Greater occipital nerve block is ineffective in chronic tension type headache

Use of corticosteroids for adult chronic pain interventions: sympathetic and peripheral nerve blocks, trigger point injections - guidelines from the American Society of Regional Anesthesia and Pain Medicine, the American Academy of Pain Medicine, the American Society of Interventional Pain Physicians, the International Pain and Spine Intervention Society, and the North American Spine Society

BACKGROUND

There is potential for adverse events from corticosteroid injections, including increase in blood glucose, decrease in bone mineral density and suppression of the hypothalamic-pituitary axis. Published studies note that doses lower than those commonly injected provide similar benefit.

METHODS

Development of the practice guideline was approved by the Board of Directors of American Society of Regional Anesthesia and Pain Medicine with several other societies agreeing to participate. The scope of guidelines was agreed on to include safety of the injection technique (landmark-guided, ultrasound or radiology-aided injections); effect of the addition of the corticosteroid on the efficacy of the injectate (local anesthetic or saline); and adverse events related to the injection. Based on preliminary discussions, it was decided to structure the topics into three separate guidelines as follows: (1) sympathetic, peripheral nerve blocks and trigger point injections; (2) joints; and (3) neuraxial, facet, sacroiliac joints and related topics (vaccine and anticoagulants). Experts were assigned topics to perform a comprehensive review of the literature and to draft statements and recommendations, which were refined and voted for consensus (≥75% agreement) using a modified Delphi process. The United States Preventive Services Task Force grading of evidence and strength of recommendation was followed.

RESULTS

This guideline deals with the use and safety of corticosteroid injections for sympathetic, peripheral nerve blocks and trigger point injections for adult chronic pain conditions. All the statements and recommendations were approved by all participants after four rounds of discussion. The Practice Guidelines Committees and Board of Directors of the participating societies also approved all the statements and recommendations. The safety of some procedures, including stellate blocks, lower extremity peripheral nerve blocks and some sites of trigger point injections, is improved by imaging guidance. The addition of non-particulate corticosteroid to the local anesthetic is beneficial in cluster headaches but not in other types of headaches. Corticosteroid may provide additional benefit in transverse abdominal plane blocks and ilioinguinal/iliohypogastric nerve blocks in postherniorrhaphy pain but there is no evidence for pudendal nerve blocks. There is minimal benefit for the use of corticosteroids in trigger point injections.

CONCLUSIONS

In this practice guideline, we provided recommendations on the use of corticosteroids in sympathetic blocks, peripheral nerve blocks, and trigger point injections to assist clinicians in making informed decisions.

Efficacy of Adding a Distal Level Block to a C2 Level Greater Occipital Nerve Block under Ultrasound Guidance in Chronic Migraine

Objective

To investigate the benefit of adding a distal level greater occipital nerve (GON) block to the proximal level GON block under ultrasound guidance in patients with chronic migraine (CM) with cutaneous allodynia (CA).

Methods

Seventy-eight patients with CM were included. A single US-guided GON block was performed at proximal and distal levels in patients with CM with CA and only at the proximal level in patients with CM without CA. Thirty (38.5%) patients with bilateral pain received bilateral GON blocks, and 48 (61.5%) with unilateral pain received unilateral GON blocks. The patients were evaluated using Numeric Rating Scale (NRS) scores before treatment and 1 and 4 weeks after treatment and through Headache Impact Test-6 (HIT-6) scores before treatment and 4 weeks after treatment.

Results

The NRS scores significantly decreased at first and fourth weeks, and the HIT-6 scores significantly decreased at fourth week (p < 0.001) compared with preintervention scores in all groups. No significant difference was found between the groups regarding the postinterventional first and fourth week when the decreases of NRS and HIT-6 scores were compared (p = 0.599). There were no significant differences in the effectiveness of unilateral and bilateral GON blocks (p > 0.001).

Conclusion

A single US-guided GON block is an effective and safe treatment option in patients with CM, providing a positive effect on pain and quality of life for 4 weeks. The addition of a distal level GON block to the proximal level GON block provides no extra benefit to patients with CM with CA.

Literature Review: Pericranial Nerve Blocks for Chronic Migraines

Purpose of Review

Headaches, especially migraines, are one of the most pervasive neurological disorders affecting up to 15.9% of the population. Current methods of migraine treatment include lifestyle changes, pharmacologic, and minimally invasive techniques such as peripheral nerve stimulation (PNS) and pericranial nerve blocks (PNB).

