Pathophysiology of tension-type headache

Novel inhibitors of nitric oxide synthase with antioxidant properties

We previously described a series of imidazole-based inhibitors substituted at N-1 with an arylethanone chain as interesting inhibitors of neuronal nitric oxide synthase (nNOS), endowed with good selectivity vs endothelial nitric oxide synthase (eNOS). As a follow up of these studies, several analogs characterized by the presence of substituted imidazoles or other mono or bicyclic nitrogen-containing heterocycles instead of simple imidazole were synthesized, and their biological evaluation as in vitro inhibitors of both nNOS and eNOS is described herein. Most of these compounds showed improved nNOS and eNOS inhibitory activity with respect to reference inhibitors. Selected compounds were also tested to analyze their antioxidant properties. Some of them displayed good capacity to scavenge free radicals and ability to reduce lipid peroxidation.

An electronic daily diary process study of stress and health behavior triggers of primary headaches in children

OBJECTIVE

To determine through a daily process study whether alleged psychological and health behavior headache triggers reliably predict headache occurrence in children.

METHODS

Twenty-five children aged 8-17 years with primary headaches reported on their expectancies for headache triggers and then used electronic diaries three times daily for 2 weeks to record headache occurrence, stressors, type and timing of food and drink intake, sleep and wake times, and sleep quality. Hypotheses pertaining to the association of presumed headache triggers and headache occurrence were evaluated using multilevel models.

RESULTS

Only changes in stress level reliably preceded the occurrence of a new headache episode. Nights in which a child had less than his/her typical sleep quantity also tended to predict headache occurrence. Consumption of certain food and drink items was found to be protective.

CONCLUSIONS

Daily stressors seem to be a more reliable trigger of children's headaches than diet or sleep factors.

Pharmacotherapy and Lifestyle Interventions for Tension-Type Headaches

The objective of this review was to evaluate the efficacy of pharmacotherapy and lifestyle interventions for tension-type headaches. Literature was obtained through a MEDLINE (1966 to April 2008) search and a bibliographic review of published articles. Key terms searched included tension-type headaches, chronic tension-type headaches, pharmacotherapy, and lifestyle therapy. The search was further limited to the English language. Tension-type headaches are the most common and least studied primary headache disorder. These headaches are characterized by mild to moderate bilateral pain that is described as dull, aching, and bandlike. Episodic tension-type headaches may be treated with mild analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen; although treatment should be individualized, data suggest that NSAIDs may be considered first line. Chronic and frequent episodic tension-type headaches often require prophylactic therapy. Although tricyclic antidepressants are considered the drugs of choice for chronic tension-type headaches, preliminary trials with venlafaxine, mirtazapine, tizanidine, and topiramate have shown promise. Lifestyle interventions such as physical therapy, behavioral therapy, and acupuncture are often employed, despite the lack of sound clinical evidence to support their use. Preliminary data support the combination of a tricyclic antidepressant and behavioral therapy for chronic tension-type headache.

Botulinum toxin: could it be an effective treatment for chronic tension-type headache?

Several clinical trials suggest that botulinum toxin type-A (BTX-A) may be an effective treatment option for patients with chronic tension-type headache (CTTH); however, controversy remains as to how the botulinum toxin optimally should be used for treating headache and which patient's profile fits this treatment. The objective of this study was to evaluate the efficacy and tolerability of BTX-A for the prophylactic treatment of CCTH in Egyptian patients. This was a randomized, single-blind, placebo-controlled study of BTX-A for the treatment of patients aged 25-50 years old with CCTH. Following a 30-day screening, headache parameters and severity assessed by the standard visual analogue scale (VAS), and the 25-item Henry Ford Hospital Headache Disability Inventory (HDI) were recorded as a baseline. Then, injection was done with either BTX-A or with saline by a combination of two methods for detecting injection sites (the fixed-site approach and follow-the-pain approach). Our study showed significant improvement after 1 month of BTX-A injection regarding headache days/month, severity measured by VAS and HDI in headache severity. There was significant reduction of prophylactic medications, and there were minor complications, but these reversed spontaneously without further treatment. BTX-A was an effective and well-tolerated prophylactic treatment in Egyptian patients with CCTH.

