Neurovascular compression of the greater occipital nerve: implications for migraine headaches

Migraine/Headache "Tender Spots" Represent Referred Pain From Nerve Compression/Neuromas and Are Not "Trigger Points"

ABSTRACT

To minimize confusion in description of the clinical examination of the patient with migraine/headaches and implement peripheral nerve concepts into the surgical approach to treating the patient with migraines, the historical origin of the phrase "trigger point" is explored. The symptoms of migraine/headache are due to stimulation of the cranial/peripheral nerve being interpreted as due to stimulation of the meningeal innervation. Use of the phrase "extraction of trigger points" is discouraged in favor of either neurolysis of a compressed nerve or resection of a neuroma, depending upon the peripheral nerve pathology.

An anatomical analysis of the occipital nerve complex: an essential tool for the application of occipital nerve blocks

BACKGROUND

Occipital nerve blocks are essential in diagnosing and treating headache disorders such as migraine, cervicogenic headache, occipital neuralgia, and cluster headache. In this study, we aimed to investigate the potential compression points of the greater occipital nerve (GON), third occipital nerve (TON), and lesser occipital nerve (LON) which are targeted to block in occipital nerve blocks and to develop a method to detect these points easily.

METHODS

To identify potential compression points of the GON, TON, and LON, we dissected 43, 41, and 26 cadavers, respectively. A rigid, transparent tool divided into 1 × 1 cm sections was placed on the external occipital protuberance to measure the determined points. The cadaveric head was viewed from above, vertically, and the coordinates corresponding to each point were noted separately.

RESULTS

Six, four, and one potential entrapment points were detected for the GON, TON, and LON, respectively. The distances of the point where the GON arose from the lower border of the obliquus capitis inferior muscle and the emerging point of the TON from the C2-C3 vertebrae to the posterior midline were statistically significant in terms of the sides (p = 0.040). Similarly, there was a statistical significance between genders for the distance of the point where the LON arose from the posterior edge of the sternocleidomastoid muscle to the posterior midline (p = 0.002).

CONCLUSIONS

We believe that with the method developed, the GON, TON, and LON compression points can be easily localized and blocked in diagnosing and treating patients experiencing headaches such as migraines, cervicogenic headaches, occipital neuralgia, and cluster headache.

Aetiologies of iatrogenic occipital nerve injury and outcomes following treatment with nerve decompression surgery

INTRODUCTION

This study analyzed the etiologies and treatment of iatrogenic occipital nerve injuries.

METHODS

Patients with occipital neuralgia (ON) who were screened for occipital nerve decompression surgery were prospectively enrolled. Patients with iatrogenic occipital nerve injuries who underwent nerve decompression surgery were identified. Data included surgical history, pain characteristics, and surgical technique. Outcomes included pain frequency (days/month), duration (h/day), intensity (0-10), migraine headache index (MHI), and patient-reported percent-resolution of pain.

RESULTS

Among the 416 patients with ON, who were screened for occipital nerve decompression surgery, 12 (2.9%) cases of iatrogenic occipital nerve injury were identified and underwent surgical treatment. Preoperative headache frequency was 30 (±0.0) days/month, duration was 19.4 (±6.9) h, and intensity was 9.2 (±0.9). Neuroma excision was performed in 5 cases followed by targeted muscle reinnervation in 3, nerve cap in 1, and muscle burial in 1. In patients without neuromas, greater occipital nerve decompression and/or lesser occipital nerve neurectomy were performed. At the median follow-up of 12 months (IQR 12-12 months), mean pain frequency was 4.0 (±6.6) pain days/month (p < 0.0001), duration was 6.3 (±8.9) h (p < 0.01), and intensity was 4.4 (±2.8) (p < 0.001). Median patient-reported resolution of pain was 85% (56.3%-97.5%) and success rate was (≥50% MHI improvement) 91.7%.

CONCLUSIONS

Iatrogenic occipital nerve injuries can be caused by various surgical interventions, including craniotomies, cervical spine interventions, and scalp tumor resections. The associated pain can be severe and chronic. Iatrogenic ON should be considered in the differential diagnosis of post-operative headaches and can be treated with nerve decompression surgery or neuroma excision with reconstruction of the free nerve end.

Localization of the greater occipital nerve through palpation of bony landmarks: A cadaveric study

OBJECTIVE

to provide anatomic confirmation that standard methods which practitioners skilled in palpation use, can reliably identify the most likely site of emergence of the greater occipital nerve in most patients. The location and frequency of subcutaneous emergence of the greater occipital nerve and occipital artery with respect to the external occipital protuberance-mastoid line are reported.

METHODS

The external occipital protuberance and the mastoid processes were identified by palpation bilaterally on 57 body donors and the medial trisection point of a line connecting these bony landmarks was identified. A 4 cm circular dissection guide divided into 4 quadrants was centered on the trisection point and used to guide the removal of a circle of skin. The in-situ location of the nerve and artery were exposed by deep dissection within the circle. The frequency of the emergence and occurrence of the nerve and artery by quadrant were analyzed.

RESULTS

In 114 total dissections the greater occipital nerve was found to emerge within the circle 96 times (84%) and the occipital artery 100 times (88%). The nerve (90%) and artery (81%) emerged from the two inferior quadrants most of the time with no difference noted between male and female donors. The greater occipital nerve and occipital artery were found to emerge together most commonly in inferior lateral quadrant. Branches of the nerve and artery traveled together most frequently through the two lateral quadrants.

CONCLUSION

This study confirmed that the medial trisection point of the external occipital protuberance-mastoid line can be located via palpation and reliably used to pinpoint the subcutaneous emergence of the greater occipital nerve and occipital artery in most individuals. When relying on palpation alone to identify the trisection point in the clinic, infusion of nerve block inferior and lateral to this point is most likely to bathe the greater occipital nerve in anesthetic.

