Clinical trial NCT06374524: Greater Occipital Nerve Block for Spontaneous Intracranial Hypotension
Official title: Role of Greater Occipital Nerve Block in Headache From Spontaneous Intracranial Hypotension: a Prospective Observational Study
Study type: OBSERVATIONAL
Overall status: NOT_YET_RECRUITING
Conditions: Spontaneous Intracranial Hypotension
Lead sponsor: University Health Network, Toronto
Sponsor class: OTHER
First posted: 2024-04-18
Enrollment: 34
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Patients with documented SIH will be recruited from the Toronto Western Hospital Intracranial Hypotension Clinic and enrolled after consent is obtained.

Brief summary: 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.

Detailed description: This a prospective observational study on 34 patients with SIH, recruited from the Toronto Western Hospital Intracranial Hypotension Clinic. Patients will receive an ultrasound-guided bilateral GONB of 5 mls of injectate of mix of local anesthetic with steroid. There is no comparator. Primary outcome is the change in intensity of headache at 30 minutes post-intervention. Secondary outcomes are change in intensity up to day 14 post-intervention, onset of headache, sitting endurance, change in SIH-associated central nervous system (CNS) symptoms, emotional functioning, patient satisfaction, analgesic consumption and side-effect, up to 14 days post-intervention

Eligibility criteria: Inclusion criteria

1. Adults of \> 18 years of age
2. Diagnosis of SIH, according to the International Classification of Headache Disorder (ICHD-3) classification (2)
3. Characteristics of pain:

   1. Baseline pain intensity NRS \> 4/10 (in upright position)

Exclusion criteria

1. 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
2. Any significant cognitive or language barrier that impedes participation
3. Patients taking opioid medications with daily Oral Morphine Equivalent (OME) of 50 mg or higher
4. Patient refusal

Primary outcomes:
measure: Change in headache intensity
timeFrame: 30 minutes post intervention
Secondary outcomes:
measure: pain intensity
timeFrame: day 1,3,7,14
measure: Onset of headache
timeFrame: at 30 minutes post-intervention and on the morning of day 1, 3, 7, and 14 post-intervention
measure: Sitting endurance
timeFrame: at 30 minutes post-intervention and on the morning of days 1, 3, 7, and 14 post-intervention (in minutes
measure: SIH associated central nerve system symptoms, such hearing loss, tinnitus, tremor, balance difficulties
timeFrame: at 30 minutes post-intervention and on days 1, 3, 7, and 14 post-intervention
measure: Level of generalized anxiety
timeFrame: at day 14 post-intervention
measure: patient satisfaction
timeFrame: at day 14 post-intervention
measure: analgesic consumption
timeFrame: daily up to day 14
measure: adverse effects
timeFrame: daily up to day 14
measure: Level of Pain Catastrophizing
timeFrame: at Day 14 post-intervention
measure: Level of depression
timeFrame: at Day 14 post-intervention
Other outcomes:
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