Recent Findings

PNBs are used to treat and prevent migraines and involves injection of local anesthetics with or without corticosteroids. PNBs include the greater occipital, supraorbital, supratrochlear, lesser occipital, auriculotemporal, sphenopalantine ganglion, and cervical root nerve blocks. Of the PNBs, the most extensively studied is the greater occipital nerve block (GONB) which has been shown to be an efficacious treatment for migraines, trigeminal neuralgia, hemi-crania continua, and post-lumbar puncture, post-concussive, cluster, and cervicogenic headaches but not medication overuse and chronic tension type headaches.

Summary

In this review, we aim to summarize the recent literature on PNBs and their efficacy in the treatment of migraines including a brief discussion of peripheral nerve stimulation.

Three men in a boat: The comparison of the combination therapy of botulinum toxin and greater occipital nerve block with bupivacaine, with botulinum toxin monotherapy in the management of chronic migraine

OBJECTIVE

This study compared the impact of the combination therapy of onabotulinum toxin A and greater occipital nerve block (GoNT-A) with onabotulinum toxin A monotherapy (BoNT-A) based on its efficacy and safety in relation to the quality of life of adult chronic migraine (CM) patients.

BACKGROUND

Prophylactic treatment of CM is still difficult and complex. Combination treatments do not have an evidence base yet.

METHODS

This retrospective study included 85 patients. For greater occipital nerve block (GONB), 4 ml of the solution prepared using 1 ml of 0.5% bupivacaine and 3 ml of saline on both sides were bilaterally applied to 30 patients. For BoNT-A treatment, a total of 155 units of onabotulinum toxin A (BOTOX®) was intramuscularly injected into 31 specific points around the head and neck in 27 patients. Both protocols were similarly applied to 28 patients for GoNT-A treatment. MIDAS and HIT-6 scores were evaluated to measure patients' quality of life three months after the treatment.

RESULTS

When MIDAS and HIT-6 score groups were statistically compared, both GONB and GoNT-A applications showed a statistically significant reduction compared to the BoNT-A application (p < 0.05). The decrease in the MIDAS and HIT-6 scores of GONB and GoNT-A applications did not show a statistical difference (p > 0.05).

CONCLUSION

The combination of BoNT-A and GONB was superior to BoNT-A applied as monotherapy. Alternately, no significant difference was found between GONB therapy and combination therapy in all data. Combination treatments were well tolerated.

Efficacy of ultrasound-guided greater occipital nerve pulsed radiofrequency therapy in chronic refractory migraine

OBJECTIVE

Ultrasound (US) guided pulsed radiofrequency (PRF) therapy can be used on the greater occipital nerve (GON) in patients with chronic migraine (CM) who are unresponsive to conservative treatments. We aimed to demonstrate the change in pain intensity, duration of migraine episodes, frequency of attacks, migraine disability, depression, and sleep disturbance scores before and after treatment in patients with CM who underwent US-guided GON PRF and the effectiveness of treatment.

PATIENTS AND METHODS

According to the International Classification of Headache Disorders III beta version diagnostic criteria, 25 of 43 patients with CM whom treated with GON PRF were included in the study. The Migraine Disability Assessment Scale (MIDAS), Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), and a visual analog scale (VAS) were used on patients before GON PRF treatment and at post treatment months 1 and 3.

RESULTS

The median duration and number of migraine episodes in the post-interventional 1st month and 3rd month were significantly shorter and fewer compared with the pre-intervention period (p < 0.001). In the comparison with the pre-intervention values, all of the scoring concepts, namely the MIDAS, VAS, BDI, and PSQI, revealed a significant drop in the postintervention 1st and 3rd month (p < 0.001).

CONCLUSION

In this study, we observed that US-guided GON PRF therapy applied at the proximal (C2) level was a safe and effective treatment option. With GON PRF, we observed a decrease in pain intensity, pain frequency, and duration of episodes, and an improvement in depression symptoms, migraine disability, and sleep disorder scores accompanying chronic migraine.