A rare variation of the infraorbital nerve, entrapping the infraorbital artery

Anatomical variations are a common feature of the human anatomy. Variation can explain some pathological conditions and is important to keep them in mind during surgical procedures. The relations between nerves and their adjacent arteries have been proposed to play a role in the generation of peripheral trigger migraines. Close opposition between nerves and arteries can lead to vascular compression of the nerve that triggers episodes of pain. We did a routine dissection of the infratemporal fossa and orbital floor by opening the maxillary sinus. Here we report a case where the infraorbital nerves form a nervous loop entrapping the infraorbital artery in the infraorbital channel. Similar cases of close nervous and arterial apposition are described for the auriculotemporal and occipital nerves. We think that accumulating knowledge of these rare variations could expand our understanding of rare conditions such as primary infraorbital neuralgia.

Therapeutic Options for Migraines in the Microsurgical Patient: A Scoping Review

BACKGROUND

There exists an increasing array of treatments proposed to prevent, alleviate, and abort symptoms of a migraine; however, for patients who undergo reconstructive microsurgery, caution must be taken to preserve vascular integrity. This study is the first-to-date scoping review of vascular and bleeding risk of current migraine therapies, with the purpose of identifying potential therapeutic agents for postoperative migraine management appropriate for microsurgical patients.

METHODS

Currently available migraine therapeutics were compiled from the UpToDate software system and the American Academy of Family Physicians. A PubMed literature review was performed for each therapeutic's effect on bleeding or vascular involvement. Data were compiled into tables of abortive, symptom-controlling and prophylactic, and nonpharmacologic treatments. Expert microsurgeons reviewed the data to provide recommendations for optimized patient care.

RESULTS

Triptans and other ergot derivatives demonstrated strong evidence of vasoconstriction and were greatly advised against for immediate postmicrosurgical use. Novel pharmaceutical therapies such as lasmiditan and calcitonin gene-related peptide antagonists have no literature indicating potential for vasoconstriction or hematoma and remain an investigational option for abortive medical treatment. For symptom control, acetaminophen appears the safest option, with clinical judgment and further research needed for use of nonsteroidal antiinflammatory drugs. Alternative treatment techniques may include migraine prophylaxis with botulinum toxin injection or nutraceutical treatment by means of magnesium supplementation or coenzyme Q10 administration, minimizing the need for additional medication in the postoperative setting.

CONCLUSIONS

Patients undergoing reconstructive microsurgery have a unique medical profile limiting the therapeutic options available to treat migraines. This review provides preliminary evidence to be considered as a guide for prescribing therapeutics for migraine in the postoperative setting.

Using optical coherence tomography and optical coherence tomography angiography to delineate neurovascular homeostasis in migraine: a review

Migraine is one of the world's most debilitating disorders, and it has recently been shown that changes in the retina can be a potential biomarker for the disease. These changes can be detected by optical coherence tomography (OCT), which measures retinal thickness, and optical coherence tomography angiography (OCTA), which measures vessel density. We searched the databases Google Scholar, ProQuest, Scopus, and Web of Science for studies in English using OCT and OCTA in migraineurs, using the search terms "optical coherence tomography," "OCT," "optical coherence tomography angiography," "OCTA" and "migraine." We found 73 primary studies, 11 reviews, and 8 meta-analyses pertaining to OCT and OCTA findings in migraineurs. They showed that migraineurs had reduced retinal thickness (via OCT), retinal vessel density, and greater foveal avascular zone area (via OCTA) than controls. OCTA changes reflect a perfusion compromise occurring in migraineurs as opposed to in healthy controls. OCT and OCTA deficits were worse in migraine-with-aura and chronic migraine than in migraine-without-aura and episodic migraine. Certain areas of the eye, such as the fovea, may be more vulnerable to these perfusion changes than other parts. Direct comparison between study findings is difficult because of the heterogeneity between the studies in terms of both methodology and analysis. Moreover, as almost all case-control studies were cross-sectional, more longitudinal cohort studies are needed to determine cause and effect between migraine pathophysiology and OCT/OCTA findings. Current evidence suggests both OCT and OCTA may serve as retinal markers for migraineurs, and further research in this field will hopefully enable us to better understand the vascular changes associated with migraine, perhaps also providing a new diagnostic and therapeutic biomarker.

Correspondence: Morphological features of the greater occipital nerve and its possible importance for interventional procedures

This response applauds Saglam et al.'s (2023) recent study on the greater occipital nerve's anatomy while urging readers to consider earlier pivotal studies overlooked. It emphasizes how prior research has significantly shaped headache treatments and provides valuable insights for future practices and discussions.

Secondary Trigger Point Deactivation Surgery for Nerve Compression Headaches: A Scoping Review

Background

Primary trigger point deactivation surgery has been successful in reducing or eliminating nerve compression headaches between 79% and 90% of the time. The aim of this review article was to discuss the factors that contribute to index trigger point deactivation surgery failure, the importance of reevaluating trigger points following failure, and the options for secondary surgery.

Methods

A literature search was performed using a combination of keywords involving "chronic headache" and "nerve deactivation surgery," in databases until February 2023.

Results

Data of 1071 patients were evaluated and included (11 articles). The failure rate after index trigger point deactivation surgery occurs is approximately 12%, primarily due to incomplete primary trigger point deactivation. Secondary trigger points may not appear until the primary trigger is eliminated, which occurs in 17.8% of patients. Reevaluation of previously diagnosed trigger points as well as uncovered trigger points and additional preoperative testing is indicated to help determine candidacy for further surgical deactivation. To address scarring that could contribute to failure, corticosteroid injection, acellular dermal matrix, adipofascial fat, or expanded polytetrafluoroethylene sleeves have been described with beneficial effects. For neuroma management, regenerative peripheral nerve interface, targeted muscle reinnervation, a combination of both, relocation nerve grafting, or nerve capping have also been described. Neurectomy can be performed when patients prefer anesthesia and/or paresthesia over current pain symptoms.

Conclusion

Secondary trigger point deactivation surgery is indicated when there is suspicion of incomplete deactivation, internal scarring, neuroma, or newly-diagnosed trigger points.

Functional outcomes between headache surgery and targeted botox injections: A prospective multicenter pilot study

Introduction

Chronic migraine headaches (MH) are a principal cause of disability worldwide. This study evaluated and compared functional outcomes after peripheral trigger point deactivation surgery or botulinum neurotoxin A (BTA) treatment in patients with MH.

