The trigeminocervical complex and migraine: current concepts and synthesis

Neck pain disability is related to the frequency of migraine attacks: a cross-sectional study

BACKGROUND

Migraine and neck pain can be critical causes of disability. The contribution of neck pain for the overall disability of individuals with migraine remains unknown.

OBJECTIVE

To contrast the disability experienced by individuals with episodic and chronic migraine with and without neck pain as captured by the Neck Disability Index.

METHODS

Disability due to neck pain was assessed using the Neck Disability Index in individuals with episodic or chronic migraine seen at a university-based headache center. Neck disability was defined as mild (score ranging from 5 to 14 points), moderate (15-24 points), severe (25-34 points) or complete (35 points or higher). To compare differences between groups, a chi-square test was applied. Log-binomial logistic regression was used to estimate disability as a function of headache status after adjustments for age, time since migraine onset, and headache intensity.

RESULTS

Sample consisted of 169 individuals, 104 with episodic migraine and 65 with chronic migraine. Any disability due to neck pain happened in 69% of those with episodic migraine, relative to 92% in chronic migraine (P < .001). Individuals with chronic migraine were at a significantly increased risk to have mild (RR = 2.5; CI 95% 1.1-6.1), moderate (RR = 3.7; CI 95% 1.5-8.8) and severe (RR = 5.1; CI 95%2.1-11.9) cervical disability relative to those with episodic migraine. Relative risks remained significant after adjustments. Time since episodic or chronic migraine onset significantly influenced the model (P = .035), but age and headache intensity did not (P = .27; P = .46).

CONCLUSION

Neck pain significantly adds to the overall disability of individuals with episodic and chronic migraine.

Prevalence of neck pain in migraine and tension-type headache: a population study

BACKGROUND

We assessed the prevalence of neck pain in the population in relation to headache.

METHODS

In a cross-sectional study, a total of 797 individuals completed a headache interview and provided self-reported data on neck pain. We identified migraine, TTH or both migraine and TTH (M+TTH) groups. Pericranial tenderness was recorded in 496 individuals. A total tenderness score (TTS) was calculated as the sum of local scores with a maximum score of 48.

RESULTS

The one-year prevalence of neck pain was 68.4% and higher in those with vs. without primary headache (85.7% vs. 56.7%; adjusted OR 3.0, 95% CI 2.0-4.4, p<0.001). Adjusting for age, gender, education and poor self-rated health, in comparison with those without headaches, the prevalence of neck pain (56.7%) was significantly higher in those with M+TTH (89.3%), pure TTH (88.4%) and pure migraine (76.2%) (p<0.05 for all three group comparisons). Individuals with neck pain had higher TTS than individuals without neck pain (15.1±10.5 vs. 8.4±8.0, p<0.001).

CONCLUSIONS

Neck pain is highly prevalent in the general population and even more prevalent in individuals with primary headaches. Prevalence is highest in coexistent M+TTH, followed by pure TTH and migraine. Myofascial tenderness is significantly increased in individuals with neck pain.

Effects of intravenous metamizole on ongoing and evoked activity of dura-sensitive thalamic neurons in rats

Migraine and tension-type headache (TTH) are the most common forms of primary headaches. A general key mechanism underlying development of both the diseases is the trigeminal system activation associated with the ascending nociceptive transmission via the trigemino-thalamo-cortical pathway. The ventroposteromedial (VPM) nucleus is a key thalamic structure, receiving afferent inflow from the craniofacial region; it holds the third-order neurons responsible for conveying sensory information from the extra- and intracranial nociceptors to the cortex. The VPM is currently seen as a therapeutic target for various antimigraine medications, which is shown to reduce the VPM neuronal excitability. A non-opioid analgesic metamizole is widely used in some countries for acute treatment of migraine or TTH. However, the precise mechanisms underlying anticephalgic action of metamizole remain unclear. The objective of our study performed in the rat model of trigemino-durovascular nociception was to evaluate the effects of intravenously administered metamizole on ongoing and evoked firing of the dura-sensitive VPM neurons. The experiments were carried out on rats under urethane-chloralose anesthesia. Cumulative administration of metamizole (thrice-repeated intravenous infusion of 150 mg/kg performed 30 min apart) in 56% of cases produced a suppression of both the ongoing activity of the thalamic VPM neurons and their responses to dural electrical stimulation. Although the inhibitory effect was prevailing, a number of VPM neurons were indifferent to the administration of metamizole. These data suggest that one of the main components of neural mechanism underlying anticephalgic action of metamizole is suppression of the thalamo-cortical nociceptive transmission associated with trigemino-vascular activation.

