Decreased sensitivity of 5-HT1D receptors in chronic tension-type headache

Psychological and Sleep Quality Differences between Chronic Daily Headache and Temporomandibular Disorders Patients

The aim of this study was to investigate whether chronic daily headache (CDH) and temporomandibular disorders (TMD) patients present with different psychological and sleep quality characteristics. Sixty-seven patients diagnosed with CDH, according to classification criteria from Silberstein et al., were matched by age and sex with 67 patients who had a primary diagnosis of myofascial pain (MP) and 67 patients with a primary diagnosis of TMJ intracapsular pain (IC) according to the Research Diagnostic Criteria for TMD. The CDH group was comprised of three mutually exclusive diagnostic groups: chronic migraine ( n = 35); chronic tension-type headache ( n = 26); ‘other CDH’ ( n = 6). All patients completed a battery of psychological and sleep quality questionnaires. All CDH subgroups showed similar psychological and sleep quality profiles. Pain intensity and duration were controlled in the multivariate analyses (MANCOVA) by treating them as covariates. The CDH and MP groups revealed higher levels of psychological distress than the IC group on most psychological domains. The MP group also revealed numerically higher levels of psychological distress in most psychological domains than the CDH group, although these differences were generally not significant. We did not find significant differences between the three groups on post traumatic stress symptoms either. Sleep quality was significantly worse in the MP group than in the CDH and IC groups. These results are discussed in the context of multimodal patient evaluation and treatments that are often necessary for successful clinical management.

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.

Design, synthesis and biological activity of novel dimethyl-{2-[6-substituted-indol-1-yl]-ethyl}-amine as potent, selective, and orally-Bioavailable 5-HT 1D agonists

A novel series of highly potent human 5-HT(1D) agonists, dimethyl-[2-[6-substituted-indol-1-yl]-ethyl]-amine, was synthesized. Structure-activity relationship (SAR) investigation revealed 4-[1-(2-dimethylamino-ethyl)-1H-indol-6-yl]-tetrahydro-thiopyran-4-ol, 11b (ALX-2732), as a potent (K(i)=2.4 nM) agonist at the human 5-HT(1D) receptor with good selectivity over the other serotonin receptor subtypes. This compound demonstrated favorable in vitro metabolic stability in human and rat liver microsomes and was found to be orally bioavailable in rats (F(po)=51%).

Conscious expectation and unconscious conditioning in analgesic, motor, and hormonal placebo/nocebo responses

The placebo and nocebo effect is believed to be mediated by both cognitive and conditioning mechanisms, although little is known about their role in different circumstances. In this study, we first analyzed the effects of opposing verbal suggestions on experimental ischemic arm pain in healthy volunteers and on motor performance in Parkinsonian patients and found that verbally induced expectations of analgesia/hyperalgesia and motor improvement/worsening antagonized completely the effects of a conditioning procedure. We also measured the effects of opposing verbal suggestions on hormonal secretion and found that verbally induced expectations of increase/decrease of growth hormone (GH) and cortisol did not have any effect on the secretion of these hormones. However, if a preconditioning was performed with sumatriptan, a 5-HT(1B/1D) agonist that stimulates GH and inhibits cortisol secretion, a significant increase of GH and decrease of cortisol plasma concentrations were found after placebo administration, although opposite verbal suggestions were given. These findings indicate that verbally induced expectations have no effect on hormonal secretion, whereas they affect pain and motor performance. This suggests that placebo responses are mediated by conditioning when unconscious physiological functions such as hormonal secretion are involved, whereas they are mediated by expectation when conscious physiological processes such as pain and motor performance come into play, even though a conditioning procedure is performed.