Prevalence and characteristics of microspurs in patients with spontaneous intracranial hypotension compared to the general population

BACKGROUND AND PURPOSE: In patients diagnosed with spontaneous intracranial hypotension (SIH), microspurs are considered the culprit lesion in most ventral dural leaks (type I). The imaging characteristics of discogenic spurs, and their prevalence in the general population has not been reported in the literature.

MATERIALS AND METHODS: This observational case-control study was conducted comparing the prevalence and characteristics of discogenic microspurs between SIH patients with a type I leak treated at a tertiary hospital between 2013 and 2023 and an age-and sex matched cohort of trauma patients.

RESULTS: Each group consisted of 85 patients (mean age 51.6 years ± 11.9 years), 74% (58/85 patients) were female. The prevalence of discogenic microspurs in the control group and SIH group was 31.8% and 90.6%, respectively.

The mean length of the culprit microspur responsible for a dural leak was larger compared to the mean length of all co-incidental microspurs from both the SIH and the control group not causing a dural leak (2.6mm versus 1.6mm, p<0.001).

Our multivariate logistic regression revealed that an increasing length of a microspur (OR 1.942, CI 1.35-2.80, p<0.001) and a narrower diameter of the spinal canal (OR 0.85, CI 0.76-0.96, p=0.008) were predictive for a dural tear.

CONCLUSIONS: A discogenic microspur is a common incidental finding and may be found in almost one third of the general population. The length of the culprit microspur and the diameter of the spinal canal are distinct morphological characteristics for type I associated CSF leaks.

ABBREVIATIONS: CI = Confidence interval; CSF = Cerebrospinal fluid; CT = Computed tomography; ED = Emergency department; MRI = Magnetic resonance imaging; OR = Odds ratio; SD = Standard deviation; SIH = Spontaneous intracranial hypotension.