Orofacial pain management: current perspectives

Some of the most prevalent and debilitating pain conditions arise from the structures innervated by the trigeminal system (head, face, masticatory musculature, temporomandibular joint and associated structures). Orofacial pain (OFP) can arise from different regions and etiologies. Temporomandibular disorders (TMD) are the most prevalent orofacial pain conditions for which patients seek treatment. Temporomandibular disorders include a number of clinical problems that involve the masticatory musculature, the temporomandibular joint (TMJ) or both. Trigeminal neuropathic pain conditions can arise from injury secondary to dental procedures, infection, neoplasias, or disease or dysfunction of the peripheral and/or central nervous system. Neurovascular disorders, such as primary headaches, can present as chronic orofacial pain, such as in the case of facial migraine, where the pain is localized in the second and third division of the trigeminal nerve. Together, these disorders of the trigeminal system impact the quality of life of the sufferer dramatically. A multidisciplinary pain management approach should be considered for the optimal treatment of orofacial pain disorders including both non-pharmacological and pharmacological modalities.

Allodynia and descending pain modulation in migraine: a resting state functional connectivity analysis

OBJECTIVE

Most migraineurs develop cutaneous allodynia during migraines, and many have cutaneous sensitization between attacks. Atypical pain modulation via the descending pain system may contribute to this sensitization and allodynia. The objective of this study was to test the hypothesis that compared with non-allodynic migraineurs, allodynic migraineurs have atypical periaqueductal gray (PAG) and nucleus cuneiformis (NCF) resting-state functional connectivity (rs-fc) with other pain processing regions.

DESIGN

Ten minutes resting-state blood-oxygen-level-dependent data were collected from 38 adult migraineurs and 20 controls. Seed-based analyses compared whole-brain rs-fc with PAG and with NCF in migraineurs with severe ictal allodynia (N = 8) to migraineurs with no ictal allodynia (N = 8). Correlations between the strength of functional connections that differed between severely allodynic and non-allodynic migraineurs with allodynia severity were determined for all migraineurs (N = 38). PAG and NCF rs-fc in all migraineurs was compared with rs-fc in controls.

RESULTS

Migraineurs with severe allodynia had stronger PAG and NCF rs-fc to other brainstem, thalamic, insula and cerebellar regions that participate in discriminative pain processing, as well as to frontal and temporal regions implicated in higher order pain modulation. Evidence that these rs-fc differences were specific for allodynia included: 1) strong correlations between some rs-fc strengths and allodynia severity among all migraineurs; and 2) absence of overlap when comparing rs-fc differences in severely allodynic vs non-allodynic migraineurs with those in all migraineurs vs controls.

CONCLUSION

Atypical rs-fc of brainstem descending modulatory pain regions with other brainstem and higher order pain-modulating regions is associated with migraine-related allodynia.

Peripheral neuromodulation and headaches: history, clinical approach, and considerations on underlying mechanisms

Implantable peripheral neurostimulation was introduced in 1969 as a potential treatment for certain neuropathic pain syndromes, primarily involving the limbs. While a few early studies included implants for occipital neuralgia, serious interest in its potential as a treatment for head pain came only after our 1999 report of positive findings in a series of patients with occipital neuralgia. Subsequent investigators confirmed these initial findings, and then extended the application to patients with various primary headache disorders, including migraine. While most found a therapeutic response, the degree of that response varied significantly, and analysis suggests that the issue of paresthesia concordancy may be central, both in explaining the data, as well as providing direction for future endeavors. Therefore, while at present peripheral neurostimulation is gaining increasing acceptance as a treatment for chronic headaches, the precise clinical indications and procedures, as well as the underlying neurophysiological mechanisms, are still being worked out.

Neurostimulation in cluster headache: A review of current progress

Purpose of review

Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide an overview of the rationale, methods and progress for each of these.

Latest findings

Results from a randomized, controlled trial investigating sphenopalatine ganglion stimulation have just been published. Reportedly the surgery is relatively simple and it is apparently the only therapy that provides relief acutely.

Summary

The rationale behind these therapies is based on growing evidence from clinical, hormonal and neuroimaging studies. The overall results are encouraging, but unfortunately not all patients have benefited. All the mentioned therapies require weeks to months of stimulation for a prophylactic effect to occur, suggesting brain plasticity as a possible mechanism, and only stimulation of the sphenopalatine ganglion has demonstrated an acute, abortive effect. Predictors of effect for all modes of neurostimulation still need to be identified and in the future, the least invasive and most effective strategy must be preferred as first-line therapy for intractable chronic cluster headache.

