Neurotoxins: Expanding Uses of Neuromodulators in Medicine—Headache

The Positive and Negative Predictive Value of Targeted Diagnostic Botox Injection in Nerve Decompression Migraine Surgery

BACKGROUND

Nerve decompression surgery is an effective treatment modality for patients who experience migraines. Botulinum toxin type A (Botox) injections have been traditionally used as a method to identify trigger sites; however, there is a paucity in data regarding its diagnostic efficacy. The goal of this study was to assess the diagnostic capacity of Botox in successfully identifying migraine trigger sites and predicting surgical success.

METHODS

A sensitivity analysis was performed on all patients receiving Botox for migraine trigger site localization followed by a surgical decompression of affected peripheral nerves. Positive and negative predictive values were calculated.

RESULTS

A total of 40 patients met our inclusion criteria and underwent targeted diagnostic Botox injection followed by a peripheral nerve deactivation surgery with at least 3 months' follow-up. Patients with successful Botox injections (defined as at least 50% improvement in Migraine Headache Index scores after injection) had significantly higher average reduction in migraine intensity (56.7% versus 25.8%; P = 0.020), frequency (78.1% versus 46.8%; P = 0.018), and Migraine Headache Index (89.7% versus 49.2%; P = 0.016) postsurgical deactivation. Sensitivity analysis shows that the use of Botox injection as a diagnostic modality for migraine headaches has a sensitivity of 56.7% and a specificity of 80.0%. The positive predictive value is 89.5% and the negative predictive value is 38.1%.

CONCLUSIONS

Diagnostic targeted Botox injections have a very high positive predictive value. It is therefore a useful diagnostic modality that can help identify migraine trigger sites and improve preoperative patient selection.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

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.

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.

Treatment Delay in Patients Undergoing Headache Surgery (Nerve Decompression Surgery)

Background

Although headache surgery has been shown to be an effective treatment option for refractory headache disorders, it has not been included as part of the headache disorder management algorithm by non-surgical providers. This study aims to evaluate the delay in surgical management of patients with headache disorders. In addition, a cost comparison analysis between conservative and operative treatment of headache disorders was performed, and the surgical outcomes of headache surgery were reported.

Methods

Among 1112 patients who were screened, 271 (56%) patients underwent headache surgery. Data regarding the onset of headache disorder and pre- and postoperative pain characteristics were prospectively collected. To perform a cost comparison analysis, direct and indirect costs associated with the conservative treatment of headache disorders were calculated.

Results

The median duration between onset of headache disorder symptoms and headache surgery was 20 (8.2-32) years. The annual mean cost of conservative treatment of headache disorders was $49,463.78 ($30,933.87-$66,553.70) per patient. Over the 20-year time period before surgery, the mean cost was $989,275.65 ($618,677.31-$1,331,073.99). In comparison, the mean cost of headache surgery was $11,000. The median pain days per month decreased by 16 (0-25) (p<0.001), the median pain intensity reduced by 4 (2-7) (p<0.001), and the median pain duration decreased by 11 hours (0-22) (p<0.001).

Conclusion

This study shows that patients experience symptoms of headache disorders for an average of 20 years prior to undergoing headache surgery. Surgical treatment not only significantly improves headache pain but also reduces healthcare costs and should be implemented in the management algorithm of headache disorders.

New anatomical insights of the superficial branch of the zygomaticotemporal nerve for treating temporal migraines: An anatomical study

