Prevalence and clinical significance of superficial abdominal reflex abnormalities in idiopathic scoliosis

Chiari Type 1 Malformation and Syringomyelia in Children: Classification and Treatment Options

Chiari type 1 malformation (CIM) is defined as tonsillar ectopia of >5 mm, while syringomyelia (SM) is defined as a cerebrospinal fluid (CSF)-filled cavity larger than 3 mm dissecting the spinal cord. Over the last decades, our understanding of these pathologies has grown; however, many controversies still exist almost in every aspect of CIM and SM, including etiology, indication for treatment, timing of treatment, surgical technique, follow-up regime, and outcome. This chapter provides a comprehensive overview on different aspects of CIM and SM and on the still existing controversies, based on the evidence presently available. Future directions for clinical research concerning CIM and SM treatment and outcome are elaborated and discussed as well.

The use of MRI in the study of patients with idiopathic scoliosis: a systematic review of the literature

Objective. To analyze the frequency of hidden neuraxial pathology in idiopathic scoliosis (IS), to substantiate the need for MRI in IS and to identify promising areas for the use of MRI in the examination of patients with IS.Material and Methods. The literature review was carried out using the PubMed and Google Scholar databases. Of the 780 papers on the research topic, 65 were selected after removing duplicates and checking for inclusion/exclusion criteria. As a result, 49 original studies were included in the analysis. Level of evidence – II.Results. According to modern literature, the main direction of using MRI in idiopathic scoliosis is the search for predictors of latent pathology of the spinal cord and craniovertebral junction. The frequency of neuraxial pathology in idiopathic scoliosis is 8 % for adolescent IS and 16 % for early IS. The main predictors of neuraxial pathology are male sex, early age of deformity onset, left-sided thoracic curve and thoracic hyperkyphosis. MRI in IS may be a useful addition to radiological diagnostic methods to identify risk factors and to study degenerative changes in the spine.Conclusion. MRI of the spine should be performed in the early stages of IS to detect latent spinal cord tethering. In type I Chiari anomalies, there is a possibility that early neurosurgery can prevent the development of scoliosis. The main signs of latent neuraxial pathology in IS are early progression of spinal deformity, left-sided thoracic curve, male gender and thoracic kyphosis over 40° according to Cobb.MRI can be used as an effective non-invasive tool in research aimed at identifying risk factors for IS, including helping to track early degeneration of intervertebral discs.

Cerebral White Matter Connectivity in Adolescent Idiopathic Scoliosis: A Diffusion Magnetic Resonance Imaging Study

Adolescent idiopathic scoliosis (AIS) is characterized by the radiographic presence of a frontal plane curve, with a magnitude greater than 10° (Cobb technique). Diffusion MRI can be employed to assess the cerebral white matter. The aim of this study was to analyze, by means of MRI, the presence of any alteration in the connectivity of cerebral white matter in AIS patients. In this study, 22 patients with AIS participated. The imaging protocol consisted in T1 and diffusion-weighted acquisitions. Based on the information from one of the diffusion acquisitions, a whole brain tractography was performed with the MRtrix tool. Tractography is a method to deduce the trajectory of fiber bundles through the white matter based on the diffusion MRI data. By combining cortical segmentation with tractography, a connectivity matrix of size 84 × 84 was constructed using FA (fractional anisotropy), and the number of streamlines as connectomics metrics. The results obtained support the hypothesis that alterations in cerebral white matter connectivity in patients with adolescent idiopathic scoliosis (AIS) exist. We consider that the application of diffusion MRI, together with transcranial magnetic stimulation neurophysiologically, is useful to search the etiology of AIS.

Superficial abdominal reflexes

The superficial abdominal reflexes are often omitted from neurological examination, but their absence or asymmetry may support a lesion involving the thoracic spinal cord, especially in young, nulliparous and thin people.