Greater occipital nerve block in patients with primary headache and early term results

Purpose: Peripheral nerve blocks have long been used in headache treatment and greater occipital nerve (GON) blocks are the most frequently preferred peripheral nerve blocks in patients with headaches in the past years. In this study, the efficacy of GON blocks in patients with primary headache disorders was evaluated. Materials and Methods: This retrospective cohort study was undertaken in April 2021 and April 2022. One hundred twenty-one patients with primary headache disorders were included. Changes in the duration and frequency of headache attacks, pain severity, and type of oral medication before and after the injection treatment during the first and third months of follow-up were evaluated. Results: The number of headache attacks decreased from 13 to 5 and the visual analogue scale(VAS) score decreased from 9 to 5 at the end of the third month in the migraine group. Similarly, the number of headache attacks decreased from 17 to 7 and the VAS score decreased from 8 to 4 in tension-type headache (TTH) group. Improvements in all parameters were found to be statistically significant in both groups. Conclusion: GON block is a low-cost, rapid and minimally invasive treatment, and our data support that this method can be an effective treatment option in patients with migraine and TTH who are resistant to oral medication by reducing the number, frequency and severity of headache attacks. In conclusion, GON blockade should be considered by clinicians as a primary treatment option in patients with migraine and TTH resistant to oral medication.

Role of Greater Occipital Nerve Block in Headache Disorders: A Narrative Review

Background

The proximity of sensory neurons in the upper cervical spinal cord to the trigeminal nucleus caudalis (TNC) neurons and the convergence of sensory input to TNC neurons from both cervical and trigeminal fibers underscore the rationale of using greater occipital nerve block (GON-block) for acute and preventive treatment in various headache disorders.

Objective

The aim of this study was to critically review the existing literature regarding the safety and efficacy of GON-block in various headache disorders.

Methods

We searched the eligible studies in English by searching in PubMed till December 31, 2020 for randomized controlled trials (RCTs), observational studies, open-label studies, case series, and case reports on the efficacy and the safety of GON-block for the treatment of headache disorders using the keywords "greater occipital nerve block", "headache" and "treatment". Studies using combination of GON-block and other peripheral nerve blocks (PNBs) and C2/C3 blocks were excluded.

Results

Seventy-two eligible studies were reviewed. Based on RCTs and open-label studies, good evidence of the efficacy of GON-block was found for migraine, cluster headache (CH), post-dural puncture headache (PDPH), cervicogenic headache (CGH), and occipital neuralgia (ON). The analgesic effect of GON-block outlasted its anesthetic effect by days to weeks. Evidence for acute and short-term (transitional) treatment was more robust than for long-term prevention. GON-block was found to be safe and the treatment-emergent adverse effects (TEAEs) were generally mild and transient.

Conclusion

GON-block is a useful modality of treatment in various headache disorders because of many attractive features such as its early effect in reducing the severity of pain, sustained effect following a single injection, easy technique, minimum invasiveness, minimum TEAE, no drug-to-drug interactions, and negligible cost.

Headache

Headache, an almost universal human experience, is one of the most common complaints encountered in medicine and neurology. Described and categorized since antiquity, with the first classification by Aretaeus of Cappadocia, other classifications followed. The evaluation of this condition may be straightforward or challenging, and, though often benign, headache may prove to be an ominous symptom. This review discusses the current diagnosis and classification of headache disorders and principles of management, with a focus on migraine, tension-type headache, trigeminal autonomic cephalgias, and various types of daily headache.

Injection Therapy for Headache and Facial Pain

Peripheral nerve blocks are an increasingly viable treatment option for selected groups of headache patients, particularly those with intractable headache or facial pain. Greater occipital nerve block, the most widely used local anesthetic procedure in headache conditions, is particularly effective, safe, and easy to perform in the office. Adverse effects are few and infrequent. These procedures can result in rapid relief of pain and allodynia, and effects last for several weeks or months. Use of nerve block procedures and potentially onabotulinum toxin therapy should be expanded for patients with intractable headache disorders who may benefit, although more studies are needed for efficacy and clinical safety.

