Endorphin patterns within the headache spectrum disorders

Molecular Hydrogen: an Emerging Therapeutic Medical Gas for Brain Disorders

Oxidative stress and neuroinflammation are the main physiopathological changes involved in the initiation and progression of various neurodegenerative disorders or brain injuries. Since the landmark finding reported in 2007 found that hydrogen reduced the levels of peroxynitrite anions and hydroxyl free radicals in ischemic stroke, molecular hydrogen's antioxidative and anti-inflammatory effects have aroused widespread interest. Due to its excellent antioxidant and anti-inflammatory properties, hydrogen therapy via different routes of administration exhibits great therapeutic potential for a wide range of brain disorders, including Alzheimer's disease, neonatal hypoxic-ischemic encephalopathy, depression, anxiety, traumatic brain injury, ischemic stroke, Parkinson's disease, and multiple sclerosis. This paper reviews the routes for hydrogen administration, the effects of hydrogen on the previously mentioned brain disorders, and the primary mechanism underlying hydrogen's neuroprotection. Finally, we discuss hydrogen therapy's remaining issues and challenges in brain disorders. We conclude that understanding the exact molecular target, finding novel routes, and determining the optimal dosage for hydrogen administration is critical for future studies and applications.

Aerobic Exercise and Plasma Beta Endorphin Levels in Patients with Migrainous Headache Without Aura

This study aims to evaluate the effects of plasma beta endorphin level and exercise on migrainous headache. Forty patients with migrainous headache without aura (MWOA), firstly exercised on a treadmill and afterwards were asked to continue an aerobic home exercise program for six weeks. On evaluation, basal plasma beta endorphin level was negatively correlated with total duration of attacks in the last month period ( P = 0.01). Exercise was found to have beneficial effects on all migraine parameters ( P < 0.0001) and to increase beta endorphin levels after the treadmill practice ( P < 0.0001) and after the home exercise program except four patients not regularly attended to the program ( P < 0.0001). Any of the changes in headache parameters was not correlated with the change in beta endorphin level. However, pre-exercise beta endorphin level was found to be negatively correlated with the changes in the number of attacks ( P < 0.05) and total duration of attacks ( P = 0.01) and also with the change in beta endorphin level due to exercise ( P < 0.0001). As a result, this study emphasizes the beneficial effect of exercise on migrainous headache, especially in patients with lower basal beta endorphin level.

The effects of laser acupuncture on chronic tension headache--a randomised controlled trial

OBJECTIVE

Headache affects the quality of life for many people throughout the world. Tension headache is among the commonest forms. Acupuncture is the most widely practised non-medicinal treatment for headaches. The purpose of this study was to explore the effects of laser acupuncture in this type of headache.

METHODS

Fifty patients with chronic tension-type headache were randomly allocated to treatment or placebo groups. Patients in the treatment group received low energy laser acupuncture to LU7, LI4, GB14, and GB20 bilaterally. Points were irradiated for 43 seconds, and the intensity was 1.3J (approximately 13J/cm2). Ten sessions were given, three per week. The placebo group was treated in a similar way except that the output power of the equipment was set to zero. The outcome variables were headache intensity (VAS), duration of attacks, and number of days with a headache per month, by daily diary, assessed monthly to three months after treatment.

RESULTS

There were significant differences between groups (P<0.001) in changes from baseline in months one, two and three, in median score for headache intensity (treatment group -5, -3 and -2, placebo group -1, 0 and 0), median duration of attacks (treatment group -6, -4 and -4, placebo group -1, 0 and 0 hours), and median number of days with headache per month (treatment group -15, -10 and -8, placebo group -2, 0 and 0).

CONCLUSION

This study suggests that laser acupuncture may be an effective treatment for chronic tension-type headache, but the results should be confirmed in larger and more rigorous trials.

Characterization of opioid receptors that modulate nociceptive neurotransmission in the trigeminocervical complex