Scoliosis in patients with Chiari malformation type I

The literature about the association between Chiari malformations (CMs) and scoliosis has been growing over the last three decades; yet, no consensus on the optimal management approach in this patient population has been reached. Spinal anomalies such as isolated syrinxes, isolated CM, and CM with a syrinx are relatively common among patients with presumed idiopathic scoliosis (IS), a rule that also applies to scoliosis among CM patients as well. In CM patients, scoliosis presents with atypical features such as early onset, left apical or kyphotic curvature, and neurological deficits. While spinal X-rays are essential to confirm the diagnosis of scoliosis among CM patients, a magnetic resonance imaging (MRI) is also recommended in IS patients with atypical presentations. Hypotheses attempting to explain the occurrence of scoliosis in CM patients include cerebellar tonsillar compression of the cervicomedullary junction and uneven expansion of a syrinx in the horizontal plane of the spinal cord. Early detection of scoliosis on routine spinal examination and close follow-up on curve stability and progression are essential initial steps in the management of scoliosis, especially in patients with CM, who may require full spine MRI to screen for associated neuro-axial anomalies; bracing and spinal fusion may be subsequently pursued in high-risk patients.

Neural Axis Abnormalities in Patients With Adolescent Idiopathic Scoliosis: Is Routine Magnetic Resonance Imaging Indicated Irrespective of Curve Severity?

Objective

Magnetic resonance imaging (MRI)-verified neural axis abnormalities (NAAs) have been described in adolescent idiopathic scoliosis (AIS), and several risk factors have been associated with the presence of NAAs in AIS patients. However, the clinical significance of these findings is unclear. The purpose of the present study was to determine the prevalence of NAAs in a large consecutive cohort of AIS patients and to evaluate the clinical significance of previously proposed risk factors.

Methods

We prospectively included AIS patients referred to a tertiary facility for evaluation. Full-spine MRI scans were performed on all included patients irrespective of curve magnitude or proposed treatment modality. MRI scans were prospectively analyzed by a neuroradiologist and the pathologic findings were confirmed by a second independent radiologist.

Results

NAA was observed in 34 of the 381 patients (8.9%): 32 patients had a syrinx, 1 patient had an arachnoid cyst, and 1 patient had a Chiari malformation. Four patients were referred for a neurosurgical evaluation but none received any neurosurgical treatment. No statistically significant difference was observed between the NAA and non-NAA groups in terms of sex, major curve size, thoracic kyphosis, left thoracic curve, curve convexity, curve progression, or level of pain (p>0.05).

Conclusion

In this prospective study examining the risk factors for NAA in AIS patients, we found that previously proposed risk factors could not predict the MRI outcomes. The finding of an NAA had no clinical implications and we do not support MRI scans as a routine diagnostic modality in all AIS patients.

Prevalence and risk factors for neural axis anomalies in idiopathic scoliosis: a systematic review

BACKGROUND

There is ongoing controversy about the routine use of magnetic resonance imaging (MRI) preoperatively in patients with presumed idiopathic scoliosis (IS). Routine MRI can help identify possible causes for the deformity and detect anomalies that could complicate deformity surgery. However, routine MRI increases health-care costs significantly and may reveal mild variations from normal findings without clinical relevance, which can still lead to anxiety and influence decision-making.

PURPOSE

Given the necessity to make evidence-based decisions both in the light of quality of care and cost control, the aim of this review is to report the prevalence of neural axis anomalies in IS and to identify risk factors associated with these anomalies.

STUDY DESIGN

A systematic review was carried out.

METHODS

An electronic search of PubMed, Embase, Cochrane, and Cinahl until May 2017 was performed. Studies were assessed by two reviewers independently according to predetermined inclusion (MRI in presumed IS) and exclusion criteria (diagnosis other than IS).

RESULTS

Fifty-one studies were included comprising 8,622 patients. In 981 patients, anomalies were found, resulting in an overall prevalence of 11.4%. The prevalence was 10.5%, 9.0%, and 14.2% when screening was performed of all IS patients, preoperative patients, or patients with presumed risk factors. The prevalence of a syrinx (3.7%), an Arnold-Chiari malformation (3.0%), or a combination of both (2.5%) was highest. Less frequent diagnoses included tethered cord (0.6%), an incidental malignancy (0.3%), and split cord malformations (0.2%). Risk factors for intraspinal anomalies included early-onset scoliosis, male gender, atypical curves, thoracic kyphosis, and abnormal neurologic findings such as reflexes and sensation.

