Regional myofascial pain syndrome and headache: principles of diagnosis and management.

Myofascial pain is frequently overlooked in dealing with headache pain. Myofascial pain is defined as pain and/or autonomic phenomena referred from active trigger points, with associated dysfunction. The trigger point is a focus of hyperirritability in the muscle, that when compressed, is locally tender, and if sensitized, gives rise to referred pain and tenderness. The therapy for myofascial pain requires enhancing central inhibition through pharmacology or behavioral techniques and simultaneously reducing peripheral inputs through physical therapies including exercises and trigger point-specific therapy.

SUNCT syndrome responsive to gabapentin (Neurontin).

A 48-year-old male suffering with SUNCT (severe unilateral neuralgiform headache with conjunctival injection and tearing, rhinorrhea and sub-clinical sweating) presented in 1996 after a 10-year history of multiple failed therapies. The symptoms included strictly left-sided ocular, as well as facial and temple pain. The pain attacks were burning, sharp, shooting and occurred 25 times daily, lasting 2 to 3 minutes with tearing and conjunctival injection. There was no associated nausea or vomiting, but there was photophobia. No other autonomic changes were reported and the pain was not triggerable. Initially Indocin (indomethacin) was tried without significant benefit. Gabapentin (Neurontin) was then started with improvement at 1800 mg per day. The patient was then lost to follow-up for 3 years, as he moved from the Los Angeles area. He returned in 1999 having stopped the gabapentin after his prescription ran out in 1996, reporting the pain returned immediately. Again gabapentin was prescribed and at 900 mg three times daily he has been pain free for 12 months.

Amitriptyline and fluphenazine in the treatment of postherpetic neuralgia.

BACKGROUND: Postherpetic neuralgia (PHN) is a vexing problem occurring in 10 to 20 percent of people with from herpes zoster (shingles). Anecdotal reports show that fluphenazine enhances the effects of amitriptyline for the treatment of PHN. The aim of this study was to determine, in a controlled manner, whether this was the case. METHODS: In a double-blind placebo-controlled study, 49 patients with PHN were randomly assigned to four treatment groups: Group 1, amitriptyline; Group 2, amitriptyline and fluphenazine; Group 3, fluphenazine; Group 4, a placebo. An active placebo was used to mimic the anticholinergic side effects of dry mouth. The study lasted 8 weeks, with weekly progress evaluations with use of visual analog scales (VAS), the McGill Pain Questionnaire (MPQ), and a side-effects scale. RESULTS: A statistically significant decrease was seen in pain in Groups 1 and 2, and no significant changes were seen in Groups 3 and 4. There was no significant difference when fluphenazine was added to amitriptyline. CONCLUSION: These data support the effectiveness of amitriptyline in treatment of PHN, but do not support the addition of fluphenazine.

Facial pain.

Facial pain is a debilitating disorder if left untreated. Too often patients are labelled as having psychopathology when face pain etiology is unclear. These patients are categorized as 'atypical', 'idiopathic' or 'psychogenic'. Idiopathic, when referring to a medical problem suggests that there is something unknown, and does not define the problem. The same applies to terms incorporating the word 'atypical'. It is postulated that the most commonly undiagnosed facial pain conditions include neuropathic and myofascial pains because their pathophysiologies are not well understood. Peripheral and central mechanisms associated with these disorders are used to provide an update of these frequently seen clinical conditions.

Depression determines illness conviction and pain impact: a structural equation modeling analysis.

OBJECTIVE: The present study sought to derive an algorithm using factor analysis and structural equation modeling (SEM) to describe headache and orofacial pain patients using measures of behavioral and psychological functioning. This investigation further examined whether the underlying factor structure differed in 3 presumed distinct diagnostic categories: myofascial, neuropathic, and neurovascular pain. DESIGN: The Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Multidimensional Pain Inventory (MPI), Beck Depression Inventory-II (BDI-II), and visual analog scale for functional limitation (VAS-FL) were administered to the subjects. A split group design was used. Exploratory factor analysis (EFA) was used to describe distinct factor domains in the first group. Confirmatory factor analysis (CFA) using SEM tested this structure in the second group and described causal relationships between the revealed (latent) factors. Analysis of variance (ANOVA) was used to test for differences in demographic variables and diagnostic group factor structure. SETTING: The Pain Center is a comprehensive, multidisciplinary pain medicine program at Cedars-Sinai Medical Center, Los Angeles, California. SUBJECTS: Three hundred and ninety (N = 390) subjects were assigned to 1 of 3 diagnostic categories: myofascial pain syndrome, neuropathic pain, or neurovascular pain. RESULTS: EFA revealed a 3-factor solution. The factors were labeled Depression, Illness Conviction, and Pain Impact, reflecting the content of their respective variables with highest loadings. CFA using SEM validated the 3-factor solution, and further revealed that Depression was a critical causal factor determining Illness Conviction and Pain Impact. No causal relationship was observed between Illness Conviction and Pain Impact. ANOVA found no differences in demographics. No difference in factor structure emerged for the 3 diagnostic categories. CONCLUSIONS: Analysis derived a 3-factor solution. The factors were Pain Impact, Illness Conviction, and Depression. SEM revealed the critical causal pathway showing that Depression determined Illness Conviction and Pain Impact. We conclude that the main target for pain treatment is depression. No differences in factor structure were found for the 3 diagnostic categories of myofascial, neuropathic, or neurovascular pain. This suggests that psychological processes are similar in chronic headache and orofacial pain patients despite their presumed distinct underlying pathophysiological mechanisms. SME is a powerful methodology to construct causal models that has been underutilized in the pain literature.

