Chiari type I malformation in children

Treatment of Chiari type I malformation in patients with and without syringomyelia: a consecutive series of 66 cases

Object

The authors describe the results of performing a standard posterior craniovertebral decompression and placement, if indicated, of a syringosubarachnoid shunt for the treatment of patients with Chiari I malformation with and without syringomyelia.

Methods

This is a retrospectively analyzed consecutive series of 66 patients (mean patient age 15 years, range 1–53 years). The uniform posterior craniovertebral decompression consisted of a small suboccipital craniectomy, a C-1 laminectomy, microsurgical reduction of the cerebellar tonsils, and dural closure with a synthetic dural graft to increase the cerebrospinal fluid space at the craniocervical junction. The presence of a large syrinx, with significant thinning of the spinal cord tissue and obliteration of the spinal subarachnoid space, particularly when combined with syrinx-related symptoms, was an indication for the placement of a syringosubarachnoid shunt.

In 32 patients Chiari I malformation alone was present, and 34 in patients it was present in combination with syringomyelia. Clinical findings included pain, neurological deficits, and spinal deformity. The presence of syringomyelia was significantly associated with the presence of scoliosis (odds ratio 74.4 [95% confidence interval 8.894–622.4]).

All patients underwent a posterior craniovertebral decompression procedure. In 22 of the 34 patients with syringomyelia a syringosubarachnoid shunt was also placed. The mean follow-up period was 24 months (range 3–95 months). Excellent outcome was achieved in 54 patients (82%) and good outcome in 12 (18%). In no patient were symptoms unchanged or worse at follow-up examination, including four patients who initially required a second operation for persistent syringomyelia. Pain was more likely to resolve than sensory and motor deficits after decompressive surgery.

Radiological examination revealed normalization of tonsillar position in all patients. The syrinx had disappeared in 15 cases, was decreased in size in 17, and remained unchanged in two.

Conclusions

Posterior craniovertebral decompression and selective placement of a syringosubarachnoid shunt in patients with Chiari I malformation and syringomyelia is an effective and safe treatment. Primary placement of a shunt in the presence of a sufficiently large syrinx appears to be beneficial. The question of if and when to place a shunt, however, requires further, preferably prospective, investigation.

Chiari Type I malformation presenting as glossopharyngeal neuralgia: case report

OBJECTIVE AND IMPORTANCE

Chiari Type I malformation is an important pathological state in which the brainstem is compressed by the cerebellar tonsil. We present a case of glossopharyngeal neuralgia caused by Chiari Type I malformation.

CLINICAL PRESENTATION

A 50-year-old male patient was admitted with glossopharyngeal neuralgia. Magnetic resonance imaging studies revealed caudal displacement of the left cerebellar tonsil.

INTERVENTION

Small occipital craniectomy and C1 laminectomy were performed. The left cerebellar tonsil was resected.

CONCLUSION

This glossopharyngeal neuralgia was caused by compression of the lower cranial nerves and brainstem by the displaced left cerebellar tonsil. Decompression and pain relief were obtained with resection of the cerebellar tonsil. The patient was pain-free 30 weeks after the operation.

Chiari type I malformation in children and adolescents with cystic fibrosis

Chiari type I malformation is characterized by herniation of the cerebellar tonsils through the foramen magnum. An association between Chiari type I malformation and cystic fibrosis (CF) has not previously been established. We report on five children and adolescents with CF in whom Chiari type I malformations were diagnosed. Three patients were 17-18 years old at time of diagnosis, one was 3 years old, and one was 10 months of age. All patients were followed at the Cystic Fibrosis Center at St. Christopher's Hospital for Children and were diagnosed with the malformations between June 1988 and June 1997. Over this same period, 400 CF patients 18 years or younger were followed routinely. All patients had the diagnosis of Chiari type I confirmed by brain-stem MRI. Neurologic findings included swallowing dysfunction, syncopal episodes, numbness of extremities, recurrent vomiting, and headaches. No two patients had the same presenting neurologic findings. Our data suggest that Chiari type I malformation is more common in CF than in the general population. The possibility of Chiari type I malformation should be included in the differential diagnosis of unexplained neurologic complaints in patients with CF.