Neuralgias of the Head: Occipital Neuralgia

Occipital neuralgia is defined by the International Headache Society as paroxysmal shooting or stabbing pain in the dermatomes of the greater or lesser occipital nerve. Various treatment methods exist, from medical treatment to open surgical procedures. Local injection with corticosteroid can improve symptoms, though generally only temporarily. More invasive procedures can be considered for cases that do not respond adequately to medical therapies or repeated injections. Radiofrequency lesioning of the greater occipital nerve can relieve symptoms, but there is a tendency for the pain to recur during follow-up. There also remains a substantial group of intractable patients that do not benefit from local injections and conventional procedures. Moreover, treatment of occipital neuralgia is sometimes challenging. More invasive procedures, such as C2 gangliotomy, C2 ganglionectomy, C2 to C3 rhizotomy, C2 to C3 root decompression, neurectomy, and neurolysis with or without sectioning of the inferior oblique muscle, are now rarely performed for medically refractory patients. Recently, a few reports have described positive results following peripheral nerve stimulation of the greater or lesser occipital nerve. Although this procedure is less invasive, the significance of the results is hampered by the small sample size and the lack of long-term data. Clinicians should always remember that destructive procedures carry grave risks: once an anatomic structure is destroyed, it cannot be easily recovered, if at all, and with any destructive procedure there is always the risk of the development of painful neuroma or causalgia, conditions that may be even harder to control than the original complaint.

Nerve block for the treatment of headaches and cranial neuralgias - a practical approach

BACKGROUND

Several studies have presented evidence that blocking peripheral nerves is effective for the treatment of some headaches and cranial neuralgias, resulting in reduction of the frequency, intensity, and duration of pain.

OBJECTIVES

In this article we describe the role of nerve block in the treatment of headaches and cranial neuralgias, and the experience of a tertiary headache center regarding this issue. We also report the anatomical landmarks, techniques, materials used, contraindications, and side effects of peripheral nerve block, as well as the mechanisms of action of lidocaine and dexamethasone.

CONCLUSIONS

The nerve block can be used in primary (migraine, cluster headache, and nummular headache) and secondary headaches (cervicogenic headache and headache attributed to craniotomy), as well in cranial neuralgias (trigeminal neuropathies, glossopharyngeal and occipital neuralgias). In some of them this procedure is necessary for both diagnosis and treatment, while in others it is an adjuvant treatment. The block of the greater occipital nerve with an anesthetic and corticosteroid compound has proved to be effective in the treatment of cluster headache. Regarding the treatment of other headaches and cranial neuralgias, controlled studies are still necessary to clarify the real role of peripheral nerve block.

Expert consensus recommendations for the performance of peripheral nerve blocks for headaches--a narrative review

OBJECTIVE

To describe a standardized methodology for the performance of peripheral nerve blocks (PNBs) in the treatment of headache disorders.

BACKGROUND

PNBs have long been employed in the management of headache disorders, but a wide variety of techniques are utilized in literature reports and clinical practice.

METHODS

The American Headache Society Special Interest Section for PNBs and other Interventional Procedures convened meetings during 2010-2011 featuring formal discussions and agreements about the procedural details for occipital and trigeminal PNBs. A subcommittee then generated a narrative review detailing the methodology.

RESULTS

PNB indications may include select primary headache disorders, secondary headache disorders, and cranial neuralgias. Special procedural considerations may be necessary in certain patient populations, including pregnancy, the elderly, anesthetic allergy, prior vasovagal attacks, an open skull defect, antiplatelet/anticoagulant use, and cosmetic concerns. PNBs described include greater occipital, lesser occipital, supratrochlear, supraorbital, and auriculotemporal injections. Technical success of the PNB should result in cutaneous anesthesia. Targeted clinical outcomes depend on the indication, and include relief of an acute headache attack, terminating a headache cycle, and transitioning out of a medication-overuse pattern. Reinjection frequency is variable, depending on the indications and agents used, and the addition of corticosteroids may be most appropriate when treating cluster headache.

CONCLUSIONS

These recommendations from the American Headache Society Special Interest Section for PNBs and other Interventional Procedures members for PNB methodology in headache disorder treatment are derived from the available literature and expert consensus. With the exception of cluster headache, there is a paucity of evidence, and further research may result in the revision of these recommendations to improve the outcome and safety of these interventions.

