Chiari I malformation associated with syringomyelia and scoliosis

Chiari I malformation associated with thoracic epidural cord lesion: case report

Many spinal cord lesions have been described previously, in association with Chiari I lesions. The authors report a unique case of a 29-year-old patient with a Chiari I malformation and an upper thoracic epidural lesion causing headaches, dysphagia and Brown-Sequard syndrome. The patient underwent a suboccipital decompression as well as a thoracic laminectomy and resection of the epidural lesion. Pathologic analysis revealed that the thoracic lesion was fibro-adipose tissue. A review of the literature failed to show any other similar cases. We discuss the possible etiologies of this case.

Chiari I malformation in the very young child: the spectrum of presentations and experience in 31 children under age 6 years

INTRODUCTION

The entity of hindbrain herniation without myelodysplasia in the very young child has been poorly described. A retrospective analysis of children diagnosed with Chiari I malformation (CM I) before their sixth birthday is presented.

METHODS

Since 1985, 31 children with CM I (0.3-5.8) years of age have been diagnosed at University of Iowa Hospitals and Clinics. Their records were reviewed for presenting symptoms, signs, radiographic findings, treatment, complications, and outcome.

RESULTS

The average age at diagnosis was 3.3 years. Sixteen patients were under age 3. Chief presenting complaints included impaired oropharyngeal function (35%), scoliosis (23%), headache or neck pain (23%), sensory disturbance (6%), weakness (3%), and other (10%). Sixty-nine percent of children under age 3 had abnormal oropharyngeal function. Three patients under age 3 (19%) had undergone fundoplication and/or gastrostomy before diagnosis of CM I. Common physical findings included abnormal tendon reflexes (68%), scoliosis (26%), abnormal gag reflex (13%), and normal examination (13%). Vocal cord dysfunction (26%, all under age 3) and syringohydromyelia (52%) were also seen. Twenty-five patients were treated surgically at our institution with posterior fossa decompression, duraplasty, and cerebellar tonsillar shrinkage. Three patients were lost to follow-up. Ninety-one percent of patients reported improved symptomatology at last follow-up (mean: 3.9 years). Three patients required reoperation for recurrence of symptoms. Syringomyelia improved in all patients. Scoliosis resolved in 2 of 8 patients, improved in 5, and stabilized in 1. There was no permanent morbidity from surgery.

DISCUSSION

We show that children with Chiari I abnormality are very likely to present with oropharyngeal dysfunction if under age 3, and either scoliosis or headache or neck pain worsened by valsalva if age 3 to 5. These symptoms are very likely to improve after Chiari decompression, which can be done with low morbidity.

CONCLUSIONS

Very young children presenting with oropharyngeal dysfunction, pain worsened by valsalva, or scoliosis should prompt the clinician to consider CM I as a possible cause.

Curve progression in scoliosis associated with Chiari I malformation following suboccipital decompression

Nine children with scoliosis and Chiari I malformations were followed 1-11 years after suboccipital decompression. Eight also had syringomyelia. Despite initial curve stabilization, at final follow-up eight curves were of the magnitude to require spinal fusion. Neither bracing nor secondary neurosurgical procedures arrested progressive curves.

Chiari I malformation associated with syringomyelia and scoliosis: a twenty-year review of surgical and nonsurgical treatment in a pediatric population

STUDY DESIGN

Retrospective review of patients with Chiari I malformation with or without associated scoliosis.

OBJECTIVES

Determine the effect of decompression of Chiari I malformation with syringomyelia on stabilization or improvement of associated scoliosis.

SUMMARY OF BACKGROUND DATA

Chiari malformations are often associated with spinal deformities, including scoliosis. Studies have suggested a causal relation between syringomyelia and scoliosis.

METHODS

Patients with Chiari I malformation and syringomyelia with or without scoliosis treated over the last 20 years were reviewed. Patients with any other anomalies were excluded. Scoliotic curves were classified by magnitude and curve type. All patients were treated with surgical decompression of the Chiari malformation with or without drainage of the syringomyelia.