Effects of posterior fossa decompression with and without duraplasty on Chiari malformation-associated hydromyelia

OBJECTIVE

The optimal surgical treatment of Chiari malformation is unclear, especially in patients with hydromyelia. Various surgical approaches have included suboccipital craniectomy, syringostomy, obex plugging, syringosubarachnoid shunting, and fourth ventriculosubarachnoid shunting. The purpose of this study is to differentiate extradural and intradural approaches in the treatment of Chiari I malformation.

METHODS

We reviewed the medical records and magnetic resonance imaging (MRI) scans of 34 surgical corrections' of Chiari malformation performed at our institution from 1988 to 1998. The age and sex of the patient, the presence of hydromyelia, the type of surgery (duraplasty or nonduraplasty), and the clinical outcome were determined.

RESULTS

Eleven patients underwent posterior fossa decompression (PFD) and C1 laminectomy without duraplasty. Eight (73%) of these patients had an improvement in symptoms. Seven of the 11 patients had hydromyelia. Of the six patients who underwent follow-up MRI, three (50%) had a decrease in the size of the hydromyelia, and all three had clinical improvement. We also noted a morphometric increase in posterior fossa volume on postoperative MRI scans in these three patients, which was not observed in those without improvement. Two of the three patients whose hydromyelia did not decrease on follow-up MRI scans worsened clinically, and one underwent a reoperation with duraplasty. Twenty-three patients underwent combined PFD, C1 laminectomy, and duraplasty. Twenty (87%) of these patients had improvement. Twelve of the patients who underwent duraplasty had hydromyelia; nine underwent follow-up MRI. All nine of these patients (100%) had a decrease in the cavity size, including eight with clinical improvement. There were 10 minor complications (seroma, 4; superficial infection, 3; cerebrospinal fluid leak, 2; aseptic meningitis and occipital nerve pain, 1) when the dura was opened, compared with one superficial wound infection that resolved in patients who underwent PFD only.

CONCLUSION

PFD, C1 laminectomy, and duraplasty for the treatment of Chiari I malformation may lead to a more reliable reduction in the volume of concomitant hydromyelia, compared with PFD and C1 laminectomy alone. However, there seems to be a subset of patients whose symptoms will resolve and whose hydromyelic cavity will decrease with the removal of bone only. These patients seem to undergo a volumetric increase in the posterior fossa. Further studies are needed to better characterize these patients, to determine which patients with Chiari I malformation are better served with bony decompression only, and which will require duraplasty to resolve their hydromyelia.

Coexistence of oto-palato-digital syndrome type II and Arnold-Chiari I malformation in an infant

A Taiwanese infant with clinically apparent oto-palato-digital syndrome type II had Arnold-Chiari I malformation. Arnold-Chiari I malformation has not been reported previously to occur in association with oto-palato-digital type II syndrome. The pathogenesis of both conditions has remain unclear although the Arnold-Cliari I malformation is most likely due to a developmental abnormality of improperly times or incomplete closure of the neural tube. We propose the physician who care for children with OPD type II must be aware of one more condition.

Pediatric syringomyelia with chiari malformation: its clinical characteristics and surgical outcomes

BACKGROUND

Most reports regarding pediatric syringomyelia have focused not only on Chiari malformation, but also on spinal dysraphism. However, the clinical characteristics of syringomyelia with spinal dysraphism are quite different from those of syringomyelia due to Chiari Type I malformation. The objectives of this study were to identify clinical characteristics of pediatric syringomyelia and to determine whether surgery prevents or corrects the scoliosis associated with syringomyelia.

METHODS

We reviewed the records of 16 pediatric patients with syringomyelia and Chiari Type I malformation. The patients' ages ranged from 3 to 15 years, with mean age of 9.8 years. None of the patients had spinal dysraphism.

