SIH-EBP Score Calculator for Spontaneous Intracranial Hypotension

SIH-EBP Score Explained

The SIH-EBP score is a simple and validated scoring system that could be used to predict the response to the first EBP in patients with spontaneous intracranial hypotension (SIH) with high accuracy. It includes two clinical and two radiological variables:

SIH-EBP scores range from 0 to 5, with patients who score 3 or more being more likely to have a first epidural blood patch response and should be considered for at least one attempt of targeted EBP before considering surgical intervention.

Patients who score <3 and subsequently fail the first EBP require more invasive imaging techniques, such as digital subtraction myelography or CT myelography to localize the spinal CSF leaks more accurately or to identify CSF-venous fistulas.

Age is used as clinical factor as older patients have been found as more likely to have a complete rather than partial response to EBPs.

Anatomically, as women tend to have smaller spinal canals it is likely that EBPs of the same volumes might be more effective in packing or sealing the CSF leaks in women than in men.

It was shown that the mean midbrain-pons angle of patients with SIH was significantly less than that of normal controls. Longer anterior epidural CSF collections were predictive of a poorer treatment response.

Classical radiological features of SIH, such as subdural fluid collections, enhancement of the pachymeninges, engorgement of venous structures, pituitary hyperemia, and sagging of the brain were not predictive of the treatment response.

About the original study

The study by Lin et al. involved data from 280 consecutive SIH patients in the derivation cohort and 78 patients in the validation cohort. The scoring system was developed and the cutoff score was determined by using the receiver operating characteristic curve. The findings were verified in an independent validation cohort.

The patients received a thorough clinical assessment with a standardized protocol, including a detailed history, neurological examination, pre- and post-gadolinium brain MRI, and HT2W MRM (and/or computed tomography (CT) myelogram before 2003). Only patients who had undergone at least one EBP were included.

The responders were more likely to be women (73.2% vs. 52.7%, P < 0.001) and had larger volumes of EBPs (30.8 ± 11.5 ml vs. 28.2 ± 10.2 ml, P = 0.048), greater midbrain-pons angles (43.5 ± 17.0° vs. 34.4 ± 18.3°, P < 0.001), and shorter anterior epidural CSF collections (8.0 ± 5.3 segments vs. 14.3 ± 6.0 segments, P < 0.001) when compared with the nonresponders.

A cutoff score ≥3 was shown to increase the odds of having a favorable treatment response to the first EBP by 10-fold (OR = 10.3, 95% CI = 6.3–16.8, P < 0.001).

The study benefits from a large sample size in derivation and validation cohorts (358 patients) with data from standardised protocols so high quality and reliable. The validity of the findings was consistent in two independent cohorts.

References

Original reference

Lin P-T, Wang Y-F, Hseu S-S, et al. The SIH-EBP Score: A grading scale to predict the response to the first epidural blood patch in spontaneous intracranial hypotension. Cephalalgia. 2023; 43(3).

Other references

Wu JW, Hseu SS, Fuh JL, et al. Factors predicting response to the first epidural blood patch in spontaneous intracranial hypotension. Brain 2017; 140: 344–352.