The zygomaticotemporal nerve is known to contribute to temporal migraines; however, its precise anatomy remains unknown. The potential accessory branches of the zygomaticotemporal nerve may be considered a cause of continued temporal migraines after surgical procedures. In this study, we defined the novel superficial branch of the zygomaticotemporal nerve (sZTN) and investigated its anatomical course, distribution, and clinical implications. Twenty-two hemifaces from 11 fixed Korean cadavers (six males, five females; mean age, 78.3 years) were used in this study. The piercing points of the sZTN through the deep and superficial layers of the deep temporal fascia, and the superficial temporal fascia were defined as P1, P2, and P3, respectively. The distance of each point from the zygomatic tubercle was measured using an image analysis software. The sZTN ascended between the bone and the temporalis after emerging from the zygomaticotemporal foramen. It then pierced the deep temporal fascia without penetrating the temporalis. After then, it pierced the superficial layer of the deep temporal fascia and turned superiorly toward the upper posterior temple. When the sZTN passed through the superficial temporal fascia, it intersected with the superficial temporal artery in every case. The novel findings of the sZTN may help in the treatment of intractable temporal migraines refractory to injection or surgical procedure. Based on our findings, targeting the sZTN may be applied as an alternative treatment strategy for patients who do not show significant improvement with treatment targeted to trigger sites.

Migraine Surgery and Determination of Success over Time by Trigger Site: A Systematic Review of the Literature

BACKGROUND

Migraine headache is a debilitating disorder that produces high costs and compromises patient quality of life. This study aimed to evaluate surgery success and the longevity of the surgical benefit by trigger site.

METHODS

A systematic literature review was performed by querying the PubMed, Embase, Scopus, and Web of Science databases. The keywords "surgery," "migraine," "outcomes," "headache index," and synonyms in titles and abstracts were used to perform the search.

RESULTS

A total of 17 articles published between 2009 and 2019 met the inclusion criteria. Six studies were prospective and 11 were retrospective. Most of the studies (77.8%, 77.8%, and 80%, respectively) reported success of migraine surgery at 12-month follow-up for trigger sites I, II, and III, respectively. For trigger site IV, the greatest Migraine Headache Index reduction (93.4%) was observed at 12-month follow-up, and the earliest Migraine Headache Index reductions (80.3% and 74.6%) were observed at 6-month follow-up. All studies that evaluated trigger sites V and VI identified surgery success at 12-month follow-up. Migraine surgery was found to remain beneficial at 22 months for trigger sites I, II, III, and IV.

CONCLUSIONS

The symptomatic improvement may initially be evident at 6 months for trigger site IV and at 12 months for trigger sites I, II, III, V, and VI. Surgical benefit in trigger sites I, II, III, and IV can persist after 22 months. Further studies are required to evaluate results at longer follow-up.

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.

Migraine Surgery at the Frontal Trigger Site: An Analysis of Intraoperative Anatomy

BACKGROUND

The development of migraine headaches may involve the entrapment of peripheral craniofacial nerves at specific sites. Cadaveric studies in the general population have confirmed potential compression points of the supraorbital and supratrochlear nerves at the frontal trigger site. The authors' aim was to describe the intraoperative anatomy of the supraorbital and supratrochlear nerves at the level of the supraorbital bony rim in patients undergoing frontal migraine surgery and to investigate associated pain.

METHODS

PATIENTS: scheduled for frontal-site surgery were enrolled prospectively. The senior author (W.G.A.) evaluated intraoperative anatomy and recorded variables using a detailed form and operative report. The resulting data were analyzed.

RESULTS

One hundred eighteen sites among 61 patients were included. The supraorbital nerve traversed a notch in 49 percent, a foramen in 41 percent, a notch plus a foramen in 9.3 percent, and neither a notch nor a foramen in one site. The senior author noted macroscopic nerve compression at 74 percent of sites. Reasons included a tight foramen in 24 percent, a notch with a tight band in 34 percent, and supraorbital and supratrochlear nerves emerging by means of the same notch in 7.6 percent or by means of the same foramen in 4.2 percent. Preoperative pain at a site was significantly associated with nerve compression by a foramen.

CONCLUSIONS

The intraoperative anatomy and cause of nerve compression at the frontal trigger site vary greatly among patients. The authors report a supraorbital nerve foramen prevalence of 50.3 percent, which is greater than in previous cadaver studies of the general population. Lastly, the presence of pain at a specific site is associated with macroscopic nerve compression.