Spontaneous intracranial hypotension with negative brain MRI findings: a systematic review of diagnostic strategies and clinical outcomes.

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a debilitating syndrome typically characterized by orthostatic headache and classic brain MRI findings. However, brain MRI abnormalities are indirect manifestations of cerebrospinal fluid (CSF) volume depletion rather than direct evidence of the leak, and some patients may present with unrevealing or absent typical brain MRI findings, posing a considerable diagnostic challenge.

METHODS

A comprehensive search of PubMed/Medline, Web of Science, and Scopus was conducted to perform a systematic review, according to PRISMA guidelines, analyzing the available evidence on MRI-negative SIH (patients without typical SIH findings on their initial brain MRI), including its clinical features, advanced diagnostic strategies, and therapeutic outcomes.

RESULTS

This analysis reveals that, in selected cohorts, brain MRI-negative SIH has been reported in a substantial minority of patients, sharing core clinical symptoms with MRI-positive SIH but often associated with longer symptom duration and higher recurrence rates. While standard qualitative brain MRI without dedicated spinal imaging or dynamic myelographic techniques is often unrevealing, advanced modalities such as CT myelography, MR myelography, and particularly digital subtraction myelography (DSM) may help to identify occult cerebrospinal fluid (CSF) leaks, including CSF-venous fistulas. Treatment with epidural blood patch may provide clinical benefit in selected patients, while targeted surgical repair of demonstrated leaks or CSF-venous fistulas may be associated with high rates of clinical improvement.

CONCLUSION

In patients with a clinical presentation suggestive of SIH, the absence of typical brain MRI findings should not automatically exclude the diagnosis but should prompt further diagnostic evaluation to improve patients' outcomes.

SYSTEMATIC REVIEW REGISTRATION: CRD420251146583. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD420251146583.