Emerging evidence of occipital nerve compression in unremitting head and neck pain

A Cross-Sectional Study Exploring the Relationship between Work-Related, Lifestyle Factors and Non-Specific Neck and Shoulder Pain in a Southeast Asian Population

BACKGROUND AND OBJECTIVES

Non-specific neck and shoulder pain (NSNSP) is prevalent among working adults. The increased use of electronic devices and prevalence of remote working and study following the COVID-19 pandemic have raised concerns about the potential rise in such conditions. This study aims to investigate the associations between work-related, lifestyle factors and NSNSP in the adult Southeast Asian Singaporean population.

MATERIALS AND METHODS

An online survey was administered electronically to Singaporeans aged 21 and above. Demographic data, NSNSP prevalence, computer and smartphone usage durations, sleep patterns, and exercise frequency were captured after obtaining informed consent (SIT institutional review board approval #2023014).

RESULTS

A total of 302 validated responses were recorded, including 212 suffering from NSNSP versus 90 in the comparison group. The NSNSP group showed significantly longer smartphone usage (5.37 ± 3.50 h/day) compared to the comparison group (4.46 ± 3.36 h/day, p = 0.04). Furthermore, the NSNSP group had lower exercise frequency (2.10 ± 1.74 days/week vs. 2.93 ± 2.21 days/week, p < 0.01) and shorter weekly exercise duration (2.69 ± 3.05 h/week vs. 4.11 ± 4.15 h/week, p < 0.01). The average NSNSP severity in this group was 34.9 ± 19.96 out of 100, correlating significantly with age (r = 0.201, p < 0.01) and BMI (r = 0.27, p < 0.01).

CONCLUSIONS

This preliminary cross-sectional study examines characteristics of adult Southeast Asians with NSNSP post-COVID-19 pandemic. The findings indicate significantly longer smartphone use and less exercise in NSNSP respondents, with both age and body mass index (BMI) demonstrating significant correlations with NSNSP severity.

Challenges of Imaging the Greater Occipital Nerve Using Magnetic Resonance Imaging

ABSTRACT

Migraine headaches are a significant global health concern, frequently managed with varying levels of success. Compression of the greater occipital nerve (GON) is hypothesized to contribute to pathology in some migraine patients, making extracranial nerve decompression surgery a potential intervention for refractory cases. However, accurate methods to image the GON along its tortuous course still need to be explored. Our group has developed magnetic resonance imaging sequences to track the GON. Yet, many challenges were met, which included navigating the GON's complex anatomy, understanding anatomical variants, and designing advanced magnetic resonance imaging sequences and coils to image the posterior scalp. Addressing these hurdles is vital to capture and understand GON pathology and guide potential interventions.

Instrumental assessment of pressure pain threshold over trigeminal and extra-trigeminal area in people with episodic and chronic migraine: a cross-sectional observational study

BACKGROUND

Central and peripheral sensitization are characterized by widespread hyperalgesia that is manifested by larger pain extent area and reduction in pressure pain threshold (PPT). PPT decreases in patients with migraine not only over the trigeminal cervical complex but also throughout the body.

METHODS

A cross-sectional study was adopted to assess the local and widespread hyperalgesia in chronic and episodic migraine patients respect to healthy controls. The guidelines of Andersen's were used to evaluate the PPT bilaterally over 3 muscles in the trigemino-cervical complex (temporalis, sub-occipitalis, trapezius) and over 1 muscle far from this area (tensor fasciae latae).

RESULTS

Thirty subjects with episodic migraine (35.8 ± 2.82 years), 30 with chronic migraine (53.03 ± 19.79 years), and 30 healthy controls (29.06 ± 14.03 years) were enrolled. The interaction effect was present for the trapezius muscle with a significant difference between the right and the left side in episodic group (p = 0.003). A group effect was highlighted in all four muscles analyzed such as suboccipital (p < 0.001), temporalis (p > 0.001), trapezius (p < 0.001), and TFL (p < 0.001). PPT was usually higher in the control group than in the episodic group which in turn was characterized by higher PPT values than the chronic group.

CONCLUSIONS

People with chronic and episodic migraine presented lower PPT than healthy controls both in the trigeminal and in the extra-trigeminal area. People with chronic migraine presented lower PPT than episodic migraine only in the trigeminal area. Temporalis and sub-occipitalis are the most sensitive muscles in people with chronic and episodic migraine.

