Down syndrome. Cervical spine abnormalities and problems

A review of the radiographs of 34 individuals with Down syndrome (DS), between 5 and 21 years of age, demonstrated subluxation of atlantoaxial instability (C1-C2) greater than 5 mm in three of the 34 individuals (9 percent). This is in general agreement with previously reported ranges of 10 to 20 percent. A review of the cervical spine radiographs of adults with DS, between 26 and 42 years of age, showed no subluxation but significant degenerative changes of the cervical spine with spur formation, narrowing of foramina, narrowing of the disc inner space, and osteophyte formation. In both the DS child and the DS adult, the cervical spine may be an area of significant potential problems. In all cases any complaints of cervical pain or historical/clinical findings suggestive of neurologic involvement should initiate evaluation of the cervical spine. Baseline radiographic studies of the cervical spine are indicated in all DS children older than 5 years of age and should be considered in all DS adults, particularly those 30 years of age and older.     

Atlantoaxial subluxation with recurrent consciousness disturbance in a boy with Lesch-Nyhan syndrome

Deficiency of the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) may cause various clinical entities such as Lesch-Nyhan syndrome (LNS). A 9.5-y-old boy with the phenotypic features of LNS, including hyperuricaemia, choreoathetosis, self-mutilation and profound neurological dysfunction, was found to have HPRT deficiency. Normocytic anaemia, hyperuricaemia (uric acid 594.8 micromol/l) and microscopic haematuria with uric acid crystals were noted. Ultrasonography showed bilateral nephrocalcinosis and urinary bladder stones. In addition, he presented with three episodes of consciousness disturbance with limb paresis, possibly caused by atlantoaxial subluxation (AAS) with compression myelopathy. The diagnosis was made by the amount of residual enzyme activity and a single nucleotide substitution on the acceptor site region of intron 5 (IVS5-1 G-->C) of the HPRT gene, inherited from his asymptomatic mother. Conclusion: Lesch-Nyhan syndrome is a devastating sex-linked recessive disorder resulting from almost complete deficiency of the activity of HPRT. This report highlights the unusual AAS in a boy with LNS presenting recurrent consciousness change. The mutation described herein is a hitherto unreported splicing error leading to exon 6 skipping of the HPRT gene.     

Atlantoaxial instability in individuals with Down syndrome: epidemiologic, radiographic, and clinical studies

Atlantoaxial instability is a relatively frequent finding in individuals with Down syndrome. We examined 404 patients with this chromosome disorder and observed their atlanto-dens intervals and spinal canal widths to be significantly different from children without Down syndrome. Significant differences were also noted between boys and girls with Down syndrome in spinal canal widths but not in atlanto-dens interval measurements. When different neck positions were compared, measurements obtained in flexion were significantly greater than in extension or in neutral position. In addition, more patients had greater than or equal to 5 mm atlanto-dens interval measurements in flexion than in extension or neutral. A total of 59 (14.6%) of 404 patients displayed atlantoaxial instability. Fifty-three (13.1%) patients had asymptomatic atlantoaxial instability, and special precautions will have to be taken with this group of children. Six (1.5%) patients had symptomatic atlantoaxial instability who underwent surgery to prevent further injury to the spinal cord. In our follow-up studies of 95 patients with Down syndrome, we did not find any significant changes during either clinical or radiographic reexaminations.     

Craniovertebral abnormalities in Down's syndrome.