RESULTS

Nystagmus was observed in 2 of the 16 patients, motor weakness in 8 patients, sensory disturbance in 10 patients, and scoliosis in 13 patients. As the initial surgical procedure, foramen magnum decompression (FMD) was performed in seven patients and syringo-subarachnoid (S-S) shunting in nine patients. The motor function improved in 7 of the 8 affected patients, and the sensory disturbance improved in 9 of the 10 affected patients. The magnetic resonance images obtained after the surgery revealed marked decrease of the syrinx size in all patients. Of the 13 patients with scoliosis, 5 showed improvement, 5 stabilization, and 3 deterioration.

CONCLUSIONS

Compared with adolescent and adult syringomyelia, pediatric syringomyelia shows a much lower incidence of sensory disturbance and pain, but quite a high incidence of scoliosis. Surgery is effective in improving or stabilizing scoliosis in these patients.

Incidence of neural axis abnormalities in infantile and juvenile patients with spinal deformity. Is a magnetic resonance image screening necessary?

STUDY DESIGN

A prospective and retrospective review of patients 10 years and younger with idiopathic scoliosis evaluated with a total spine magnetic resonance imaging (MRI) scan.

OBJECTIVES

To determine the incidence of neural axis abnormalities in infantile and juvenile patients with idiopathic scoliosis without neurologic findings on history and examination, to determine the need for a screening MRI in this age group.

SUMMARY OF BACKGROUND DATA

In previous studies, a 19.2% and 26% incidence of neural axis abnormalities were found in infantile and juvenile patients with "idiopathic" scoliosis, respectively, raising the question of routine MRI screening of the spinal canal in these patients.

METHODS

A prospective study included 34 consecutive patients newborn to 10 years of age treated between 1992 and 1996 at a spinal deformity clinic with idiopathic scoliosis > 20 degrees without neurologic findings. In addition, a retrospective review of 64 patients age newborn to 10 years of age with idiopathic scoliosis was performed. All patients were evaluated by a total spine MRI protocol for examination of neural axis abnormalities.

RESULTS

The incidence of neural axis abnormalities in the prospective group of 34 patients was 17.6% (6 of 34); the incidence of neural axis abnormalities was 20.3% (13 of 64) in the retrospective group. Of 6 patients in the infantile age range, 3 (50%) had neural axis abnormalities.

CONCLUSIONS

A total spine MRI is recommended at presentation in patients with juvenile onset idiopathic scoliosis (> 20 degrees) because of the high incidence of neural axis abnormalities. Further study appears warranted to establish the incidence of neural axis abnormalities in infantile idiopathic scoliosis to determine the need for total spine MRI screening in this age group.

Hindbrain herniation syndromes: the Chiari malformations (I and II)

Hindbrain hernias with or without hydrosyringomyelia were difficult diagnostic problems before the availability of magnetic resonance imaging. Today, the problem seems not to be in evaluating the anatomical extent of the caudal herniation of the cerebellum, but in determining which patient should be considered for operative intervention and the extent of the surgery. Chiari I patients are presenting at younger ages, occasionally with irritability as their only symptom. Should all of these children be submitted to an operation? Chiari II patients are now operated on with the first detectable symptom or evidence of a syrinx, and yet medullary dysfunction from the Chiari II malformation remains the leading cause of death in treated myelomeningoceles today. Our knowledge of the natural history of the untreated conditions and the increased safety of the operation has made surgical intervention a much more viable option for this group of patients.

Chiari I malformation associated with syringomyelia and scoliosis

STUDY DESIGN

A retrospective review of a series of 12 children who underwent suboccipital foraminotomy and duroplasty for Chiari I malformation.

OBJECTIVE

To assess the effects of this surgery on associated syringomyelia and scoliosis.

SUMMARY OF BACKGROUND DATA

Suboccipital foraminotomy for the treatment of syringomyelia associated with Chiari I malformation was greatly stimulated by Gardner's hydrodynamic theory, and its results proved to be encouraging. However, several authors reported improvement or stabilization of associated scoliosis after this surgery.