Preoperative visualization of the greater occipital nerve with magnetic resonance imaging in candidates for occipital nerve decompression for headaches

Occipital nerve decompression is effective in reducing headache symptoms in select patients with migraine and occipital neuralgia. Eligibility for surgery relies on subjective symptoms and responses to nerve blocks and Onabotulinum toxin A (Botox) injections. No validated objective method exists for detecting occipital headache pathologies. The purpose of the study is to explore the potential of high-resolution Magnetic Resolution Imaging (MRI) in identifying greater occipital nerve (GON) pathologies in chronic headache patients. The MRI protocol included three sequences targeting fat-suppressed fluid-sensitive T2-weighted signals. Visualization of the GON involved generating 2-D image slices with sequential rotation to track the nerve course. Twelve patients underwent pre-surgical MRI assessment. MRI identified four main pathologies that were validated against intra-operative examination: GON entanglement by the occipital artery, increased nerve thickness and hyperintensity suggesting inflammation compared to the non-symptomatic contralateral side, early GON branching with rejoining at a distal point, and a connection between the GON and the lesser occipital nerve. MRI possesses the ability to visualize the GON and identify suspected trigger points associated with headache symptoms. This case series highlights MRI's potential to provide objective evidence of nerve pathology. Further research is warranted to establish MRI as a gold standard for diagnosing extracranial contributors in headaches.

The Postconcussion Syndrome and Posttraumatic Headaches in Civilians, Soldiers, and Athletes

Posttraumatic headaches are one of the most common and controversial secondary headache types. After a mild traumatic brain, an estimated 11% to 82% of people develop a postconcussion syndrome, which has been controversial for more than 160 years. Headache is estimated as present in 30% to 90% of patients after a mild head injury. Most headaches are tension-type-like or migraine-like. Headaches in civilians, soldiers, athletes, and postcraniotomy are reviewed. The treatments are the same as for the primary headaches. Persistent posttraumatic headaches can continue for many years.

A Novel Ultrasound-Guided "Three in One" Approach Plus Interfascial Plane Blocks for the Treatment of Cervicogenic Headache

Objective

Cervicogenic headache (CEH) is a condition resulting from upper cervical spine dysfunction and associated structural and soft tissue abnormalities, significantly impacting patients' quality of life. To acquire better therapeutic results, we presented a novel ultrasound-guided "three in one" approach plus interfascial plane (IFP) blocks for the treatment of CEH. This approach allows for the modulation of C2 dorsal root ganglion (DRG), third occipital nerve (TON), and C3 medial branch with one-point puncture. Additionally, it allows for IFP blocks between the upper neck and occipital muscles within the same scanning plane.

Patients and Methods

We evaluated patients diagnosed with CEH from July 2021 to December 2022 in our pain clinic. We included those who did not respond to conservative treatment and single occipital nerve block, therefore received nerve block or pulsed radiofrequency (PRF) using the "Three in One" approach plus IFP blocks. The accuracy of the ultrasound-guided C2 DRG puncture procedures was confirmed through fluoroscopy with C-arm and the sensory testing of PRF. The therapeutic effect of these interventions was assessed using the numerical rating scale (NRS) scores during telephone follow-ups at 1, 3, and 6 months.

Results

Utilizing the "Three in One" approach, a total of 5 patients diagnosed with CEH underwent nerve block plus IFP blocks, while 2 patients underwent PRF plus IFP blocks. Employing ultrasound-guided C2 DRG puncture procedures, the needle tip's correct placement was confirmed through both fluoroscopy and sensory testing of PRF. Notably, none of the cases experienced any complications associated with the approach. Subsequent follow-up assessments revealed an improvement in the NRS scores for CEH in all patients.

Conclusion

The ultrasound-guided "Three in One" approach plus IFP blocks may be a potential effective method for the treatment of CEH.

