Cosmetic The Lesser and Third Occipital Nerves and Migraine Headaches Krishna S. Dash, M.D., Jeffrey E. Janis, M.D., and Bahman Guyuron, M.D. Cleveland and Akron, Ohio; and Dallas, Texas Background: Reports of a correlation Results: The location of emergence of between relief of migraine headaches and the lesser occipital nerve was determined to resection of corrugator muscles or injec- be an area centered 65.4 Ϯ 11.6 mm from tion of botulinum A toxin have renewed midline and 53.3 Ϯ 15.6 mm below the line interest in finding the cause of migraine between the external auditory canals. The headaches and identifying the trigger sites. third occipital nerve was found 13.2 Ϯ 5.3 Four trigger sites have been described. One mm from midline and 62.0 Ϯ 20.0 mm down of these is along the course of the greater from the line between the two external au- occipital nerve. Recent anatomical studies ditory canals. of this nerve have defined its location with Conclusions: This information can be respect to external landmarks, leading to used to conduct clinical trials of chemoden- new studies with gratifying results. There is a ervation of these nerves in an attempt to elim- subset of patients who undergo chemoden- inate migraine symptoms in the subset of pa- ervation or surgical release of the greater oc- tients who continue to experience residual cipital nerve and note improvement or elim- symptoms after surgical release of the greater ination of the symptoms along the greater occipital nerve. (Plast. Reconstr. Surg. 115: occipital nerve course but who experience an 1752, 2005.) emergence of migraine headache symptoms laterally. The authors propose the lesser oc- cipital nerve as the source of pain in those who experience headaches laterally and in- Recent studies have challenged the traditional volvement of the third occipital nerve in teaching of exclusive centrally mediated activa- those who notice residual symptoms in the tion of migraine headaches, suggesting instead a midportion of the occipital region. major contribution from the peripheral trigger sites.1 Four such peripheral trigger sites have Methods: To test this hypothesis anatom- been described.4 Three of these areas (frontal, ically, 20 cadaver heads were dissected to temporal, and occipital) correspond to a partic- trace the course of the lesser occipital nerve ular sensory nerve (supraorbital/supratrochlear, and third occipital nerve and define the lo- zygomaticotemporal, and greater occipital, re- cation of these nerves with respect to ex- spectively) that is thought to be the cause of ternal landmarks. The midline and a line migraine symptoms originating from that lo- drawn between the inferiormost points of cation. The fourth trigger point corresponds the external auditory canals were used to to the nasal septum and turbinates. obtain standardized measurements of The senior author of this article (Guyuron) these nerves. has studied the first two trigger points (su- praorbital and zygomaticotemporal nerves) From Akron Summa Health Systems; the Department of Plastic Surgery, University of Texas Southwestern Medical Center; and Case Western Reserve University. Received for publication May 28, 2004; revised July 2, 2004. DOI: 10.1097/01.PRS.0000161679.26890.EE 1752 Vol. 115, No. 6 / OCCIPITAL NERVE STUDY 1753 and described the improvement or elimination for providing sensory innervation to the supe- of migraine headaches in patients who were rior ear, postauricular skin, and skin of the treated with injections of botulinum A toxin to lateral neck.5–8 The third occipital nerve is the the corrugator supercilii muscle, underwent dorsal ramus of C3. The third occipital nerve surgical resection of the corrugator supercilii provides sensory innervation to the medial pos- muscle, or underwent transection of the zygo- terior scalp and neck.5–7 Most anatomy text- maticotemporal nerve.1,2 A more recent study books do not provide detailed descriptions of guided by the senior author has examined the either the lesser occipital nerve or the third third trigger point, or occipital area, specifi- occipital nerve. However, there have been sev- cally identifying sites of muscular penetration eral sophisticated studies that have examined of the greater occipital nerve and external the course of these nerves through dissections landmarks important in locating these sites.3 from the root to the periphery. Most of these Results from this study revealed a consistent studies did not examine the nerves in relation location of muscular investment of the greater to external landmarks. Becser et al. conducted occipital nerve.3 As a result of this study, the one such anatomical study of the lesser occip- senior author has injected botulinum toxin A ital nerve in which they concluded that there into this area on patients who described mi- was wide variability in the location of this nerve graine symptoms originating from the occipital and, therefore, no