Posttraumatic headache

Headache is a common symptom after traumatic head injury and is a frequent feature of the postconcussive syndrome. A variety of headache subtypes can be precipitated by head trauma, although posttraumatic headaches most often resemble migraine or tension-type headache. A lack of clinical trials limits evidence-based treatment recommendations for both acute and chronic posttraumatic headaches. However, numerous pharmacologic and nonpharmacologic interventions can be used to successfully manage posttraumatic headaches. This article reviews the classification, epidemiology, prognosis, and pathophysiology of headaches after head trauma and provides a practical clinical approach for evaluating and treating patients with posttraumatic headaches.

Effect of cortical spreading depression on basal and evoked traffic in the trigeminovascular sensory system

AIM

To use an animal model to test whether migraine pain arises peripherally or centrally.

METHODS

We monitored the spontaneous and evoked activity of second-order trigeminovascular neurons in rats to test whether traffic increased following a potential migraine trigger (cortical spreading depression, CSD) and by what mechanism any such change was mediated.

RESULTS

Neurons (n = 33) responded to stimulation of the dura mater and facial skin with A-δ latencies. They were spontaneously active with a discharge rate of 6.1 ± 6.4 discharges s(-1). Injection of 10 µg lignocaine into the trigeminal ganglion produced a fully reversible reduction of the spontaneous discharge rate of neurons. Neuronal discharge rate returned to normal by 90 min. Lignocaine reduced the evoked responses of neurons to dural stimulation to 37% and to facial skin stimulation to 53% of control. Induction of CSD by cortical injection of KCl increased the spontaneous discharge rate of neurons from 2.9 to 16.3 discharges s(-1) at 20 min post CSD. Injection of 10 µg lignocaine into the trigeminal ganglion at this time failed to arrest or reverse this increase. Injection of lignocaine prior to the initiation of CSD failed to prevent the subsequent development of CSD-induced increases in discharge rates.

CONCLUSIONS

These results suggest that there is a continuous baseline traffic in primary trigeminovascular fibres and that CSD does not act to increase this traffic by a peripheral action alone - rather, it must produce some of its effect by a mechanism intrinsic to the central nervous system. Thus the pain of migraine may not always be the result of peripheral sensory stimulation, but may also arise by a central mechanism.

Validation of the peripheral trigger point theory of migraine headaches: single-surgeon experience using botulinum toxin and surgical decompression

BACKGROUND

Migraine headache is a widespread neurovascular disorder that is often suboptimally or incompletely treated. This article confirms the efficacy of botulinum toxin treatment with surgical decompression as a deactivator of migraine headache trigger sites through the retrospective analysis of a single surgeon's experience.

METHODS

A retrospective chart review was performed on 24 patients presenting with the diagnosis of migraine headache. Botulinum toxin type A injections were used to identify frontal, temporal, and/or occipital trigger points. The nasal trigger point was diagnosed with a decongestant trial, intranasal examination, and computed tomographic scan. Those patients with more than one trigger point underwent multiple surgical procedures, which were performed concomitantly during the same operation. All botulinum toxin injections, surgical procedures, and patient meetings were conducted by the principal investigator (J.E.J.), minimizing intrapatient treatment variability and multiprovider bias.

RESULTS

Patient progress was tracked by consolidating migraine frequency, severity, and duration as a Migraine Headache Index. Nineteen patients (79.2 percent) benefited from surgery. Two patients (8.3 percent) reported migraine elimination and 17 patients (70.8 percent) reported significant improvement of their migraine symptoms. Among those patients who responded to surgery, average improvement from baseline levels was 96.9 percent. Among the entire patient population, average improvement was 78.2 percent from baseline. The mean postsurgical follow-up was 661 days.

CONCLUSION

This study found botulinum toxin treatment with surgical decompression to be a potent deactivator of migraine headache trigger sites, corroborating the findings of the current literature in the field and underlining the reproducibility of the treatment.

CLINICAL QUESTION/LEVEL OF EVIDENCE

: Therapeutic, IV.(Figure is included in full-text article.).

