Spontaneous Intracranial Hypotension (SIH) is a debilitating neurological disorder caused by a cerebrospinal fluid leak (CSF), with an estimated incidence of 5 per 100,000 persons per year, of which mostly women between the ages of 35 years and 55 years. The typical presentation is moderate-to-severe orthostatic headache and several other possible neurological symptoms, that significantly impact patients' quality of life.
Treatment of SIH usually starts with conservative measures, consisting of strict supine bed rest, hydration, caffeine, and simple analgesics. The vast majority of patients will require invasive treatments for their CSF leak, such as epidural blood patches, fibrin glue patches, endovascular coiling, and/or surgical repair. These specialized treatments are only offered in tertiary care centers and require specialized personnel and resources, which implicates a certain waiting time for the patients before permanent treatment is offered. In the meantime, due to the lack of an effective and accessible alternative, patients continue to suffer.
The greater occipital nerve block (GONB) has been reported as a simple, safe, and effective treatment to provide short-to-intermediate term relief of migraine, cervicogenic headache, cluster headache, occipital neuralgia, and more recently, post-dural puncture headaches (PDPH). As the pathophysiology of intracranial hypotension caused by SIH or PDPH is very similar, it is stipulated that the effect of GONB will be similar for SIH patients. However, to date, no studies exploring the efficacy of GONB for SIH have been performed.
The investigators propose to do a prospective observational study to explore the outcome of GONB for SIH. GONB can serve as a bridge therapy to control the debilitating headache of SIH while patients are awaiting permanent SIH treatment. Moreover, GONB can be performed by physicians of different specialties including neurology, which makes it an accessible treatment for all patients. Lastly, by offering better symptom control, this intervention could potentially restore patients' ability to work and reduce healthcare costs.
Adults of > 18 years of age
Diagnosis of SIH, according to the International Classification of Headache Disorder (ICHD-3) classification (2)
Baseline pain intensity NRS > 4/10 (in upright position)
Contraindications to GONB: ongoing infection (systemic or located at the site of injection), intake of anticoagulants (not aspirin), allergy to injectate, contra-indication to injectate of steroids
Any significant cognitive or language barrier that impedes participation
Patients taking opioid medications with daily Oral Morphine Equivalent (OME) of 50 mg or higher
Patient refusal
Patients with documented SIH will be recruited from the Toronto Western Hospital Intracranial Hypotension Clinic and enrolled after consent is obtained.
Cohort
Prospective
greater occipital nerve block
Procedure/SurgeryPatients will receive an ultrasound-guided bilateral GONB (distal approach) of 5 mLs of injectate of bupivacaine 0.25% (5 mLs) + depomedrol 40 mg in 1 mL (3 mLs to each side).
Change in headache intensity
The difference in the change in intensity of headache, as measured on an 11-point Numerical Rating Scale (NRS), measured 30 minutes after the intervention, after being positioned in an upright position for 10 minutes, compared to baseline.
pain intensity
The difference in the change in intensity of headache, as measured on an 11-point Numerical Rating Scale (NRS) where 0 means no pain and 10 worst pain imaginable
Onset of headache
The time of onset or worsening of headache when positioned in a sitting position
Sitting endurance
The duration of tolerance in an upright position (i.e. how long the patient can stay in an upright position until the headache becomes unbearable and urges the patient to lie down))
SIH associated central nerve system symptoms, such hearing loss, tinnitus, tremor, balance difficulties
To assess the impact of SIH-associated symptoms such as tinnitus, tremor, and balance abnormalities
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