A 6-year clinical assessment of electronic facial thermography.

OBJECTIVE: To report the findings a 6-year clinical application of ET on patients with orofacial pain. METHODS: ET was conducted (in a blinded manner) using an Agema 870 unit at 0.1 degree C thermal accuracy. A newly devised thermal classification system was applied: 'normal' when zone delta T was from 0.0 to +/-0.25 degree C, "hot' when zone delta T was > +0.35 degree C, 'cold' when zone delta T was < -0.35 degree C, and 'equivocal' when zone delta T was +/-(0.26-0.35) degree C. Study populations consisted of 164 dental patients mainly with diagnostic problems and 164 matched (control) subjects. RESULTS: Our prospective, matched study determined that subjects with 'hot' thermograms had the clinical diagnoses of sympathetically maintained pain, peripheral nerve mediated pain, TMJ arthropathy, and maxillary sinusitis. Subjects with 'cold' thermograms were found to have the clinical diagnoses of peripheral nerve-mediated pain and sympathetically independent pain. Subjects with 'normal' thermograms were found to have the clinical diagnosis of cracked tooth syndrome, trigeminal neuralgia, pretrigeminal neuralgia, or psychogenic facial pain. The new system of thermal classification resulted in 92% (301 of 328) agreement in classification of pain patients and matched controls. CONCLUSION: These studies suggest that ET has promise in aiding the formation of a differential diagnosis of orofacial pain and may help in understanding mechanisms of pain as well as directing therapies.

Orofacial pain - an overview.

Orofacial pain is a complex problem that requires careful assessment, understanding and appropriate therapy. This article reviews the function of the nervous system as it pertains to orofacial pain and introduces an organ based classification system that can be used to help differentiate the patient with orofacial pain. Current concepts in the pathogenous of each disorder and therapies are reviewed.

Benign indomethacin-responsive headaches presenting in the orofacial region: eight case reports.

Indomethacin-responsive headaches can present in the orofacial region. According to the classification of headache by the International Headache Society, indomethacin-responsive headaches include chronic paroxysmal hemicrania, hemicrania continue, benign cough headache, benign exertional headache, and sharp, short-lived headache pain syndrome. The mechanism by which indomethacin produces its therapeutic effects in these headache disorders remains speculative. A review of indomethacin-responsive headaches and eight cases in which the presenting symptom was orofacial pain are reported. Because these headache disorders are rare but may present as facial pain, they should be considered in the differential diagnosis of orofacial pain. A comprehensive evaluation prior to performing irreversible treatments is essential when an idiopathic facial pain presents to the dental clinician.

Thermographic assessment of neuropathic facial pain.

Ongoing pain, intermittent sharp pain, or intermittent dull aching pain around the teeth can evoke the suspicion of tooth pathology. However, when no dental cause can be found clinically or radiographically, the differential diagnosis involving neuropathic pain and pulpal pathology is still a challenge. Neuropathic facial pains are still too often misdiagnosed as tooth pain of dental origin, resulting in unnecessary dental extraction or endodontic therapy. The purpose of this study was to determine if electronic thermography was able to differentiate neuropathic facial pains presenting as toothache from pulpal pathology. Electronic thermography was used to compare asymptomatic subjects and subjects with neuropathic facial pains. Asymptomatic subjects and subjects with trigeminal neuralgia, pre-trigeminal neuralgia, and pulpal pain without periapical pathology showed no thermographic difference in the territory of the pain complaint when compared to the opposite nonpainful side. Patients with sympathetically maintained traumatic trigeminal neuralgia (atypical odontalgia) and half of the group with sympathetically independent traumatic trigeminal neuralgia presented with "hot" thermograms. The other half of the patients with sympathetically independent traumatic trigeminal neuralgia displayed "cold" thermograms in the area of their pain complaints. Electronic thermography was the least selective test for the group showing "cold" thermogram patterns (80% agreement with the thermographic characterization criteria). These data suggest that electronic thermography may be helpful in differentiating neuropathic pains from pulpal pathology.

Traumatic dysesthesia of the trigeminal nerve.

Traumatic injury to the peripheral nerves often results in persistent discomfort. Substance P has been implicated as a mediator of pain, and depletion of this neurotransmitter has been shown to reduce pain. Subjects suffering from traumatic dysesthesia of the trigeminal nerve were treated with capsaicin, a substance P depleter with significant long-term effects. This form of therapy may be used individually or in combination with other pharmacologic interventions in the treatment of traumatic trigeminal dysesthesia.

Chronic paroxysmal hemicrania presenting as toothache.