Occipital nerve block is effective in craniofacial neuralgias but not in idiopathic persistent facial pain

Occipital nerve block (ONB) has been used in several primary headache syndromes with good results. Information on its effects in facial pain is sparse. In this chart review, the efficacy of ONB using lidocaine and dexamethasone was evaluated in 20 patients with craniofacial pain syndromes comprising 8 patients with trigeminal neuralgia, 6 with trigeminal neuropathic pain, 5 with persistent idiopathic facial pain and 1 with occipital neuralgia. Response was defined as an at least 50% reduction of original pain. Mean response rate was 55% with greatest efficacy in trigeminal (75%) and occipital neuralgia (100%) and less efficacy in trigeminal neuropathic pain (50%) and persistent idiopathic facial pain (20%). The effects lasted for an average of 27 days with sustained benefits for 69, 77 and 107 days in three patients. Side effects were reported in 50%, albeit transient and mild in nature. ONBs are effective in trigeminal pain involving the second and third branch and seem to be most effective in craniofacial neuralgias. They should be considered in facial pain before more invasive approaches, such as thermocoagulation or vascular decompression, are performed, given that side effects are mild and the procedure is minimally invasive.

Ultrasound-guided greater occipital nerve block for patients with occipital headache and short term follow up

BACKGROUND

The greater occipital nerve (GON) block has been frequently used for different types of headache, but performed with rough estimates of anatomic landmarks. Our study presents the values of the anatomic parameters and estimates the effectiveness of the ultrasound-guided GON blockade.

METHODS

The GON was detected using ultrasound technique and distance from external occipital protuberance (EOP) to GON, from GON to occipital artery and depth from skin to GON was measured in volunteers. Patients with occipital headache were divided into two groups (ultrasound-guided block: group S, conventional blind block: group B) and GON block was performed. The same parameters were measured on group S and VAS scores were assessed at pretreatment, 1 week and 4 weeks after treatment on both groups.

RESULTS

The GON had distance of 23.1 ± 3.4 mm (right) and 20.5 ± 2.8 mm (left) from EOP to GON. Its depth below the skin was 6.8 ± 1.5 mm (right) and 7.0 ± 1.3 mm (left). The distance from GON to occipital artery was 1.5 ± 0.6 mm (right) and 1.2 ± 0.6 mm (left) in volunteers. Initial VAS score of group S and group B patients were 6.4 ± 0.2 and 6.5 ± 0.2. VAS score of 4 weeks after injection were 2.3 ± 0.2 on group S and 3.8 ± 0.3 on group B (P = 0.0003).

CONCLUSIONS

The parameters measured in this study should be useful for GON block and ultrasound-guided blockade is likely to be a more effective technique than blind blockade in occipital headache treatment.

Drug and Nondrug Treatment in Tension-type Headache

Tension-type headache (TTH) is a common primary headache with tremendous socioeconomic impact. Establishment of an accurate diagnosis is important before initiation of any treatment. Nondrug management is crucial. Information, reassurance and identification of trigger factors may be rewarding. Psychological treatments with scientific evidence for efficacy include relaxation training, EMG biofeedback and cognitive-behavioural therapy. Physical therapy and acupuncture are widely used, but the scientific evidence for efficacy is sparse. Simple analgesics are the mainstays for treatment of episodic TTH. Combination analgesics, triptans, muscle relaxants and opioids should not be used, and it is crucial to avoid frequent and excessive use of simple analgesics to prevent the development of medication-overuse headache. The tricyclic antidepressant amitriptyline is drug of first choice for the prophylactic treatment of chronic TTH. The efficacy is modest and treatment is often hampered by side effects. Thus, treatment of frequent TTH is often difficult and multidisciplinary treatment strategies can be useful. The development of specific nonpharmacological and pharmacological managements for TTH with higher efficacy and fewer side effects is urgently needed. Future studies should also examine the relative efficacy of the various treatment modalities; for example, psychological, physical and pharmacological treatments, and clarify how treatment programs should be optimized to best suit the individual patient.

Ultrasonic doppler flowmeter-guided occipital nerve block

BACKGROUND

Greater occipital nerve block is used in the treatment of headaches and neuralgia in the occipital area. We evaluated the efficacy of ultrasonic doppler flowmeter-guided occipital nerve block in patients experiencing headache in the occipital region in a randomized, prospective, placebo-controlled study.

METHODS

Twenty-six patients, aged 18 to 70, with headache in the occipital region, were included in the study. Patients received a greater occipital nerve block performed either under ultrasonic doppler flowmeter guidance using 1% lidocaine or the traditional method. Sensory examination findings in the occipital region were evaluated.

RESULTS

The complete block rate of greater occipital nerve blockade in the doppler group was significantly higher than in the control group respectively (76.9% vs. 30.8%, P < 0.05). Only one patient in the control group had a complication (minimal bleeding).