Brain tumor headaches: from bedside to bench

Although most people who have headache pain do not present with an underlying mass lesion, a large number of patients with brain tumors do report headache (as many as 60% in our institution). The problem for clinicians is that the tumor-headache association is not universal, as evidenced by anecdotal reports of patients with large tumors and increased intracranial pressure, but a complete absence of headache pain. In this review, we examine more than 80 years of research on brain tumor headaches, delineating the link between tumor location, laterality, growth rate, and pain. Most importantly, we position our review within the context of current etiological theories and propose new models involving the peripheral and central sensitization of nociresponsive neurons. This review will help clinicians understand why debulking surgery sometimes fails to alleviate neoplastic headache pain in select patients. A brief examination of headaches as a result of surgery and adjuvant chemoradiation therapy is also provided. Headaches can be an early indicator of central nervous system tumors. However, headaches are present in a wide variety of other condition, and are sometimes (surprisingly) absent in patients with primary neoplasms or metastatic tumors. This observation complicates the possibility of linking headaches to brain tumors. Nevertheless, some generalizations concerning brain tumor headaches can be drawn. The following sections review these generalizations, presenting caveats where appropriate. Lingering questions in the field are also addressed and presented together with promising future research avenues.

Triptan-induced enhancement of neuronal nitric oxide synthase in trigeminal ganglion dural afferents underlies increased responsiveness to potential migraine triggers

Migraine is a common neurological disorder often treated with triptans. Triptan overuse can lead to increased frequency of headache in some patients, a phenomenon termed medication overuse headache. Previous preclinical studies have demonstrated that repeated or sustained triptan administration for several days can elicit persistent neural adaptations in trigeminal ganglion cells innervating the dura, prominently characterized by increased labelling of neuronal profiles for calcitonin gene related peptide. Additionally, triptan administration elicited a behavioural syndrome of enhanced sensitivity to surrogate triggers of migraine that was maintained for weeks following discontinuation of drug, a phenomenon termed 'triptan-induced latent sensitization'. Here, we demonstrate that triptan administration elicits a long-lasting increase in identified rat trigeminal dural afferents labelled for neuronal nitric oxide synthase in the trigeminal ganglion. Cutaneous allodynia observed during the period of triptan administration was reversed by NXN-323, a selective inhibitor of neuronal nitric oxide synthase. Additionally, neuronal nitric oxide synthase inhibition prevented environmental stress-induced hypersensitivity in the post-triptan administration period. Co-administration of NXN-323 with sumatriptan over several days prevented the expression of allodynia and enhanced sensitivity to stress observed following latent sensitization, but not the triptan-induced increased labelling of neuronal nitric oxide synthase in dural afferents. Triptan administration thus promotes increased expression of neuronal nitric oxide synthase in dural afferents, which is critical for enhanced sensitivity to environmental stress. These data provide a biological basis for increased frequency of headache following triptans and highlight the potential clinical utility of neuronal nitric oxide synthase inhibition in preventing or treating medication overuse headache.

Animal models of headache: from bedside to bench and back to bedside

In recent years bench-based studies have greatly enhanced our understanding of headache pathophysiology, while facilitating the development of new headache medicines. At present, established animal models of headache utilize activation of pain-producing cranial structures, which for a complex syndrome, such as migraine, leaves many dimensions of the syndrome unstudied. The focus on modeling the central nociceptive mechanisms and the complexity of sensory phenomena that accompany migraine may offer new approaches for the development of new therapeutics. Given the complexity of the primary headaches, multiple approaches and techniques need to be employed. As an example, recently a model for trigeminal autonomic cephalalgias has been tested successfully, while by contrast, a satisfactory model of tension-type headache has been elusive. Moreover, although useful in many regards, migraine models are yet to provide a more complete picture of the disorder.

Do pediatric headaches respond to bilateral lower cervical paraspinous bupivacaine injections?

OBJECTIVE

Bilateral lower cervical paraspinous intramuscular bupivacaine injections have recently been reported as a therapeutic modality for headache pain in adult patients presenting to an emergency department. In this study, we accomplished a retrospective review of all pediatric patients with headaches who were treated with this technique in an emergency department setting over a 16-month period. The therapeutic response of all pediatric patients who received bilateral lower cervical paraspinous intramuscular bupivacaine injections for headache pain is described in this article.

METHODS

Three separate databases were reviewed to capture all patients younger than 18 years with a diagnosis of headache who received bilateral cervical injections between June 30, 2003, and December 1, 2004, in the Medical College of Georgia and Children's Medical Center emergency departments. Their medical records were retrospectively reviewed to determine their response to this procedure.

