Assessing the Diagnostic Value of Brain White Matter Hyperintensities and Clinical Symptoms in Predicting the Detection of CSF Venous Fistula in Patients with Suspected Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) due to CSF venous fistula (CVF) is increasingly recognized as a secondary cause of headaches, with symptoms often overlapping with primary headache syndromes such as migraine. While brain MRI studies have focused on features indicative of SIH, findings that support an alternate headache etiology, such as the bifrontal white matter hyperintensities (WMH) often seen in migraines, have not been explored in this context. This study assesses 1) the quantity and distribution of WMH and 2) the presenting clinical features in patients with and without CVF found on dynamic decubitus CT myelography (dCTM).

MATERIALS AND METHODS: 72 consecutive patients underwent clinical workup for SIH due to suspected CVF, including pre-procedural brain and spine MRI followed by dCTM. Brain imaging features were analyzed, including Bern score, quantitative WMH burden, and WMH distribution. Demographics and clinical symptoms present at the time of presentation were recorded. Imaging features were compared between groups with and without CVF using parametric or nonparametric comparisons according to variable normality. Multivariate logistic regression explored the relationships between imaging features, clinical symptoms, and the presence of CVF.

RESULTS: The cohort included 40 patients with (CVF+) and 32 patients without (CVF-), with no significant age or sex differences. CVF+ patients had significantly higher Bern scores and significantly fewer WMH. There were significant differences in the frequencies of WMH patterns between groups, with a migrainous pattern observed most frequently in CVF-patients. Logistic regression combining Bern score, WMH burden, and WMH pattern demonstrated a better fit for predicting CVF than using Bern score or WMH features alone. Fourteen clinical symptoms showed the greatest differences between CVF+ and CVF-groups. Logistic regression demonstrated a positive association between CVF detection and a pressure/throbbing headache quality, and negative associations for neck pain, facial pain, phonophobia, and anhedonia/depression.

CONCLUSIONS: These findings suggest a negative association between CVF detection, increased burden of WMH, and a migrainous WMH pattern. Symptom analysis describes distinct clinical phenotypes, challenging orthostatic headache as a defining characteristic. These results support a comprehensive assessment of imaging and clinical presentations in the workup of suspected SIH.

ABBREVIATIONS: SIH = spontaneous intracranial hypotension; CVF = CSF venous fistula; WMH = white matter hyperintensities; dCTM = dynamic CT myelography; dDSM = dynamic digital subtraction myelography; PPV = positive predictive value; NPV = negative predictive value Received month day, year; accepted after revision month day, year.