single correct location at location. In patients who had a positive re- which to block it.9 The current study intends to sponse to these injections, a partial resection of reexamine the anatomy of the lesser occipital the semispinalis muscle was performed. In his nerve and the third occipital nerve, specifically most recent study, the senior author has de- with respect to muscle penetration and exter- scribed 34 such patients, 21 of whom experi- nal landmarks, and determine the consistency enced complete relief of migraine symptoms of this localization. after partial resection of the semispinalis mus- cle and 13 of whom experienced a decrease of at least 50 percent in either the severity or MATERIALS AND METHODS frequency of their migraines.4 Twenty fresh human cadaver heads were The symptoms of this latter group of 13 pa- used for this study. Each cadaver head was tients are the focus of the current study. It is marked in the following way: A fine hemostat our belief that the persistence of symptoms in was placed in each external auditory meatus at the occipital area despite adequate release of the inferiormost portion of the canal. A silk the greater occipital nerve is secondary to en- suture was used to connect these two points, trapment of other nerves in this area. Specifi- creating a transverse line across the occiput cally, the third occipital nerve, because of its that was illustrated with a marking pen. The proximity to the greater occipital nerve, is a spinous processes were used to identify the logical choice. Furthermore, in the 13 patients midline, and a vertical line was drawn connect- with persistent symptoms, some described a ing these processes. A 19-gauge needle dipped shifting of their symptoms laterally.4 This infor- in methylene blue was then inserted into the mation prompted an investigation of the lesser skin to mark the skin and subcutaneous tissues occipital nerve as well, because it is located along the course of both the transverse and lateral to the greater occipital nerve. Thus, the vertical lines (Fig. 1). purpose of the present study was to examine Both the vertical and horizontal lines were the anatomy of the third occipital nerve and incised and the skin flaps were raised (Fig. 2). lesser occipital nerve and to identify external Next, the trapezius muscle was elevated in a landmarks and the muscles that they pierce to medial to lateral direction. Similarly, the sple- reach the subcutaneous plane, to aid in the nius muscle and semispinalis muscle were treatment of these areas through either che- raised as separate muscle flaps (Fig. 3). On modenervation or surgical release. In addition, each side, the distance from the greater occip- the anatomy of the greater occipital nerve was ital nerve to the vertical and horizontal lines reexamined to confirm the previous findings. was calculated. Also determined was whether the nerve pierced the trapezius muscle or the PERTINENT ANATOMY semispinalis muscle and, if so, the location of The lesser occipital nerve is the ventral ra- this muscular investment. During this part of mus of C2 and sometimes C3. It is responsible the dissection, the third occipital nerve was 1754 PLASTIC AND RECONSTRUCTIVE SURGERY, May 2005 FIG. 1. Marking of a cadaver head. Inferiormost position of each external auditory canal was used to draw the trans- verse line, whereas the spinous processes were used to draw FIG. 3. Trapezius and splenius muscle flaps raised to re- the vertical line. These lines were marked transcutaneously veal the semispinalis muscle. Note the greater occipital nerve with a 19-gauge needle. (GON) penetrating the semispinalis muscle. FIG. 2. Elevated skin and subcutaneous tissue. FIG. 4. Dissection of the greater occipital nerve (GON) and the third occipital nerve (TON). found and its location as it pierced the semi- RESULTS spinalis muscle was recorded (Fig. 4). Atten- tion was then turned laterally. The lesser occip- Greater Occipital Nerve ital nerve was located as it emerged from the The greater occipital nerve was found on posterior border of the sternocleidomastoid both sides of 19 cadavers. In the remaining muscle (Fig. 5). The precise location of its cadaver, the muscles had been damaged cen- emergence was then determined by calculating trally. In all cases in which the nerve was found, the distance from the lesser occipital nerve to the greater occipital nerve was found to pierce the vertical and horizontal lines. the semispinalis capitis muscle. In one cadaver, Vol. 115, No. 6 / OCCIPITAL NERVE STUDY 1755 TABLE I Greater Occipital Nerve* Left Right Mean horizontal distance to midline, mm 11.0 11.8 Median horizontal distance, mm 11.5 11 Range, mm 0–17 8–28 SD, mm 4.8 4.6 Mean vertical distance from line between the external auditory canals, mm 26 27 Median vertical distance, mm 28.5 30 Range, mm 7–37 9–43 SD, mm 9.6 11.7 Percentage piercing the semispinalis muscle 100 100 * Data are from 19 cadavers.