Anatomic Anomalies of the Nerves Treated during Headache Surgery

Background

Headache surgery is a well-established, viable option for patients with chronic head pain/migraines refractory to conventional treatment modalities. These operations involve any number of seven primary nerves. In the occipital region, the surgical targets are the greater, lesser, and third occipital nerves. In the temporal region, they are the auriculotemporal and zygomaticotemporal nerves. In the forehead, the supraorbital and supratrochlear are targeted. The typical anatomic courses of these nerves are well established and documented in clinical and cadaveric studies. However, variations of this "typical" anatomy are quite common and relatively poorly understood. Headache surgeons should be aware of these common anomalies, as they may alter treatment in several meaningful ways.

Methods

In this article, we describe the experience of five established headache surgeons encompassing over 4000 cases with respect to the most common anomalies of the nerves typically addressed during headache surgery. Descriptions of anomalous nerve courses and suggestions for management are offered.

Results

Anomalies of all seven nerves addressed during headache operations occur with a frequency ranging from 2% to 50%, depending on anomaly type and nerve location. Variations of the temporal and occipital nerves are most common, whereas anomalies of the frontal nerves are relatively less common. Management includes broader dissection and/or transection of accessory injured nerves combined with strategies to reduce neuroma formation such as targeted reinnervation or regenerative peripheral nerve interfaces.

Conclusions

Understanding these myriad nerve anomalies is essential to any headache surgeon. Implications are relevant to preoperative planning, intraoperative dissection, and postoperative management.

Nonpharmacologic Treatments for Chronic and Episodic Migraine: A Systematic Review and Meta-Analysis

BACKGROUND

Minimally invasive techniques for treatment-resistant migraine have been developed on recent insights into the peripheral pathogenesis of migraines. Although there is a growing body of evidence supporting these techniques, no study has yet compared the effects of these treatments on headache frequency, severity, duration, and cost.

METHODS

PubMed, Embase, and Cochrane Library databases were searched to identify randomized placebo-controlled trials that compared radiofrequency ablation, botulinum toxin type A (BT-A), nerve block, neurostimulation, or migraine surgery to placebo for preventive treatment. Data on changes from baseline to follow-up in headache frequency, severity, duration, and quality of life were analyzed.

RESULTS

A total of 30 randomized controlled trials and 2680 patients were included. Compared with placebo, there was a significant decrease in headache frequency in patients with nerve block ( P = 0.04) and surgery ( P < 0.001). Headache severity decreased in all treatments. Duration of headaches was significantly reduced in the BT-A ( P < 0.001) and surgery cohorts ( P = 0.01). Quality of life improved significantly in patients with BT-A, nerve stimulator, and migraine surgery. Migraine surgery had the longest lasting effects (11.5 months) compared with nerve ablation (6 months), BT-A (3.2 months), and nerve block (11.9 days).

CONCLUSIONS

Migraine surgery is a cost-effective, long-term treatment to reduce headache frequency, severity, and duration without significant risk of complication. BT-A reduces headache severity and duration, but it is short-lasting and associated with greater adverse events and lifetime cost. Although efficacious, radiofrequency ablation and implanted nerve stimulators have high risks of adverse events and explantation, whereas benefits of nerve blocks are short in duration.

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.

Breaking the cycle: unraveling the diagnostic, pathophysiological and treatment challenges of refractory migraine

Background

Refractory migraine is a poorly described complication of migraine in which migraine has chronified and become resistant to standard treatments. The true prevalence is unknown, but medication resistance is common in headache clinic patient populations. Given the lack of response to treatment, this patient population is extremely difficult to treat with limited guidance in the literature.

Objective

To review the diagnostic, pathophysiological, and management challenges in the refractory migraine population.

Discussion

There are no accepted, or even ICHD-3 appendix, diagnostic criteria for refractory migraine though several proposed criteria exist. Current proposed criteria often have low bars for refractoriness while also not meeting the needs of pediatrics, lower socioeconomic status, and developing nations. Pathophysiology is unknown but can be hypothesized as a persistent "on" state as a progression from chronic migraine with increasing central sensitization, but there may be heterogeneity in the underlying pathophysiology. No guidelines exist for treatment of refractory migraine; once all guideline-based treatments are tried, treatment consists of n-of-1 treatment trials paired with non-pharmacologic management.