RESULTS

Twenty-five patients were identified, ranging in age from 19 months to 16.5 years. Nineteen patients (76%) had associated scoliosis. The majority of the patients with scoliosis (13 of 19) sought treatment for spinal deformity, and only 6 had for pain or neurologic symptoms. Eleven of 19 patients with scoliosis (58%) underwent fusion. Eight of 19 (42%) patients have not undergone fusion: 3 have experienced progress, 1 remains in a stable condition, and 4 have experienced improvement of curvature since undergoing decompression. The mean age of patients who experienced progress after decompression was 14.5 years, compared to 6 years for patients who experienced improvement.

CONCLUSION

Early decompression of Chiari I malformation with syringomyelia and scoliosis resulted in improvement or stabilization of the spinal deformity in 5 cases. Each of these patients underwent decompression before 8 years of age and before the curve was severe. However, this series represents a few patients demonstrating this trend, and further follow-up and investigation are warranted.

Adult scoliosis in syringomyelia associated with Chiari I malformation

STUDY DESIGN

In adult syringomyelia associated with Chiari I malformation, the spinal deformity, the configuration of cerebellar tonsillar descent, the configuration of syrinx, and the clinical evaluation before and after surgery were investigated.

OBJECTIVES

To investigate the characteristics of the scoliosis in syringomyelia associated with Chiari I malformation.

SUMMARY OF BACKGROUND DATA

In previous studies, the clinical characteristics of pediatric scoliosis associated with syringomyelia have been reported.

METHODS

In this study, 42 patients with syringomyelia were treated. All the patients were 20 years of age or older. They were divided into three groups: Group 1 comprising those without scoliosis, Group 2 composed of those with scoliosis of 10 degrees or more but less than 20 degrees, and Group 3 consisting of those with scoliosis of 20 degrees or more. Investigations conducted with the three groups included determining the curve patterns of scoliosis, the degree of thoracic kyphosis, the configuration of cerebellar tonsillar descent, the configuration of syrinx, the morbidity period, and the clinical evaluation before and after surgery.

RESULTS

There were 12 patients in Group 1, 21 patients in Group 2, and 9 patients in Group 3. The concomitant rate of adult syringomyelia with scoliosis was 71.4%. As scoliosis advanced, the kyphotic angle also increased. The concordance in laterality between the cerebellar tonsil and curve convex was 70%. Findings showed that the more advanced the scoliosis was, the more aggravated the neurologic symptoms were, and the poorer the surgical outcomes tended to be.

CONCLUSIONS

In adult syringomyelia with scoliosis, the morbidity period is long, the syrinx is long, the neurologic symptoms are aggravated, and the surgical outcomes tend to be poor.

Surgical treatment of Chiari I malformation: indications and approaches

Chiari I malformation is a well-described entity characterized by hindbrain herniation through the foramen magnum. Although the exact origin of congenital Chiari I malformation is unknown, it appears to be caused by a mismatch between the volume of the posterior fossa neural elements and the posterior fossa cranial content. Several theories have been proposed to describe the resultant pathophysiology of this mismatch. It is clear, however, that abnormal cerebrospinal fluid flow and velocity play a role in the symptoms and signs associated with this disorder. The authors will review the pathophysiology, clinical presentation, and treatment options for patients with Chiari I malformation.

Syringomyelia presenting as ulnar neuropathy at the elbow

OBJECTIVES

Syringomyelia may present with confusing, unilateral patterns of segmental muscle involvement and dissociated sensory loss. The objective of this study was to report a patient with Chiari malformation type 1 (CM1) and syringomyelia who had an unusual presentation suggesting ulnar neuropathy at the elbow.

RESULTS

A 24-year-old woman presented with clinical evidence of ulnar neuropathy at the elbow except that there was disproportionate abductor digiti mini (ADM) atrophy and weakness, equivocal ipsilateral abductor pollicis brevis weakness and hyporeflexia in both arms. Nerve conduction studies revealed marked amplitude reduction of the left ulnar ADM-compound muscle action potential (ADM-CMAP) with a normal first dorsal interosseous-CMAP amplitude, no focal slowing or conduction block, and a normal ulnar sensory response amplitude. Electromyography (EMG) showed multi-segmental, left C7-T1 fibrillations and chronic reinnervation changes. Magnetic resonance imaging (MRI) of the cervical spine demonstrated CM1 and syringomyelia.

