Operational measures
Three invasive therapeutic strategies for treating cluster headaches have been proposed:
- destructive procedures,
- local blockades and
- neuromodulatory procedures.
In view of the diverse therapeutic alternatives available today that are highly effective, surgical therapeutic measures should be the last resort in therapy. They should only be considered after patients have been extensively treated with all possible relevant pharmacological options in specialized centers.
Treatment-refractory situations can only arise in less than 1% of cluster headache patients. As a rule, only patients with chronic cluster headaches are eligible for surgical procedures, which is around 27% of those affected. Of the approximately 240,000 patients with cluster headaches in Germany, this amounts to around 64,800 people. 1% of these patients with treatment-refractory courses includes around 648 patients. If an estimated 50% of these are eligible for invasive procedures, such procedures are probably relevant for around 300 people in Germany.
Destructive procedures
The transection or decompression of the intermediate nerve or the superficial petrosal nerve greater and direct interventions in the area of the trigeminal nerve have only historical significance due to unsatisfactory long-term results and have been abandoned. Neuromodulatory procedures have come to the fore due to improved electronic stimulation options.
Blockade of the occipital nerve
Injection of local anesthetics and corticosteroids into the area of the ipsilateral occipital nerve can be therapeutically effective. This process was first described by Anthony (1985). Recent open studies confirm its effectiveness. Suboccipital injection of a mixture of short-acting and long-acting betamethasone is also effective: 85% of patients became pain-free within a week. The effectiveness is expected when using corticosteroids due to the systemic effect. It remains to be seen whether the local application is crucial.
Deep brain stimulation
In recent years, it has been suggested that those affected should also undergo invasive surgical procedures. Based on structural and functional imaging studies, deep brain stimulation in the area of the posterior hypothalamus was performed in open individual case series. Convincing effects could not be conveyed. In open studies, improvement rates between 50 and 70% are reported. In the only placebo-controlled, double-blind study to date, no significant difference between real stimulation and simulated stimulation could be described. Fatal consequences with fatal intracranial bleeding occurred. Catastrophic outcomes for individual sufferers are documented in publicly maintained internet diaries. Added to this are the high costs of the procedure of over 30,000 euros and the complex postoperative treatment. Based on the current data situation, neither a theoretical rationale nor a practical justification for the use of deep brain stimulation for cluster headaches can be understood. The data to date do not justify a place in the treatment of cluster headaches.
Occipital nerve stimulation [media id=46] Occipital nerve stimulation is a peripheral invasive nerve stimulation procedure for the treatment of cluster headaches. After a local incision, an electrical stimulation electrode is usually placed horizontally in the area of the first cervical vertebra and fixed. A trial stimulation with an external pulse generator can then take place over several weeks before a pulse generator is permanently implanted. There are only small open case series of occipital nerve stimulation for the treatment of chronic cluster headaches. The effectiveness appears to be about the same to better than that of deep brain stimulation with the advantage of fewer severe side effects. Occipital nerve stimulation is less invasive and less likely to cause complications than deep brain stimulation. If the disease is refractory to therapy despite specialized treatment, this experimental procedure can be considered in individual cases as part of a scientific study. Based on the mechanism of action, an indirect pain-modulating effect can be assumed; no influence on the actual course of the disease is expected. The large spontaneous fluctuation of cluster headaches must always be taken into account.
When using bilateral occipital nerve stimulation to treat treatment-refractory chronic cluster headaches, an average reduction in attack intensity of 50% can be assumed. The additional acute medication required is reduced by an average of 77%. The results show that, unlike other preventive therapy for cluster headaches, this does not involve a complete cessation of the active period, but rather only a partial reduction in attack intensity and frequency.
Occipital nerve stimulation is currently not a therapeutic option in the open treatment of patients with cluster headaches. However, it is the preferred option for treatment-refractory cases and if invasive treatment is to be considered.
Neurostimulation of the sphenopalatine ganglion (GSP)
In 2011, Schoenen introduced neurostimulation of the sphenopalatine ganglion (GSP) for the treatment of cluster headaches. So far, 22 people have taken part in the study (Pathway CH-1), which is investigating the safety and effectiveness of the ATI neurostimulator; A total of around 40 patients are planned for the study. Stimulation data from the titration phase are available for 7 of these 22 patients. Pain relief within 15 minutes (primary endpoint of the study) was achieved in 67% of treated headache attacks (n=48). At the same time, the frequency of headaches in the majority of patients decreased with stimulation; Compared to the 4-week period before the start of the study, headache frequency fell by at least 50 percent in 70 percent of patients during the study. The procedure should also be investigated for chronic migraines.
The neurostimulation system, which is in the testing phase, consists of a novel implantable mini-stimulator. It is about the size of an almond and is designed to treat severe headaches including cluster headaches and migraines. This neurostimulator is implanted into the gums without any visible scars or cosmetic impairment. The electrode tip of the implant is placed on the sphenopalatine ganglion (GSP) behind the cheekbone. After implanting the mini stimulator, the patient can use an external remote control, which is similar to a large cell phone, to trigger the stimulation that leads to headache relief if necessary. After the pain has been treated, the remote control device is removed from the cheek and the stimulation therapy is switched off.
In the multicenter Pathway CH-1 study, the stimulation parameters are set and, if necessary, adjusted in a titration phase. The patients' headaches are then treated in a randomized experimental phase with one of three different stimulation doses, including a placebo.