Methods

A long-term, multicenter, and prospective study was performed. Patients with chronic migraine were recruited at the Ohio State University and Massachusetts General Hospital and included in each treatment group according to their preference (BTA or surgery). Assessment tools including the Migraine Headache Index (MHI), Migraine Disability Assessment Questionnaire (MIDAS) total, MIDAS A, MIDAS B, Migraine Work and Productivity Loss Questionnaire-question 7 (MWPLQ7), and Migraine-Specific Quality of Life Questionnaire (MSQ) version 2.1 were used to evaluate functional outcomes. Patients were evaluated prior to treatment and at 1, 2, and 2.5 years after treatment.

Results

A total of 44 patients were included in the study (surgery=33, BTA=11). Patients treated surgically showed statistically significant improvement in headache intensity as measured on MIDAS B (p = 0.0464) and reduced disability as measured on MWPLQ7 (p = 0.0120) compared to those treated with BTA injection. No statistical difference between groups was found for the remaining functional outcomes. Mean scores significantly improved over time independently of treatment for MHI, MIDAS total, MIDAS A, MIDAS B, and MWPLQ 7 (p<0.05). However, no difference in mean scores over time was observed for MSQ.

Conclusions

Headache surgery and targeted BTA injections are both effective means of addressing peripheral trigger sites causing headache pain. However, lower pain intensity and work-related disabilities were found in the surgical group.

Neurovascular Compression-Induced Intracranial Allodynia May Be the True Nature of Migraine Headache: an Interpretative Review

PURPOSE OF REVIEW

Surgical deactivation of migraine trigger sites by extracranial neurovascular decompression has produced encouraging results and challenged previous understanding of primary headaches. However, there is a lack of in-depth discussions on the pathophysiological basis of migraine surgery. This narrative review provides interpretation of relevant literature from the perspective of compressive neuropathic etiology, pathogenesis, and pathophysiology of migraine.

RECENT FINDINGS

Vasodilation, which can be asymptomatic in healthy subjects, may produce compression of cranial nerves in migraineurs at both extracranial and intracranial entrapment-prone sites. This may be predetermined by inherited and acquired anatomical factors and may include double crush-type lesions. Neurovascular compression can lead to sensitization of the trigeminal pathways and resultant cephalic hypersensitivity. While descending (central) trigeminal activation is possible, symptomatic intracranial sensitization can probably only occur in subjects who develop neurovascular entrapment of cranial nerves, which can explain why migraine does not invariably afflict everyone. Nerve compression-induced focal neuroinflammation and sensitization of any cranial nerve may neurogenically spread to other cranial nerves, which can explain the clinical complexity of migraine. Trigger dose-dependent alternating intensity of sensitization and its synchrony with cyclic central neural activities, including asymmetric nasal vasomotor oscillations, may explain the laterality and phasic nature of migraine pain. Intracranial allodynia, i.e., pain sensation upon non-painful stimulation, may better explain migraine pain than merely nociceptive mechanisms, because migraine cannot be associated with considerable intracranial structural changes and consequent painful stimuli. Understanding migraine as an intracranial allodynia could stimulate research aimed at elucidating the possible neuropathic compressive etiology of migraine and other primary headaches.

Feasibility of Ultrasound Measurements of Peripheral Sensory Nerves in Head and Neck Area in Healthy Subjects

Background

Current diagnostic methods for nerve compression headaches consist of diagnostic nerve blocks. A less-invasive method that can possibly aid in the diagnosis is ultrasound, by measuring the cross-sectional area (CSA) of the affected nerve. However, this technique has not been validated, and articles evaluating CSA measurements in the asymptomatic population are missing in the current literature. Therefore, the aim of this study was to determine the feasibility of ultrasound measurements of peripheral extracranial nerves in the head and neck area in asymptomatic individuals.

Methods

The sensory nerves of the head and neck in healthy individuals were imaged by ultrasound. The CSA was measured at anatomical determined measurement sites for each nerve. To determine the feasibility of ultrasound measurements, the interrater reliability and the intrarater reliability were determined.

Results

In total, 60 healthy volunteers were included. We were able to image the nerves at nine of 11 measurement sites. The mean CSA of the frontal nerves ranged between 0.80 ± 0.42 mm2 and 1.20 ± 0.43 mm2, the mean CSA of the occipital nerves ranged between 2.90 ± 2.73 mm2 and 3.40 ± 1.91 mm2, and the mean CSA of the temporal nerves ranged between 0.92 ± 0.26 mm2 and 1.40 ± 1.11 mm2. The intrarater and interrater reliability of the CSA measurements was good (ICC: 0.75-0.78).

Conclusions

Ultrasound is a feasible method to evaluate CSA measurements of peripheral extracranial nerves in the head and neck area. Further research should be done to evaluate the use of ultrasound as a diagnostic tool for nerve compression headache.

Long-term results of migraine surgery and the relationship between anatomical variations and pain

BACKGROUND

Migraine headache surgery has been recently reported and supported by studies as management to provide long-term relief in migraine sufferers. This study aimed to monitor the long-term results of patients who underwent migraine surgery in our clinic and determine the relationship between pain and anatomical anomalies.

METHODS

A prospective review was conducted of 93 patients who underwent surgery for migraine headaches performed between 2017 and 2021 by the senior author (M.U.) and had at least 12 months of follow-up. Anatomical data were obtained by recording the findings during surgery. Migraine surgery was performed bilaterally in all patients. Anatomical symmetry differences between the right and left sides were recorded.

RESULTS

A total of 79 (84.9%) patients experienced at least 50% reduction in migraine headache. Furthermore, 13 (14%) patients reported complete elimination of migraine headache. A significant difference was found before and after surgery in Migraine Disability Assessment score, migraine headache index, frequency, duration, and pain (p < 0.001). Also, 30 (32.3%) of the patients had bilateral headaches and 63 (67.7%) had primarily unilateral headaches. Then, 51 (81%) patients with mostly unilateral headache were anatomically asymmetrical and 12 (12%) were anatomically symmetrical. Patients with mostly unilateral headache were found to be anatomically highly asymmetrical (p < 0.005).

CONCLUSIONS

This study shows that surgical treatment is effective and long-term protection and has mild complications that are easily tolerated by the patient. The fact that headache side and anatomical asymmetry were significant in this study supports the peripheral mechanism.