RESULTS

The headaches of 13 patients younger than 18 years were treated with this procedure. The mean headache severity was 9.15, and the mean duration of headache was 3.16 days. Six (46.2%) of 13 patients had complete relief of their headaches, whereas 5 (38.4%) of 13 patients had partial relief. No significant relief was documented in 2 (15.4%) of 13 patients. A therapeutic response was documented in 11 (84.6%) of 13 of the patients.

CONCLUSIONS

These retrospective observations suggest that bilateral lower cervical paraspinous intramuscular injections with small amounts of bupivacaine may have a therapeutic role in the management of headache pain in children, and their rate of therapeutic response may be similar to that recently reported for adult headache patients.

[Impact of physiotherapy, massages and lymphatic drainage in migraine therapy]

Physical treatment, spinal manipulative therapy and massages are often recommended to treat migraine as a prophylactic therapy. Clinical experience and theoretical concepts support their usefulness. However, data on these therapies are scarce. On the basis of the available studies, it is impossible to determine whether or not these therapies are effective. There is a lack of well-designed prospective, randomized controlled trials with a sufficiently long follow-up to observe these therapies. Due to the high acceptance of physical treatment on the one hand and preconceptions about drug treatment on the other, these types of therapies may be an alternative option for some patients if their efficacy is established. A cost-benefit analysis of theses therapies should consider the long amount of time required for them compared with drug intake.

Combined occipital and supraorbital neurostimulation for the treatment of chronic migraine headaches: Initial experience

A novel approach to the treatment of chronic migraine headaches based on neurostimulation of both occipital and supraorbital nerves was developed and reduced to clinical practice in a series of patients with headaches unresponsive to currently available therapies. Following positive trials, seven patients with chronic migraine and refractory chronic migraine headaches had permanent combined occipital nerve–supraorbital nerve neurostimulation systems implanted. The relative responses to two stimulation programs were evaluated: one that stimulated only the occipital leads and one that stimulated both the occipital and supraorbital leads together. With follow-up ranging from 1 to 35 months all patients reported a full therapeutic response but only to combined supraorbital–occipital neurostimulation. Occipital nerve stimulation alone provided a markedly inferior and inadequate response. Combined occipital nerve–supraorbital nerve neurostimulation systems may provide effective treatment for patients with chronic migraine and refractory chronic migraine headaches. For patients with chronic migraine headaches the response to combined systems appears to be substantially better than occipital nerve stimulation alone.

Prevalence of Facial Pain in Migraine: A Population-Based Study

Unilateral head pain focused on frontal, orbital or parietal regions is a leading symptom of migraine attacks. Rarely, head pain in migraine can extend involving the maxillary or mandibular region of the face, sometimes isolated facial pain is the only and atypical presentation of migraine. The prevalence of these unusual symptoms in migraine is unknown. We aimed to estimate the true prevalence of facial pain in migraine in a population-based sample of 517 migraine patients in Germany. In 46 (8.9%) cases migraine pain involved the head and the lower half of the face. Patients with facial pain suffer more trigemino-autonomic symptoms than migraine patients (47.8% vs. 7.9%; α2 = 66.23, P < 0.001). In one case isolated facial pain without headache was the leading symptom of migraine. Our results demonstrate that facial pain is not unusual in migraine, whereas isolated facial migraine is extremely rare.

Low-Frequency Short-Time Nociceptive Stimulation of the Greater Occipital Nerve does not Modulate the Trigeminal System

Occipital stimulation in a small group of refractory chronic migraine and cluster headache patients has been suggested as a novel therapeutic approach with promising results. In an earlier study we have shown that a drug-induced block of the greater occipital nerve (GON) inhibits the nociceptive blink reflex (nBR). Now, we sought to examine the effects of low-frequency (3 Hz) short-time nociceptive stimulation of the GON on the trigeminal system. We recorded the nBR responses before and after stimulation in 34 healthy subjects. Selectivity of GON stimulation was confirmed by eliciting somatosensory evoked potentials of the GON upon stimulation. In contrast to an anaesthetic block of the occipital nerve, no significant changes of the R2-latencies and R2-response areas of the nBR can be elicited following GON stimulation. Various modes of electrical stimulation exist with differences in frequency, stimulus intensity, duration of stimulation and pulse width. One explanation for a missing modulatory effect in our study is the relatively short duration of the stimulation.

