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CSF-space volumetric change following posterior fossa decompression in paediatric Chiari type-I malformation: a
Sidharth Mantha1,2, Liam G Coulthard3,4, Robert Campbell4,5,6
1Kenneth G Jamieson Department of Neurosurgery, Royal Brisbane and Women's Hospital, Herston, QLD, 4029, Australia. sidharth.mantha@health.qld.gov.au.
Insights
In pediatric Chiari type-I malformation (CIM), cerebrospinal fluid (CSF) cisternal volume changes after decompression do not correlate with clinical outcomes. However, pre-operative FM-C2 cistern volume may predict better post-operative results in children with CIM.
Area of Science:
- Neurosurgery
- Pediatric Neurology
- Radiology
Background:
- Previous studies indicated poorer clinical outcomes in younger children with Chiari type-I malformation (CIM).
- Understanding cerebrospinal fluid (CSF) dynamics is crucial for managing pediatric CIM.
- Quantifying volumetric changes in CSF spaces may offer insights into treatment efficacy.
Purpose of the Study:
- To quantify CSF volumetric changes in the posterior fossa and upper cervical canal before and after decompression surgery in pediatric patients with CIM.
- To determine if these volumetric changes correlate with post-operative clinical outcomes.
- To investigate the role of a novel FM-C2 cistern measurement in predicting outcomes.
Main Methods:
- Retrospective analysis of magnetic resonance images from pediatric patients with CIM.
- Semi-automated measurement of CSF spaces (posterior fossa and novel FM-C2 cistern) pre- and post-operatively.
- Correlation of volumetric and morphometric data with clinical outcomes using the Chicago Chiari Outcome Scale (CCOS).
Main Results:
- All measured CSF spaces showed a significant increase in volume post-operatively.
- No correlation was found between CSF volume changes or post-operative CSF volumes and CCOS scores.
- Pre-operative FM-C2 cistern volume was positively correlated with total CCOS and was smaller in younger children (0-6 years).
Conclusions:
- CSF volumetric changes in the posterior cranial fossa and upper cervical canal do not correlate with age-related clinical outcome differences in pediatric CIM.
- The pre-operative volume of the FM-C2 cistern may serve as a predictor for favorable post-operative outcomes in pediatric CIM patients.
Objective:
We have previously reported inferior post-operative clinical outcomes in younger children with Chiari type-I malformation (CIM). We sought to quantify the CSF volumetric changes pre- and post-decompression, in a paediatric cohort, to determine whether cisternal volume change is associated with clinical outcomes.
Methods:
In this retrospective clinical study, the CSF spaces of the posterior fossa (supracerebellar/quadrigeminal, prepontine, fourth ventricle, cisterna magna) were measured on magnetic resonance images pre- and post-operatively using a semi-automated method. Additionally, we describe a novel CSF space of the upper cervical canal incorporating the subarachnoid space from the foramen magnum to the inferior cortex of the C2 body, FM-C2 cistern. Morphometric measurements included the pB-C2 distance, clivoaxial angle, clival length, clival angle and Boogard's angle. Volumetric and morphometric data were correlated with clinical outcomes at 4-12 months post-operatively as measured by the Chicago Chiari Outcome Scale (CCOS).
Results:
Of 59 adequate clinical cases, 57 and 36 patients had acceptable imaging for morphometric and volumetric analysis respectively. All CSF spaces measured had a significant increase in volume post-operatively (p < 0.05). There was no correlation between the change in volume or post-operative CSF volumes and CCOS. The pre-operative volume of the FM-C2 was positively correlated with total CCOS (Wald [Formula: see text], [Formula: see text]) and was significantly smaller in the 0-6-year age group (2.38 ± 1.27 ml vs. 3.67 ± 1.56 ml, p = 0.014). No morphometric measurement changed significantly after surgery or demonstrated a relationship with CCOS.
Conclusions:
Volumetric changes in the CSF cisterns of the posterior cranial fossa and upper cervical canal do not correlate with the age-related differences in clinical outcomes in paediatric CIM. The pre-operative volume of the FM-C2 cistern may have a role in predicting the likelihood of a beneficial post-operative outcome in paediatric CIM.