Minimally Invasive Nerve- and Muscle-Sparing Surgical Decompression for Occipital Neuralgia

BACKGROUND

Occipital neuralgia is a well-defined type of headache, and its treatment algorithm is still debated across medical specialties. From the analysis of the literature, it appears that surgical decompression of the occipital nerves is the most effective invasive approach to improve the quality of life of patients with occipital neuralgia refractory to medications. The authors describe here a minimally invasive nerve- and muscle-sparing technique to decompress the occipital nerves.

METHODS

The results in terms of reduction of migraine days per month, use of medications, pain evaluation, and decrease in Migraine Headache Index were analyzed by means of a retrospective chart review of 87 patients who underwent nerve- and muscle-sparing surgical decompression of the greater and lesser monolateral or bilateral occipital nerves in their institution and were followed up for at least 12 months. The surgical technique is described in detail.

RESULTS

Surgical decompression significantly reduced occipital neuralgia burden (at least 50% improvement) in 91% of patients, with 45% reporting a complete remission of occipital pain. Days with pain per month decreased by 80%, chronic background pain intensity decreased by 81%, and pain intensity during crisis decreased by 76%. Accordingly, drug use dropped by approximately 70%. Only minor complications were reported in four patients.

CONCLUSIONS

The described technique could contribute to and further support surgical decompression as the first option among the invasive approaches to treat occipital neuralgia. Results corroborate previous findings, adding a less-invasive, nerve- and muscle-sparing approach.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

The occipital artery: a meta-analysis of its anatomy with clinical correlations

The occipital artery arises as one of the main branches of the external carotid artery. The goal of the present meta-analysis was to provide a detailed analysis of the complete anatomy of the occipital artery using the available data in the literature. The main online medical databases such as PubMed, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar were used to gather all studies on anatomical variations, course, branches, and the close anatomical area of the occipital artery. A total of 65 studies were indicated, evaluated, and included in this meta-analysis. The occipital artery was found to run in the groove with a prevalence of 83.93% (95% confidence intervals: 50.53-100.00%). The occipital artery forming a common trunk with another artery had a prevalence of 13.91% (95% confidence intervals: 9.15-19.47%). The mean maximal diameter of the occipital artery was set to 2.26 mm (standard error = 0.15). The mean maximal diameter of the occipital segment of the occipital artery was found to be 1.24 mm (standard error = 0.15). The mean occipital artery length was set to 131.93 mm (standard error = 3.02). In conclusion, the authors of the present study believe that this is the most accurate and up-to-date meta-analysis regarding the anatomy of the occipital artery. Knowledge about this structure can be of great use when performing revascularization procedures, such as the occipital artery-posterior inferior cerebellar artery bypass, or reconstructive procedures, such as the occipital artery fascial flap.

Increasing Collaboration between Headache Medicine and Plastic Surgery in the Surgical Management of Chronic Headache

Introduction

Chronic headache is one of the most disabling conditions afflicting humankind. The management of chronic headaches has, to date, been only partially successful. The goal of this paper is to highlight the importance of collaboration between surgeons and headache physicians in treating this condition.

Methods

We present a narrative review of migraine pathophysiology, its medical and surgical treatment options, and the important role of collaboration between headache physicians and surgeons.

Results

Migraine headaches can be treated with both medication-based regimens and surgery. Novel medications such monoclonal antibodies directed at the CGRP molecule or its receptor have recently been FDA approved as an effective treatment modality in chronic migraines. However, these medications are associated with a high cost, and there is a paucity in data regarding effectiveness compared to other treatment modalities. The pathophysiology of headache likely exists along a spectrum with peripheral - extracranial and meningeal - factors at one end and central - brain - factors at the other, with anatomic and physiologic connections between both ends. Recent evidence has clearly shown that surgical decompression of extracranial nerves improves headache outcomes. However, appropriate patient selection and preoperative diagnosis are of paramount importance to achieve excellent outcomes.

Conclusions

Surgeons and headache physicians who are interested in providing treatment for patients with chronic headache should strive to form a close collaboration with each other in order to provide the optimal plan for migraine/headache patients.

Nonsurgical Treatment of Neuralgia and Cervicogenic Headache: A Systematic Review and Meta-analysis

Background:

Extracranial compression of peripheral sensory nerves is one of many origins of chronic headaches. Identifying these patients can be difficult, and they are often diagnosed with neuralgia or cervicogenic headache. The recent literature provides the outcomes of surgical decompression in patients with these headaches. This study aimed to give an overview of the current literature on the nonsurgical treatment options and to evaluate the effectiveness of these treatments in patients with neuralgia and cervicogenic headache.

Methods:

Databases were searched to identify all published clinical studies investigating nonsurgical treatment outcomes in patients with neuralgia or cervicogenic headaches. Studies that reported numerical pain scores, nonnumerical pain scores, headache-free days, or the number of adverse events after nonsurgical treatment were included.

Results:

A total of 22 articles were included in qualitative analysis. The majority of studies included patients who received injection therapy. Treatment with oral analgesics achieved good results in only 2.5% of the patients. Better outcomes were reported in patients who received local anesthetics injection (79%) and corticosteroid injection (87%). Treatment with botulinum toxin injection yielded the highest percentage of good results (97%; 95% CI, 0.81–1.00). The duration of headache relief after injection therapy varied from 30 minutes to 5 months.

Conclusions:

The nonsurgical treatment of patients with neuralgia or cervicogenic headache is challenging. Injection therapy in patients with these types of headaches achieved good pain relief but only for a limited time. Surgical decompression may result in long-lasting pain relief and might be a more sustainable treatment option.

Single midline incision approach for decompression of greater, lesser and third occipital nerves in migraine surgery

Background

The traditional approach for occipital migraine surgery encompasses three separate surgical incisions in the posterior neck to decompress the greater occipital nerves (GON), lesser occipital nerves (LON), and third occipital nerves (TON). Other incisions have been investigated, including singular transverse incisions. We sought to evaluate a single, vertical midline incision approach for decompression of all six occipital nerves.

