSTT were found to be 6.9 mm at C1 level, 6.7 mm at C2 level, 9.3 mm at C3 level, 14.2 mm at C4 level, 14.1 mm at C5 level, 13.8 mm at C6 level and 12.8 mm at C7 level. The maximum value of BDI in the group with non-ossified os terminale was 12 mm, and in the group with ossified os terminale it was 10 mm. The UNL of BCDI determined for females was 5.1 mm, while the UNL for males was 5.6 mm.

CONCLUSION

We propose the obtained values as the UNL values for ADI, BDI, BCDI and PVSTT on CT images in the pediatric population from 1 to 15 years.

Basilar impression as complication of Grisel's syndrome

Grisel's syndrome presents a rare disease. Here, we present a peculiar case of Grisel's syndrome with an unfavorable course developing a basilar impression. This highlights the importance of close clinical and radiological follow‐up even in cases where the course seems uncomplicated.

Neurological and spinal manifestations of the Ehlers-Danlos syndromes

The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders characterized by joint hypermobility, skin extensibility, and tissue fragility. This communication briefly reports upon the neurological manifestations that arise including the weakness of the ligaments of the craniocervical junction and spine, early disc degeneration, and the weakness of the epineurium and perineurium surrounding peripheral nerves. Entrapment, deformation, and biophysical deformative stresses exerted upon the nervous system may alter gene expression, neuronal function and phenotypic expression. This report also discusses increased prevalence of migraine, idiopathic intracranial hypertension, Tarlov cysts, tethered cord syndrome, and dystonia, where associations with EDS have been anecdotally reported, but where epidemiological evidence is not yet available. Chiari Malformation Type I (CMI) has been reported to be a comorbid condition to EDS, and may be complicated by craniocervical instability or basilar invagination. Motor delay, headache, and quadriparesis have been attributed to ligamentous laxity and instability at the atlanto-occipital and atlantoaxial joints, which may complicate all forms of EDS. Discopathy and early degenerative spondylotic disease manifest by spinal segmental instability and kyphosis, rendering EDS patients prone to mechanical pain, and myelopathy. Musculoskeletal pain starts early, is chronic and debilitating, and the neuromuscular disease of EDS manifests symptomatically with weakness, myalgia, easy fatigability, limited walking, reduction of vibration sense, and mild impairment of mobility and daily activities. Consensus criteria and clinical practice guidelines, based upon stronger epidemiological and pathophysiological evidence, are needed to refine diagnosis and treatment of the various neurological and spinal manifestations of EDS. © 2017 Wiley Periodicals, Inc.

Down syndrome-A narrative review with a focus on anatomical features

Down syndrome (DS) is the most common aneuploidy of chromosome 21, characterized by the presence of an extra copy of that chromosome (trisomy 21). Children with DS present with an abnormal phenotype, which is attributed to a loss of genetic balance or an excess dose of chromosome 21 genes. In recent years, advances in prenatal screening and diagnostic tests have aided in the early diagnosis and appropriate management of fetuses with DS. A myriad of clinical symptoms resulting from cognitive, physical, and physiological impairments caused by aberrations in various systems of the body occur in DS. However, despite these impairments, which range from trivial to fatal manifestations, the survival rate of individuals with DS has increased dramatically from less than 50% during the mid-1990s to 95% in the early 2000s, with a median life expectancy of 60 years reported recently. The aim of this narrative review is to review and summarize the etiopathology, prenatal screening and diagnostic tests, prognosis, clinical manifestations in various body systems, and comorbidities associated with DS. Clin. Anat. 29:568-577, 2016. © 2015 Wiley Periodicals, Inc.

Preoperative evaluation and comprehensive risk assessment for children with Down syndrome

Down syndrome is a common chromosome disorder affecting all body systems. This creates unique physiologic concerns that can affect safety during anesthesia and surgery. Little consensus exists, however, on the best way to evaluate children with Down syndrome in preparation for surgery. We review a number of salient topics affecting these children in the perioperative period, including cervical spine instability, cardiovascular abnormalities, pulmonary hypertension, upper airway obstruction, hematologic disturbances, prematurity, low birth weight, and the use of supplements and alternative therapies. Recommendations include obtaining a complete blood count to detect an increased risk for bleeding or stroke, and cardiology evaluation to identify patients with pulmonary hypertension, as well as undiagnosed or residual heart disease. Pediatric cardiac anesthesiologists and intensivists should be involved as needed. The potential for cervical spine instability should be considered, and the anesthesiologist may wish to have several options available both for the medications and equipment used. The child's family should always be asked if he or she is on any nutritional supplements, as some products marketed to families may have secondary effects such as inhibition of platelet function. Using this evaluation in presurgical planning will allow physicians to better consider the individual circumstances for their patients with Down syndrome. Our goal was to optimize patient safety by choosing the most appropriate setting and perioperative personnel, and to mitigate those risk factors amenable to intervention.

A cervical flexion-extension MRI study in Down syndrome

OBJECTIVE

To assess what kind of information MR examination in flexed and extended positions provides in Down syndrome subjects with suspected cranio-cervical instability.

