Stimulators and Headache
By Stewart J. Tepper, MD
People with severe headache are often desperate enough to contemplate surgery, such as stimulator placement. When should you consider stimulators?
Diagnosis
Get a proper diagnosis first. Doing treatment before diagnosis is putting cart before horse. ACHE can provide names of board-certified headache specialists or members of the American Headache Society.
Treatment before surgery
With specific diagnosis, try daily medications, sometimes in combination with non-drug therapy, behavioral and physical. Diagnosis and orthodox treatment with pre-set goals usually works without surgery.
Daily headache
Surgery is usually done for some form of daily headaches. Short, sharp headaches occur less than 4 hours per day, the trigeminal autonomic cephalalgias (TACs), such as cluster headache. Or the headaches can be difficult-to-treat forms of chronic migraine (CM), headaches at least 15 days per month, at least 4 hours per day.
TACs, especially cluster, can be very severe, and disabling, and resistant to therapy, After exhausting conventional medications, cluster surgery can be reasonable.
CM treatment offers additional interventions before surgery. Medication overuse headache (MOH) must be identified, and overused medications completely weaned. Medication rebound should be a 100% contraindication to surgery; there is no substitute for wean.
OnabotulinumtoxinA is FDA-approved for CM, and should be administered according to the FDA-approved protocol by a specifically trained headache specialist before considering surgery.
Inpatient or day-hospital structured headache programs are also available. All are multi-week programs involving headache medicine specialists, psychology, infusions, physical therapies, and other disciplines. Patients with CM and MOH should go through one of these programs before contemplating surgery.
Stimulators and headache
Stimulators include occipital nerve stimulators (ONS), deep brain stimulators (DBS), and sphenopalatine ganglion (SPG) stimulators. None is FDA-approved for primary headaches; these three stimulators, as well as others, are being studied.
Occipital nerve stimulators
In the European Union, device approval is faster and more streamlined than in the US. In Sept 2011, an ONS was given a CE Mark, a European regulatory approval, for CM. This device consists of wires surgically placed at the back of the skull and neck, with another wire going to a battery implanted in the chest, like a pacemaker. The European-approved ONS found 41% improvement after 12 weeks of stimulation, compared to 13% improvement in controls. Thus, ONS does not eliminate daily headaches, rather it decreases them. Studies on ONS for cluster and related TACs also show promise.
Problems with ONS:
- We may be a long way from US regulatory approval. Further studies are clearly necessary and underway. If you can, get into a study. We still don’t really know that ONS works in TACs or CM.
- Implanted wires can move, called lead migration.
- Infection can occur, sometimes requiring hardware removal.
- Getting insurance reimbursement is challenging.
- It can take months for ONS to work, if it is going to work. Sometimes headache can switch sides, so placement on both sides is probably wise.
Deep brain stimulators
Deep brain stimulators are inserted into the brain center, with wires that come out of the brain, connecting to a battery, again in the chest. Only a skilled neurosurgeon can do this procedure. DBS has been used world-wide in small numbers of patients with cluster or TACs, but is not approved from a regulatory standpoint anywhere in the world.
Problems with DBS:
- Placement can be dangerous. DBS is the most invasive headache surgery. Death and stroke have both been reported with DBS. Infection, lead migration, and hardware failure can also occur. Most neurosurgeons favor other, less invasive surgery, such as ONS first, before DBS.
- DBS is not a cure, and does not work in everyone.
- Average time to improvement in cluster was 42 days post-surgery.
- Headaches, especially cluster, can switch sides, which might require a second neurosurgery.
- Since DBS is experimental, insurance is reluctant to pay. A clinical trial, if available, is the way to go.
Sphenopalatine ganglion stimulation
The SPG is located in the skull near the upper teeth. Getting to this structure is tricky, and a skilled surgeon is necessary.
Currently, SPG stimulation for cluster and migraine studies are underway in Europe. The device being studied is placed by a maxillofacial surgeon going through the mouth. The studied device has no external wires or battery; rather, a stimulator like a cell phone is placed against the cheek and activated as-needed. Plans are to study this device in the US. At the time of this writing (Feb 2012), SPG stimulation is not approved for use anywhere in the world.
Problems for SPG stimulation:
- It has not been established to work in migraine, and studies are very preliminary.
- It is not clear for which cluster patients it works.
- It is not approved or commercially available anywhere in the world at the time of this writing (Feb 2012).
- At the time of this writing, US SPG studies are not underway, for either cluster or migraine. When these US studies do begin, participation in them would be best for those interested.
- Once again, based on other stimulator experiences, device migration, infection, and hardware failure may be future problems.
Conclusions
Before contemplating stimulator surgery, see a headache specialist and get a specific diagnosis. First, try conventional treatment. Wean from overused medications is critical. There is no substitute, and must be absolute.
OnabotulinumtoxinA is the only FDA-approved treatment for CM. Do not proceed to surgery without having tried this with a CM diagnosis.
Complete a day-hospital or inpatient structured multidisciplinary headache program if you have chronic daily headache resistant to the above treatments.
Only then should you contemplate stimulator surgery. No stimulator is US-approved; an ONS has CE Mark regulatory approval in Europe. Consider less invasive surgery, ONS or SPG stimulation, before considering DBS. Participation in a clinical study is best; insurance approval for stimulators is rare.
The future for stimulators is hopeful. We are just beginning to study these promising approaches for difficult-to-treat headaches.
Stewart J. Tepper, MD, Professor of Medicine, Department of Neurology, Cleveland Clinic Lerner College of Medicine, Cleveland, OH.