Methods

Using 10 cadaveric hemi-sides (5 fresh cadaver head and necks). Anatomic landmarks and the location of the bilateral GON, LON, and TON were marked according to previous anatomic studies. A single, midline 9-cm incision was made, and lateral skin flaps were raised to decompress or avulse all six nerves.

Results

Through the midline incision, the GON and TON were identified at 3.5 and 6.2 cm, respectively, inferior to a line bisecting the external auditory canal (EAC) and 1.5 cm lateral to the midline. The LON was identified as 6-cm inferior and 6.5-cm medial to a line bisecting the EAC in the plane just above the investing layer of the deep cervical fascia until the posterior border of the sternocleidomastoid was encountered. The LON had the greatest amount of variation but was identified lateral to the posterior border of the SCM.

Conclusions

A single midline incision approach allows for successful identification and decompression of all six occipital nerves in migraine surgery.

The Greater Occipital Nerve and Its Dynamic Compression Points: Implications in Migraine Surgery

BACKGROUND

The greater occipital nerve is a common compression site for migraine or chronic headache, and variable relationships with the occipital artery have been shown in anatomical studies. Despite surgical decompression, there are still a subset of patients who have an incomplete response. In this article, the authors describe an observed clear and very consistent pattern between the nerve and artery, including both dynamic and static compression points, that must be evaluated for adequate treatment.

METHODS

Seventy-one patients underwent occipital nerve decompression with high-definition videos and photographs, and the dynamic relationship between the greater occipital nerve and the occipital artery was recorded in a retrospective review.

RESULTS

A consistent pattern existed in 92 percent of patients, as follows: (1) hidden proximal dynamic compression of the bottom surface of the nerve as the occipital artery comes laterally to dive under the greater occipital nerve; (2) more apparent dynamic compression on the upper surface of the nerve as the occipital artery loops back on top of the greater occipital nerve; (3) intertwining compression after the bifurcation of the greater occipital nerve as the artery wraps around the medial branch; and (4) parallel travel of the terminal branch of the greater occipital nerve with the occipital artery in close proximity.

CONCLUSIONS

There is a consistent pattern in the relationship between the greater occipital nerve and the occipital artery after its exit from the trapezius fascia. It is possible that this relationship creates dynamic compression points, including hidden areas, that can only be deactivated by radical excision of the vessel.

RPNI, TMR, and Reset Neurectomy/Relocation Nerve Grafting after Nerve Transection in Headache Surgery

In the context of headache surgery, greater occipital nerve (GON) transection is performed when the nerve appears severely damaged, if symptoms are recurrent or persistent, and when neuromas are excised. Lesser occipital nerve (LON) excision is commonly performed during the primary decompression surgery. Advanced techniques to address the proximal nerve stump after nerve transection such as regenerative peripheral nerve interface (RPNI), targeted muscle reinnervation (TMR), relocation nerve grafting, and reset neurectomy have been shown to improve chronic pain and neuroma formation. These techniques have not been described in the head and neck region.

Efficacy and Safety of Migraine Surgery: A Systematic Review and Meta-analysis of Outcomes and Complication Rates

OBJECTIVE

The objectives of this study are to assess the efficacy and safety of peripheral nerve surgery for migraine headaches and to bibliometrically analyze all anatomical studies relevant to migraine surgery.

SUMMARY BACKGROUND DATA

Migraines rank as the second leading cause of disability worldwide. Despite the availability of conservative management options, individuals suffer from refractive migraines which are associated with poor quality of life. Migraine surgery, defined as the peripheral nerve decompression/trigger site deactivation, is a relatively novel treatment strategy for refractory migraines.

METHODS

EMBASE and the National Library of Medicine (PubMed) were systematically searched for relevant articles according to the PRISMA guidelines. Data was extracted from studies which met the inclusion criteria. Pooled analyses were performed to assess complication rates. Meta-analyses were run using the random effects model for overall effects and within subgroup fixed-effect models were used.

RESULTS

A total of 68 studies (38 clinical, 30 anatomical) were included in this review. There was a significant overall reduction in migraine intensity (P < 0.001, SE = 0.22, I2 = 97.9), frequency (P < 0.001, SE = 0.17, I2 = 97.7), duration (P < 0.001, SE = 0.15, I2 = 97), and migraine headache index (MHI, P < 0.001, SE = 0.19, I2 = 97.2) at follow-up. A total of 35 studies reported on migraine improvement (range: 68.3%-100% of participants) and migraine elimination (range: 8.3%-86.5% of participants). 32.1% of participants in the clinical studies reported complications for which the most commonly reported complications being paresthesia and numbness, which was mostly transient, (12.11%) and itching (4.89%).

CONCLUSION

This study demonstrates improved migraine outcomes and an overall decrease in MHI as well as strong evidence for the safety profile and complication rate of migraine surgery.

The Great Auricular Nerve Trigger Site: Anatomy, Compression Point Topography, and Treatment Options for Headache Pain

BACKGROUND

Peripheral nerve decompression surgery can effectively address headache pain caused by compression of peripheral nerves of the head and neck. Despite decompression of known trigger sites, there are a subset of patients with trigger sites centered over the postauricular area coursing. The authors hypothesize that these patients experience primary or residual pain caused by compression of the great auricular nerve.

METHODS

Anatomical dissections were carried out on 16 formalin-fixed cadaveric heads. Possible points of compression along fascia, muscle, and parotid gland were identified. Ultrasound technology was used to confirm these anatomical findings in a living volunteer.

RESULTS

The authors' findings demonstrate that the possible points of compression for the great auricular nerve are at Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle in the dense connective tissue before entry into the parotid gland (point 2), and within its intraparotid course (point 3). The mean topographic measurements were as follows: Erb's point to the mastoid process at 7.32 cm/7.35 (right/left), Erb's point to the angle of the mandible at 6.04 cm/5.89 cm (right/left), and the posterior aspect of the sternocleidomastoid muscle to the mastoid process at 3.88 cm/4.43 cm (right/left). All three possible points of compression could be identified using ultrasound.

CONCLUSIONS

This study identified three possible points of compression of the great auricular nerve that could be decompressed with peripheral nerve decompression surgery: Erb's point (point 1), at the anterior border of the sternocleidomastoid muscle (point 2), and within its intraparotid course (point 3).