1. Opioid agonists have been used for many years to treat all forms of headache, including migraine. We sought to characterize opioid receptors involved in craniovascular nociceptive pathways by in vivo microiontophoresis of micro -receptor agonists and antagonists onto neurons in the trigeminocervical complex of the cat. 2. Cats were anaesthetized with alpha-chloralose 60 mg kg(-1), i.p. and 20 mg kg(-1), i.v. supplements after induction and surgical preparation using halothane. Units were identified in the trigeminocervical complex responding to supramaximal electrical stimulation of the superior sagittal sinus, and extracellular recordings of activity made. 3. Seven- or nine-barrelled glass micropipettes incorporating tungsten recording electrodes in their centre barrels were used for microiontophoresis of test substances onto cell bodies. 4. Superior sagittal sinus (SSS)-linked cells whose firing was evoked by microiontophoretic application of L-glutamate (n=8 cells) were reversibly inhibited by microiontophoresis of H(2)N-Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol (DAMGO) (n=12), a selective micro -receptor agonist, in a dose dependent manner, but not by control ejection of sodium or chloride ions from a barrel containing saline. 5. The inhibition by DAMGO of SSS-linked neurons activated with L-glutamate could be antagonized by microiontophoresis of selective micro -receptor antagonists D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP) or D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), or both, in all cells tested (n=4 and 6, respectively). 6. Local iontophoresis of DAMGO during stimulation of the superior sagittal sinus resulted in a reduction in SSS-evoked activity. This effect was substantially reversed 10 min after cessation of iontophoresis. The effect of DAMGO was markedly inhibited by co-iontophoresis of CTAP. 7. Thus, we found that micro -receptors modulate nociceptive input to the trigeminocervical complex. Characterizing the sub-types of opioid receptors that influence trigeminovascular nociceptive transmission is an important component to understanding the pharmacology of this synapse, which is pivotal in primary neurovascular headache.

Differential sensitivity to morphine challenge in migraine sufferers and headache-exempt subjects

The effectiveness of a therapeutic dose of morphine in relieving migraine attacks was compared with placebo. Morphine was no more effective than placebo and provoked severe side effects. When low-dose morphine was administered to normal non-headache controls and migraineurs when headache-free, physical and psychologic reactions were induced only in migraineurs. On pupillometric study, only migraineurs had defective morphine-miosis. It is suggested that the observed clinical phenomena in response to morphine can be explained by differences in expression and sensitivity of some opioid receptor subtypes in migraine.

Cerebrospinal fluid analyses in migraine patients and controls

To investigate the role of central neurotransmitters in the pathogenesis of migraine, we measured cerebrospinal fluid (CSF) levels of certain amino acids (glycine, taurine, glutamine) and metabolites of biogenic amines (5-hydroxyindoleacetic acid and homovanillic acid) in 38 migraine patients and compared them with the levels from 10 headache-free controls. The levels of taurine, glycine and glutamine were significantly higher in the migraine patients (p < 0.0001 for taurine and glycine; p < 0.0009 for glutamine); there were no significant differences among the three migraine subgroups (infrequent migraine, frequent migraine and transformed migraine). In seven patients subsequently treated with divalproex sodium, CSF taurine levels decreased significantly from pretreatment baseline values. These data support the concept that migraine is at least in part a disorder of central neurotransmission.

Somatosensory evoked potentials and headache: a further examination of the central theory

The central theory of headache was investigated by examining the amplitude of the somatosensory evoked potential (SSEP) in headache sufferers and headache-free controls. The P1-N1 amplitude was found to be greater, and to increase more rapidly with increasing stimulus intensity, for headache subjects than for controls. The N1-P2 amplitude was also found to be larger for headache subjects than for controls, but there was no significant difference between groups on the rate at which this component increased with stimulus intensity. When the P1-N1 and N1-P2 amplitudes were assessed in headache subjects, during and between attacks, no significant differences between conditions were observed. No significant differences between tension and migraine sufferers were observed on either component. It was concluded that the central nervous systems of headache sufferers may be more reactive to somatosensory input than those of headache-free persons and that this might be an important factor in the pathophysiology of headache.

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. Ninety CDH outpatients were investigated using a computerized record chart. The main observed forms were: (a) chronic tension-type headache--migraine with interparoxysmal headache, an evolved form of migraine in which a constant low severity headache develops between attacks; (b) transformed migraine, an evolved form of migraine with progressive worsening of the disease which reaches the level of continuous pain with the disappearance of typical migraine attacks. Interval headaches in migraine with interparoxysmal headache partly fulfil the IHS criteria for chronic tension-type headache. Analgesic drug abuse plays a prominent role in inducing CDH and in determining its clinical features.

Calcitonin and beta-endorphin secretion

Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. This hormone mainly acts in preventing bone resorption. Furthermore, calcitonin is involved in other biological actions, and in particular it is able to relieve pain independently of its peripheral effects on bone. Here, we examine the possible mechanisms of calcitonin-induced analgesia, with particular regard to the opioid system involvement. Several studies in animals and in humans demonstrate that calcitonin increases plasma beta-endorphin levels, acting at the hypothalamic and/or at the pituitary level, either directly or indirectly, through monoaminergic neurotransmitters. However, this calcitonin-induced beta-endorphin release has not always been observed. These different results are discussed, and a possible implication of sex and/or calcitonin dose employed has been examined. We conclude that the analgesic effects of calcitonin are multifactorial, and beta-endorphin plays its own specific role.