CONCLUSIONS

This systematic review shows that a significant number of patients have intraspinal anomalies on preoperative MRI in (presumed) IS. The prevalence of finding spinal axis abnormalities increases in preselected patient groups with specific risk factors.

Clinical manifestations and radiological characteristics in patients with idiopathic syringomyelia and scoliosis

PURPOSE

To clarify the clinical manifestation and radiological characteristics of idiopathic syringomyelia (IS) and to investigate the relationship between syrinx and scoliotic curves in IS-related scoliosis patients.

METHODS

Fifty-five patients with IS and scoliosis were identified and reviewed retrospectively from June 2009 to December 2016. Radiographic features of syrinx, scoliosis and clinical manifestations of neurological deficits were collected. The syrinx/cord (S/C) ratio was defined as the anteroposterior diameter of syrinx divided by the diameter of spinal cord at the same level. Patients were classified into two groups, the thoracic group (T group, apex vertebra located from T2 to intervertebral disk of T11-T12) and the thoracolumbar/lumbar group (TL/L group, apex vertebra located from T12 to L5).

RESULTS

There was no correlation between the radiological features of idiopathic syrinx and scoliotic curve parameters. The TL/L group had a lower level of most caudal extent (13.7 compared with 10.6, P = 0.029) and lower level of largest S/C ratio (12.0 compared with 8.7, P = 0.016) than that in T group. The deviated side of syrinx was not coincident with major curve convexity (27.2% concordance rate, P = 0.522) or dominant side of neurological deficit (16.3% concordance rate, P = 0.212).

CONCLUSIONS

Patients with major curves located on the thoracolumbar or lumbar spine had a much lower caudal extent and lower level of greatest S/C ratio compared to patients with major curves located on the thoracic spine. No significant relationships were detected between syrinx features, scoliotic curve parameters and neurological deficits. These slides can be retrieved under Electronic Supplementary Material.

Intraspinal anomalies in early-onset idiopathic scoliosis

Aims

In the United Kingdom, lower incidences of intraspinal abnormalities in patients with early onset idiopathic scoliosis have been observed than in studies in other countries. We aimed to determine the rates of these abnormalities in United Kingdom patients diagnosed with idiopathic scoliosis before the age of 11 years.

Patients and Methods

This retrospective study of patients attending an urban scoliosis clinic identified 71 patients satisfying a criteria of: clinical diagnosis of idiopathic scoliosis; age of onset ten years and 11 months or less; MRI screening for intraspinal abnormalities. United Kingdom census data combined with patient referral data was used to calculate incidence.

Results

Mean age at diagnosis was six years with 39 right-sided and 32 left-sided curves. Four patients (5.6%) were found to have intraspinal abnormalities on MRI. These consisted of: two combined Arnold-Chiari type 1 malformations with syrinx; one syrinx with a low lying conus; and one isolated syrinx. Overall annual incidence of early onset idiopathic scoliosis was one out of 182 000 (0.0006%).

Conclusion

This study reports the lowest rates to date of intraspinal anomalies in patients with early onset idiopathic scoliosis, adding to knowledge regarding current incidences of these abnormalities as well as any geographical variation in the nature of the disease. Cite this article: Bone Joint J 2017;99-B:829–33.

Clinical investigation and imaging

Adolescent idiopathic scoliosis (AIS) affects 2-4 % of children and is diagnosed between age 10 and skeletal maturity. The female to male ratio for mild curves less than 20° is 1.5:1; however, progression to a severe deformity occurs more often in females (Weinstein in JAMA 289(5):559-567, 2003). Despite significant ongoing research, including into the genetic basis for AIS, there are currently no identifiable causes, and therefore the disorder still remains a diagnosis of exclusion. History, physical examination and radiographic assessment must exclude other possible causes of spinal deformity and are crucial in predicting the risk of curve progression. History should focus on family history, menarche, presence or absence of pain, sports activities and neurologic changes. Physical examination concentrates on anthropometric data, pubertal staging, neurologic testing and specific investigation of the spine, with the Adams' forward bending test being the most meaningful step to evaluate trunk rotation. Definitive diagnosis cannot be made without imaging. The gold standard remains plain radiography with assessment of the Cobb angle on a standing coronal radiograph of the entire spine. A lateral X-ray is used for assessing sagittal balance and for evaluating the deformity in the sagittal plane. If available, surface topography can accompany the follow-up in AIS, reducing the radiation exposure. The role of magnetic resonance imaging (MRI) in AIS is an ongoing matter of debate. Common indications for MRI are the presence of an atypical curve pattern and abnormal neurological findings.

