SPG Stimulation


Electrical stimulation of the sphenopalatine ganglion (SPG) is a relatively new therapy option for cluster headache. However, manipulating the SPG in order to treat cluster headache isn't really new at all. In fact, the SPG has been a major target for the treatment of cluster headache for over 100 years1.

Back in the old days, doctors would inject local anaesthetics into the SPG or use other non-pharmacological measures to manipulate the SPG in order to relieve the debilitating cluster pain. Today, with the introduction of a novel, tiny neurostimulator, it has also become possible to electrically stimulate the SPG in order to produce a simular effect2 and literally switch off cluster headache attacks. When electrically stimulating the SPG, pain relief is believed to occur as a result of the target pain reflexes associated with cluster headache being blocked5. The following image shows a DVT image of my skull in order to give you an idea of where abouts the SPG is located (red circle).

The tiny neurostimulator consists of a chip and an antenna-like structure which contains six electrodes. It is implanted into the sphenopalatine fossa (a cavity in the skull, roughly located behind the root of the nose, which hosts the SPG) on the site of the pain. The surgeon implants the neurostimulator at the SPG through a small incision in the upper gum above the second molar and fixes it in the upper jaw bone using two to three tiny screws, so that it will stay in place3.

Under normal circumstances, i.e. when you are not suffering from an acute cluster attack, the neurostimulator is inactive. However, in the event of an acute attack, the neurostimulator can be activated through induction currents emitted by a remote controller. Consequently, if you suffer an attack, you simply turn on the remote controller and place it at a specific spot on your cheek bone. The remote controller will then connect to the neurostimulator and vibrate until you've found the right position.

Once you have found the right position, the remote controller will start ramping up the stimulation intensity. After a few seconds of ramping, you will feel a tingling sensation somewhere deep in your nose. Normally, you should ramp up until the tingling sensation becomes somewhat uncomfortable in order to achieve an adequate stimulation intensity. It does actually feel slightly weird at first, however, you'll get used to it.

 

References:

1. ATI Technologies (2013): SPG Stimulation. (URL: http://www.ati-spg.com/europe/de/therapy/spg-stimulation/, accessed on 15.04.2013)

2. ATI Technologies (2013): ATI System. (URL: http://www.ati-spg.com/europe/de/therapy/ati-system/, accessed on 15.04.2013)

3. ATI Technologies (2013): Implantationsverfahren. (URL: http://www.ati-spg.com/europe/de/therapy/implant/, accessed 15.04.2014)

4. ATI Technologies (2012): ATI Neurostimulationssystem. (URL: http://www.ati-spg.com/europe/de/therapy/ati-system/ATI%20Physician%20Brochure%20(Deutsch%20M117-01).pdf, accessed on 15.04.2013)

5. ATI technologies (2013): About the Therapy. (http://www.ati-spg.com/europe/en/ati-neurostimulation-system/about-the-therapy/, accessed on 03.12.2013)

6. Schoenen, J., Jensen, R.H, Lanteri-Minet, M., JA Láinez, M., Gaul, C., Goodman, A.M., Caparso, A., May A. (2013): Stimulation of the sphenopalatine ganglion (SPG) for cluster headache treatment. Pathway CH-1: A randomized, sham-controlled study. Cephalgia 0(0) 1-15.

Images:

6. ATI Technologies (2013): Media Kit. (URL: http://www.ati-spg.com/europe/en/company/media-kit/, zuletzt abgerufen am 15.04.2013)

7. DVT images kindly provided by UKE Hamburg.