The ligamentous laxity associated with atlantoaxial subluxation has been assumed as a normal occurrence in 15-20% of Down's syndrome patients. The occipitoatlantoaxial instability that accompanies this entity has been poorly recognized. The medical records and radiographic findings of 18 symptomatic patients with Down's syndrome and cervicomedullary compromise were reviewed (1979-1991). All patients were evaluated prospectively under protocol for abnormalities of the cranial vertebral junction. There were 11 males and 7 females (age 3-42). 'Fixed' atlantoaxial luxation was seen in 8 (5 developed precipitous onset of cervical medullary compression). Occipitoatlantoaxial instability was present in 9 and associated rotary luxation in 9. The average predental space was 8 mm in the neutral position in 18 individuals. Two adolescents had previously undergone atlantoaxial dorsal fusion with subsequent progressive basilar invagination due to unrecognized occipitoatlantal instability. An os odontoideum was seen in 3 patients. Irreducible invagination in 2 was treated with anterior decompression followed by dorsal occipital cervical fixation. The occipital cervical fixation was utilized in 10 individuals. Atlantoaxial dorsal fusion was made in 7 and 2 patients with acute rotary luxation of C1 and C2 were treated with immobilization. Halo immobilization in two individuals following a dorsal occipital cervical fixation produced an anterior fusion at the cranial vertebral complex indicating active vertebral ligamentous pathology. The review focuses on increased incidence of occiput cervical instability in the spectrum of craniovertebral junction abnormalities associated with Down's syndrome. A large percentage has an odontoid ossicle probably as a result of repeated minor trauma. The results of surgical stabilization have been shown to be excellent.     

Diagnosis of Atlantoaxial Subluxation in Morquio's Syndrome and Spondyloepiphyseal Dysplasia Congenita

Compression of the spinal cord due to atlantoaxial subluxation was diagnosed in a patient with Morquio's syndrome and in another with spondyloepiphyseal dysplasia (SED) congenita by cervical radiography and magnetic resonance imaging (MRI). The patient with Morquio's syndrome, a 15 year old boy, had no neurologic symptoms and his somatosensory evoked potential (SSEP) was normal. However, MRI demonstrated spinal cord compression at C1-C2. In contrast, the patient with SED congenita, an 11 year old girl, had neck pain, hyperreflexia and loss of vibration sense in both legs. These findings were explained by the absence of P3 and later waves in SSEP and by compression of the spinal cord observed on MRI. Both SSEP and MRI should be used for evaluating disorders in which atlantoaxial subluxation might be present.     

Clinical predictors and radiological reliability in atlantoaxial subluxation in Down's syndrome.

Clinical signs and symptoms that might predict atlantoaxial subluxation were studied prospectively in 135 of 180 children with Down''s syndrome aged 6-14 years who form the Hester Adrian Research Centre cohort. Lateral radiographs of the cervical spine were taken in flexed, extended, and neutral positions, and the percentage of abnormalities in each view was 14, 10, and 10%, respectively. Gait was the only significant clinical predictor. The relative risk of having an abnormal neck radiograph with an abnormal gait was 2.91 (95% confidence interval (CI) 1 to 8). The sensitivity was 50% and the specificity 81%. Nineteen children had repeat radiographs to assess the reliability of radiological diagnosis. Six had abnormalities; five of 19 (26%) had an abnormality on the first radiograph, and four of 19 (21%) had an abnormality on a second radiograph, but only three (15%) had an abnormality on both occasions in any view (95% CI 0 to 25). We conclude that radiographs of the cervical spine are unreliable at identifying atlantoaxial subluxation in children with Down''s syndrome, and we failed to identify any reliable clinical predictor.     

以寰枢关节半脱位为首发表现的全身型幼年特发性关节炎1例

目的探讨以寰枢关节半脱位为首发症状的全身型幼年特发性关节炎(SoJIA)临床特点。方法回顾性分析1例以寰枢关节半脱位为首发症状的SoJIA患儿的临床资料。结果患儿,男,9岁,以颈部活动障碍为首发症状,病程第3天出现发热,第23天病情迅速进展,红细胞、血小板、血红蛋白急剧下降,凝血功能障碍,双肺大量渗出;彩色超声示腹腔、胸腔、心包等多浆膜腔积液,根据2001年国际风湿病学会联盟修订标准,确诊SoJIA合并巨噬细胞活化综合征,予血液灌流、滤过,并予甲基泼尼松龙联合环孢素A治疗,病情缓解。结论对于无明显骨骼畸形或急性炎症等诱因情况而出现的自发性寰枢关节脱位伴全身症状的患儿,应警惕全身型幼年特发性关节炎可能。     