METHODS

A retrospective review was conducted on 12 patients who underwent suboccipital foraminotomy for Chiari I malformation associated with syringomyelia. Neurologic Impairment, extent of syringomyelia, and severity of associated spinal deformity were assessed preoperatively and at a 4.5-year average follow-up (range, 2.1-12 years). Anomaly of superficial abdominal reflexes was found in all cases, and para or tetraparesis in three cases. Syringomyelia was of variable localization and extent. Scoliosis was present in 7 cases (greater than 40 degrees in 5 cases).

RESULTS

Diminution or complete disappearance of syringomyelia was observed in 11 cases, 3 months to 1 year after surgery. Superficial abdominal reflexes anomaly improved in four cases. Minimal neurologic deficit persisted in one case. Scoliosis improved in one case, remained unchanged in one case, and progressed in the five cases with preoperative severe deformity, requiring instrumentation and fusion.

CONCLUSIONS

Improvement of syringomyelia and neurologic deficit, observed with suboccipital foraminotomy, supports the theory that abnormal hydrodynamics of the cerebral spinal fluid is most likely to cause these deficits.

Chiari I malformation: association with seizures and developmental disabilities

Chiari I malformation, a congenital abnormality in which deformed cerebellar tonsils are displaced downward through the foramen magnum, commonly presents in patients with headache or symptoms of dysfunction of the cerebellum, brain stem, and cervical spinal cord. We report 11 children with Chiari I malformation who presented with seizures and developmental delay in motor or language function with or without autistic features. To our knowledge, an association between Chiari I malformation and seizures or neurodevelopmental deficits or both has not been previously reported. We believe that Chiari I malformation should not be considered an incidental finding in these patients, but may be a marker for subtle cerebral dysgenesis. Chiari I and II malformations may constitute a complex but continuous spectrum, related to the timing and severity of a shared underlying embryologic mechanism.

Necrotising fasciitis as a complication of steroid injection

Necrotising fasciitis is described as a complication of steroid injection of a painful shoulder in a previously well female. This case highlights a very rare life threatening emergency after steroid injection. Early recognition, resuscitation, and aggressive surgical management are essential to prevent mortality in this condition.

Neck pain as a presenting symptom in malignant hypertension

Neck pain, unrelated to trauma, is relatively common and is usually presumed to be musculoskeletal in origin. A patient presented with an unusual and serious cause of neck pain-malignant hypertension. The mechanism of the neck pain may be incipient tonsillar herniation of the cerebellum caused by raised intracranial pressure.

Chiari type I malformation, glossopharyngeal neuralgia and central sleep apnoea in a child

We describe the case of an 8-year-old child who presented with sleep breathing disorders associated with glossopharyngeal neuralgia. Polysomnographic studies showed central sleep apnoea lasting 10 to 18 seconds in an average frequency of 63 times for every hour of sleep. Magnetic resonance imaging (MRI) studies showed a caudal displacement of the cerebellar tonsils down to C3 level, associated with a syringomyelic cavity in the upper cervical cord and an extramedullary cystic collection at C2. Surgical decompression of the cranio-cervical junction completely relieved the apnoea and the glossopharyngeal neuralgia immediately following the procedure. MRI study performed one month later showed the complete disappearance of the syringomyelic cavity. Two years later this child remains asymptomatic. In childhood the association of Chiari type I malformation with sleep apnoea and glossopharyngeal neuralgia has not been previously reported. The successful outcome after surgery suggests a compressive mechanism on the brainstem and on the IX cranial nerve to explain these two clinical features in our patient.

Atypical idiopathic scoliosis in childhood

Scoliosis, common in preadolescent females is a finding which warrants investigation in any other age group or if the clinical or neuroimaging features are atypical even in the preadolescent female. The cause of scoliosis are numerous but include several important conditions some of which are treatable and some of which are genetic. A rational approach to sequencing the neuroimaging studies to be used is based on what the clinical suspicions are and the results of the initial studies.

Neurofibromatosis type 1 and type I Chiari malformation: an unusual association

We report an 11-year-old boy with neurofibromatosis type 1 (NF1) and asymptomatic type I Chiari malformation. This association may be considered a pure coincidence, due to the relative frequency of the two conditions, but recent reports describing the same association suggest that type I Chiari malformation probably should be added to the list of abnormalities of the central nervous system reported in patients affected by NF1.

