Table of contents
Spontaneous intracranial hypotension
What's new
Added 2024 ACR and 2023 SIH-SIG guidelines for the diagnosis and management of spontaneous intracranial hypotension.
Background
Overview
Definition
SIH is a condition characterized by a decrease in CSF pressure, often due to a CSF leak, which can occur spontaneously or secondary to trauma.
1
Pathophysiology
The pathophysiology of SIH involves the leakage of CSF, leading to a reduction in CSF volume and ICP. This can cause the brain to sag, leading to traction on pain-sensitive structures and resulting in symptoms such as orthostatic headache, neck pain, and dizziness.
1
2
Epidemiology
The incidence of SIH is estimated at 5 per 100,000 person-years, with a peak incidence at 40 years and women being affected twice as often as men.
3
Risk factors
Risk factors for SIH include connective tissue disorders, minor trauma, and certain medications. However, in many cases, the cause of the CSF leak remains unknown. In approximately 50% of cases, the location of the spinal CSF leak remains undetectable.
2
4
Disease course
The clinical course of SIH varies. Patients generally present with headaches that start after standing, sitting, straining, or coughing, often relieved by returning to a seated or lying position. Other associated symptoms may include neck pain, back pain, headaches, dizziness, and nausea. While some patients may experience spontaneous resolution of symptoms, others may have debilitating presentation.
1
5
Prognosis and risk of recurrence
The prognosis of SIH is generally favorable with appropriate management. While the condition can be debilitating, many patients experience symptom improvement or resolution with treatment. Outcomes can vary, and some patients may experience continued or recurrent leaks with chronic symptoms.
1
5
Guidelines
Key sources
The following summarized guidelines for the evaluation and management of spontaneous intracranial hypotension are prepared by our editorial team based on guidelines from the American College of Radiology (ACR 2024) and the Multidisciplinary Specialist Interest Group on Spontaneous Intracranial Hypotension (SIH-SIG 2023).
1
2
3
4
5
6
7
Screening and diagnosis
Diagnosis: as per SIH-SIG 2023 guidelines, suspect SIH in patients presenting with any of the following, especially with symptoms commonly associated with SIH:
orthostatic headache other than following iatrogenic dural puncture or major trauma
"end of the day" or "second half of the day" headache with improvement of the headache on lying flat
thunderclap headache followed by orthostatic headache
new daily persistent headache with an initial orthostatic quality. The presence of associated symptoms.
E
Show 3 more
Diagnostic investigations
Brain and spine imaging: as per ACR 2024 guidelines, obtain brain and whole-spine MRI to assist in localizing a potential CSF leak in adult patients with orthostatic headache from suspected intracranial hypotension, without recent spinal intervention that could cause CSF leakage.
B
Show 2 more
More topics in this section
Myelography
ICP monitoring
Diagnostic procedures
Medical management
Conservative management: as per SIH-SIG 2023 guidelines, offer conservative management in all patients with suspected SIH for up to 2 weeks from symptom onset, while offering non-targeted epidural blood patch as soon as possible if symptoms do not resolve with conservative management alone.
E
Show 3 more
More topics in this section
Management of headache
Nonpharmacologic interventions
Orthostatic rehabilitation: as per SIH-SIG 2023 guidelines, consider offering orthostatic rehabilitation addressing both deconditioning affecting skeletal muscle and deconditioning affecting autonomic postural responses in patients who have been bedbound, especially with symptoms of orthostatic intolerance or pre-existing postural tachycardia syndrome and/or hypermobility syndromes.
E
Therapeutic procedures
Epidural blood patch: as per SIH-SIG 2023 guidelines, offer a non-targeted epidural blood patch in all patients with a clinical and/or imaging diagnosis of SIH, after no more than 2 weeks of conservative management.
E
Show 7 more
More topics in this section
Endovascular treatment
Surgical interventions
Indications for surgery
As per SIH-SIG 2023 guidelines:
Consider offering surgical management in patients with SIH with a causative lesion identified on digital subtraction myelography or CT myelography remaining symptomatic after appropriate conservative management and/or non-targeted epidural blood patches. Take into consideration the response to previous treatments, severity of symptoms, site and type of the leak or CSF-venous fistula, feasibility and risk of surgery, and patient preference when deciding to offer surgery. Engage in a discussion with the neurosurgeon, neurologist, neuroradiologist, and patient to decide between surgery and targeted patching.
E
Perform surgery by a neurosurgeon with expertise in managing spinal CSF leaks, with an exact technique based on specific requirements of the leak type/site.
E
Specific circumstances
Asymptomatic patients: as per SIH-SIG 2023 guidelines, refer asymptomatic patients with radiological evidence of SIH to a specialist center for multidisciplinary team discussion.
E
Show 3 more
More topics in this section
Patients with subdural hematoma
Patients with cerebral venous thrombosis
Patients with superficial siderosis
Follow-up and surveillance
Follow-up: as per SIH-SIG 2023 guidelines, obtain follow-up in all patients as follows:
Situation
Guidance
Early
24-48 hours, review for complications following any intervention
Intermediate
10-14days, following epidural blood patching
3-6 weeks following surgery
Late
3-6 months, following any intervention
E
Show 2 more