CONCLUSIONS

Ultrasonic doppler flowmeter-guided occipital nerve block may be a useful method for patients suffering headache in the occipital region.

Adverse effect profile of lidocaine injections for occipital nerve block in occipital neuralgia

To determine whether there are differences in the adverse effect profile between 1, 2 and 5% Lidocaine when used for occipital nerve blocks (ONB) in patients with occipital neuralgia. Occipital neuralgia is an uncommon cause of headaches. Little is known regarding the safety of Lidocaine injections for treatment in larger series of patients. Retrospective chart analysis of all ONB was performed at our headache clinic during a 6-year period on occipital neuralgia patients. 89 consecutive patients with occipital neuralgia underwent a total of 315 ONB. All the patients fulfilled the IHS criteria for Occipital Neuralgia. Demographic data were collected including age, gender, and ethnicity. The average age of this cohort was 53.25 years, and the majority of patients were females 69 (78%). Ethnicity of patients was diverse, with Caucasian 48(54%), Hispanics 31(35%), and others 10 (11%). 69 patients had 1%, 18 patients had 2% and 29 patient were given 5% Lidocaine. All Lidocaine injections were given with 20 mg Depo-medrol and the same injection technique and location were used for all the procedures. Eight patients (9%)had adverse effects to the Lidocaine and Depo-medrol injections, of which 5 received 5% and 3 received 1% Lidocaine. Majority of patients who had adverse effects were female 7(87%), and had received bilateral blocks (75%). ONB is a safe procedure with 1% Lidocaine; however, caution should be exerted with 5% in elderly patients, 70 or older, especially when administering bilateral injections.

8. Occipital neuralgia

Occipital neuralgia is defined as a paroxysmal shooting or stabbing pain in the dermatomes of the nervus occipitalis major and/or nervus occipitalis minor. The pain originates in the suboccipital region and radiates over the vertex. A suggestive history and clinical examination with short-term pain relief after infiltration with local anesthetic confirm the diagnosis. No data are available about the prevalence or incidence of this condition. Most often, trauma or irritation of the nervi occipitales causes the neuralgia. Imaging studies are necessary to exclude underlying pathological conditions. Initial therapy consists of a single infiltration of the culprit nervi occipitales with local anesthetic and corticosteroids (2 C+). The reported effects of botulinum toxin A injections are contradictory (2 C+/-). Should injection of local anesthetic and corticosteroids fail to provide lasting relief, pulsed radio-frequency treatment of the nervi occipitales can be considered (2 C+). There is no evidence to support pulsed radio-frequency treatment of the ganglion spinale C2 (dorsal root ganglion). As such, this should only be done in a clinical trial setting. Subcutaneous occipital nerve stimulation can be considered if prior therapy with corticosteroid infiltration or pulsed radio-frequency treatment failed or provided only short-term relief (2 C+).

Peripheral nerve blocks and trigger point injections in headache management - a systematic review and suggestions for future research

Interventional procedures such as peripheral nerve blocks (PNBs) and trigger point injections (TPIs) have long been used in the treatment of various headache disorders. There are, however, little data on their efficacy for the treatment of specific headache syndromes. Moreover, there is no widely accepted agreement among headache specialists as to the optimal technique of injection, type, and doses of the local anesthetics used, and injection regimens. The role of corticosteroids in this setting is also debated. We performed a PubMed search of the literature to find studies on PNBs and TPIs for headache treatment. We classified the abstracted studies based on the procedure performed and the treated condition. We found few controlled studies on the efficacy of PNBs for headaches, and virtually none on the use of TPIs for this indication. The most widely examined procedure in this setting was greater occipital nerve block, with the majority of studies being small and non-controlled. The techniques, as well as the type and doses of local anesthetics used for nerve blockade, varied greatly among studies. The specific conditions treated also varied, and included both primary (eg, migraine, cluster headache) and secondary (eg, cervicogenic, posttraumatic) headache disorders. Trigeminal (eg, supraorbital) nerve blocks were used in few studies. Results were generally positive, but should be taken with reservation given the methodological limitations of the available studies. The procedures were generally well tolerated. Evidently, there is a need to perform more rigorous clinical trials to clarify the role of PNBs and TPIs in the management of various headache disorders, and to aim at standardizing the techniques used for the various procedures in this setting.

