- St. Peter's Hospital Spine and Neurosurgery, Albany, New York, USA
Correspondence Address:
Thomas J. Lovely
St. Peter's Hospital Spine and Neurosurgery, Albany, New York, USA
DOI:10.4103/2152-7806.100369
Copyright: © 2012 Peleggi AF. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.How to cite this article: Peleggi AF, Lovely TJ. Treatment of delayed Chiari malformation and syringomyelia after lumboperitoneal shunt placement: Case report and treatment recommendations. Surg Neurol Int 30-Aug-2012;3:101
How to cite this URL: Peleggi AF, Lovely TJ. Treatment of delayed Chiari malformation and syringomyelia after lumboperitoneal shunt placement: Case report and treatment recommendations. Surg Neurol Int 30-Aug-2012;3:101. Available from: http://sni.wpengine.com/surgicalint_articles/treatment-of-delayed-chiari-malformation-and-syringomyelia-after-lumboperitoneal-shunt-placement-case-report-and-treatment-recommendations/
Abstract
Background:Delayed Chiari malformation with syringomyelia is an uncommon and sparsely reported complication after lumbar cisternal shunting. A number of treatments have been implemented with varying degrees of success. After review of these modalities, a treatment plan was devised and implemented.
Case Description:A 15-year-old girl was diagnosed with idiopathic intracranial hypertension (pseudotumor cerebri) and had placement of a Medtronic Spetzler lumboperitoneal shunt. She did well for 10 years and then developed a 3-week history of headache, balance problems, and sensory loss. Workup demonstrated a new Chiari malformation and cervical syrinx. She underwent initial placement of a ventriculoperitoneal shunt, followed by ligation of the lumboperitoneal shunt. She then had a suboccipital decompression and duraplasty. Follow-up at 6 months showed relief of her symptoms and MRI demonstrated resolution of the Chiari malformation and syrinx.
Conclusion:Delayed Chiari malformation and/or syringomyelia after lumbar shunting is best treated with placement of a ventricular device and ligation of the lumbar shunt. The Chiari malformation and/or syrinx should be surgically addressed for persistent symptoms or progression of the structural abnormality.
Keywords: Acquired chiari malformation, idiopathic intracranial hypertension, lumboperitoneal shunt, pseudotumor cerebri, syringomyelia
INTRODUCTION
First recognized in the late 1970s and 1980s, a sparsely reported delayed complication of lumbar cisternal shunting is the formation of an “acquired” Chiari I malformation with or without the formation of a syrinx.[
CASE REPORT
An overweight 15-year-old girl developed severe headache and visual loss with papilledema. A cranial magnetic resonance imaging (MRI) scan, MR angiogram, and MR venogram were negative. Serial lumbar punctures revealed elevated opening pressures consistent with idiopathic intracranial hypertension, i.e. pseudotumor cerebri [
At age 25, she developed a 3-week history of severe headache and intractable nausea and vomiting. Vision remained intact as did her motor exam. However, decreased touch and pinprick sensation were noted in the left upper extremity. Repeat MRI of the head and cervical spine demonstrated an acquired Chiari I malformation with cerebellar tonsillar ectopia extending 16 mm below the foramen magnum, and a cervical syrinx from C2 extending to the T8 level [
We assumed that the new findings were the result of cranial spinal CSF pressure differentials caused by the lumbar drain. Weight reduction can result in resolution of pseudotumor cerebri. Because the patient had not undergone substantial weight loss and was not experiencing papilledema, it was assumed that the pseudotumor cerebri continued to be managed by her lumbar drain and that the drain was still working. The patient underwent placement of a right frontal programmable ventricular peritoneal shunt utilizing stereotactic navigation and ligation of the LP shunt. Postoperatively, she continued to have severe headaches, nausea, and vomiting. Follow-up computed tomography (CT) showed decreased ventricular size and persistent Chiari malformation. Secondary to persistent symptoms, a suboccipital craniectomy, C1 laminectomy, and duraplasty were performed 5 days after shunting. Bipolar cautery was used to shrink the tonsils and clear egress of CSF from the fourth ventricle was noted prior to closure. With shrinkage of the ventricles, there appeared to be excessive ventricular tubing, so the proximal catheter was repositioned. The patient's symptoms gradually resolved over time, including the sensory symptoms in her left arm. A follow-up MRI done 6 months postoperatively revealed a complete resolution of both the Chiari malformation and the syrinx [
DISCUSSION
First recognized in the late 1970s and 1980s, acquired Chiari malformation and/or syringomyelia as a delayed symptomatic complication of lumbar cisternal shunting has been reported only sporadically.[
Delayed Chiari malformation and/or syringomyelia have been noted after lumbar cisternal shunting regardless of the underlying etiology. It has been described in cases of pseudotumor cerebri, shunting of cysts, and communicating hydrocephalus. It has been described in lumbar shunts to the peritoneum or ureter.[
A number of treatment modalities have been employed to resolve these complications, with varying degrees of success. For some patients, a cranial enlargement was successful without manipulation of the lumbar shunt.[
In a number of reports, the lumbar shunt was ligated and replaced with a ventricular atrial or peritoneal shunt without suboccipital decompression.[
Placing ventriculoperitoneal shunts in pseudotumor cerebri patients is technically challenging and shunts may have a higher failure rate as the ventricles are usually small.
A review of the various treatments for acquired Chiari malformations and/or syringomyelia after lumbar shunting in these reports suggests that the greatest treatment success occurs with ligation of the lumbar drainage and placement of a ventricular device. This is a logical result if it is assumed that alterations in the cranial spinal fluid pressures across the foramen magnum are responsible.[
In conclusion, acquired Chiari malformation and/or syringomyelia as a delayed complication after lumbar cisternal shunting occurs with some frequency, particularly in the pediatric population, but is not always symptomatic. Our review of these reported cases suggest the most effective treatment option is to remove the responsible factor of cranial cervical pressure differentials by replacing the lumbar shunt with a ventricular device. This procedure is made more feasible even with smaller ventricles using a stereotactic navigation device. Even if ventricular shunting is successful in alleviating symptoms, the patient should be monitored. Shunts alone may fail to resolve the Chiari malformation or syrinx, which may still progress to cause symptoms requiring treatment. Therefore, we suggest a low threshold for suboccipital decompression if symptoms persist or the structural abnormalities worsen.
ACKNOWLEDGMENT
The authors wish to thank Mrs. Mary Barown for her help in preparation of this manuscript.
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