Are intraspinal anomalies in early onset idiopathic scoliosis as common as once thought? A two centre United Kingdom study

PURPOSE

Rates of neural axis abnormalities in infantile and juvenile idiopathic scoliosis may be as high as 50 %. We aimed to determine the rates of neural axis abnormalities in early onset idiopathic scoliosis patients in a British population.

METHODS

This retrospective study at two British spinal deformity clinics identified 72 patients satisfying the inclusion criteria of: (1) age at diagnosis of 7 years and younger, (2) idiopathic scoliosis and (3) magnetic resonance imaging of the neuraxis.

RESULTS

The mean age at diagnosis was 3.6 years and the mean Cobb angle was 47° with a near equal distribution of left (32) and right (36) sided curves. Eight (11.1 %) neural axis abnormalities consisting of two syrinxes, one Arnold-chiari Type I malformation and five combined (Arnold-chiari malformation Type I and syrinx) anomalies were identified.

CONCLUSIONS

This multi-centre study on the largest number of British subjects to date helps to establish the rates of neural axis abnormalities.

Different curve pattern and other radiographical characteristics in male and female patients with adolescent idiopathic scoliosis

STUDY DESIGN

Retrospective radiographical study.

OBJECTIVE

To compare the sex differences in curve patterns and radiographical characteristics in patients who have adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Sex differences in AIS have been documented in the incidence of curve progression, response to bracing, and outcomes of surgical treatment. However, limited information is available about the relation between sex and scoliosis curve patterns and radiographical presentations.

METHODS

A total of 359 male and 999 female patients with AIS with major curve of 20° or more were recruited. Standard posteroanterior and lateral radiographs of spine were reviewed to classify scoliosis curve patterns as typical or atypical and to measure curve severity and thoracic kyphosis. In 351 surgically treated patients, side-bending films were used to assess curve flexibility. Comparisons between male and female patients were made by subgrouping patients according to curve patterns and severity.

RESULTS

Atypical curves were more frequently observed in male (19.8%) than in female patients (8.9%) (P < 0.01). Sex differences were also found in the distribution of curve types. Main thoracic curve was the most common curve type in both sexes. Furthermore, significantly higher incidence of main thoracic curve in patients with severe AIS than in patients with moderate AIS was found in male (P < 0.001) but not in female patients. In patients with severe AIS who had typical curve patterns that included a major thoracic curve, male patients had larger magnitude of thoracic curve, more severe thoracic kyphosis, and more rigid thoracic and lumbar curves than female patients.

CONCLUSION

Atypical curve patterns were more predominant in male than in female patients with AIS. The thoracic curve in male patients with AIS might have higher incidence of progression than that in female patients. The higher rigidity of both thoracic and lumbar curves in male patients with AIS with severe curves might contribute to the lower curve correction rate and poor response to brace than in female cases.

The correlation between coronal balance and neuroaxial abnormalities detected on MRI in adolescent idiopathic scoliosis

INTRODUCTION

The indications for magnetic resonance imaging in presumed adolescent idiopathic scoliosis (AIS) have not been established, with some studies suggesting that rates of spinal cord abnormalities are low and question the use of the routine MRI in AIS.

OBJECTIVE

Given the restraints on MRI resources the authors performed a retrospective audit to see if the presence of coronal or sagittal misbalance-balance could be used as a surrogate marker for the presence of spinal cord abnormalities in this patient group and hence reduce the need for unnecessary MRI scans.

