The clinical neurophysiology of tension-type headache.

Despite being widely investigated, the pathogenesis of tension-type headache (TTH) continues to be debated. Among the different approaches used to explore the mechanisms underlying TTH, clinical neurophysiology plays an important role. Studies to date have focused mainly on two areas: (1) evaluation of peripheral factors (i.

Drug consumption in medication overuse headache is influenced by brain-derived neurotrophic factor Val66Met polymorphism.

Medication overuse headache (MOH) can be considered a clinical condition at the boundaries between drug addiction and chronic pain disorder. The common 196G > A single-nucleotide polymorphism of BDNF gene, resulting in a valine 66 to methionine (Val66Met), is related with behaviour disorders and substance abuse. With the aim of identifying a worsening factor in MOH, rather than the detection of a specific risk factor for the development of the disease, we investigated whether the presence of a functional BDNF polymorphism might determine clinical differences within a group of 90 MOH patients, particularly in monthly drug consumption, that is the hallmark of disease.

The wolframin His611Arg polymorphism influences medication overuse headache.

Homozygosis for wolframin (WFS1) mutations determines Wolfram syndrome (WS), and common polymorphisms of WFS1 are associated with psychiatric illnesses and dependence behaviour. To test the influence of WFS1 polymorphisms on medication overuse headache (MOH), a chronic headache condition related to symptomatic drugs overuse, we analyzed 82 MOH patients for the WFS1 His611Arg polymorphism, and performed a comparison between clinical features of Arg/Arg (R/R) and non-R/R individuals. Individuals harbouring the R/R genotype showed significantly higher monthly drug consumption (t=-3.

The essential oil of bergamot enhances the levels of amino acid neurotransmitters in the hippocampus of rat: implication of monoterpene hydrocarbons.

The effects of bergamot essential oil (BEO) on the release of amino acid neurotransmitters in rat hippocampus have been studied by in vivo microdialysis and by in vitro superfusion of isolated nerve terminals. Intraperitoneal administration of BEO (100microl/kg) significantly elevated the extracellular concentration of aspartate, glycine and taurine in a Ca(2+)-dependent manner. A dose-relation study generated a bell-shaped curve.

Uncommon primary headaches.

Purpose Of Review: The new International Classification of Headache Disorders was recently published by the International Headache Society. Several uncommon primary headaches, including some new clinical entities (e.g.

The lower limb flexion reflex in humans.

The flexion or flexor reflex (FR) recorded in the lower limbs in humans (LLFR) is a widely investigated neurophysiological tool. It is a polysynaptic and multisegmental spinal response that produces a withdrawal of the stimulated limb and resembles (having several features in common) the hind-paw FR in animals. The FR, in both animals and humans, is mediated by a complex circuitry modulated at spinal and supraspinal level.

Effects of acute and chronic restraint stress on nitroglycerin-induced hyperalgesia in rats.

Nitric oxide (NO) plays an important role in initiation and maintenance of pain, and NO precursor nitroglycerin is able to activate spinal and brain structures involved in nociception. It is also known that acute and chronic stress induce biochemical changes affecting both pain threshold and behaviour, and that the biological pattern of depression can be mimicked in the laboratory using chronic unavoidable stress paradigms (learned helplessness). We, therefore, evaluated the effects of acute and chronic immobilization stress on pain response to nitroglycerin administration in the rat.

Central components of the analgesic/antihyperalgesic effect of nimesulide: studies in animal models of pain and hyperalgesia.

Unlabelled: The analgesic action of NSAIDs has been attributed to the peripheral inhibition of prostaglandin synthesis via the blockade of the enzyme cyclo-oxygenase (COX) and prevention of bradykinin and cytokine-induced hyperalgesia via inhibition of the release of tumour necrosis factor-alpha. However, it is becoming increasingly evident that NSAIDs exert their analgesic effect through several mechanisms. Recent data suggest that significant expression of COX-2 is found in the central nervous system, where COX-2 seems to have, together with nitric oxide, an important role in spinal nociceptive transmission.

Trigeminofacial reflexes in primary headaches.

Nociceptive processing in trigeminal system is likely to undergo to significant changes in chronic pain disorders such as in primary headache. The electrophysiological testing of brainstem reflexes seems to offer a valuable adjunct to the clinical evaluation, providing direct evidence for central dysmodulation of sensory and pain neurotransmission, i.e.

Effects of nimesulide on nitric oxide-induced hyperalgesia in humans--a neurophysiological study.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to induce analgesia mainly via the inhibition of cyclo-oxygenase. Several reports suggest that chronic pain is mediated by central sensitization, an N-methyl-D-aspartate (NMDA)-mediated phenomenon influenced by cyclo-oxygenase activity and nitric oxide (NO). In this double-blind study, we evaluated the effects of a preferential inhibitor of the inducible isoform of cyclo-oxygenase-2, nimesulide, on the spinal nociceptive flexion reflex (RIII reflex) before and after administration of an NO donor in healthy volunteers.

Electrophysiological evidence for trigeminal neuron sensitization in patients with migraine.

The electrically elicited corneal reflex is a useful tool for exploring the trigeminal system in humans and it may provide additional evidence pointing to a dysfunction of this system in migrainous patients. Tactile perception, corneal reflex and pain thresholds were studied in 48 migraine without aura patients during pain-free periods and compared with those observed in 24 controls. Twenty-eight of the patients had strictly unilateral headache, while the other 20 had bilateral or side-shifting pain during attacks.