The Role of Cervical Dysfunction in Migraine: A Systematic Review

This systematic review evaluates the strength of the evidence for the role of cervical musculoskeletal dysfunction in migraine. In this review, cervical musculoskeletal dysfunction will refer to the abnormal sensory afferentation from cervical region structures contained within the receptive field of the trigeminocervical nucleus. Electronic database searches using MEDLINE, PubMed and CINAHL were performed, and 17 studies investigating cervical musculoskeletal dysfunction in people with migraine were selected for review. The methodological quality of the included studies was assessed by two independent reviewers using a customized checklist. The review found that intersubject differences were inadequately reported and controlled, which resulted in grouping of participants with varying pathologies and symptoms. A diverse range of assessment procedures was used by the reviewed studies, which made comparison of their findings difficult. The assessment procedures were mainly used to quantify the degree of cervical musculoskeletal dysfunction, rather than to identify a cause and effect relationship between cervical structure and migrainous pain. Although animal study evidence proposes a role for cervical musculoskeletal dysfunction in migraine, this systematic review of the literature found that there is currently no convincing evidence to confirm this phenomenon in humans.

Convergence of cutaneous, musculoskeletal, dural and visceral afferents onto nociceptive neurons in the first cervical dorsal horn

The convergence of cutaneous, musculoskeletal, dural and visceral afferents onto nociceptive neurons in the first cervical dorsal horn was investigated in urethane/chloralose-anesthetized rats. Electrical stimulation was applied to facial, neck, shoulder and forepaw skin, cornea (COR), dura, second cervical (C2) nerve, hypoglossal nerve, temporomandibular joint, masseter (MAS) muscle and superior laryngeal nerve. In addition, acetic acid was injected intraperitoneally and microinjection of glutamate was applied to the tongue, MAS muscle, splenius cervicis muscle, dura and intrapericardial area. A total of 52 nociceptive neurons classified as wide dynamic range (n = 28) or nociceptive-specific (n = 24) was studied. All nociceptive neurons received afferent input from the skin and at least one COR, musculoskeletal, dural or visceral afferent source in the trigeminal (V) or cervical area but input from afferent sources caudal to the C2 innervation territory was sparse. The proportion of neurons responding to COR, dural, C2 nerve, hypoglossal nerve, temporomandibular joint, MAS muscle and superior laryngeal nerve stimulations was 87, 54, 85, 52, 73, 64 and 31%, respectively. Electrical stimulation of all tested sites showed a double logarithmic stimulus-response relation, and cluster analysis of the excitability to COR, musculoskeletal, dural and visceral stimulations revealed two groups of neurons, one mainly containing wide dynamic range neurons and one mainly containing nociceptive-specific neurons. These findings indicate that afferent convergence in first cervical dorsal horn nociceptive neurons may be limited to the craniofacial area and that they may play an important role in the integration of craniofacial and upper cervical nociceptive inputs.

Does neck pain determine the outcome of adolescent headache?

The aim of the study was to examine the influence of concomitant neck pain (NP) on the outcome of headache (HA) frequency and HA type in adolescence. A population-based sample of 13-year-olds with or without HA (n = 228) was followed for 3 years. NP was evaluated at the beginning of the follow-up on the basis of recorded muscle tenderness and self-reported symptoms. During the 3 years of follow-up, changes in both HA type and frequency were common. NP interfering with daily activities at the age of 13 years predicted change from non-frequent (0-1/month) to monthly HA (>1/month), especially in boys (P = 0.03 boys, P = 0.06 girls). The use of physiotherapy predicted persistence of monthly HA in boys (P = 0.004). The changes in HA type were not predictable by NP. In conclusion, the risk of worsening HA in adolescence is more probable if the HA is associated with NP interfering with daily activities.

Temporomandibular disorders, head and orofacial pain: cervical spine considerations

Head and orofacial pain originates from dental, neurologic, musculoskeletal, otolaryngologic, vascular, metaplastic, or infectious disease. It is treated by many health care practitioners, such as dentists, oral surgeons, and physicians. The article focuses on the nonpathologic involvement of the musculoskeletal system as a source of head and orofacial pain. The areas of the musculoskeletal system that are reviewed include the temporomandibular joint and muscles of mastication--collectively referred to as temporomandibular disorders (TMDs) and cervical spine disorders. The first part of the article highlights the role of physical therapy in the treatment of TMDs. The second part discusses cervical spine considerations in the management of TMDs and head and orofacial symptoms. It concludes with and overview of the evaluation and treatment of the cervical spine.