METHODS

We performed a retrospective review of imaging of patients with AIS at our centre over a 2-year-period. All MRI scans were reported by the senior author and the presence of spinal cord abnormalities noted. All plain films were assessed by a senior SpR and ST2 orthopaedic surgeons for Cobb angle, coronal balance, sagittal balance and Lenke classification.

RESULTS

A total of 171 patients were identified with AIS. Of these, a total of 15 patients (9%) were found to have neural axis anomalies on MRI including syringomyelia, Chiari malformations and dural ectasia. The average Cobb angle was 44.9° with coronal balance varying from 67.2 mm left to 40.2 mm right. Sagittal balance varied from 125 mm negative to 83 mm positive. No correlation was found between coronal/sagittal misbalance and the presence of neural axis anomalies.

CONCLUSIONS

Our audit demonstrates that neither coronal nor sagittal misbalance should be used as an indicator of neural axis abnormalities.

Back pain in children: a holistic approach to diagnosis and management

Back pain is a relatively common complaint presenting to the primary care practitioner and is addressed with increasing frequency in the pediatric literature. Back pain is not uncommon in adolescents and often is symptomatic of a relatively benign musculoskeletal etiology. Back pain in children less than 10 years of age and most especially less than 4 years of age can signal a more alarming underlying condition. Evaluation requires a complete history including psychosocial and cultural considerations. Additionally a thorough clinical examination, strategic lab work and judicious imaging are imperative. Management and appropriate referral is specific to the underlying disease process. A holistic, individualized plan of care with inherent involvement of the child and parent/caregiver is essential to ensure safety and enhance outcomes.

Magnetic resonance imaging evaluation of patients with idiopathic scoliosis: a prospective study of four hundred seventy-two outpatients

STUDY DESIGN

A prospective study of magnetic resonance imaging findings in outpatients with idiopathic scoliosis.

OBJECTIVE

The purpose of this study was to determine the prevalence of neural axis abnormalities in outpatients with scoliosis and to analyze the characteristics of patients who had such abnormalities.

SUMMARY OF BACKGROUND DATA

In previous studies, neural axis abnormalities were found in 2.9% to 37% of patients with idiopathic scoliosis. The current guidelines for MRI screening in scoliosis are valuable, and the proposed indications for performing MRI in the literature include early onset, atypical curvature, double thoracic curve (King type-5), rapid progression, male gender, and abnormal neurologic findings.

METHODS

A total of 472 outpatients with a primary diagnosis of idiopathic scoliosis were examined for neural axis abnormalities by magnetic resonance imaging. Logistic regression was used to determine significant predictors of neural axis abnormalities on MRI.

RESULTS

The incidence of neural axis abnormalities on MRI was 3.8% (18 of 472 patients). Among the 18 patients, 6 had a Chiari I malformation alone, 10 had a Chiari I malformation combined with syringomyelia, and 2 had a syringomyelia without Chiari I malformation. Male gender, patients younger than 11 years old, and abnormal superficial abdominal reflexes were significantly associated with the detection of neural axis abnormalities on MRI.

CONCLUSION

We recommend routine use of MRI in male patients, younger than 11 years old, and abnormal superficial abdominal reflexes. Even if a patient has no specific indications for MRI, we recommend its routine use in preoperative planning.

Right thoracic curves in presumed adolescent idiopathic scoliosis: which clinical and radiographic findings correlate with a preoperative abnormal magnetic resonance image?

STUDY DESIGN

Prospective case control study.

OBJECTIVE

This study investigated preoperative presumed adolescent idiopathic scoliosis (AIS) patients with right thoracic curves to determine which clinical and radiographic findings correlate with neural axis abnormalities on magnetic resonance imaging (MRI).

SUMMARY OF BACKGROUND DATA

Neural axis abnormalities on MRI are not uncommon in patients with left thoracic curves, increased thoracic kyphosis, and in children less than 10 years old. For adolescents with right thoracic curves, less is known regarding which clinical and/or radiographic characteristics accompany neural axis abnormalities.