Conclusion

Refractory migraine is poorly described diagnostically, its pathophysiology can only be guessed at by extension of chronic migraine, and treatment is more the art than science of medicine. Navigating care of this refractory population will require multidisciplinary care models and an emphasis on future research to answer these unknowns.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

Ipsilateral Limb Extension of Referred Trigeminal Facial Pain due to Greater Occipital Nerve Entrapment: A Case Report

We report a very rare case of referred pain associated with entrapment of the greater occipital nerve (GON) occurring not only in the ipsilateral hemiface but also in the ipsilateral limb. There is an extensive convergence of cutaneous, tooth pulp, visceral, neck, and muscle afferents onto nociceptive and nonnociceptive neurons in the trigeminal nucleus caudalis (medullary dorsal horn). In addition, nociceptive input from trigeminal, meningeal afferents projects into trigeminal nucleus caudalis and dorsal horn of C1 and C2. Together, they form a functional unit, the trigeminocervical complex (TCC). The nociceptive inflow from suboccipital and high cervical structures is mediated with small-diameter afferent fibers in the upper cervical roots terminating in the dorsal horn of the cervical cord extending from the C2 segment up to the medullary dorsal horn. The major afferent contribution is mediated by the spinal root C2 that is peripherally represented by the greater occipital nerve (GON). Convergence of afferent signals from the trigeminal nerve and the GON onto the TCC is regarded as an anatomical basis of pain referral in craniofacial pain and primary headache syndrome. Ipsilateral limb pain occurs long before the onset of the referred facial pain. The subsequent severe hemifacial pain suggested GON entrapment. The occipital nerve block provided temporary relief from facial and extremity pain. Imaging studies found a benign osteoma in the ipsilateral suboccipital bone, but no direct contact with GON was identified. During GON decompression, severe entrapment of the GON was observed by the tendinous aponeurotic edge of the trapezius muscle, but the osteoma had no contact with the nerve. Following GON decompression, the referred trigeminal and extremity pain completely disappeared. The pain referral from GON entrapment seems to be attributed to the sensitization and hypersensitivity of the trigeminocervical complex (TCC). The clinical manifestations of TCC hypersensitivity induced by chronic entrapment of GONs are diverse when considering the occurrence of extremity pain as well as facial pain.

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.

The Significance of Pain Drawing as a Screening Tool for Cervicogenic Headache and Associated Symptoms in Chronic Fatigue

Purpose

Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) present with a broad spectrum of symptoms, including headache. A simple, yet powerful tool – the pain drawing identifies essential aspects such as pain distribution. The aim with this study was to 1) evaluate the significance of pain drawing as a screening tool for cervicogenic headache using a predefined C2 pain pattern, 2) assess whether there was an association between dizziness/imbalance and a C2 pain pattern, and 3) compare subgroups according to the pain drawing with respect to pain characteristics and quality of life.

Patients and Methods

Pain drawings and clinical data from 275 patients investigated for ME/CFS were stratified into: 1) cervicogenic headache as determined by a C2 pain pattern, 2) headache with no C2 pain pattern, and 3) no headache. For inference logistic regression presented with odds ratios (OR) and 95% confidence intervals (95% CI) and Kruskal–Wallis test were applied.

Results

One hundred sixteen participants (42%) were stratified to the group for which the pain drawing corresponded to the C2 pain pattern, thus indicating putative cervicogenic origin of the headache. Dizziness/imbalance was strongly associated with a C2 pain pattern; OR 6.50 ([95% CI 2.42–17.40] p ˂ 0.00), whereas this association was non-significant for patients with headache and no C2 pain pattern. Those demonstrating a C2 pain pattern reported significantly higher pain intensity (p = 0.00) and greater pain extent (p = 0.00) than the other groups, and lower health-related quality of life (p = 0.00) than the group with no headache.

Conclusion

For patients with chronic fatigue who present with a C2 pain pattern (interpreted as cervicogenic headache) the pain drawing seems applicable as a screening tool for signs associated with neuropathic and more severe pain, dizziness and reduced quality of life as detection of these symptoms is essential for targeted treatment.

Bony Decompression of a Chronically Painful Intercostal Nerve Yields Immediate and Long-Lasting Pain Relief: A Case Report

CASE

The case of an active 16-year-old adolescent girl who presented with rib malunion and 1 year of unremitting intercostal nerve pain after sustaining multiple rib fractures is presented. She underwent successful bony and soft-tissue decompression of her eighth and ninth intercostal nerves to relieve neurogenic symptoms.

