- Department of Neurosurgery, Burns and Trauma Center, Ben Arous, Tunis, Tunisia
Department of Neurosurgery, Burns and Trauma Center, Ben Arous, Tunis, Tunisia
DOI:10.25259/SNI-234-2019Copyright: © 2019 Surgical Neurology International This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
How to cite this article: Aslam Hentati, Mohamed Badri, Kamel Bahri, Ihsen Zammel. Acquired Chiari I malformation due to lumboperitoneal shunt: A case report and review of literature. 10-May-2019;10:78
How to cite this URL: Aslam Hentati, Mohamed Badri, Kamel Bahri, Ihsen Zammel. Acquired Chiari I malformation due to lumboperitoneal shunt: A case report and review of literature. 10-May-2019;10:78. Available from: http://surgicalneurologyint.com/surgicalint-articles/9315/
Background:The Type I malformations are supposed to be the result of mesodermal defects that create a congenitally small posterior fossa. However, Chiari malformation could be also “iatrogenic” and then called “acquired” Chiari I malformation. In this study, the authors report the clinical feature of a patient who developed a Chiari I malformation after lumboperitoneal shunt.
Case Description:A 35-year-old woman has been suffering from idiopathic intracranial hypertension and rhinorrhea due to an anterior skull base defect. A valveless lumboperitoneal shunt followed by surgical closure of the defect was performed. Six months later, she suffered from major continuous occipital headaches. The neurological examination found a mild cerebellar gait ataxia and cerebellar dysarthria. The cerebral magnetic resonance imaging (MRI) showed a ptosis of the cerebellar tonsils and a disappearance of the cisterna magna; there was no syringomyelia. This herniation was not present before shunt was performed. A replacement of the lumboperitoneal shunt with a pressure-regulated valve chamber was performed. After a 1-year follow-up, the patient reports a marked decrease of the headache as well as the ataxia, and the last cerebral MRI showed resolution of the Chiari I malformation.
Conclusions:Symptomatic acquired Chiari malformation with or without syringomyelia as a delayed complication after lumbar shunting is a rare complication, particularly reported in the pediatric population, but could also occur to adult patients. Treating these patients by correcting the shunt’s valve could be enough, but should be monitored, as it may fail to resolve the Chiari malformation even years after treatment.
Keywords: Chiari malformation, Complication, Lumbar shunt
The Chiari I malformation was first described by Chiari, in 1891.[
In this study, we report the clinical features of a patient who developed a Chiari I malformation after lumboperitoneal shunt.
A 35-year-old woman has been suffering from idiopathic intracranial hypertension for 8 years. For 3 years, the patient has had rhinorrhea due to an anterior skull base defect. A valveless lumboperitoneal shunt followed by surgical closure of the defect was performed. Six months later, she suffered from major continuous occipital headaches with nauseas. The neurological examination found a mild cerebellar gait ataxia with limb incoordination and cerebellar dysarthria. Cranial nerve examination was normal. The cerebral magnetic resonance imaging (MRI) showed a ptosis of the cerebellar tonsils and a disappearance of the cisterna magna [
Chiari malformation type I (CM-I) has traditionally been defined as a dislocation of the cerebellar tonsils 5 mm or more below the foramen magnum on sagittal MRI.[
Unlike the “classic” CM-I, ACM is defined by the herniation of cerebellar tonsils subsequent normal hindbrain in prior brain imaging, and it is not related to CVJ malformations.[
The incidence of ACM due to LP shunt varies in different series. Chumas et al. reviewed a series of 143 patients to determine the incidence of ACM and found that the incidence of hindbrain herniation may be as high as 70% in asymptomatic patients with LP shunts.[
All reported patients with ACM were children, except for the case described in this paper and the one reported by Padmanabhan et al.[
ACM with or without syringomyelia had been noted after lumbar shunting regardless of the underlying etiology[
While the cause of the ACM is debatable, most authors consider that it is a result of CSF pressure differentials across the cranial cervical junction, created by the drainage.[
The “classic” CM-I is being increasingly diagnosed, but its optimal surgical treatment remains controversial.[
As for ACM due to LP shunt, the number of reported cases (27) is too limited to make clear and undoubtful therapeutic recommendations, but three possible strategies have been described:
To put a valve to a valveless shunt. To resite the shunt. To decompress the craniocervical junction.
To put a valve to a valveless shunt.
To resite the shunt.
To decompress the craniocervical junction.
Putting a valve to an LP shunt or resiting it could be an efficient solution to isolated ACMs. However, these techniques could not be enough when ACM is associated with syringomyelia, as symptoms did not resolve or could even get worse after a short or long follow-up. Craniocervical junction’s decompression could be required days or even years after shunt revision. It is also reported that isolated ACM could be treated by posterior fossa decompression alone, with good clinical and radiological outcome. Thus, a good and long follow-up after surgery is required, as a clinical relapse could lead to recite the shunt. Sullivan et al. and Riffaud et al. (patients number 1 and 25) reported a good recovery of patients having an ACM associated with syringomyelia after putting a valve to an LP shunt or resisting it.[
Symptomatic ACM, a rare complication of lumbar shunt, is particularly described in the pediatric population but could also occur to adult patients. The review of these reported cases suggests that the association with syringomyelia could be decisive about the need of decompression of the craniocervical junction.
Patients treated by only correcting the lumbar shunt should be monitored, as a relapse of the complication could happen years after initial treatment.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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