Evidence of alpha-N-acetyl beta-endorphin in human cerebrospinal fluid

Alpha-N-acetyl-beta-endorphin (Ac-beta-EP) is a post-translational product of beta-endorphin (beta-EP) with no analgesic properties. Ac beta-EP is present in human fetal and adult pituitary gland and cross-reacts in all available beta-EP assays. This study evaluates levels of Ac-beta-EP in the cerebrospinal fluid (CSF) of 22 normal subjects and 15 chronic headache sufferers. Since dopamine may play a role in the acetylation process, homovanillic acid levels were also determined. After extraction and high performance liquid chromatographic (HPLC) fractionation of CSF, an immunoreactive Ac-beta-EP peak was detected coeluting with reference peptide. Ac-beta-EP was detectable in all but 5 normal subjects. In headache sufferers, Ac-beta-EP levels were always detectable and their mean value was significantly higher than that of healthy subjects (11.6 +/- 11.8 vs 3.9 +/- 3.6 fmol/ml; P less than 0.01). Conversely, CSF beta-endorphin (beta-EP) concentrations were decreased in headache patients (9.8 +/- 9.4 vs 15.7 +/- 9.7 fmol/ml; P less than 0.05), and as a consequence the beta-EP/Ac-beta-EP ratio was also markedly reduced (P less than 0.005). No difference was observed for CSF homovanillic acid concentrations. These data demonstrate that HPLC coupled to radioimmunoassay allows the identification of low but significant amounts of Ac beta-EP in human CSF. This compound represents a confounding factor when beta-EP immunoreactivity is assessed by conventional methods. In headache sufferers, Ac-beta-EP levels were higher than normal, whereas beta-EP concentrations were lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Pain sensitivity and headache: an examination of the central theory

The central theory of headache was investigated by examining pain sensitivity in headache sufferers and headache-free controls. Headache subjects had lower pain threshold and tolerance levels than controls for electrical stimulation of the finger. Headache subjects also had a lesser tolerance for pain induced by the application of ice to the temporal region, but there was no significant difference between groups on temporal ice pain threshold. Sensitivity to finger pain was not affected by the presence or absence of headache at the time of testing. No significant differences between tension and migraine subjects were observed; neither were headache subjects, reporting unilateral headaches, significantly more sensitive to temporal ice pain on the side affected by headache. It was concluded that headache sufferers may be more sensitive to pain than headache-free persons but, that this heightened sensitivity is not specific to the head, and in itself, seems unable to account for the locus of headache.

Neuroendocrine evidence of deranged noradrenergic activity in chronic migraine

Migraine is a psychobiological disorder in which a recurrent failure of opioid and adrenergic systems might occur, as plasma and CSF studies suggest. In order to elucidate the relationship between noradrenergic and opioidergic functions, the plasma beta-endorphin (beta-EP) response to clonidine and the cortisol response to dexamethasone were evaluated together in 25 patients suffering from migraine without aura, and with chronic tension headache (MTH). Baseline beta-EP plasma levels and beta-EP response to clonidine were significantly lower in MTH subjects than in controls, suggesting a postsynaptic hypothalamo-pituitary impairment. Forty-four percent of the MTH subjects showed either a lack of suppression of plasma cortisol following dexamethasone administration, or basal cortisol concentrations higher than controls and suppressors, suggesting a disinhibition of the hypothalamopituitary-adrenal (HPA) axis. An inverse correlation was found between pain severity and beta-EP secretion induced by clonidine (delta max), and no relationship was found between beta-EP and mood. These data suggest a failure of central noradrenergic activity, or perhaps an impaired secretion of beta-EP not related to HPA axis hyperactivity or to affective state.

Catecholamine response to light in migraine

The effect of the shift from a low to a high luminosity of the environment on the urinary excretion of norepinephrine (NE) and epinephrine (E) was studied in migraineurs (26 cases) and controls (25 cases). In the latter the shift from a low to high light exposure increased NE excretion; in contrast, in migraineurs exposure to high luminosity resulted in a depression of NE excretion and an augmentation of E excretion. The possible participation of E discharge produced by photostimulation or by other stimuli in the pathogenesis of migraine attack is discussed.

Abnormal dexamethasone suppression test in daily chronic headache sufferers

The dexamethasone suppression test (DST) was administered in 48 daily chronic headache (DCH) sufferers, 37 of whom also suffered from mild to severe depression. In 14 of 48 subjects (29.2%), cortisol values at 1600h were greater than 50 ng/ml, despite normal suppression at 0800h. The escapers showed basal cortisol values and (Depression scale) scores on the Minnesota Multiphasic Personality Inventory higher than suppressors. Thus, a group of DCH sufferers appeared to share a biochemical defect often seen in endogenous depression. The escape from dexamethasone suppression could be a psychobiological indicator of vulnerability to develop depressive disorder and/or chronic pain complaints.