CONCLUSION

When conservative treatment fails, chronic intercostal nerve pain due to chest wall trauma may be effectively managed with surgical bony decompression of the offending intercostal bundle(s). Anatomic knowledge of the intercostal nerve and a critical history and physical examination were critical for accurate diagnosis and surgical decompression of the patient's intercostal nerve.

Postdural Puncture Headache-Risks and Current Treatment

PURPOSE OF REVIEW

This manuscript aims to review the risks and the current treatments for postdural puncture headache (PDPH).

RECENT FINDINGS

PDPH is a relatively frequent complication after neuraxial blocks. It is typically orthostatic in nature, presenting as a positional and dull aching or throbbing headache, with added dysregulation of auditory and/or visual signals. Certain characteristics, such as female sex and young age, may predispose patients to the development of PDPH, as may factors such as previous PDPH, bearing down during the second stage of labor, and the neuraxial technique itself. Long-term complications including chronic headache for years following dural puncture have brought into question of the historical classification of PDPH as a self-limiting headache. So far, the underlying mechanism governing PDPH remains under investigation, while a wide variety of prophylactic and therapeutic measures have been explored with various degree of success. In case of mild PDPH, conservative management involving bed rest and pharmacological management should be used as first-line treatment. Nerve blocks are highly efficient alternatives for PDPH patients who do not respond well to conservative treatment. In case of moderate-to-severe PDPH, epidural blood patch remains the therapy of choice. An interdisciplinary approach to care for patients with PDPH is recommended to achieve optimal outcomes.

Prevalence of neck pain in migraine: A systematic review and meta-analysis

BACKGROUND

Neck pain is a frequent complaint among patients with migraine and seems to be correlated with the headache frequency. Neck pain is more common in patients with chronic migraine compared to episodic migraine. However, prevalence of neck pain in patients with migraine varies among studies.

OBJECTIVE

To estimate the prevalence of neck pain in patients with migraine and non-headache controls in observational studies.

METHODS

A systematic literature search on PubMed and Embase was conducted to identify studies reporting prevalence of neck pain in migraine patients. This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data was extracted by two independent investigators and results were pooled using random-effects meta-analysis. The protocol was registered with PROSPERO (CRD42021264898).

RESULTS

The search identified 2490 citations of which 30 contained relevant original population based and clinic-based data. Among these, 24 studies provided data eligible for the analysis. The meta-analysis for clinic-based studies demonstrated that the pooled relative frequency of neck pain was 77.0% (95% CI: 69.0-86.4) in the migraine group and 23.2% (95% CI:18.6-28.5) in the non-headache control group. Neck pain was more frequent in patients with chronic migraine (87.0%, 95% CI: 77.0-93.0) compared to episodic migraine (77.0%, 95% CI: 69.0-84.0). Neck pain was 12 times more prevalent in migraine patients compared to non-headache controls and two times more prevalent in patients with chronic migraine compared to episodic migraine. The calculated heterogeneity (I² values) ranged from 61.3% to 72.0%.

CONCLUSION

Neck pain is a frequent complaint among patients with migraine. The heterogeneity among the studies emphasize important aspects to consider in future research of neck pain in migraine to improve our understanding of the driving mechanisms of neck pain in a major group of migraine patients.

Decompression of the Greater Occipital Nerve for Occipital Neuralgia and Chronic Occipital Headache Caused by Entrapment of the Greater Occipital Nerve

BACKGROUND

 Chronic entrapment of the greater occipital nerve (GON) can not only manifest in typical stabbing pain of occipital neuralgia (ON) but also lead to continuous ache and pressure-like pain in the occipital and temporal areas. However, the effect of GON decompression on these symptoms has yet to be established. We report the follow-up results of GON decompression in typical cases of ON and chronic occipital headache due to GON entrapment (COHGONE).

METHODS

 A 1-year follow-up study of GON decompression was conducted on 11 patients with typical ON and 39 COHGONE patients with GON entrapment. The degree of pain reduction was analyzed using the numerical rating scale-11 (NRS-11) score and percent pain relief before and 1 year after surgery. A success was defined by at least a 50% reduction in pain measured via NRS-11 during the 12-month follow-up. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Postoperative outcome was also evaluated using the Barrow Neurological Institute (BNI) pain intensity score. The difference in GON decompression between the patients with typical ON and those with COHGONE was studied.

