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Neurostimulation for the Treatment of Chronic Head and Facial Pain: A Literature Review.

BACKGROUND
Head and facial pain is a common and often difficult to treat disorder. Routine treatments sometimes fail to provide acceptable relief, leaving the patient searching for something else, including narcotics and surgery. Recently, neuromodulation has been expanding to provide another option. Secondary to its potentially temporary nature and relatively manageable risk profile, several reviews have suggested trialing neuromodulation prior to starting narcotics or invasive permanent surgeries. There is evidence that neuromodulation can make a difference in those patients with intractable severe craniofacial pain.


OBJECTIVES
To provide a basic overview of the anatomy, epidemiology, pathophysiology and common treatments of several common head and facial disorders. Furthermore, to demonstrate the suggested mechanisms of neuromodulation and the evidence currently existing for the use of neuromodulation.


METHODS
A comprehensive review was performed regarding the available literature through targeting articles reporting on the use of neuromodulation to treat pain of the head and face.


RESULTS
We compiled and discuss the current evidence available in treating head and facial pain. The strongest evidence currently for neuromodulation is for occipital nerve stimulation for migraine, transcutaneous vagal nerve stimulation for migraine and cluster headache, sphenopalatine ganglion microstimulation for cluster headache, and transcutaneous supraorbital and supratrochlear nerve stimulation for migraine. In addition, there is moderate evidence for occipital nerve stimulation in treating occipital neuralgia.


LIMITATIONS
Neuromodulation has been trialed and is promising in several craniofacial pain disorders; however, there remains a need for large-scale, randomized, placebo-controlled clinical trials to further evaluate the efficacy and safety of most treatments. Much of the current data relies on case reports without randomization or placebo controls.


CONCLUSIONS
With advancing techniques and technology, neuromodulation can be promising in treating intractable pain of the head and face. Although more randomized controlled trials are warranted, the current literature supports the use of neuromodulation in intractable craniofacial pain.


KEY WORDS
Neuromodulation, headache, facial pain, craniofacial pain, migraine, cluster headache, trigeminal neuralgia, occipital neuralgia, peripheral nerve stimulator, high cervical spinal cord stimulator, peripheral nerve field stimulator.