Atlantoaxial instability in Down syndrome: roentgenographic, neurologic, and somatosensory evoked potential studies

To identify patients with Down syndrome and asymptomatic atlantoaxial instability who are at increased risk for developing neurologic symptoms, we studied 27 patients with this skeletal disorder and compared them with an age- and sex-matched group of 27 patients with Down syndrome without atlantoaxial instability. A third group of six patients had symptomatic atlantoaxial instability. The mean atlanto-dens intervals and the mean spinal canal widths among the three groups were significantly different. There were no significant differences in mean composite neurologic scores and somatosensory evoked responses between patients in the asymptomatic group and those in the control group. However, when a subsample of patients with high and low latencies (greater than 1 SD below and above the mean) was formed and comparisons were made with roentgenographic findings, there was a high correspondence between somatosensory evoked potential latencies and atlanto-dens interval measurements. We conclude that no single assessment technique, but a combined approach using roentgenographic, CT scan, neurologic, and neurophysiologic investigations, will provide information of the risk status of patients with Down syndrome and atlantoaxial instability.     

Odontoid hypoplasia with vertebral cervical subluxation and ventriculomegaly in metatropic dysplasia

Our experience with 12 patients with metatropic dysplasia has demonstrated two important and treatable complications: odontoid hypoplasia with subluxation of the first and second cervical vertebrae, and ventriculomegaly. Hypoplasia and lack of ossification of the odontoid process were noted in all cases. Subluxation of these two vertebrae was demonstrated in all six patients who had lateral flexion-extension radiographs; three had subluxation even in a neutral position, and sudden odontoid dislocation developed in another after a simple fall. Four individuals have had surgical fusion of the cervical vertebrae; one child died suddenly, 1 week before scheduled surgery. In the three patients in whom computed tomography scans of the head were obtained, enlarged ventricles were found; one had symptomatic increased intracranial pressure and required a shunt. We recommend that odontoid hypoplasia be evaluated in all patients with metatropic dysplasia. If subluxation is proved, atlantoaxial fusion should be performed before damage to the cervical part of the spinal cord results. Serial head circumference measurements and evaluation for hydrocephalus are also recommended.     

Down syndrome: imaging of multiorgan involvement.

Down syndrome (trisomy 21) has many manifestations that affect multiple organ systems, and we describe the wide array of imaging findings. Common cardiovascular and gastrointestinal entities are congenital heart disease (atrioventricular canal), bowel atresias (duodenal and anal), and Hirschsprungs disease. Children with Down syndrome have an 18-20 fold increased incidence of leukemia. Pulmonary hypoplasia, lung cysts, and pig bronchus (origin of the right upper lobe bronchus from the trachea) have been described. Neurologic findings include mineralizing vasculopathy of the basal ganglia, Moyamoya disease, and cerebellar/vermian hypoplasia. Musculoskeletal manifestations are numerous and include eleven ribs, hypersegmented sternum, abnormal pelvis, joint laxity/dislocations, and DDH (developmental dysplasia of the hip). Of special importance is the "triple jeopardy" of the upper cervical spine (atlanoaxial subluxation, hypoplastic posterior arch of C1, and atlantooccipital instability) and the resulting controversial cervical spine radiographic screening of children with Down syndrome. Knowledge of the many anomalies associated with Down syndrome can aid the clinician, not only in diagnosing abnormalities in these patients, but also in counseling families for potential problems that can occur in these children.     

Skeletal dysplasia and myelopathy in congenital disorder of glycosylation type IA

We report on a boy with a congenital disorder of glycosylation (CDG) Ia and a severe narrowing of the spinal canal caused by atlantoaxial subluxation with anterior displacement of C1. C1-laminectomy improved the progressive paresis. Progressive paresis caused by spinal cord compression is a hitherto unrecognized complication in patients with CDG-Ia.     