Human resting muscle tone (HRMT): narrative introduction and modern concepts

Human resting muscle (myofascial) tone (HRMT) is the passive tonus or tension of skeletal muscle that derives from its intrinsic (EMG-silent) molecular viscoelastic properties. The word tone has been used to convey varying clinical and physiological features that have led to confusion and controversy. HRMT is the vital low-level, passive tension, and resistance to stretch that contributes importantly to maintain postural stability in balanced equilibrium positions. In contrast, co-contraction of muscle is an active neuromotor control that provides greater levels of tonus for increased stabilization. Functionally, HRMT is integrated with other passive fascial and ligamentous tensional networks of the body to form a biotensegrity system. This review aims to achieve better understandings of HRMT and its functional roles. Nature is frugal and man's adaptations to gravitational forces and erect postures seemingly evolved mechanisms in skeletal muscle tissues to economically enhance stability. Normal passive muscle tone helps to maintain relaxed standing body posture with minimally increased energy costs (circa 7% over supine), and often for prolonged durations without fatigue. Available data infer polymorphic variations in normal myofascial tone. However, few quantitative studies have been performed to establish normal frequency distributions of degrees of myofascial tone. Clinical experience indicates that persons with certain symptomatic musculoskeletal conditions may have palpably increased resting muscle firmness or hardness (EMG-silent), such as that of the upper trapezius in tension-type headache, and the lumbodorsal extensors (hartspann) in degenerative lumbar disc disease and ankylosing spondylitis. In summary, resting skeletal muscle tone is an intrinsic viscoelastic tension exhibited within the body's kinematic chains. It functions inseparably from fascial (i.e., myofascial) tissues and ligamentous structures. Thus, HRMT is a passive myofascial property which operates within networks of tensional tissues, i.e., biotensegrity. This passive tension is the CNS-independent component resulting from intrinsic molecular interactions of the actomyosin filaments in sarcomeric units of skeletal muscle and myofibroblast cells. The overarching CNS-activated muscle contractions generate far greater tensions transmitted by fascial elements. Interdisciplinary research on HRMT and its biodynamics promises greater effectiveness of clinical practitioners and productivity of investigators, which warrants priority attention.

Similarities in stress physiology among patients with chronic pain and headache disorders: evidence for a common pathophysiological mechanism?

One common feature of chronic musculoskeletal pain and headaches are that they are both influenced by stress. Among these, tension-type headache (TTH), fibromyalgia (FMS) and chronic shoulder/neck pain (SNP) appear to have several similarities, both with regard to pathophysiology, clinical features and demographics. The main hypothesis of the present study was that patients with chronic pain (TTH, FMS and SNP) had stress-induced features distinguishing them from migraine patients and healthy controls. We measured pain, blood pressure, heart rate (HR) and skin blood flow (BF) during (1 h) and after (30 min) controlled low-grade cognitive stressor in 22 migraine patients, 18 TTH patients, 23 FMS patients, 29 SNP patients and 44 healthy controls. FMS patients had a lower early HR response to stress than migraine patients, but no differences were found among FMS, TTH and SNP patients. Finger skin BF decreased more in FMS patients compared to migraine patients, both during and after the test. When comparing chronic pain patients (chronic TTH, FMS and SNP) with those with episodic pain (episodic TTH and migraine patients) or little or no pain (healthy controls), different adaptation profiles were found during the test for systolic and diastolic blood pressure, HR and skin BF in the chronic group. In conclusion, these results suggest that TTH, FMS and SNP patients may share common pathophysiological mechanisms regarding the physiological responses to and recovery from low-grade cognitive stress, differentiating them from episodic pain conditions such as migraine