Nerve blocks in the treatment of headache

Nerve blocks and neurostimulation are reasonable therapeutic options in patients with head and neck neuralgias. In addition, these peripheral nerve procedures can also be effective in primary headache disorders, such as migraine and cluster headaches. Nerve blocks for headaches are generally accomplished by using small subcutaneous injections of amide-type local anesthetics, such as lidocaine and bupivicaine. Targets include the greater occipital nerve, lesser occipital nerve, auriculotemporal nerve, supratrochlear and supraorbital nerves, sphenopalatine ganglion, cervical spinal roots, and facet joints of the upper cervical spine. Although definitive studies examining the usefulness of nerve blocks are lacking, reports suggest that this area deserves further attention in the hope of acquiring evidence of effectiveness.

Occipital nerve blocks: when and what to inject?

INTRODUCTION

Occipital nerve block (ONB) is a promising treatment for headaches. Its indications, selection criteria, and best techniques are not clear, however.

OBJECTIVE

To summarize in narrative format what is known about ONBs and what needs to be learned.

METHODS

MD Consult and Google Scholar were searched using the terms occipital, suboccipital, block, and injection to identify relevant articles that were reviewed. This process was repeated for all additional pertinent articles identified from these articles, and so on, until no additional articles were identified.

RESULTS

A total of 21 articles were identified.

CONCLUSIONS

Occipital nerve block is an effective treatment for cervicogenic headache, cluster headache, and occipital neuralgia. While a double blinded randomized placebo controlled clinical trial is lacking, multiple open label studies reported favorable results for migraine. Two other possible uses of ONB worthy of further study are use as a rescue treatment and as an adjunctive treatment for medication overuse headache. ONB may be effective for tension headache, but only under very specific circumstances. ONB is either ineffective or only effective under as yet unstudied circumstances for hemicrania continua and chronic paroxysmal hemicrania. Some practitioners use occipital nerve (ON) tenderness to palpation (TTP) or reproduction of headache pain with ON pressure (RHPONP) as selection criteria for identifying appropriate patients. While only a clinical trial can produce a definitive answer, current evidence suggests that these selection criteria are not necessary for cervicogenic headache or cluster headache. Occipital neuralgia by definition involves TTP of the ONs. Whether RHPONP or ON TTP predicts success in migraine is unclear, and may relate to whether steroids are used. A single blinded randomized controlled trial evaluating local anesthetic with steroids vs local anesthetic alone for transformed migraine reported slightly worse results with steroids, but there are several alternate explanations for this finding other than steroids being counterproductive. The technique of repetitive ONBs deserves further study.

Anatomical variations of the occipital nerves: implications for the treatment of chronic headaches

BACKGROUND

The anatomy of the greater and lesser occipital nerves has come under increased scrutiny with the increased appreciation of their role in the causation of chronic occipital headaches. Classic anatomical descriptions of their paths have differed from some recent published reports.

METHODS

Measurements of the courses of the greater and lesser occipital nerves were conducted bilaterally in 125 individuals, consisting of 112 live intraoperative measurements and 13 cadaver specimens. In addition to nerve width and trajectory in the occiput, measurements of the distance of the nerves from the occipital protuberance were performed.

RESULTS

The greater occipital nerve had a diameter of 3.8 +/- 1.6 mm, and emerged from the semispinalis capitis muscle 14.9 +/- 4.5 mm lateral to the midline and 30.2 +/- 5.1 mm inferior to the occipital protuberance. The nerve almost always (98.5 percent) pierces the body of the semispinalis capitis muscle, and in 6.1 percent of individuals it is split by fibers of this muscle or in the trapezial tunnel. The nerve then travels in a superolateral course. In 43.9 percent of patients, the nerves were asymmetric on the two sides. The lesser occipital nerve had a diameter of 1.2 +/- 1.6 mm and was often located along the posterior border of the sternocleidomastoid muscle.

CONCLUSIONS

The course of these two nerves differs in several critical aspects from that described in classic anatomical reports. These findings have direct implications for application of nerve blocks and surgical decompression of these nerves.

