Related Experiment Videos
Third Ventricular Volume as an Adjunct Imaging Marker for CSF-Venous Fistulas Causing Spontaneous Intracranial
Sevda Alipour Khabir1, David F Black1, Daniel J Blezek1
1From the Mayo Clinic, Department of Radiology (S.A.K., D.F.B., D.J.B., S.A.M., O.M., J.P.W., I.T.M.), Rochester, MN and Guys and St. Thomas's and Kings College Hospital Foundation Trusts (L.C.J.), Department of Radiology, London, UK.
Background:
CSF-venous fistulas (CVFs) are an increasingly recognized cause of spontaneous intracranial hypotension (SIH); however, brain MRI findings may be normal in approximately 20% of patients, underscoring the need for additional imaging markers. This study aimed to evaluate third ventricular volume as an adjunct imaging biomarker for patients with CVF causing SIH, particularly in patients with low-risk conventional MRI findings.
Methods:
A total of 32 patients with myelographically confirmed CVF who underwent pre-treatment brain MRI were included. Third ventricular volume and total ventricular CSF volume were measured and converted to age- and sex-adjusted normative percentiles (Combinostics, Tampere, Finland). Small third ventricular volume and low total ventricular CSF volume were defined as values below the 25th normative percentile. Findings were evaluated in the overall cohort and stratified by Bern score, with low-probability Bern score defined as 0-2.
Results:
The mean age was 55.7 years, and 21/32 patients were female. Mean third ventricular percentile was 21.9 ± 27.2 and mean total ventricular CSF percentile was 35.4 ± 23.7. In the overall cohort, 22/32 patients (68.8%) had small third ventricular volume, whereas 10/32 patients (31.3%) had low total ventricular CSF volume. Among patients with Bern scores of 0-2, 5/10 patients (50.0%) had small third ventricular volume, compared with 1/10 patients (10.0%) with low total ventricular CSF volume. Third ventricular percentile showed a weak to moderate positive correlation with total ventricular CSF percentile (ρ = 0.45, p = 0.0097); however, among the 22 patients with small third ventricular volume, 14 (63.6%) had preserved total ventricular CSF volume, representing 43.8% of the overall cohort (14/32). Exploratory symptom-based analyses did not identify statistically significant associations with small third ventricular volume.
Conclusion:
Reduced third ventricular volume was common in patients with CVF-related SIH and was more frequently observed than low total ventricular CSF volume, including among patients with low-probability Bern scores. Third ventricular volumetry may provide a useful adjunct imaging marker for CVF-related SIH, particularly when brain MRI findings are nondiagnostic.
Related Concept Videos
Increased Intracranial Pressure l: Introduction
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Cerebral Edema ll: Pathophysiology
Cerebral Edema l: Introduction
Increased Intracranial Pressure ll: Pathophysiology
Anatomy of the Brain: Ventricles