Neuroma of The Supraorbital Nerve Following Forehead Flap Reconstruction - Presentation and Surgical Management

ABSTRACT

Localized pain or headache from neuroma formation is a rare and challenging complication of forehead flap surgery. Here the authors present a patient who developed local pain and dysesthesia following iatrogenic injury to the left supraorbital nerve during forehead flap elevation. Following a diagnostic nerve block in clinic, surgical excision of the neuroma was performed through an upper blepharoplasty approach. The patient had immediate postoperative pain relief and remains pain free at fifteen-month follow-up. The authors describe etiology, workup, and surgical management of sensory nerve injury during forehead flap reconstruction.

Trigger-Site Deactivation Surgery for Nerve Compression Headaches

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Identify patients who are candidates for headache surgery. 2. Counsel the patient preoperatively with regard to success rates, recovery, and complications. 3. Develop a surgical plan for primary and secondary nerve decompression. 4. Understand the surgical anatomy at all trigger sites. 5. Select appropriate International Classification of Diseases, Tenth Revision, and CPT codes.

SUMMARY

Headache surgery encompasses release of extracranial peripheral sensory nerves at seven sites. Keys to successful surgery include correct patient selection, detailed patient counseling, and meticulous surgical technique. This article is a practical step-by-step guide, from preoperative assessment to surgery and postoperative recovery. International Classification of Diseases, Tenth Revision, and CPT codes, in addition to complications and salvage procedures, are discussed. Intraoperative photographs, videos, and screening questionnaires are provided.

The Evolution of Migraine Surgery: Two Decades of Continual Research. My Current Thoughts

SUMMARY

A mere serendipitous finding has culminated in a life-changing development for patients and a colossally fulfilling field for many surgeons. The surgical treatment of migraine headaches has been embraced by many plastic surgeons after numerous investigations ensuring that the risks are minimal and the rewards inestimable. Seldom has a plastic surgery procedure been the subject of such scrutiny. Through retrospective, prospective pilot, prospective randomized, prospective randomized with sham surgery, and 5-year follow-up studies, the safety, efficacy, and longevity of the given operation have been confirmed. Although the first decade of this journey was focused on investigating effectiveness and risk profile, the second decade was largely devoted to improving results, reducing invasiveness, and shortening recovery. Multiple publications in peer-reviewed journals over the past 20 years, several independent studies from reputable surgeons at recognized centers, and over 40 studies from the author's center have established the surgical treatment of headaches as a standard practice.

Surgical Management of Occipital Neuralgia: A Systematic Review of the Literature

BACKGROUND

Occipital neuralgia (ON) is a primary headache disorder characterized by severe, paroxysmal, shooting or stabbing pain in the distribution of the greater occipital, lesser occipital, and/or third occipital nerves. Both medical and surgical options exist for treating headaches related to ON. The purposes of this study are to summarize the current state of surgical ON management through a systematic review of the literature and, in doing so, objectively identify future directions of investigation.

METHODS

We performed a systematic review of primary literature on surgical management for ON of at least level IV evidence. Included studies were analyzed for level of evidence, therapeutic intervention, study design, sample size, follow-up duration, outcomes measured, results, and risk of bias.

RESULTS

Twenty-two studies met the inclusion criteria. All 22 studies used patient-reported pain scores as an outcome metric. Other outcome metrics included complication rates (7 studies; 32%), patient satisfaction (7 studies; 32%), quality of life (7 studies; 18%), and analgesic usage (3 studies; 14%). Using the ROBINS-I tool for risk of bias in nonrandomized studies, 7 studies (32%) were found to be at critical risk of bias, whereas the remaining 15 studies (68%) were found to be at serious risk of bias.

CONCLUSIONS

Greater occipital nerve decompression seems to be a useful treatment modality for medically refractory ON, but further prospective, randomized data are required.

Muscle Fascia Changes in Patients with Occipital Neuralgia, Headache, or Migraine

SUMMARY

In an ongoing effort to understand the pathogenesis of occipital neuralgia/headache/migraine, it is critical to describe the anatomical/tissue changes encountered during surgery. Greater occipital nerve anatomical studies mainly focus on the greater occipital nerve course through muscle/fascial planes and interaction with the occipital vessels. However, structural soft-tissue changes have not been described in detail. Anecdotally, trapezius fascia is thickened at the greater occipital nerve trigger site. This study further investigates this observation. Patients undergoing greater occipital nerve decompression surgery were enrolled prospectively in this observational study (n = 92). Tissue changes were recorded intraoperatively. The resulting data were examined. Trapezius fascia was more than 3 mm thick and appeared fibrotic in 86 patients (94 percent), whereas semispinalis muscle appeared normal in all subjects. The greater occipital nerve was macroscopically abnormal, defined as edematous, flattened, and discolored in 29 cases (32 percent). The occipital artery interacted significantly with the greater occipital nerve in 88 percent of cases. The authors conclude that the tissue structure is abnormal in patients undergoing greater occipital nerve decompression surgery. This is the first study that describes the prevalence of thickened and fibrotic appearing trapezius fascia at the occipital trigger site, a phenomenon encountered in the vast majority of patients (94 percent). This structural anomaly has a resemblance to thickened fascial tissues seen in other nerve compression syndromes, and could be related to microtrauma/overuse or actual trauma in the head and neck region.

A Comprehensive Review of Surgical Treatment of Migraine Surgery Safety and Efficacy

BACKGROUND

Recent clinical experience with migraine surgery has demonstrated both the safety and the efficacy of operative decompression of the peripheral nerves in the face, head, and neck for the alleviation of migraine symptoms. Because of the perceived novelty of these procedures, and the paranoia surrounding a theoretical loss of clinical territory, neurologists have condemned the field of migraine surgery. The Patient Safety Subcommittee of the American Society of Plastic Surgeons ventured to investigate the published safety track record of migraine surgery in the existing body of literature.

METHODS

A comprehensive review of the relevant published literature was performed. The relevant databases and literature libraries were reviewed from the date of their inception through early 2018. These articles were reviewed and their findings analyzed.

RESULTS

Thirty-nine published articles were found that demonstrated a substantial, extensively replicated body of data that demonstrate a significant reduction in migraine headache symptoms and frequency (even complete elimination of headache pain) following trigger-site surgery.