METHODS

A total of 529 presumed AIS patients with Lenke 1-4 right thoracic curve patterns had MRI evaluation before surgery. Thirty-six of these patients had abnormal MRIs (syrinx, Chiari malformation, and/or tethered cord). To differentiate between those with normal MRIs (n = 493) and those with abnormal MRIs (n = 36), the following preoperative clinical parameters were evaluated: age, gender, height, weight, asymmetric abdominal reflexes, thoracic rotation (scoliometer), coronal balance, trunk shift, shoulder elevation, and the Scoliosis Research Society (SRS)-30 questionnaire. Radiographically, thoracic curve magnitude, thoracic rotation (Nash-Moe), coronal balance, trunk shift, length of thoracic curve, location of curve apex, sagittal balance, thoracic kyphosis (T2-T12), and lumbar lordosis were evaluated.

RESULTS

Neural axis abnormalities were found in 6.8%. Those with abnormal MRI findings had significantly greater clinical thoracic rotation (mean difference, 2.4°) and significantly greater radiographic thoracic kyphosis (mean difference 5.9°). However, there were no significant differences in: age (14.9 vs. 14.7 years), height for age (when adjusted for gender), asymmetric abdominal reflexes (3.5% normal MRI group vs. 6.1% abnormal group), coronal balance (clinical or radiographic), trunk shift(clinical or radiographic), shoulder elevation, thoracic curve magnitude (61.4° normal MRI group vs. 63.6° abnormal group), length of thoracic curves (7.0 segments normal group vs. 7.2 segments abnormal group), location of curve apexes, radiographic sagittal balance, or any domains of the preoperative SRS-30 questionnaire.

CONCLUSION

Of preoperative presumed AIS patients with right thoracic curves who underwent MRI evaluation of the neural axis, 6.8% were found to have neural axis abnormalities, with those having increased rotation and/or increased kyphosis at higher risk. Surgeons should use this information when deciding whether a preoperative MRI is indicated in those with right thoracic AIS curve patterns.

The utility of superficial abdominal reflex in the initial diagnosis of scoliosis: a retrospective review of clinical characteristics of scoliosis with syringomyelia

Background

With increasing use of magnetic resonance imaging (MRI), underlying syringomyelia is increasingly found in patients with presumed idiopathic scoliosis. To determine the indications for MRI in the differential diagnosis of scoliosis, several clinical characteristics of syringomyelia have been reported. Neurological signs, particularly abnormal superficial abdominal reflex (SAR), are important in establishing the initial diagnosis of scoliosis. However, the prevalence of abnormal SAR in patients with scoliosis and the sensitivity of this sign in predicting syringomyelia are not well known. We aimed to determine the diagnostic utility of SAR and other characteristics of syringomyelia in patients with scoliosis.

Methods

We reviewed the medical records of 93 patients with scoliosis, 90 of whom underwent corrective surgery. All patients underwent MRI to determine the presence of syringomyelia. Mean age at surgery was 12.5 years. Abnormal SAR was defined as unilateral or bilateral absence or hyporeflexia of SAR. We calculated indices of diagnostic utility of abnormal SAR for non-idiopathic scoliosis and for syringomyelia. Abnormal SAR, left thoracic curve pattern, gender, and curve flexibility were compared between scoliosis with syringomyelia and idiopathic scoliosis. Logistic regression analysis was performed with the existence of syringomyelia as the dependent variable and curve flexibility as the independent variable.

Results

Abnormal SAR was observed in 20 patients (prevalence 22%). All 6 patients with myopathic scoliosis displayed bilateral absence of SAR. The sensitivity of abnormal SAR for non-idiopathic scoliosis was 38%, with 96% specificity, 90% PPV (positive predictive value), and 60% NPV (negative predictive value). Syringomyelia was identified in 9 of the 93 patients (9.7%); 8 of these had abnormal SAR. The sensitivity of abnormal SAR for syringomyelia in presumed idiopathic scoliosis was 89%, with 95% specificity, 80% PPV, and 98% NPV. Gender, abnormal neurological findings, and curve flexibility differed significantly between patients with syringomyelia and those with idiopathic scoliosis (P < 0.05). In the logistic regression model, the area under the receiver operating characteristic (ROC) curve was 0.79 and the cut-off value of curve flexibility for syringomyelia was 50% (P = 0.08).