Thyroid function in young children with Down syndrome

A retrospective review of thyroid function tests (TFTs) was performed on 49 young children (aged 4 months to 3 years) with Down syndrome compared with age-matched controls screened for hypothyroidism because of developmental delay or failure to thrive. Three of the 49 children with Down syndrome had congenital hypothyroidism; of the three, one had Hirschsprung's disease and two had duodenal atresia. Thyroiditis was uncommon, with only two children having thyroid antibodies present: one had acquired hypothyroidism and the other acquired hyperthyroidism. Twenty-seven percent of the Down syndrome cohort had mildly increased thyrotropin (TSH) and normal thyroxine levels. When compared with children with Down syndrome who had normal TFTs, no significant differences in sex, growth rate, maternal age, associated anomalies, developmental or specific thyroid symptoms were present. Transient elevations of TSH level were common in children with Down syndrome whether or not TSH values were initially normal or elevated. Routine neonatal and sequential thyroid screening in young children with Down syndrome is warranted.     

Atlantoaxial instability in individuals with Down syndrome: a fresh look at the evidence

In 1984, the Committee on Sports Medicine of the American Academy of Pediatrics published in this journal a statement on the remarkably high incidence of atlantoaxial instability among individuals with Down syndrome. On the assumption that this instability, demonstrable through a specified series of lateral x-ray films of the neck, constituted a predisposition to cervical spine dislocation with subsequent spinal cord compression, the Academy supported and made more specific a series of recommendations that had originated from the Kennedy Foundation a year previously. In essence, for those persons who are found to have the radiographic sign of instability, participation in sports should be restricted. Because the implementation of these recommendations could deprive tens of thousands of individuals with Down syndrome of activities that are emotionally and physically beneficial and because of the rarity of reported cervical dislocations associated with injury, a case review was done. Included were those cases cited as support for the recommendations along with additional reports that had been omitted and a few cases reported subsequently. Little support for the hypothesis that atlantoaxial "instability" is a predisposing factor to "dislocation" was found, although much was found to indicate an urgent need for carefully designed longitudinal studies. Because nearly all of the cases of actual dislocation were preceded by at least several weeks of readily detectable physical signs, a physical examination with careful attention to neurologic signs prior to participation in sports is more predictive of potential or impending dislocation than the radiologic criteria currently recommended.     

Grisel syndrome as a complication of Kawasaki disease: a case report and review of the literature

Grisel syndrome is a non-traumatic atlantoaxial subluxation and a rare complication of any inflammatory condition of the upper neck and otolaryngological procedures. Delayed diagnosis causes neurological impairment, ranging from radiculopathy to paralysis and death. Kawasaki disease is a very frequent and important acute febrile vasculitis of childhood that is seen worldwide, and upper neck involvement (cervical lymphadenopathy) is one of the common symptoms of Kawasaki disease. A case of Grisel syndrome that occurred as a complication of Kawasaki disease is reported. This is the first case report, in English, of Grisel syndrome as a complication of Kawasaki disease. Conclusion: Pediatricians should be aware of Grisel syndrome as a possible complication of Kawasaki disease.     

Working memory in children and adolescents with Down syndrome: evidence from a colour memory experiment

BACKGROUND: This paper reports information on the visual and verbal short-term memory of individuals with Down syndrome. METHODS: Colour memory in 16 children and adolescents with Down syndrome was compared with that of 16 typically developing children matched for receptive vocabulary. It was suggested that focal colours should be remembered more successfully than non-focal colours on the basis that the former could be remembered using a verbal recoding strategy. However, children with Down syndrome, for whom a deficit in verbal short-term memory makes the use of such a strategy unlikely, should remember focal and non-focal colours equally well. More importantly, if individuals with Down syndrome have more developed visual memory abilities than control children, they should outperform them in recognising non-focal colours. RESULTS: Although the group with Down syndrome demonstrated significantly better Corsi blocks performance than controls, and displayed similar levels of colour knowledge, no advantage for colour memory was found. Non-focal colours were remembered by individuals with Down syndrome as successfully as focal colours but there was no indication of a visual memory advantage over controls. Focal colours were remembered significantly more successfully than non-focal colours by the typically developing children. CONCLUSION: Their focal colour memory was significantly related to digit span, but only Corsi span was related to focal colour memory in the group with Down syndrome.     