CONCLUSIONS

Migraine surgery is a valid method of treatment for migraine sufferers when performed by experienced plastic surgeons following a methodical protocol. These operations are associated with a high level of safety. The safety and efficacy of migraine surgery should be recognized by plastic surgeons, insurance companies, and the neurology societies.

Trigger Site Inactivation for the Surgical Therapy of Occipital Migraine and Tension-type Headache: Our Experience and Review of the Literature

Literature from the last decade has shown a correlation between resection of the occipital muscles and vessels and relief from migraine and tension-type headaches.

The Greater Occipital Nerve and Obliquus Capitis Inferior Muscle: Anatomical Interactions and Implications for Occipital Pain Syndromes

BACKGROUND

The compression/injury of the greater occipital nerve has been identified as a trigger of occipital headaches. Several compression points have been described, but the morphology of the myofascial unit between the greater occipital nerve and the obliquus capitis inferior muscle has not been studied yet.

METHODS

Twenty fresh cadaveric heads were dissected, and the greater occipital nerve was tracked from its emergence to its passage around the obliquus capitis inferior. The intersection point between the greater occipital nerve and the obliquus capitis inferior, and the length and thickness of the obliquus capitis inferior, were measured. In addition, the nature of the interaction and whether the nerve passed through the muscle were also noted.

RESULTS

All nerves passed either around the muscle loosely (type I), incorporated in the dense superficial muscle fascia (type II), or directly through a myofascial sleeve within the muscle (type III). The obliquus capitis inferior length was 5.60 ± 0.46 cm. The intersection point between the obliquus capitis inferior and the greater occipital nerve was 6.80 ± 0.68 cm caudal to the occiput and 3.56 ± 0.36 cm lateral to the midline. The thickness of the muscle at its intersection with the greater occipital nerve was 1.20 ± 0.25 cm. Loose, tight, and intramuscular connections were found in seven, 31, and two specimens, respectively.

CONCLUSIONS

The obliquus capitis inferior remains relatively immobile during traumatic events, like whiplash injuries, placing strain as a tethering point on the greater occipital nerve. Better understanding of the anatomical relationship between the greater occipital nerve and the obliquus capitis inferior can be clinically useful in cases of posttraumatic occipital headaches for diagnostic and operative planning purposes.

Entrapment Neuropathy: A Concept for Pathogenesis and Treatment of Headaches-A Narrative Review

Entrapment neuropathy is a known cause of neurological disorders. In the head and neck area, this pathophysiological mechanism could be a trigger for headache. Over the last few decades, injection of botulinum toxin type A in the muscles that are causing the compression as well as surgical decompression have proved to be effective treatment methods worldwide for large numbers of patients with daily headaches. In particular the entrapment of the supraorbital nerves in the glabellar musculature and the occipital nerves in the neck musculature are triggers for headache disorders for which many patients are still seeking an effective treatment. This article reviews the literature and aims to bring the concept of neural entrapment to the attention of a wider audience. By doing so, we hope to give more exposure to an effective and relatively safe headache treatment.

Surgical Treatment of Migraine Headache: Back to the Future

Understanding the history and evolution of ideas is key to developing an understanding of complex phenomena and is the foundation for surgical innovation. This historical review on migraine surgery takes us back to the beginnings of interventional management for migraine centuries ago, and reflects on present practices to highlight how far we have come. From Al-Zahrawi and Ambroise Paré to Bahman Guyuron, two common themes of the past and present have emerged in the treatment of migraine headache. Extracranial treatment of both nerves and vessels is being performed and analyzed, with no consensus among current practitioners as to which structure is involved. Knowledge of past theories and new insights will help guide our efforts in the future. One thing is clear: Where we are going, there are no roads. At least not yet.

Surgical Therapy of Temporal Triggered Migraine Headache

Background

The auriculotemporal and zygomaticotemporal nerves are the 2 primary trigger points in the temporal area of migraine headache. Different surgical approaches are described in literature, either open or endoscopic ones.

Methods

We described and delineated the currently adopted strategies to treat temporal trigger points in migraine headache. Furthermore, we reported our personal experience in the field.

Results

Regardless of the type of approach, outcomes observed were similar and ranged from 89% to 67% elimination / >50% reduction rates. All procedures are minimally invasive and only minor complications are reported, with an incidence ranging from 1% to 5%.

Conclusions

Just like upper limb compressive neuropathies, migraine headache is believed to be caused by chronic compression of peripheral nerves (ie, the terminal branches of trigeminal nerve) caused by surrounding structures (eg, muscles, vessels, and fascial bands) the removal of which eventually results in improvement or elimination of migraine attacks. Particular attention should be paid to the close nerve/artery relationship often described in anatomical studies and clinical reports.

Positional Patterns Among the Auriculotemporal Nerve, Superficial Temporal Artery, and Superficial Temporal Vein for use in Decompression Treatments for Migraine

This study aimed to clarify intersection patterns and points among the superficial temporal artery (STA), superficial temporal vein (STV), and auriculotemporal nerve (ATN) based on surface anatomical landmarks to provide useful anatomical information for surgical decompression treatments of migraine headaches in Asians. Thirty-eight hemifaces were dissected. The positional patterns among the ATN, STA, and STV were divided into three morphological types. In type I, the ATN ran toward the temporal region and superficially intersected the STA and STV (n = 32, 84.2%). In type II, the ATN ran toward the temporal region and deeply intersected the STA and STV (n = 4, 10.5%). In type III, the ATN ran toward the temporal region and deeply intersected the STV alone (n = 2, 5.3%). The intersection points of types II and III were 10.3 ± 5.6 mm (mean ± SD) and 10.4 ± 6.1 mm anterior and 42.1 ± 21.6 mm and 41.4 ± 18.7 mm superior to the tragus, respectively. The ATN superficially intersected the STA and STV in all the Korean cadaver, while the ATN deeply intersected the STA and STV in 15% of the Thai cadavers. The pattern of the ATN deeply intersecting the STA and STV was less common in present Asian populations than in previously-reported Caucasian populations, implying that migraine headaches (resulting from the STA and STV compressing the ATN) are less common in Asians.