RESULTS

 GON decompression was successful in 43 of 50 patients (86.0%) and percent pain relief was 72.99 ± 25.53. Subjective improvement based on a 10-point Likert scale was 7.9 ± 2.42 and the BNI grade was 2.06 ± 1.04. It was effective in both the ON and COHGONE groups, but the success rate was higher in the ON group (90.9%) than in the COHGONE group (84.6%), showing statistically significant differences in the results based on average NRS-11 score, percent pain relief, subjective improvement, and BNI grades (p < 0.05, independent t-test).

CONCLUSION

 GON decompression is effective in chronic occipital headache and in ON symptoms induced by GON entrapment.

State of the Art and Advances in Peripheral Nerve Surgery

This review is intended to describe and actualize the basic knowledge of the three basic entities that affect the peripheral nerve system and can be treated by surgery: nerve trauma, chronic nerve compressions, and tumors.Regarding trauma, emphasis is given on the timing of surgery, given the fact that the moment in which the surgery is performed and the employed microsurgical reconstruction technique are the most important factors in the final result. Open lesions with associated nerve injury should be managed with an early exploration carried out before 7 days. Closed injuries are usually deferred, with few exceptions, from 3 to 6 months after the trauma.In turn, chronic compressions require an appropriate clinical, neurophysiological, and imaging diagnosis. Isolated sensory symptoms can be treated actively though without surgery: motor signs like atrophy should be regarded as a sign for immediate surgery, as a deferred treatment might cause an irreversible nerve and muscular damage. Endoscopic approaches are a valuable tool for treatment in selected neuropathies.Finally, nerve tumors demand a thorough preoperative evaluation, as benign tumors are treated in a very different way when compared to malignant lesions. Benign tumors can usually be safely and completely resected without sacrificing the nerve of origin. When malignancy is confirmed, extensive resection to optimize patient survival is the main objective, potentially at the expense of neurological function. This may then be followed by adjuvant radiation and/or chemotherapy, depending on the nature of the tumor and the completeness of resection attained. The role of nerve biopsy remains controversial, and several modern diagnostic techniques might be helpful.

Decompression of the Greater Occipital Nerve for Persistent Headache Attributed to Whiplash Accompanying Referred Facial Trigeminal Pain

OBJECTIVE

Persistent headache attributed to whiplash (PHAW) is defined as a headache that occurs for the first time in close temporal relation to whiplash lasting more than 3 months. We investigated the results of decompression of the greater occipital nerve (GON) in patients with PHAW who presented with referred trigeminal facial pain caused by sensitization of the trigeminocervical complex) along with occipital headache.

METHODS

A 1-year follow-up study of GON decompression was conducted in 7 patients with PHAW manifesting referred facial trigeminal pain. The degree of pain reduction was analyzed using the numeric rating scale (NRS-11) and percent pain relief before and 1 year after surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. Clinical characteristics of headache and facial pain and surgical findings were studied.

RESULTS

GON decompression was effective in all 7 patients with PHAW manifesting referred trigeminal pain, with a percent pain relief of 83.06 ± 17.30. The pain had disappeared in 3 of 7 patients (42.9%) within 6 months and no further treatment was needed. Patients' assessment of subjective improvement based on a 10-point Likert scale was 7.23 ± 1.25. It was effective in both occipital and facial pain.

CONCLUSIONS

Although chronic GON entrapment itself is an individual constitutional issue, postwhiplash inflammatory changes seem to trigger chronic occipital headaches in GON distribution and unexplained referred trigeminal pain caused by sensitization of the trigeminocervical complex.

Headache Related to PPE Use during the COVID-19 Pandemic

PURPOSE OF REVIEW

Personal protection equipment (PPE)-associated headache is an unusual secondary headache disorder that predominantly occurs in healthcare workers as a consequence of the donning of protective respirators, face masks and/or eyewear. The appreciation of this entity is important given the significant ramifications upon the occupational health of healthcare workers and could additionally have an impact on persons living with pre-existing headache disorder(s).