Treatment of Headaches in the ED With Lower Cervical Intramuscular Bupivacaine Injections: A 1-Year Retrospective Review of 417 Patients

OBJECTIVE

The primary objective of this retrospective chart review is to describe 1 year's experience of an academic emergency department (ED) in treating a wide spectrum of headache classifications with intramuscular injections of 0.5% bupivacaine bilateral to the spinous process of the lower cervical vertebrae.

BACKGROUND

Headache is a common reason that patients present to an ED. While there are a number of effective therapeutic interventions available for the management of headache pain, there clearly remains a need for other treatment options. The intramuscular injection of 1.5 mL of 0.5% bupivacaine bilateral to the sixth or seventh cervical vertebrae has been used to treat headache pain in our facility since July 2002. The clinical setting for the study was an academic ED with an annual volume of over 75,000 patients.

METHODS

We performed a retrospective review of over 2805 ED patients with the discharge diagnosis of headache and over 771 patients who were coded as having had an anesthetic injection between June 30, 2003 and July 1, 2004. All adult patients who had undergone paraspinous intramuscular injection with bupivacaine for the treatment of their headache were gleaned from these 2 larger databases and were included in this retrospective chart review. A systematic review of the medical records was accomplished for these patients.

RESULTS

Lower cervical paraspinous intramuscular injections with bupivacaine were performed in 417 patients. Complete headache relief occurred in 271 (65.1%) and partial headache relief in 85 patients (20.4%). No significant relief was reported in 57 patients (13.7%) and headache worsening was described in 4 patients (1%). Overall a therapeutic response was reported in 356 of 417 patients (85.4%). Headache relief was typically rapid with many patients reporting complete headache relief in 5 to 10 minutes. Associated signs and symptoms such as nausea, vomiting, photophobia, phonophobia, and allodynia were also commonly relieved.

CONCLUSION

Our observations suggest that the intramuscular injection of small amounts of 0.5% bupivacaine bilateral to the sixth or seventh cervical spinous process appears to be an effective therapeutic intervention for the treatment of headache pain in the outpatient setting.

Invertebrate modeling of a migraine channelopathy

Migraine is a chronic episodic disorder that has been linked to abnormalities in serotonin signaling and abnormal function of a presynaptic voltage-gated calcium channel, CACNA1A. Although the importance of serotonin to migraine tendency suggests a link between serotonergic signaling and CACNA1A function, the nature of this connection remains unclear in vertebrate studies. This article reviews findings, based on an invertebrate model of CACNA1A dysfunction, which suggest a potential connection between serotonergic and calcium channel abnormalities in migraine. Neurons of the invertebrate species Caenorhabditis elegans express a voltage-gated calcium channel, UNC-2, which is the closest ortholog in C. elegans of human CACNA1A. Mutations in unc-2, the gene that encodes this invertebrate channel, cause the animals to be lethargic and uncoordinated. By identifying the genes that could be altered in such a way as to suppress the lethargic phenotype of unc-2, a signaling pathway has been identified through which UNC-2 calcium channel function antagonizes a transforming growth factor-beta (TGF-beta) pathway modulating locomotion. In C. elegans, serotonergic signaling can inhibit the rate of movement. The UNC-2/transforming growth factor-beta pathway identified regulates the expression of a gene encoding the rate-limiting enzyme for serotonin synthesis, tryptophan hydroxylase. The evolutionary and functional relationship between the UNC-2 channel and the migraine-associated CACNA1A channel was further confirmed through experiments showing that transgenic expression of human CACNA1A can suppress the lethargic and serotonin-deficient phenotypes of unc-2 mutant animals. The findings in this invertebrate model constitute the first direct demonstration of how CACNA1A function might affect the levels of serotonin, a neurotransmitter known to be important in migraine.

Potential therapeutic use of melatonin in migraine and other headache disorders

There is increasing evidence that headache disorders are connected with melatonin secretion and pineal function. Some headaches have a clearcut seasonal and circadian pattern, such as cluster and hypnic headaches. Melatonin levels have been found to be decreased in both migraine and cluster headaches. Melatonin mechanisms are related to headache pathophysiology in many ways, including its anti-inflammatory effect, toxic free radical scavenging, reduction of pro-inflammatory cytokine upregulation, nitric oxide synthase activity and dopamine release inhibition, membrane stabilisation, GABA and opioid analgesia potentitation, glutamate neurotoxicity protection, neurovascular regulation, 5-HT modulation and the similarity in chemical structure to indometacin. The treatment of headache disorders with melatonin and other chronobiotic agents, such as melatonin agonists (ramelteon and agomelatin), is promising and there is a great potential for their use in headache treatment.

