Natural history of spontaneous intracranial hypotension: a clinical and imaging study

Although spontaneous intracranial hypotension (SIH) is well studied, there are few studies of the clinical and imaging history of SIH without interventional treatments. For example, what is the natural history of those who are untreated or treated only with conservative measures?

To conduct a retrospective study examining changes in imaging findings for patients with SIH without interventional treatments and to study associations between imaging findings and clinical symptoms.

Included patients had a clinical diagnosis of SIH, were seen at Mayo Clinic between 1999 and 2021, had a brain MRI scan indicating SIH (Bern score), and had a brain MRI scan 6 or more months later without intervening leak-related interventional treatment. Bern scores were assigned for the first and last MRI scans prior to treatment. Patients were also grouped into three qualitative categories: overall improvement of symptoms, stable symptoms, or worsened symptoms based on patient report during the clinical visit at the time of the follow-up brain MRI scan.

Among 46 patients with untreated SIH, the Bern score improved over time in 11 (24%), was stable in 30 (65%), and worsened in 5 (11%). Two patients (4.3%) showed complete resolution of all abnormalities by the Bern scoring criteria. Symptoms improved in 7 (15%), were stable in 29 (63%), and worsened in 10 (22%).

In patients with brain MRI evidence of SIH, almost 25% demonstrated radiographic improvement, and 15% reported clinical improvement, during at least 6 months of observation or conservative treatment. Most had stable, persistent MRI abnormalities and symptoms when SIH was untreated.