RECENT FINDINGS

There has been a renewed interest and recognition of PPE-associated headaches amongst healthcare professionals, largely brought about by the ongoing COVID-19 pandemic which has besieged healthcare systems worldwide. De novo PPE-associated headaches may present with migrainous or tension-type features and can be viewed as a subtype of external compression headache. The prognosis of the disorder is generally favourable, given that most headaches are short-lived without long-term sequalae. Several aetiologies have been postulated to account for the development of these headaches. Notably, these headaches can affect the occupational health and work performance of healthcare workers. In this review, we discuss the epidemiology, clinical characteristics, probable etiopathogenesis, management and prognosis of PPE-associated headaches in the context of the COVID-19 pandemic. Future directions for research and PPE development are proposed.

Association of Personal Protective Equipment with De Novo Headaches in Frontline Healthcare Workers during COVID-19 Pandemic: A Cross-Sectional Study

OBJECTIVES

 This study aimed to determine the association of personal protective equipment (PPE) usage with new-onset headaches and exacerbation of pre-existing headache disorders among healthcare workers at the frontlines during coronavirus disease 2019 (COVID-19) pandemic.

MATERIALS AND METHODS

 A descriptive cross-sectional survey was conducted across Pakistan in June-July 2020. The study was approved by Ethical Committee, Armed Forces Institute of Dentistry, Rawalpindi (IRB form no.905/Trg-ABP 1K2). A qualitative questionnaire was developed and was shared via different social networks. The questionnaire was closed when 241 responses were received.

STATISTICAL ANALYSIS

 Descriptive analysis was performed on demographic data. Chi-squared analysis was performed between demographic data and PPE-usage patterns among participants with or without de novo headaches. Univariable and multivariable logistic regression models were used to compare variables with the development of new-onset headaches. Chi-squared test was also performed between demographic data and other factors that may be causing new-onset headaches. A p-value < 0.05 was considered significant.

RESULTS

 A total of 241 healthcare workers participated, of which 68 participants (28.2%) reported de novo headaches since the start of the pandemic. Incidence of pre-existing headaches (odds ratio [OR] = 1.91; 95% confidence interval [CI]: 0.99-0.37; p = 0.049) was associated with new-onset headaches. Post hoc multivariable logistic regression analysis stated that incidence of pre-existing headaches (OR = 1.88; 95% CI: 0.94-3.78; p = 0.75) and age (OR = 2.21; 95% CI: 0.47-10.33; p = 0.36) was independently associated with new-onset PPE-induced headaches but was not statistically significant. Chi-squared analysis showed a statistically significant relationship between other factors (sleep deprivation, emotional stress, etc.) and department of activity, gender, and occupation (p < 0.05).

CONCLUSION

 Healthcare workers with previous history of pre-existing headaches were found to be more susceptible to PPE-induced headaches during COVID-19 pandemic. However, age and the department where the healthcare workers performed may also be risk factors.

Peripheral Occipital Nerve Decompression Surgery in Migraine Headache

Migraine headache in the occipital region is characterized by a recurrent pain of moderate to severe intensity. However, the diagnosis can be difficult because of the multitude of symptoms overlapping with similar disorders and a pathophysiology that is not well-understood. For this reason, the medical management is often complex and ineffective.

Neck Pain- and Unsteadiness-Inducing Activities and their Relationship to the Presence, Intensity, Frequency, and Disability of Headaches

(1) Background: Headache is a significant public health problem. Despite the association between headache and neck pain, little is known about the relationships among specific activities that generate neck pain and headache. The aim of this study was to identify the specific activities that result in neck pain and unsteadiness, and determine how they are linked to headache in university students. (2) Methods: One hundred and six patients with physician-diagnosed headache and 92 healthy university students completed surveys assessing demographics; the presence, frequency, intensity, and disability of headaches; and activities generating neck pain and unsteadiness. (3) Results: The presence of headache was related to female gender (p = 0.001), neck pain when reading or watching television (p = 0.024), and unsteadiness when moving the head (p = 0.005). Headache-related disability was associated with intensity of neck pain (p < 0.001), neck pain when reading or watching television (p = 0.033), and stumbling (p < 0.001). Headache frequency was related to smoking (p = 0.004), the duration of neck pain-associated symptoms (p = 0.047), and neck pain when driving (p = 0.039). Intensity of headache was associated with female gender (p = 0.002), smoking (p = 0.013), and neck pain-related sleep alterations (p = 0.024). (4) Conclusions: Female gender, smoking, neck pain, and unsteadiness when moving the head are factors related to headache in university students.