Tension-type headache in the elderly

Tension-type headache is the most common primary headache disorder seen in adults. Although the prevalence peaks in the fourth and fifth decades of life, significant fractions of the elderly continue to experience either episodic or chronic tension-type headaches. Many secondary headache disorders may present with headaches symptomatically compatible with the diagnosis of tension-type headache. Because numerous secondary headache disorders are more likely to be seen in older adults, the diagnosis of tension-type headache requires vigilance for and exclusion of organic disease. Once the diagnosis of tension-type headache is made, numerous nonpharmacologic and pharmacologic management options are available to reduce the frequency and severity of episodes. Special dosing considerations must be considered in the elderly. Advancing age is a positive prognostic factor in the remission of episodic and chronic tension-type headaches.

Muscle pain in the head: overlap between temporomandibular disorders and tension-type headaches

PURPOSE OF REVIEW

A variety of painful problems can affect the muscles in the head and face. Both temporomandibular disorders and tension-type headaches are believed to have a significant contribution from the skeletal muscles and have several clinical features in common. It still unclear, however, to what extent these two prevalent disorders are separate entities or have similar pathophysiological background.

RECENT FINDINGS

There is now reasonably good evidence that myofascial temporomandibular disorder patients are more likely to have a tension-type headache problem and vice versa, but the overlap is not complete. Studies have documented similarities regarding sensitization of the nociceptive pathways, dysfunction of the endogenous pain modulatory systems as well as contributing genetic factors, but there are also a number of distinct differences between temporomandibular disorders and tension-type headaches that need to be considered.

SUMMARY

Using the current classification systems, myofascial temporomandibular disorder pain and tension-type headache disorders do overlap and appear to share many of the same pathophysiological mechanisms, but it would be premature to consider them as identical entities since the importance of, for example, the affected muscles and associated function and genetic background needs to be established. Orofacial pain and headache specialists should collaborate to further develop diagnostic procedures and management strategies of temporomandibular disorders and tension-type headaches.

Understanding psychological stress, its biological processes, and impact on primary headache

Psychological stress is generally acknowledged to be a central contributor to primary headache. Stress results from any challenge or threat, either real or perceived, to normal functioning. The stress response is the body's activation of physiological systems, namely the hypothalamic-pituitary-adrenal axis, to protect and restore functioning. Chronic activation of the stress response can lead to wear and tear that eventually can predispose an individual to disease. There are multiple ways that stress and headache are closely related. Stress can (a) be a predisposing factor that contributes to headache disorder onset, (b) accelerate the progression of the headache disorder into a chronic condition, and (c) precipitate and exacerbate individual headache episodes. How stress impacts headache is not often understood. However, stress is assumed to affect primary headache by directly impacting pain production and modulation processes at both the peripheral and central levels. Stress can also independently worsen headache-related disability and quality of life. Finally, the headache experience itself can serve as a stressor that compromises an individual's health and well-being. With the prominent role that stress plays in headache, there are implications for the evaluation of stress and the use of stress reduction strategies at the various stages of headache disorder onset and progression. Future directions can help to develop a better empirical understanding of the pattern of the stress and headache connections and the mechanisms that explain the connections. Further research can also examine the interactive effects of stress and other factors that impact headache disorder onset, course, and adjustment.

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.

Tension-type headache in the elderly

Tension-type headache is the most common primary headache disorder seen in adults. Although the prevalence peaks in the fourth and fifth decades of life, significant fractions of the elderly continue to experience either episodic or chronic tension-type headaches. Many secondary headache disorders may present with headaches symptomatically compatible with the diagnosis of tension-type headache. Because numerous secondary headache disorders are more likely to be seen in older adults, the diagnosis of tension-type headache requires vigilance for and exclusion of organic disease. Once the diagnosis of tension-type headache is made, numerous nonpharmacologic and pharmacologic management options are available to reduce the frequency and severity of episodes. Special dosing considerations must be considered in the elderly. Advancing age is a positive prognostic factor in the remission of episodic and chronic tension-type headaches.