Due to increased media attention, Michigan Headache & Neurological Institute (MHNI) has received a number of inquiries about the use of sphenopalatine ganglion (SPG) blocks for headache. The SPG block is not a new treatment, but one MHNI has utilized for several years.
Sphenopalatine Ganglion Blocks for Headache
The association between the sphenopalatine ganglion and various pain disorders has been established in medical literature for over one hundred years. In early 20th century, blockade of the SPG was considered an effective treatment for everything from TMJ to hiccups. Current application includes the following conditions: trigeminal neuralgia, atypical facial pain, acute migraine, acute and chronic cluster headache, and various facial neuralgias.
The sphenopalatine ganglion is a collection of nerves deep in the mid face region, behind the nasal cavity. It contains both autonomic and sensory nerves. It is also associated with the trigeminal nerve, the principal nerve involved in headache disorders. The sphenopalatine ganglion is believed to be involved in some of the pain and autonomic events associated with head pain including runny or stuffy nose, tearing of eyes, sweating, etc. These autonomic symptoms are typically seen in cluster headache attacks, but may also be seen in migraine.
During a nerve block, anesthesia is administered and local anesthetic is administered to the ganglion to reduce its activity. The SPG block procedure is minimally invasive and can be performed on an outpatient basis. It involves a small plastic catheter being directed into the region of the SPG. The duration of relief varies and the procedure may be repeated several times before optimum results are achieved.
Why the Renewed Interest?
Traditional sphenopalatine ganglion block techniques involve either fluoroscopically-guided needles inserted through the cheek or large cotton-tipped applicators inserted up through the nose. The needle techniques require a high level of physician training and expertise. They also have the potential to cause significant patient discomfort and risk and can be time-consuming. When cotton-tipped applicators are utilized, it can be difficult to determine the exact amount of anesthetic reaching the desired area.
Recently, a number of improved catheter-based nasal applicators (Sphenocath, Tx360, Allevio) have been developed and approved for use when performing SPG blocks. These new applicators promise faster and more precise application, and have the potential to cause less patient discomfort.
In fact, MHNI was a clinical research site during the development of the Tx360 Nasal Applicator. Some of our study patients did experience benefit after a series of treatments.
Our physicians continue to use nasal applicators, as well as other methods, to deliver anesthetic to the SPG. All decisions to perform this procedure, and by what method, are based on the individual patient's case.
Neuromodulation of the Sphenopalatine Ganglion
Focus has also increased on the use of neuromostimulation of the SPG nerve to prevent headaches. Neuromodulation involves using electrical stimulation, often via an implantable device, to alter nerve transmission, activation, and/or processing.
Support for SPG neuromodulation in the class of headache disorders known as Trigeminal Autonomic Cephalalgias (e.g., cluster headaches) is currently stronger than it is for migraine. This is in part due to greater success in past clinical trials, but may also be related to the more overt autonomic symptoms present in these disorders. Given the large number of people affected by migraine and its disabling potential, MHNI believes both warrant further investigation.
MHNI is one of a select group of headache specialty centers in the country participating in a clinical research study involving implantation of an SPG neurostimulator to treat chronic cluster headache.
- Khan S, Schoenen, J and Ashina, M. Sphenopalatine ganglion neuromodulation in migraine: What is the rationale? Cephalalgia. 2014, Vol. 34(5) 382-391
- Windsor, RE and Jahnke, S. Sphenopalatine Ganglion Blockade: A Review and Proposed Modification of the Transnasal Technique. Pain Physician. 2004;7:283-286.