Mechanism of Action of OnabotulinumtoxinA in Chronic Migraine: A Narrative Review

Objective

To review the literature on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Background

OnabotulinumtoxinA is a chronic migraine preventive treatment that significantly reduces headache frequency. The traditional mechanism described for onabotulinumtoxinA – reducing muscle contractions – is insufficient to explain its efficacy in migraine, which is primarily a sensory neurological disease.

Methods

A narrative literature review on the mechanism of action of onabotulinumtoxinA in chronic migraine.

Results

Following injection into tissues, onabotulinumtoxinA inhibits soluble N‐ethylmaleimide‐sensitive fusion attachment protein receptor (SNARE)‐mediated vesicle trafficking by cleaving one of its essential proteins, soluble N‐ethylmaleimide‐sensitive fusion attachment protein (SNAP‐25), which occurs in both motor and sensory nerves. OnabotulinumtoxinA inhibits regulated exocytosis of motor and sensory neurochemicals and proteins, as well as membrane insertion of peripheral receptors that convey pain from the periphery to the brain, because both processes are SNARE dependent. OnabotulinumtoxinA can decrease exocytosis of pro‐inflammatory and excitatory neurotransmitters and neuropeptides such as substance P, calcitonin gene‐related peptide, and glutamate from primary afferent fibers that transmit nociceptive pain and participate in the development of peripheral and central sensitization. OnabotulinumtoxinA also decreases the insertion of pain‐sensitive ion channels such as transient receptor potential cation channel subfamily V member 1 (TRPV1) into the membranes of nociceptive neurons; this is likely enhanced in the sensitized neuron. For chronic migraine prevention, onabotulinumtoxinA is injected into 31‐39 sites in 7 muscles of the head and neck. Sensory nerve endings of neurons whose cell bodies are located in trigeminal and cervical ganglia are distributed throughout the injected muscles, and are overactive in people with migraine. Through inhibition of these sensory nerve endings, onabotulinumtoxinA reduces the number of pain signals that reach the brain and consequently prevents activation and sensitization of central neurons postulated to be involved in migraine chronification.

Conclusion

OnabotulinumtoxinA likely acts via sensory mechanisms to treat chronic migraine.

Headaches Associated With Personal Protective Equipment - A Cross-Sectional Study Among Frontline Healthcare Workers During COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease of pandemic proportions. Healthcare workers in Singapore working in high-risk areas were mandated to wear personal protective equipment (PPE) such as N95 face mask and protective eyewear while attending to patients.

OBJECTIVES

We sought to determine the risk factors associated with the development of de novo PPE-associated headaches as well as the perceived impact of these headaches on their personal health and work performance. The impact of COVID-19 on pre-existing headache disorders was also investigated.

METHODS

This is a cross-sectional study among healthcare workers at our tertiary institution who were working in high-risk hospital areas during COVID-19. All respondents completed a self-administered questionnaire.

RESULTS

A total of 158 healthcare workers participated in the study. Majority [126/158 (77.8%)] were aged 21-35 years. Participants included nurses [102/158 (64.6%)], doctors [51/158 (32.3%)], and paramedical staff [5/158 (3.2%)]. Pre-existing primary headache diagnosis was present in about a third [46/158 (29.1%)] of respondents. Those based at the emergency department had higher average daily duration of combined PPE exposure compared to those working in isolation wards [7.0 (SD 2.2) vs 5.2 (SD 2.4) hours, P < .0001] or medical ICU [7.0 (SD 2.2) vs 2.2 (SD 0.41) hours, P < .0001]. Out of 158 respondents, 128 (81.0%) respondents developed de novo PPE-associated headaches. A pre-existing primary headache diagnosis (OR = 4.20, 95% CI 1.48-15.40; P = .030) and combined PPE usage for >4 hours per day (OR 3.91, 95% CI 1.35-11.31; P = .012) were independently associated with de novo PPE-associated headaches. Since COVID-19 outbreak, 42/46 (91.3%) of respondents with pre-existing headache diagnosis either "agreed" or "strongly agreed" that the increased PPE usage had affected the control of their background headaches, which affected their level of work performance.

CONCLUSION

Most healthcare workers develop de novo PPE-associated headaches or exacerbation of their pre-existing headache disorders.