**4. Clinical course**

muscles, thus freeing the nerve. If patients present both trigger points, an 8-cm-long medial incision is made and dissection of all abovementioned muscles and vessels (occipital arteries)

Auriculotemporal neuralgia has been described in the neurology literature as a syndrome "characterized by attacks of paroxysmal, moderate to severe pain on the preauricular area, often spreading to the ipsilateral temple." Chim et al. in a study concerning the anatomical variations of compression points of the auriculotemporal nerve have identified three specific points that could be surgically treated [5]. The preauricular fascial band compression points (compression points 1 and 2) in the preauricular course of the auriculotemporal nerve were found centered at 13.1 and 11.9 mm anterior and 5.0 and 17.2 mm superior to the most anterosuperior point of the external auditory meatus. The other compression point (compression point 3) is represented by the crossover in the temporal scalp between the auriculotemporal and the superficial temporal artery. Guyuron et al. developed the technique for endoscopic decompression of the zygomaticotemporal branch of the trigeminal nerve, and recently, it has been recognized that the failure of Site II surgery may be because of the lack of identification and decompression of the auriculotemporal nerve. For this reason commonly the auriculotemporal nerve decompression is performed in conjunction with the zygomaticotemporal decompression [5, 6]. We report the endoscopic surgical techniques to decompression-avulsion of the auriculotemporal nerve [5, 6, 15]. The point of maximal tenderness is marked, and Doppler findings to determinate vessel location may be used to avoid injury to the surrounding nerves or difficulty to place the endoscopic access devices. Both techniques can be combined with decompression of the trigger Site II; in that case auriculotemporal nerve is addressed first. In local anesthesia, five- to seven-port incision is designed for Site II surgery, and the 1.5-cm lateral incision is made and is extended anteriorly if necessary. Dissection to identify the vessel and nerve should be performed with blunt tip scissors along the direction of the vessel. The vessel and nerve are commonly found in the superficial layers and along the superficial temporal fascia. The use of blunt tip bipolar and regular suction is enough to safely ligate the vessel and nerve after identification. Although the area of dissection is far cephalad to the temporal branch of the facial nerve, caution should be exercised. The deep temporal fascia is then identified, and placement of endoscope is performed. If one is concerned about an unusually anterior temporal artery causing compression and pain (scars beyond the hairline or proximity to the temporal branch of the facial nerve), ligation of the main trunk of the auriculotemporal nerve in the preauricular area is chosen. The area of maximal tenderness above the temporomandibular joint, which hosts the main trunk of the auriculotemporal nerve, is accessed, and the vessel and nerve are ligated in this area. A 1.5-cm incision is performed 0.5 cm in front of the tragus and above the temporomandibular joint area with the aid of Doppler. The main trunk of the auriculotemporal nerve is identified first, and the vessel is then located in the deeper plane, commonly associated with another small nerve branch. Caution should be used to avoid injury to the facial nerve, which is deep to the dissection, and to the commonly visualized vein, which is in a more superficial plane. Even with vessel ligation in this area, auriculotemporal nerve decompression and superficial temporal artery ligation in

and isolation of both nerves are performed [15].

108 Current Perspectives on Less-known Aspects of Headache

**3.4. Auriculotemporal nerve**

As stated previously, 30% of MH patients still suffer from debilitating chronic MH since they are refractory to current medical management. Moreover, not all patients may benefit from the existing therapies due to the possible adverse events and contraindications. It's our shared opinion that patients diagnosed with MH who, despite or not conservative treatment, are still symptomatic may be eligible for the surgery [9]. Being affected by mental illness and children under 16 years are the only excluding criteria.

All procedures are minimally invasive and are performed under local-assisted anesthesia as 1-day surgery with an average surgery time of less than 1 h. No drainage needs to be positioned. Patients should keep ice on the surgical area for 24 h following surgical procedure in order to lower the risk for complication of the postoperative course (e.g., hematoma, bleeding, edema). Patients must be fasting from midnight and may start feeding again since the second hour after surgery. Patients are permitted to resume ordinary activities in 1 week and heavy exercise in 3 weeks. Patients have to medicate each two days the surgical wound with Betadine and can take a shower since the day after surgery. Stitches have to be removed on the fourteenth postoperative day. The postoperative edema of the upper lid following frontal migraine surgery is almost a certainty and resolves in the following 3/5 days, while the ecchymosis will vanish by the second postoperative week. Boric water applications three times a day may help the process of reabsorption of the edema. As the edema may move in the posterior orbicular space determining the compression of the optic nerve, patients' sight must be assessed during 12 h that follow the frontal migraine surgery in order to perform a prompt surgical decompression as soon as the patient reports changes in his/her sight. However it is just an eventual complication that currently we have never observed in our clinical practice.

Patients should fill a daily headache diary and complete MH questionnaires assessing MH parameters following surgery. The same questionnaires are given preoperatively in order to assess changes in MH. Patients may be seen after initial recovery, at 1 month, and then every 3 months for 1 year.

Almost 90% of the patients can recognize more than one MH trigger site; the surgical deactivation may be performed at all sites during the same surgical procedure [10]. However, we routinely deactivate the main trigger site first, and then a second or third surgery is performed at the remaining sites 3 months after each surgery.

MH recurrence may occur from 1 up to 3 months after surgery; thus the result may be regarded as permanent only after the third postoperative month [5, 6, 9]. The frontal area has the highest rate of MH relapse [5, 6, 9].

Furthermore, patients should be informed when signing the informed consent that deactivation of a MH trigger site may unmask secondary headaches in almost 17.8% of patients and that more than one surgery may be needed [9].