Atlantoaxial rotary subluxation in children

Traumatic torticollis is an uncommon complaint in the emergency department (ED). One important cause in children is atlantoaxial rotary subluxation. Most children present with pain, torticollis ("cock-robin" position), and diminished range of motion. The onset is spontaneous and usually occurs following minor trauma. A thorough history and physical examination will eliminate the various causes of torticollis. Radiographic evaluation will demonstrate persistent asymmetry of the odontoid in its relationship to the atlas. Computed tomography, especially a dynamic study, may be needed to verify the subluxation. Treatment varies with severity and duration of the abnormality. For minor and acute cases, a soft cervical collar, rest, and analgesics may be sufficient. For more severe cases, the child may be placed on head halter traction, and for long-standing cases, halo traction or even surgical interventions may be indicated. We describe two patients with atlantoaxial rotary subluxation, who presented with torticollis, to illustrate recognition and management in the ED.     

Down syndrome and craniovertebral instability. Topic review and treatment recommendations

The diagnosis and management of occipital-atlantal and atlantoaxial instability in Down syndrome patients is a challenging problem in pediatric spine surgery. To date, no systematic review of this topic has been presented on this confusing and sometimes contentious issue. This topic review will focus on the biomechanical and radiographic foundations for which treatment recommendations in Down syndrome patients are made. In addition, otolaryngologic and anesthetic considerations in Down syndrome are also discussed, as well as advances in surgery that have made the operative fusion of these patients easier and safer. Copyright Copyright 1999 S. Karger AG, Basel     

Comparative Performance Levels of Female and Male Infants with Down Syndrome

Superior performance of the part of girls with Down syndrome as compared to boys with Down syndrome has been demonstrated repeatedly in the literature on a number of developmental variables. In only one recent study on infants with Down syndrome ranging in age from 3-30 months have the performance levels of the two sexes been shown to be similar. The present study was designed to examine sex differences on mental and motor performance between female and male infants with Down syndrome under two years of age. In support of the most recent study which evaluated sex differences among slightly older infants but in contrast to four earlier studies which evaluated sex differences in older children with Down syndrome, no significant between-group differences were found between the female and male infants tested on any of the mental or motor measures used in this study. Implications of these findings for developmental therapists are discussed.     

Keeping children and young people with Down syndrome healthy

Down syndrome (trisomy 21) is a common identifiable cause of intellectual disability. People with Down syndrome are individuals, and while there are many shared characteristics, there is considerable variability in how the syndrome manifests. Understanding the condition and its impact on individual lives can help maintain and promote health, and enable individuals to achieve their potential. There are some conditions that are more frequently seen in individuals with Down syndrome, and as such it is important not to fall into the trap of labelling all symptoms as ‘part of Down syndrome’. Awareness of some of the more frequently seen conditions will help in understanding and aid timely investigation and management - enabling individuals to access the support and care they need. In this article, we focus on our role as health professionals in supporting families, children and young people with Down syndrome. We describe some of the conditions seen more commonly in individuals with Down syndrome and our role in screening, identification and management of these.     

Antiphospholipid antibodies and Down syndrome: a case series

To describe the clinical profiles of five patients with Down syndrome and elevated levels of antiphospholipid antibodies. Medical records of all 149 patients screened for anticardiolipin antibodies (aCL) in the pediatric hematology or pediatric rheumatology clinics at New England Medical Center between 1996 and 1998 were retrospectively reviewed, and patients with Down syndrome identified. Thirty-four patients (23%) had elevated IgG titers of aCL antibodies. Of these, five had Down syndrome (15%). Two presented with discoloration of the distal digits, and one each with thrombocytopenia, autoimmune hepatitis, and undifferentiated autoimmune disease. The mothers of two of the four individuals with available family history had experienced frequent miscarriages. An association may exist between Down syndrome and antiphospholipid antibodies, in particular an increased frequency of aCL antibodies. Screening patients with Down syndrome and certain clinical findings may prove useful.