Sleep-related breathing disorders. 6. Obstructive sleep apnoea syndrome in infants and children: established facts and unsettled issues

The presence of increased upper airway resistive loads during sleep can now be diagnosed by paediatricians. However, diagnostic criteria need to be further clarified to allow accurate identification of episodes of partial airway obstruction. New technological advances can be expected to help to determine the clinical usefulness of ambulatory testing during sleep and thus to establish the indications for polysomnographic investigations in the laboratory. A thorough investigation of the anatomical abnormalities that contribute to airways obstruction is essential for selecting the most appropriate therapy. However, the order in which these investigations should be performed remains unclear. The diagnostic tools, including questionnaires and sleep testing, and methods aimed at investigating pathophysiological mechanisms should be standardised for multicentre studies. Familial factors should be taken into account. The best strategy for preventing the complications of the OSA syndrome is to identify the disorder as early as possible. This requires close cooperation between adult physicians and paediatricians called upon to evaluate sleep-related disorders.

Scoliosis as the first sign of a cystic spinal cord lesion

We reviewed the cases of ten patients with scoliosis as the first sign of a cystic spinal cord lesion with the aim of identifying and studying early patient and curve characteristics. All patients were examined with magnetic resonance (MR) imaging of the brain and spinal cord and quantitative thermal testing (QTT). The mean Cobb angle was 22 degrees and the curves were right thoracic in seven patients, left thoracic in two, and left lumbar in one, when first seen for scoliosis. In six patients the cystic lesion was found in routine screening for syringomyelia, which is performed in all cases of congenital and juvenile scoliosis and in adolescent scoliosis before bracing. In four patients, it took up to 17 years following the initial diagnosis of scoliosis before neurologic deterioration warranted MR imaging, disclosing two Chiari I associated syrinxes and two cystic spinal cord tumors. QTT revealed a subclinically decreased sensation in two of the patients with no findings other than scoliosis. It also verified the decreased sensation in all patients in whom neurologic deterioration had complicated the clinical course of their scoliosis. More frequent spinal MR screening of patients with supposed juvenile or adolescent idiopathic scoliosis is indicated, regardless of curve type, to exclude a neurogenic cause. QTT documents subclinical as well as overt decreased sensation, and is valuable in the serial follow-up of these patients to monitor the progress or the response to treatment of the cystic lesion.

Spinal cord injury without radiographic abnormality and Chiari malformation

Spinal cord injury without radiographic abnormality and asymptomatic Chiari I malformation have an unusual coincidence. A young boy who had recently fallen from his porch was transferred to the neurosurgery service with a high cervical central cord syndrome. Careful study demonstrated no radiographic abnormality and, although the patient was previously quite well, magnetic resonance imaging revealed Chiari I malformation. Although expectedly uncommon, reports of three other similar cases support a less than independent relationship between these two processes. All four children, each aged 2 years, were premorbidly asymptomatic and were playing when they fell from low elevations; two were on a couch. All were evaluated by primary authorities 12 to 48 hours before definitive admission, and all had normal plain film examinations. Three of the four children suffered injuries in flexion, the fourth in extension. Three realized a 5-minute to 3-hour delay before the onset of symptoms, and three suffered gradual progression of deficit. Magnetic resonance imaging was the most commonly applied and productive diagnostic medium, demonstrating cerebellar ectopia in three of three cases. Two children were surgically treated, and all achieved at least a functional outcome. Similarities among these cases support a common mechanism of injury, and indicate careful counseling in children with asymptomatic Chiari I malformation and consideration of operative decompression in those children with progressive neurological injury and deficit.

Sudden death revealing Chiari type 1 malformation in two children

We report the first two fatal cases of sudden unprovoked cardiorespiratory arrest in children with previously undiagnosed Arnold-Chiari type 1 malformation. This diagnosis should be considered in children with unexplained cardiorespiratory arrest. The risk of sudden death in Arnold-Chiari type 1 malformation reinforces the indication for early neurosurgical procedure.