METHODS

Between 2005 and 2008, 35 subjects with DS were recruited in the study. Ethics committee approval was granted and a signed informed consent was obtained from the parents. All the subjects were affected by hypotonic status and ligament laxity established by clinical evaluation, but were asymptomatic about focal neurological symptoms due to medullar damage caused by cranio-cervical instability. Each patient underwent lateral supine radiographs and MR imaging in the neutral, active flexed and extended positions. For evaluating the atlanto-axial and atlanto-occipital joint stability, multiple measurements were calculated.

RESULTS

A significant reduction of anterior subarachnoid space in flexed position was evident in DS subjects compared to healthy controls in neutral and flexed positions. Both, space available for cord and ligamentous thickness showed significant differences between DS subjects and healthy controls. In DS subjects with occipito-cervical instability, the anterior subarachnoidal space reduction was significantly reduced in flexed position.

CONCLUSIONS

In DS subjects with asymptomatic cranio-cervical instability, anterior subarachnoidal evaluation and ligamentous status could add new information about the risk of spinal cord damage.

Atlantoaxial dislocation in a patient with nonsyndromic symmetrical dwarfism: Report of a rare case

Congenital anomalies of the craniovertebral junction (CVJ) are complex developmental defects. We describe a patient with atlantoaxial dislocation (AAD) and short stature whose morphopathologydid not fit into any of the previously described syndromic constellations. The patient underwent a reduction of the AAD followed by fixation with C1-C2 transarticular screws. Although numerous syndromes have been linked to both dwarfism and craniovertebral junction anomalies, this patient did not fit into any of these patterns. It is possible that this may be one of the many as yet unrecognized patterns of congenital anomalies.

Diagnosis and management of Down syndrome

Down syndrome is the commonest chromosomal disorder causing mild to moderate intellectual disability, yet it is one of the neglected disorder amongst practicing physicians. Children with Down syndrome when intervened early by speech therapy, physiotherapy and occupational therapy and given proper medical attention for different health issues, can have a better long term outcome as compared to other genetic causes of intellectual disability. This paper would help the general practitioners to identify children with Down syndrome and to manage the common problems associated with this condition.

Imaging findings in Down syndrome

Down syndrome, or trisomy 21, is the most common chromosomal anomaly and is characterized by intellectual disability and a typical facies. People with Down syndrome can have abnormalities of multiple organ systems. Cardiac and respiratory system involvement is the most common cause of morbidity and mortality, although every organ system can be affected. Patients may present prenatally with findings on screening sonography. If the diagnosis is not made prenatally, it is apparent at birth because of the characteristic facial features and musculoskeletal findings. Children with Down syndrome present to the radiology department at various ages depending on the severity of the specific finding. The purpose of this paper is to review the most common antenatal and postnatal imaging findings of Down syndrome as they manifest throughout the body.

Asymptomatic moyamoya syndrome, atlantoaxial subluxation and basal ganglia calcification in a child with Down syndrome

Down syndrome, the most common chromosomal abnormality, may be associated with various neurologic complications such as moyamoya syndrome, cervical spinal cord compression due to atlantoaxial subluxation, and basal ganglia damage, as well as epileptic seizures and stroke. Many cases of Down syndrome accompanied by isolated neurologic manifestations have been reported in children; however, Down syndrome with multiple neurologic conditions is rare. Here, we have reported a case of Down syndrome in a 10-year-old girl who presented with asymptomatic moyamoya syndrome, atlantoaxial subluxation with spinal cord compression, and basal ganglia calcification. To the best of our knowledge, this is the first report of Down syndrome, in a child, which was accompanied by these 3 neurologic complications simultaneously. As seen in this case, patients with Down syndrome may have neurologic conditions without any obvious neurologic symptoms; hence, patients with Down syndrome should be carefully examined for the presence of neurologic conditions.

Occipitocervical fusion using a contoured rod and wire construct in children: a reappraisal of a vintage technique

OBJECT

Many methods to stabilize and fuse the craniocervical junction have been described. One of the early designs was a contoured (Luque) rod fixated with wires, the so-called Hartshill-Ransford loop. In this study, the authors report their 20-year experience with this surgical technique in children.

METHODS

The authors reviewed the medical records of patients 18 years of age or younger who underwent dorsal occipitocervical fusion procedures between March 1992 and March 2012 at Le Bonheur Children's Hospital using a contoured rod and wire construct. Data on basic patient characteristics, causes of instability, neurological function at presentation and at last follow-up, details of surgery, complications, and radiographic outcome were collected.