CONCLUSIONS

Syringomyelia may clinically mimic ulnar neuropathy at the elbow.

Idiopathic scoliosis: the relation between the vertebral canal and the vertebral bodies

STUDY DESIGN

The axial length of the vertebral canal and the anterior aspect of the vertebrae were measured in 36 skeletons, 15 with probable idiopathic scoliosis.

OBJECTIVES

To compare the discrepancy in length of the vertebral canal and the anterior spinal column in skeletons having probable idiopathic scoliosis with the degree of deformity.

SUMMARY AND BACKGROUND DATA

In idiopathic scoliosis, the vertebral bodies rotate toward the convexity of the curve, whereas the vertebral canal tends to retain a midline position. The vertebral canal therefore will be relatively short. The degree of shortening has not been described previously, nor its relation with the degree of deformity.

METHODS

The axial length of the vertebral canal and the anterior aspect of the vertebral bodies were measured in 36 skeletons: 8 with normal spines, 13 with kyphosis, and 15 with probable idiopathic scoliosis. The relative shortening in the scoliotic spines was correlated with the Cobb angle and the degree of rotation.

RESULTS

No significant difference in length was found between the vertebral canal and the vertebral column in the normal spines. The kyphotic spines had canals significantly longer than the vertebral length (P<0.025). All but one of the scoliotic spines had short vertebral canals (P<0.01). The degree of discrepancy was related to the Cobb angle (r = -0.50; P< 0.05), and particularly to the degree of rotation (r = -0.88; P< 0.001).

CONCLUSIONS

The findings have surgical and etiologic implications. The results are consistent with a conceivable hypothesis that in some patients with idiopathic scoliosis, there may be impaired growth in the length of the spinal cord, the posterior elements are tethered, and as the vertebral bodies continue to grow, they become lordotic and then rotate.

Correlation between curve severity, somatosensory evoked potentials, and magnetic resonance imaging in adolescent idiopathic scoliosis

STUDY DESIGN

A prospective study in patients with adolescent idiopathic scoliosis of different clinical severity using whole-spine magnetic resonance imaging and somatosensory evoked potentials.

OBJECTIVES

To correlate the presence of magnetic resonance imaging structural abnormalities with somatosensory evoked potential-detected functional disorders in the hind brain and spinal cord and the Cobb's angle in patients with adolescent idiopathic scoliosis and to compare the result with those in healthy matched control subjects.

SUMMARY OF BACKGROUND DATA

Many different types of neurologic dysfunction have been reported in scoliosis. With the advent of magnetic resonance imaging, there are increased reports on the association of idiopathic scoliosis and syringomyelia, Chiari I malformation, or tonsillar ectopia. The actual link between structural and functional disorder in idiopathic scoliosis is, however, unclear.

METHODS

Posterior tibial nerve evoked potentials and whole-spine magnetic resonance imaging were performed in 36 healthy control subjects, 135 patients with adolescent idiopathic scoliosis with Cobb's angle less than 45 degrees, and 29 patients with Cobb's angle more than 45 degrees.

RESULTS

Tonsillar ectopia or syringomyelia, detected by magnetic resonance imaging, or functional disturbance in the somatosensory pathway, detected by somatosensory evoked potentials, was found to be significantly more frequent in the group of patients with severe scoliosis curvature, with an incidence of 31% and 27.6%, respectively. Incidence of tonsillar ectopia was 33.3% in patients with abnormal somatosensory evoked potentials in contrast to the much lower incidence of 2.9% in patients with normal somatosensory evoked potentials. There was a significant structural and functional link. The incidence of syringomyelia in patients with and without tonsillar ectopia was 33.3% and 0.7%, respectively.

CONCLUSIONS

In patients with adolescent idiopathic scoliosis with severe curve, the significant association with tonsillar ectopia and abnormal somatosensory function points to a neural origin. Disorders in the somatosensory function may be one of the mechanisms linking tonsillar ectopia to scoliosis. Somatosensory evoked potentials and magnetic resonance imaging may have important diagnostic and predictive value and may help in the management of adolescent idiopathic scoliosis.