Tension-type headache: current research and clinical management

Tension-type headache (TTH) is the most common form of headache, and chronic tension-type headache (CTTH) is one of the most neglected and difficult types of headache to treat. The pathogenesis of TTH is multifactorial and varies between forms and individuals. Peripheral mechanisms (myofascial nociception) and central mechanisms (sensitisation and inadequate endogenous pain control) are intermingled: the former predominate in infrequent and frequent TTH, whereas the latter predominate in CTTH. Acute therapy is effective for episodes of TTH, whereas preventive treatment--which is indicated for frequent and chronic TTH--is, on average, not effective. For most patients with CTTH, the combination of drug therapies and non-drug therapies (such as relaxation and stress management techniques or physical therapies) is recommended. There is clearly an urgent need to improve the management of patients who are disabled by headache. This Review summarises the present knowledge on TTH and discusses some of its more problematic features.

Future therapeutic perspectives for tension-type headache

The therapy for tension-type headache remains insufficient, and recent advances have been scarce. Although tricyclic antidepressants are at the forefront of treatment advances, upcoming agents tentatively modifying central sensitization are promising. Botulinum toxin failed to meet expectations. This article reviews current treatments, emphasizing newer approaches. Much remains to be achieved.

Greater occipital nerve block for migraine and other headaches: Is it useful?

Peripheral nerve blocks have long been used in headache treatment. The most widely used procedure for this purpose has been greater occipital nerve (GON) block. The rationale for using GON block in headache treatment comes from evidence for convergence of sensory input to trigeminal nucleus caudalis neurons from both cervical and trigeminal fibers. Although there is no standardized procedure for GON blockade, the nerve is usually infiltrated with a local anesthetic (lidocaine, bupivacaine, or both). A corticosteroid is sometimes added. Several studies suggested efficacy of GON block in the treatment of migraine, cluster headache, and chronic daily headache. However, few were controlled and blinded. Despite a favorable clinical experience, little evidence exists for the efficacy of GON block in migraine treatment. Controlled studies are needed to better assess the role of GON block in the treatment of migraine and other headaches.

Combination of low-dose mirtazapine and ibuprofen for prophylaxis of chronic tension-type headache

Chronic headaches are difficult to treat and represent the biggest challenge in headache centres. Mirtazapine has a prophylactic and ibuprofen an acute effect in tension-type headache. Combination therapy may increase efficacy and lower side effects. We aimed to evaluate the prophylactic effect of a combination of low-dose mirtazapine and ibuprofen in chronic tension-type headache. Ninety-three patients were included in the double-blind, placebo-controlled, parallel trial. Following a 4-week run-in period they were randomized to four groups for treatment with a combination of mirtazapine 4.5 mg and ibuprofen 400 mg, placebo, mirtazapine 4.5 mg or ibuprofen 400 mg daily for 8 weeks. Eighty-four patients completed the study. The primary efficacy parameter, change in area under the headache curve from run-in to the last 4 weeks of treatment, did not differ between combination therapy (190) and placebo (219), P = 0.85. Explanatory analyses revealed worsening of headache already in the third week of treatment with ibuprofen alone. In conclusion, the combination of low-dose mirtazapine and ibuprofen is not effective for the treatment of chronic tension-type headache. Moreover, the study suggests that daily intake of ibuprofen worsens headache already after few weeks in chronic tension-type headache.

Tension-type headache: the most common, but also the most neglected, headache disorder

PURPOSE OF REVIEW

Tension-type headache is the most common type of headache and, in its chronic form, one of the most neglected and difficult types of headache to treat. Recently published data will be reviewed.

RECENT FINDINGS

The prevalence of frequent tension-type headache increased significantly from 1989 to 2001, and several risk factors have been identified. The incidence decreases markedly with age. The prognosis is fairly favorable for the episodic forms. Chronic tension-type headache, coexisting migraine, sleep problems and not being married were identified as risk factors for a poor outcome. Previous reports of sensitization of the central nervous system in patients with chronic tension-type headache were confirmed by the findings of generalized pain hypersensitivity both in skin and in muscles, and of a decrease in the volume of gray matter in brain structures. A promising new animal model of tension-type headache has been developed. In addition, the efficacy of a prophylactic drug, mirtazapine, with fewer side-effects than the tricyclic antidepressants has been demonstrated.

SUMMARY

The new data on the prevalence, incidence and prognosis of tension-type headache are valuable for health care planning and in daily clinical practice. The increased knowledge with regard to abnormal central pain modulation, together with the development of an animal model, hold promise for much-needed improvements in the understanding of pathophysiological mechanisms and treatment.