RESULTS

Twenty patients (11 male) were identified, with a mean age of 5.5 years (range 1-18 years) and a median follow-up of 43.5 months. Fourteen patients had atlantooccipital dislocation, 2 patients had atlantoaxial fracture-dissociations, 2 had Down syndrome with occipitocervical and atlantoaxial instability, 1 had an epithelioid sarcoma from the clivus to C-2, and 1 had an anomalous atlas with resultant occipitocervical instability. Surgical stabilization extended from the occiput to C-1 in 3 patients, C-2 in 6, C-3 in 8, and to C-4 in 3. Bone morphogenetic protein was used in 2 patients. Two patients were placed in a halo orthosis; the rest were kept in a hard collar for 6-8 weeks. All patients were neurologically stable after surgery. One patient with a dural tear experienced wound dehiscence with CSF leakage and required reoperation. Eighteen patients went on to achieve fusion within 6 months of surgery; 1 patient was initially lost to follow-up, but recent imaging demonstrated a solid fusion. There were no early hardware or bone failures requiring hardware removal, but radiographs obtained 8 years after surgery showed that 1 patient had an asymptomatic fractured rod. There were no instances of symptomatic junctional degeneration, and no patient was found to have increasing lordosis over the fused segments. Five (31%) of the 16 trauma patients required a shunt for hydrocephalus.

CONCLUSIONS

Despite the proliferation of screw-fixation techniques for craniocervical instability in children, the contoured rod-wire construct remains an effective, less expensive, and technically easier alternative that has been in use for almost 30 years. It confers immediate stability, and therefore most patients will not need to be placed in a halo device postoperatively. A secondary observation in our series was the high (30%) rate of hydrocephalus requiring a shunt in patients with traumatic instability.

C2/3 instability: unusual cause of cervical myelopathy in a child with Down syndrome

We report a rare cause of cervical myelopathy (CM) in a 10-year-old Down syndrome (DS) girl. She presented with progressive CM over 1 year affecting her ability to ambulate or feed herself. The myelopathy was secondary to C2/3 instability. Surgical reduction and instrumented fusion have significantly improved her neurological status. This case emphasizes the importance of close follow-up of DS patients for early diagnosis and treatment of cervical spine abnormalities.

Neurobiological elements of cognitive dysfunction in down syndrome: exploring the role of APP

Down syndrome (DS) is the most common cause of cognitive dysfunction in children. Additionally, most adults with DS will eventually show both clinical and neuropathologic hallmarks of Alzheimer's disease (AD). The hippocampal formation constitutes the primary target for degeneration in both AD and DS. Over the past few years, we have studied the molecular mechanisms behind degeneration of this region and its major inputs in mouse models of DS. Our investigation has suggested that the loss of hippocampal inputs, particularly cholinergic and noradrenergic terminals, leads to de-afferentation of this region in the Ts65Dn mouse model of DS. Interestingly, we were able to link the overexpression of amyloid precursor protein (App) gene to degeneration of cholinergic and noradrenergic neurons in DS mouse models. We examined the underlying mechanisms of degeneration of multiple systems with extensive projections to the hippocampus in DS and its mouse models and the role of App overexpression in neurodegeneration. Understanding mechanisms behind hippocampal dysfunction has helped us to test several therapeutic strategies successfully in mouse models of DS. Here we review these strategies and mechanisms and discuss ways to translate our findings into possible interventions in humans.

C1-2 instability from os odontoideum mimicking intramedullary spinal cord tumor

Os odontoideum is a common cause of atlantoaxial instability in the pediatric population. The authors present the cases of 2 patients whose initial clinical presentation and MR imaging findings were suggestive of an intramedullary neoplasm, but whose ultimate diagnosis was determined to be cervical spine instability and cord injury due to os odontoideum.

Complications of adenotonsillectomy

PURPOSE OF REVIEW

Tonsillectomy and adenoidectomy are two of the most commonly performed pediatric surgical procedures. As with all surgical intervention, tonsillectomy and adenoidectomy are associated with a host of potential complications. Fortunately, for most children undergoing adenotonsillectomy (T&A), complications are rare. This review is intended to summarize recent reports, which may lead to prevention and treatment of T&A complications.

RECENT FINDINGS

The presented reports of complications and risk factors for complications in children undergoing T&A highlight perioperative medical management as a means to decrease perioperative complications. Certain tonsillectomy techniques, such as microdebrider intracapsular tonsillectomy, may lead to decreased posttonsillectomy hemorrhage and dehydration. Despite published recommendations, preoperative assessments for bleeding diatheses vary among practitioners. Conversely, guidelines for evaluation of posttonsillectomy hemorrhage are lacking. Some pediatric populations, such as children with coagulopathy, neurologic disease, and obesity, have increased risk of perioperative complications, and recent reports regarding their care are presented.

SUMMARY

We present recent data pertinent to the contemporary management of medical and surgical complications of T&A, with particular focus on specific at-risk pediatric populations. In the patient groups illustrated in this review, anticipation of complications may decrease complications or lead to improved management of complications when they occur.

Clinical practice. The care of children with Down syndrome

Down syndrome (DS) is one of the most common chromosomal abnormalities. Because of medical advances and improvements in overall medical care, the median survival of individuals with DS has increased considerably. This longer life expectancy requires giving the necessary care to the individual with DS over their total longer lifespan. DS medical guidelines are designed for the optimal care of the child in whom a diagnosis of DS has been confirmed. We present an overview of the most important issues related to children with DS based on the most relevant literature currently available.