Conclusion

Abnormal SAR was a useful indicator not only for syringomyelia, but also for myogenic scoliosis.

Scoliosis in pediatric patients: comorbid disorders and screening

Scoliosis is one of the most commonly encountered pediatric spinal deformities. Knowledge of comorbid disorders associated with scoliosis is required in order to rule out other serious conditions. A thorough knowledge of the clinical scenarios associated with each of these disorders will help guide the pediatric practitioner in their work-up of associated conditions and possible further referrals. The aim of this review is to discuss the comorbidities associated with scoliosis and review appropriate screening tools aiding diagnosis.

Intraspinal anomalies in infantile idiopathic scoliosis: prevalence and role of magnetic resonance imaging

STUDY DESIGN

Retrospective case series of magnetic resonance imaging (MRI) findings in patients with presumed infantile idiopathic scoliosis (IIS).

OBJECTIVE

To identify the prevalence of intraspinal anomalies in patients with presumed IIS at a single, large volume institution and further define the role for a screening MRI.

SUMMARY OF BACKGROUND DATA

Idiopathic scoliosis in patients less than 10 years of age has been shown to carry a higher prevalence of concordant intraspinal anomalies, up to 20%, in juveniles, when compared to the adolescent age group. Few studies exist assessing the prevalence of intraspinal anomalies in the IIS patient population. Dobbs et al (2002) reported a 21.7% prevalence of neural axis abnormalities in 46 patients with presumed IIS across 3 combined spinal deformity clinics and recommended a screening MRI for all IIS patients with a curve >20 degrees.

METHODS

A retrospective review of the medical records of 54 patients at a single institution with a presumed diagnosis of IIS was performed. All patients satisfied the strict inclusion criteria of: curve > or =20 degrees, age <36 months at diagnosis, normal neurologic examination (i.e., normal tone, motor strength, reflexes, etc.), absence of any concomitant syndromes or congenital anomalies, and an MRI of the spine from skull to coccyx.

RESULTS

MRI revealed a neural axis abnormality in 7 (13%) of 54 patients who underwent an MRI. In this subset of 7 patients, 5 (71.4%) required neurosurgical intervention. Tethered cord requiring surgical release was identified in 3 patients, Chiari malformation requiring surgical decompression was found in 2 patients, and a small nonoperative syrinx was found in 2 patients.

CONCLUSION

This study represents the largest evaluation of intraspinal anomalies in IIS to date. Our patient population exhibited a smaller percentage (13%) of neural axis abnormalities than previously reported. On the basis of these findings, the close observation may be a reasonable alternative to an immediate screening MRI in patients presenting with presumed IIS and a curve >20 degrees.

Delayed-onset neurological deficit following correction of severe thoracic kyphotic deformity

✓There are many potential risks associated with spinal deformity correction procedures including transient and/or permanent neurological deficits. Typically, neurological deficits caused by the surgical correction of spinal kyphosis occur acutely during surgery or immediately after surgery. Delayed postoperative neurological deficits are extremely rare.

The authors report a case of delayed neurological deficit that occurred 48 hours after surgical correction of thoracic hyperkyphosis. An 18-year-old man with myotonic dystrophy presented with a 110° T7–L1 kyphosis. The patient underwent an uneventful two-stage correction procedure of the hyperkyphotic deformity. First, anterior discectomies and fusion were performed from T-7 to L-1 using rib autograft, and all segmental vessels were preserved. Subsequently, on the same day, the patient underwent posterior Smith–Petersen osteotomies and T7–L2 pedicle screw fixation. Intact somatosensory and motor evoked potentials were maintained throughout both operations. Postoperatively, he remained neurologically intact without sequelae for nearly 48 hours. On postoperative Day 2, the patient developed delayed monoplegia of the left leg and sensory level loss below T-10.

Medical management enabled complete reversal of the patient's monoplegia and sensory loss. At 2-year follow-up, the patient had no adverse neurological sequelae.

In this case, a delayed postoperative neurological deficit occurred following spinal hyperkyphosis correction. The authors discuss the possible etiological mechanisms behind this complication and suggest strategies for its management.