Klippel-Feil sequence and sleep-disordered breathing in two children

We report two children with severe sleep-disordered breathing associated with Klippel-Feil sequence. In both patients, minor vertebral anomalies were associated with a major hindbrain anomaly. In one child, the Klippel-Feil sequence had been diagnosed previously, but the hindbrain anomaly was not recognized. Two years later, this child developed fatal obstructive sleep apnea. In the other child, neither the Klippel-Feil sequence nor hindbrain anomaly had been identified before the child's presentation with sleep-disordered breathing characterized by bradypnea and stridor. Because many of the complications of hindbrain anomalies may be amenable to neurosurgical treatment, we recommend that patients with Klippel-Feil sequence be followed for the development of sleep-disordered breathing. Sleep complaints need prompt evaluation with polysomnography, whereas neurologic signs require imaging with attention to the cervicomedullary junction. Unsuspected CNS disorders must be considered in children who present with stridor or serious respiratory disturbances during sleep.

Scoliosis in pediatric Chiari malformations without myelodysplasia

A prospective study was undertaken in 1985 to better understand how the surgical manipulation of hindbrain herniation affected abnormal spinal curvature. Eleven patients under 16 years of age with Chiari malformation (not associated with myelodysplasia) and scoliosis of at least 15 degrees were studied. The mean curve angle at the time of original treatment was 29 degrees, with the convexity to the right in seven patients. The curvature was rapidly progressing in four patients. The most common presenting signs were myelopathy and weakness. Investigative procedures included spine radiographs with the patient standing and magnetic resonance (MR) imaging of the brain, spinal cord, and craniovertebral junction. Eight children had associated hydrosyringomyelia. Surgical intervention consisted of a dorsal posterior fossa decompression in all patients and a transoral ventral decompression of the cervicomedullary junction in five. All patients were followed at 3, 6, and 12 months, and at yearly intervals thereafter with clinical evaluations, spine radiographs in the standing position, and postoperative MR imaging. The mean follow-up period was 35 months. The scoliosis improved in eight patients, stabilized in one, and progressed in two. Only one child required postoperative spinal fusion and instrumentation for progression of scoliosis. Hematomyelia or hematobulbia was associated with persistent scoliosis in two patients. The presence of hydrosyringomyelia and bone erosion did not preclude curve improvement. All patients under 10 years of age had resolution of their scoliosis, despite preoperative curves of more than 40 degrees. These findings emphasize the importance of early surgical intervention, with the restoration of normal cerebrospinal fluid dynamics at the craniovertebral junction in children with symptomatic Chiari malformations.

Chiari malformation type I in a child with velopharyngeal insufficiency

A five-year-old girl was referred for chronic and stable velopharyngeal insufficiency. Pharyngoplasty was performed, without significant improvement, and further neurological investigation was undertaken. Clinical examination and electromyography led to a suspicion of denervation of the IX, X and XI cranial nerves. Magnetic resonance imaging revealed a type 1 Chiari malformation.

Spinal cord and brain stem anomalies in scoliosis. MR screening of 26 cases

The spinal cord and brain were examined with magnetic resonance (MR) in 26 patients with idiopathic scoliosis to study the prevalence of spinal cord and brainstem anomalies. Two patients had small centrally located spinal cord syrinxes, one at C6-C8 and the other at T6-T8, without association with any brainstem or cerebellar deformity. The lowest position of the cerebellar tonsils was 0.5 cm below the foramen magnum, which was also seen in 2 other patients. Scoliosis associated with syringomyelia may be more common than previously thought, and may be wrongly classified as idiopathic. A neurogenic cause of scoliosis should always be considered, and at least in atypical cases be excluded by MR imaging of the spinal cord. MR should be mandatory before bracing or operative correction of scoliosis.

Central sleep apnea and arterial compression of the medulla

We report a 5-year-old with central sleep apnea associated with compression of the medulla oblongata by abnormal looping of the left vertebral artery. The magnetic resonance imaging findings raise the possibility that compression of the respiratory center by an aberrant vertebral artery might cause central sleep apnea.