Chronic paroxysmal hemicrania is an intermittent head-pain problem that is characterized by pain paroxysms lasting about 15 minutes. The attacks usually produce pain in the frontotemporal region and are responsive to indomethacin. A set of symptoms that defines chronic paroxysmal hemicrania is presented, and two cases in which the presenting symptom was toothache are reported. It is emphasized that clinicians should consider chronic paroxysmal hemicrania in the differential diagnosis of orofacial pain.

The use of methylergonovine (Methergine) in the initial control of drug induced refractory headache.

This study investigated the efficacy of methylergonovine maleate (Methergine) in the treatment of drug induced refractory headache (DIRH). Sixty consecutive patients (51 female and 9 male) diagnosed with DIRH were treated with methylergonovine maleate for a maximum of six months, using a within subject design. All patients were withdrawn from the medications they were taking upon entering the study. Concurrently, they were given 0.2-0.4 mg of methylergonovine maleate three times a day. Patients were provided the means to control breakthrough episodes of headache. Treatment outcome was assessed using a patient self-report scale (much better, better, same, worse, and much worse), and also visual analogue pain intensity scales. The side effects of the drug were assessed with patient self-report. Methylergonovine was effective in 44 (73%) patients. Twelve (20%) patients reported unchanged pain and 4 (6%) patients got worse. Side effects were reported by 24 patients. These were predominantly abdominal cramping. It is concluded that methylergonovine maleate is effective in the initial control of drug induced refractory headache. However, because methylergonovine is a metabolic byproduct of methysergide, the possibility or fibrotic disorders needs to be considered if methylergonovine is to be used for long term therapy.

Is atypical odontalgia a psychological problem?

Several authors have asserted that psychological factors are the underlying cause of atypical odontalgia. However, objective evidence is lacking to support this claim. In this study, the Minnesota Multiphasic Personality Inventory was used to assess psychological functioning of an atypical odontalgia population. Means of the standard scores for each Minnesota Multiphasic Personality Inventory scale were within normal ranges. Standard scores for atypical odontalgia profiles compared with standard scores for a chronic headache group (matched for age, sex, and chronicity) were similar and scales for both groups were within normal ranges. These findings fail to support psychological dysfunction as a primary condition associated with patients suffering from atypical odontalgia.

Cough headache presenting as a toothache: a case report.

Benign cough headache (BCH) presents as an intermittent, usually bilateral, severe bursting or explosive pain brought on by coughing. Some of the known conditions which can mimic the pain experienced in BCH are subarachnoid hemorrhage, increased intracranial pressure, intracranial tumors, and even toothache. Careful evaluation must be carried out in order to differentiate between these conditions. A case of BCH which presented as a toothache is reported. The evaluation for exertional headaches, and for headaches brought on by coughing, is discussed.

The effects of streptomycin/lidocaine block on trigeminal neuralgia: a double blind crossover placebo controlled study.

This study investigated the long term effect of a peripheral sensory block using streptomycin sulphate on trigeminal neuralgia. A total of twenty subjects, thirteen with idiopathic trigeminal neuralgia (ITN) and seven with traumatic trigeminal neuralgia (TTN) were studied. A double-blind placebo controlled randomized design was used. After the clinical assessment subjects were randomly assigned to receive either 1 g of streptomycin with 3 ml 2% lidocaine, or 3 ml lidocaine alone. The injections were performed adjacent to the branches that served the painful site. These were intraoral injections, more specifically infraorbital and inferior alveolar blocks. Patients received five blocks of either streptomycin/lidocaine or lidocaine alone for a period of five consecutive weeks. On the sixth week they were crossed over. Measures of pain intensity and pain frequency were used to assess treatment outcome. Patients also recorded their side-effects. Repeated measures analysis of variance was used to compare the treatment outcomes between the active and placebo groups. There was no statistically significant differences in the treatment outcomes regarding frequency and intensity of pain attacks. The sensory function of the treated nerves was also not affected. Side effects including facial swelling and pain were a common finding in the patients receiving streptomycin. This study demonstrated no beneficial effects of streptomycin blockade for idiopathic and traumatic trigeminal neuralgia.

A retrospective study of patients with cluster headaches.

Referred pain in the midface and teeth is a common clinical feature of the cluster headache and cluster headache-like disorders. It is not unusual therefore for patients with cluster headaches to go to the dentist. In this report, 33 cases of cluster headache, which met the International Headache Society classification criteria, and which were seen by us during a 2-year period, are reviewed. Fourteen (42%) of 33 patients who were seen by dental practitioners and who received some form of ineffective dental or pharmacologic treatment are described here. Since almost 50% of the cluster headache patients described here received inappropriate dental treatment, it is hoped that this review and retrospective assessment will make the dental practitioner aware of this disorder and provide a broader perspective in the treatment of pain in the orofacial region. Clinical presentation, pathogenesis, and treatment of cluster headaches are discussed.

Trigeminal neuralgia: how to rule out the wrong treatment.

Toothache is difficult to diagnose and treat appropriately when traditional dental diagnostic test results are negative. This study looked at 61 patients who were treated for pretrigeminal or trigeminal neuralgia. Of these, 61 percent were incorrectly diagnosed and treated.