Prospective Analysis of the Greater Occipital Nerve Location in Patients Undergoing Occipital Nerve Decompression

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.

Nerve blocks for occipital headaches: A systematic review and meta-analysis

Migraine surgeons have identified six "trigger sites" where cranial nerve compression may trigger a migraine. This study investigates the change in headache severity and frequency following nerve block of the occipital trigger site. This PRISMA-compliant systematic review of five databases searched from database inception through May 2020 is registered under the PROSPERO ID: CRD42020199369. Only randomized controlled trials utilizing injection treatments for headaches with pain or tenderness in the occipital scalp were included. Pain severity was scored from 0 to 10. Headache frequency was reported as days per week. Included were 12 RCTs treating 586 patients of mean ages ranging from 33.7 to 55.8 years. Meta-analyses of pain severity comparing nerve blocks to baseline showed statistically significant reductions of 2.88 points at 5 to 20 min, 3.74 points at 1 to 6 weeks, and 1.07 points at 12 to 24 weeks. Meta-analyses of pain severity of nerve blocks compared with treatment groups of neurolysis, pulsed radiofrequency, and botulinum toxin type A showed similar headache pain severity at 1 to 2 weeks, and inferior improvements compared with the treatment groups after 2 weeks. Meta-analyses of headache frequency showed statistically significant reductions at 1 to 6-week follow-ups as compared with baseline and at 1 to 6 weeks as compared with inactive control injections. The severity and frequency of occipital headaches are reduced following occipital nerve blocks. This improvement is used to predict the success of migraine surgery. Future research should investigate spinous process injections with longer follow-up.

Minimally Invasive Preganglionic C2 Root Section for Occipital Neuralgia: 2 Case Reports and Operative Video

BACKGROUND

Occipital neuralgia is a painful condition that is believed to occur from processes that affect the greater, lesser, or third occipital nerves. Diagnosis is often made with a combination of classical symptoms, tenderness over the occipital region, and response to occipital nerve blocks. Cervical computed tomography or MRI may be obtained in multiple positions to detect any impingement. Diagnosis can be made with MRI tractography. Nonsurgical treatments include local anesthetic and steroid injections, anticonvulsant medications, botulinum toxin injections, physical therapy, acupuncture, transcutaneous electrical stimulation, cryoneurolysis, and radiofrequency ablation. Surgical treatments include greater occipital nerve decompression, C2 root section, intradural dorsal root rhizotomy, C1-2 fusion, and occipital nerve stimulation. Although stimulation has been favored in the past decade, complications and maintenance of the devices have led us to return to C2 ganglionectomy.

OBJECTIVE

To report on the use of a minimally invasive technique for C2 ganglionectomy to treat occipital neuralgia.

METHODS

Review demographic, surgery, and outcome data of a minimally invasive C2 root ganglionectomy used to treat to 2 patients with occipital neuralgia.

RESULTS

We report on 2 patients with clinically stereotypical unilateral occipital neuralgia confirmed by greater occipital nerve block, but with no imaging correlate. Both were successfully managed by C2 ganglionectomy through an 18-mm tubular retractor and outpatient surgery. Accompanying text, still photographs, and video describe the technique in detail.

CONCLUSION

Minimally invasive C2 ganglionectomy can be used to successfully treat occipital neuralgia.

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.

Modified Skin Incision and Location of Burr-Hole Surgery via a Retrosigmoid Approach: An Anatomical Study

Objective  This study aims to reduce the tissue damage during craniotomy with retrosigmoid approach. A modified sickle-shaped skin incision was developed, and a new burr-hole positioning method was proposed. Methods  Five adult cadaveric heads (10 sides) were used in this study. The sickle-shaped skin incision was performed during craniotomy. The nerves, blood vessels, and muscles were observed and measured under a microscope. Additionally, 62 dry adult skull specimens (left sided, n  = 35; right sided, n  = 27) were used to measure the distance between the most commonly used locating point (asterion [Ast] point) and the posteroinferior point of the transverse sigmoid sinus junction (PSTS) (Ast-PSTS), as well as the distance between the new locating O point and the PSTS (O-PSTS). Then, the reliability of the new locating O point was validated on the same five adult cadaveric heads (10 sides) used for the sickle-shaped skin incision. Results  The sickle-shaped skin incision reduced the damage to the occipital nerves, blood vessels, and muscles during the surgery via a retrosigmoid approach. The dispersion and variability of O-PSTS were smaller than those of Ast-PSTS. Conclusion  The sickle-shaped skin incision of the retrosigmoid approach can reduce the tissue damage and can completely expose the structures in the cerebellopontine angle. The modified O point is a more reliable locating point for a burr-hole surgery than the Ast point.