Stereotactic topography of the greater and third occipital nerves and its clinical implication

This study aimed to provide topographic information of the greater occipital (GON) and third occipital (3ON) nerves, with the three-dimensional locations of their emerging points on the back muscles (60 sides, 30 cadavers) and their spatial relationship with muscle layers, using a 3D digitizer (Microscribe G2X, Immersion Corp, San Jose CA, USA). With reference to the external occipital protuberance (EOP), GON pierced the trapezius at a point 22.6 ± 7.4 mm lateral and 16.3 ± 5.9 mm inferior and the semispinalis capitis (SSC) at a point 13.1 ± 6.0 mm lateral and 27.7 ± 9.9 mm inferior. With the same reference, 3ON pierced, the trapezius at a point 12.9 ± 9.3 mm lateral and 44.2 ± 21.4 mm inferior, the splenius capitis at a point 10.0 ± 5.3 mm lateral and 59.2 ± 19.8 mm inferior, and SSC at a point 11.5 ± 9.9 mm lateral and 61.4 ± 15.3 mm inferior. Additionally, GON arose, winding up the obliquus capitis inferior, with the winding point located 52.3 ± 11.7 mm inferior to EOP and 30.2 ± 8.9 mm lateral to the midsagittal line. Knowing the course of GON and 3ON, from their emergence between vertebrae to the subcutaneous layer, is necessary for reliable nerve detection and precise analgesic injections. Moreover, stereotactic measurement using the 3D digitizer seems useful and accurate for neurovascular structure study.

Targeted Peripheral Nerve-directed Onabotulinumtoxin A Injection for Effective Long-term Therapy for Migraine Headache

Background:

Onabotulinumtoxin A (BOTOX) is an FDA-approved treatment for chronic migraine headaches (MHs) that involves on-label, high-dose administration across 31 anatomic sites. Anatomically specific peripheral nerve trigger sites have been identified that contribute to MH pathogenesis and are amenable to both BOTOX injection and surgical decompression. These sites do not always correlate with the on-label FDA-approved injection pattern, but represent a more targeted approach. The efficacy of peripheral nerve–directed BOTOX injection as an independent long-term therapeutic option has not been investigated.

Methods:

The technique for peripheral nerve–directed therapeutic long-term BOTOX injection is described. A retrospective review was subsequently completed for 223 patients with MH. Sixty-six patients elected to proceed with diagnostic BOTOX injections. Of these, 24 continued long-term therapeutic BOTOX injections, whereas 42 matriculated to surgery. Outcomes were tracked.

Results:

Initial outcomes included significant improvement in migraine headache index (MHI) (53.5 ± 83.0, P < 0.006), headache days/mo (9.2 ± 12.7, P < 0.0009), and migraine severity (2.6 ± 2.5, P < 0.00008) versus baseline. MHI improved from the initiation of diagnostic injections to the establishment of steady-state injections (P < 0.002), and further improved over time (P < 0.05, mean follow-up 615 days) with no desensitization observed. Decompressive surgery resulted in significant improvement in MHI (100.8 ± 109.7, P < 0.0000005), headache days/mo (10.8 ± 12.7, P < 0.000002), migraine severity (3.0 ± 3.8, P < 0.00001), and migraine duration in hours (16.8 ± 21.6, P < 0.0007). MHI improvement with surgery was better than long-term BOTOX injections (P < 0.05).

Conclusions:

Though inferior to surgical decompression, preliminary data demonstrate that targeted peripheral nerve–directed BOTOX injection is an effective primary therapy for MH representing a possible alternative to nondirected BOTOX injection with decreased dosage requirements and potentially decreased cost.

A comparison of outcome of medical and surgical treatment of migraine headache: In 1 year follow-up

BACKGROUND

This study was designed to compare the efficacy of the medical treatment versus the surgical treatment approach to decompression of trigger point nerves in patients with migraine headaches.

MATERIALS AND METHODS

Fifty volunteers were randomly assigned to the medical treatment group (n = 25) or the surgical treatment group (n = 25) after examination by the team neurologist to ensure a diagnosis of migraine headache. All patients received botulinum toxin type A to confirm the trigger sites. The surgical treatment group underwent surgical deactivation of the trigger site(s). The medical treatment group underwent prophylactic pharmacologic interventions by the neurologist. Pretreatment and 12-month posttreatment migraine headache frequency, duration, and intensity were analyzed and compared to determine the success of the treatments.

RESULTS

Nineteen of the 25 patients (76%) in the surgical treatment group and 10 of the 25 patients (40%) in the medical treatment group experienced a successful outcome (at least a 50% decrease in migraine frequency, duration, or intensity) after 1 year from surgery. Surgical treatment had a significantly higher success rate than medical treatment (P < 0.001). Nine patients (36%) in the surgical treatment group and one patient (4%) in the medical treatment group experienced cessation of migraine headaches. The elimination rate was significantly higher in the surgical treatment group than in the medical treatment group (P < 0.001).

CONCLUSIONS

Based on the 1-year follow-up data, there is strong evidence that surgical manipulation of one or more migraine trigger sites can successfully eliminate or reduce the frequency, duration, and intensity of migraine headaches in a lasting manner.

Intramuscular Lipoma-Induced Occipital Neuralgia on the Lesser Occipital Nerve

Occipital neuralgia (ON) is commonly characterized by a neuralgiform headache accompanied by a paroxysmal burning sensation in the dermatome area of the greater, lesser, or third occipital nerve. The authors report a rare case of ON caused by an intramuscular lipoma originating from the lesser occipital nerve.A 52-year-old man presented with sharp pain in the left postauricular area with a 3 × 2-cm palpable mass. Computed tomography revealed a mass suspiciously resembling an intramuscular lipoma within splenius muscle. In the operation field, a protruding mass causing stretching of the lesser occipital nerve was found. After complete resection, the neuralgiform headache symptom had resolved and the intramuscular lipoma was confirmed through histopathology.Previous studies on the causes of ON have reported that variation in normal anatomic structures results in nerve compression. Occipital neuralgia, however, caused by intramuscular lipomas in splenius muscles have not been previously reported, and the dramatic resolution following surgery makes it an interesting case worth reporting.