Peripheral neurostimulation for treatment of intractable occipital neuralgia

OBJECTIVE

Medically intractable pain caused by occipital neuralgia (ON) can be very difficult to control with traditional pain management. Peripheral nerve stimulation (PNS) may serve as a good alternative to destructive surgical manipulations used currently for the treatment of severe ON.

METHODS

We analyzed records of 14 consecutive patients (9 women and 5 men; mean age, 43.3 yr) with intractable ON treated with PNS during the period from April 2002 to November 2004. Five patients had unilateral and nine had bilateral PNS electrodes inserted for trial, which was considered successful if patient reported at least 50% decrease of pain on the visual analogue scale. Ten patients proceeded with system internalization, and their long-term results were analyzed.

RESULTS

At the time of the last follow-up examination (5-32 mo, mean 22 mo), seven patients (70%) with implanted PNS systems continue to experience beneficial effects of stimulation, including adequate pain control, continuous employment, and decrease in oral pain medications intake. Two patients had their systems explanted because of loss of stimulation effect or significant improvement of pain, and one patient had part of his hardware removed because of infection.

CONCLUSION

Overall, the beneficial effect from chronic stimulation in our series persisted in more than half of the patients for whom procedure was considered and in 80% of those who significantly improved during the trial and proceeded with internalization. Thus, chronic PNS may be a safe and relatively effective method for long-term treatment of chronic pain syndrome in patients with medically intractable ON.

Sinus headache: a neurology, otolaryngology, allergy, and primary care consensus on diagnosis and treatment

Sinus headache is a widely accepted clinical diagnosis, although many medical specialists consider it an uncommon cause of recurrent headaches. The inappropriate diagnosis of sinus headache can lead to unnecessary diagnostic studies, surgical interventions, and medical treatments. Both the International Headache Society and the American Academy of Otolaryngology-Head and Neck Surgery have attempted to define conditions that lead to headaches of rhinogenic origin but have done so from different perspectives and in isolation of each other. An interdisciplinary ad hoc committee convened to discuss the role of sinus disease as a cause of headache and to review recent epidemiological studies that suggest sinus headache (headache of rhinogenic origin) and migraine are frequently confused with one another. This committee reviewed available scientific evidence from multiple disciplines and concluded that considerable research and clinical study are required to further understand and delineate the role of nasal pathology and autonomic activation in migraine and headaches of rhinogenic origin. However, this group agreed that greater diagnostic and therapeutic attention needs to be given to patients with sinus headaches.

Craniofacial inputs to upper cervical dorsal horn: implications for somatosensory information processing

The aim of this study was to characterize the properties of somatosensory neurons in the first 2 cervical spinal dorsal horns (C1 and C2 DHs) and compare them with those previously described for the rostral subnucleus caudalis (rVc). A total of 74 nociceptive neurons classified as wide-dynamic-range (WDR) or nociceptive-specific (NS), as well as 72 low-threshold mechanoreceptive (LTM) neurons, was studied in urethane/chloralose-anesthetized rats. The majority of LTM neurons were located in laminae III/IV and had a small mechanoreceptive field (RF) that included the posterior face and cervical tissues. In contrast, the nociceptive neurons were located in laminae I/II or V/VI, and the RF of each C1 and C2 DH nociceptive neuron included a part of the face and in 47% of them the RF included a region supplied by upper cervical afferents. There was a gradual caudal shift in the neuronal RF from nasal/intraoral tissues towards the neck as recording sites progressed from rVc to C1 and C2 DHs. In contrast to LTM neurons, many C1 and C2 DH nociceptive neurons received mechanosensitive convergent afferent inputs from cervical and craniofacial deep tissues (e.g., tongue muscles or temporomandibular joint), and over 50% could be activated by hypoglossal (XII) nerve electrical stimulation. We propose that C1 and C2 DHs represent part of the caudal extension of the Vc, and that Vc and C1 and C2 DHs may act together as one functional unit to process nociceptive information from craniofacial and cervical tissues, including that from deep craniofacial tissues.

New Onset Migraine With Aura Following Head Injury: A Case Report

A patient is described who developed recurrent headaches following a traumatic injury in the vicinity of the right greater occipital nerve (GON) that fulfill IHS criteria for migraine with aura. Both aura and headache can be triggered by pressure over the GON and relieved by local anesthetic blockade.