A Correlation between Upper Extremity Compressive Neuropathy and Nerve Compression Headache

BACKGROUND

Compressive neuropathies of the head/neck that trigger headaches and entrapment neuropathies of the extremities have traditionally been perceived as separate clinical entities. Given significant overlap in clinical presentation, treatment, and anatomical abnormality, the authors aimed to elucidate the relationship between nerve compression headaches and carpal tunnel syndrome, and other upper extremity compression neuropathies.

METHODS

One hundred thirty-seven patients with nerve compression headaches who underwent surgical nerve deactivation were included. A retrospective chart review was conducted and the prevalence of carpal tunnel syndrome, thoracic outlet syndrome, and cubital tunnel syndrome was recorded. Patients with carpal tunnel syndrome, cubital tunnel syndrome, and thoracic outlet syndrome who had a history of surgery and/or positive imaging findings in addition to confirmed diagnosis were included. Patients with subjective report of carpal tunnel syndrome/thoracic outlet syndrome/cubital tunnel syndrome were excluded. Prevalence was compared to general population data.

RESULTS

The cumulative prevalence of upper extremity neuropathies in patients undergoing surgery for nerve compression headaches was 16.7 percent. The prevalence of carpal tunnel syndrome was 10.2 percent, which is 1.8- to 3.8-fold more common than in the general population. Thoracic outlet syndrome prevalence was 3.6 percent, with no available general population data for comparison. Cubital tunnel syndrome prevalence was comparable between groups.

CONCLUSIONS

The degree of overlap between nerve compression syndromes of the head/neck and upper extremity suggests that peripheral nerve surgeons should be aware of this correlation and screen affected patients comprehensively. Similar patient presentation, treatment, and anatomical basis of nerve compression make either amenable to treatment by nerve surgeons, and treatment of both entities should be an integral part of a formal peripheral nerve surgery curriculum.

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.

Patient Pain Sketches Can Predict Surgical Outcomes in Trigger-Site Deactivation Surgery for Headaches

BACKGROUND

Patient selection for headache surgery is an important variable to ensure successful outcomes. In the authors' experience, a valuable method to visualize pain/trigger sites is to ask patients to draw their pain. The authors have found that there are pathognomonic pain patterns for each site, and typically do not operate on patients with atypical pain sketches, as they believe such patients are poor surgical candidates. However, a small subset of these atypical patients undergo surgery based on other strong clinical findings. In this study, the authors attempt to quantify this clinical experience.

METHODS

Patients were prospectively enrolled and completed pain sketches at screening. One hundred six diagrams were analyzed/categorized by two independent, blinded reviewers as follows: (1) typical (pain over nerve distribution, expected radiation); (2) intermediate (pain over nerve distribution, atypical radiation); or (3) atypical (pain outside of normal nerve distribution, atypical radiation). Preoperative and postoperative Migraine Headache Index was compared between subgroups using unpaired t tests.

RESULTS

Migraine Headache Index improvement was 73 ± 38 percent in the typical group, 78 ± 30 percent in the intermediate group, and 30 ± 40 percent in the atypical group. There was a significant difference in Migraine Headache Index between the typical and atypical groups (p = 0.03) and between the intermediate and atypical groups (p < 0.01). The chance of achieving Migraine Headache Index improvement greater than 30 percent in the atypical group was 20 percent.

CONCLUSIONS

Patient pain sketches classified as atypical (facial pain, atypical pain point origin, diffuse pain) can predict poor outcomes in headache surgery. As the authors continue to develop patient selection criteria for headache surgery, patient sketches should be considered as an effective, cheap, and simple-to-interpret tool for selecting candidates for surgery.