Diagnostic issues in chronic daily headache.

A number of patients attending specialty headache centers complain of very frequent, almost continuous headaches, which are usually grouped together under the term chronic daily headache (CDH), a category which does not appear in the International Headache Society (IHS) classification published in 1988. More than 10 years later, this issue is still debated, also in light of the foreseen revised classification. Several terms have been used to define the clinical picture of CDH, and different criteria have been proposed for the diagnosis of these forms.

Asymmetrical reduction of the nociceptive flexion reflex threshold in cluster headache.

The nociceptive flexion reflex (NFR) of the lower limbs (RIII reflex) was examined bilaterally in 54 cluster headache (CH) patients suffering from episodic CH (ECH) and chronic CH (CCH). Fifteen ECH patients were examined in both remission and active phases. The RIII reflex threshold (Tr) and the threshold of pain sensation (Tp) were significantly reduced on the symptomatic side in patients with episodic CH during the bout.

Effects of hypnosis on diffuse noxious inhibitory controls.

The neurophysiological mechanisms of hypnotic analgesia are still under debate. It is known that pain occurring in one part of the body (counterstimulation) decreases pain in the rest of the body by activating the diffuse noxious inhibitory controls (DNICs). The aim of this study was to explore the effects of hypnosis on both pain perception and heterotopic nociceptive stimulation.

Reciprocal circuits involved in nitroglycerin-induced neuronal activation of autonomic regions and pain pathways: a double immunolabeling and tract-tracing study.

This study uses tract-tracing protocols to determine the circuitry of specific nuclei involved in nitroglycerin-induced activation. Combined retrograde and anterograde tracers were injected into nuclei which consistently demonstrate robust Fos expression following our systemic nitroglycerin injection paradigm. The nuclei, which conform to these criteria, that we have evaluated in this study are the locus coeruleus, parabrachial nucleus and paraventricular nucleus of the hypothalamus.

Different effect of high doses of naloxone on spinal reflexes in normal subjects and chronic paraplegic patients.

There is still controversy over the effects of naloxone on spinal reflexes in view of the fact that both facilitatory and inhibitory activities have been observed. Dosage, supraspinal influences and interactions with different opiate receptors may account for the different findings. We investigated the effect of placebo (saline) and high doses of naloxone (1.

Headache coding and diagnostic-related groups: a survey of one year's admissions to a neurological department.

In 1995, the introduction of Diagnostic Related Groups (DRGs) within the Italian National Health Service (NHS) significantly changed the mode of payment for hospital admissions. The ICD-IX system is the fundamental instrument by which to identify various clinical entities; however, its codes still refer to an old international classification of diseases. Headache disorders are now diagnosed according to the new classification of the International Headache Society, and their recognition using ICD-IX codes appears to be increasingly inadequate.

Factors associated with pain complaints in a clinical sample of postmenopausal women.

The aims of this study were to evaluate the relationships occurring between pain complaints and postmenopausal status, and to look at the correlation between such complaints and other symptoms commonly related to the climacterium. A clinical sample of 99 consecutive postmenopausal patients requiring medical help were studied: 36 complained of muscle-skeletal pains whereas 33 presented with headache limiting daily activity. Climacteric syndrome, level of distress, coping style and bone mineral density were assessed with appropriate questionnaires and instruments.

Comparative study with EMG, pressure algometry and manual palpation in tension-type headache and migraine.

According to International Headache Society classification criteria, the presence of pericranial muscle disorder in tension-type headache should be evaluated using one of the following methods: EMG, pressure algometry or manual palpation. The purpose of this study was to compare the results of these three methods in 15 patients with episodic tension-type headache, 29 with chronic tension-type headache and 22 presenting migraine without aura compared to those obtained in healthy individuals. Algometric and EMG recordings at the frontalis muscle during mental arithmetic were more impaired in episodic and chronic tension headache patients than in controls and migraine patients.

Migraine without aura and reproductive life events: a clinical epidemiological study in 1300 women.

A retrospective study was conducted on 1300 women suffering from migraine without aura referred to the Headache Centers of Parma and Pavia from 1984 to 1990. All the data concerning their reproductive life, and the modifications induced by it on the course of headache were obtained from record-charts. Migraine frequently started at menarche (10.

An epidemiological approach to the nosography of chronic daily headache.

Chronic daily headache (CDH), a heterogeneous group of headaches, includes different forms that occur daily, or almost daily, over a prolonged period of time. The nosography of this group is still a matter of debate, and in the most recent classification of the IHS (1988) only a few types of CDH are included: chronic tension-type headache, coexisting migraine. This study is an epidemiological approach to identifying the clinical features of CDH and the possible factors involved in changing episodic headache in CDH.

Effects of etoperidone on sympathetic and pituitary-adrenal responses to diverse stressors in humans.

The effects of the psychotropic drug etoperidone on the response to laboratory stressors was investigated in a controlled study. Cardiovascular and hormonal (catecholamines, corticotropin, and cortisol) measurements were made in a group of young, healthy volunteers during a cold pressor test (CPT), a mental arithmetic test (MAT), and insulin-induced hypoglycaemia (ITT). One-week treatment with etoperidone (ETO) (150 mg/day, orally) reduced basal and stress-induced values of systolic and diastolic blood pressure (BP) on CPT, while it did not alter catecholamine output in response to the stressor.