Articles on Inflammation & Migraine
Mast cells activate the renin angiotensin system and contribute to migraine: a hypothesis. [Review] [47 refs] Ba'albaki H. Rapoport A. Headache. 48(10):1499-505, 2008. Migraine is a chronic disease with episodic attacks, which, when frequent or severe, can be associated with poor quality of life, increased health resource utilization, lost productivity, and significant disability. Preventive therapy can therefore have a significant beneficial clinical and economic impact. However, many migraineurs are treated suboptimally. There is increasing evidence that activation and degranulation of meningeal mast cells result in meningeal irritation, vascular dilation, and stimulation of nearby nociceptive nerve endings of the trigeminal nerve, thus potentially contributing to the pathogenesis of migraine headache. The renin angiotensin system and its peptides are well represented in the mammalian central nervous system and can also promote neurogenic inflammation. Interestingly, mast cells are capable of releasing renin and increasing local production of Angiotensin II. We therefore hypothesize that mast cells contribute to migraine headache through activation of the renin angiotensin system. This hypothesis may help explain the association between migraine and cardiovascular disease as well as observations that medications that modulate the renin angiotensin system can reduce migraine-related morbidity in patients with frequently recurring migraine attacks.
Vascular actions of estrogens: functional implications. [Review] [400 refs] Miller VM. Duckles SP. Pharmacological Reviews. 60(2):210-41, 2008. The impact of estrogen exposure in preventing or treating cardiovascular disease is controversial. But it is clear that estrogen has important effects on vascular physiology and pathophysiology, with potential therapeutic implications. Therefore, the goal of this review is to summarize, using an integrated approach, current knowledge of the vascular effects of estrogen, both in humans and in experimental animals. Aspects of estrogen synthesis and receptors, as well as general mechanisms of estrogenic action are reviewed with an emphasis on issues particularly relevant to the vascular system. Recent understanding of the impact of estrogen on mitochondrial function suggests that the longer lifespan of women compared with men may depend in part on the ability of estrogen to decrease production of reactive oxygen species in mitochondria. Mechanisms by which estrogen increases endothelial vasodilator function, promotes angiogenesis, and modulates autonomic function are summarized. Key aspects of the relevant pathophysiology of inflammation, atherosclerosis, stroke, migraine, and thrombosis are reviewed concerning current knowledge of estrogenic effects. A number of emerging concepts are addressed throughout. These include the importance of estrogenic formulation and route of administration and the impact of genetic polymorphisms, either in estrogen receptors or in enzymes responsible for estrogen metabolism, on responsiveness to hormone treatment. The importance of local metabolism of estrogenic precursors and the impact of timing for initiation of treatment and its duration are also considered. Although consensus opinions are emphasized, controversial views are presented to stimulate future research.
Casanova MF. The minicolumnopathy of autism: A link between migraine and gastrointestinal symptoms. [Review] [91 refs] Medical Hypotheses. 70(1):73-80, 2008. Gastrointestinal symptoms are common medical problems among autistic patients. A leaky gut and viruses have been proposed as possible culprits but evidence for these etiological agents remains elusive. In this article, we put forward an alternate etiology: abdominal migraines. Recent postmortem studies in autism indicate the presence of a minicolumnopathy and its relationship to both serotonergic abnormalities and a hyperexcitable cortex. These features of phenomenology are also observed in miganeurs. A putative relationship between autism and migraine is further suggested by similarities in clinical histories and laboratory evidence. Some commonalities include the presence of neuroinflammation, sensory overstimulation (e.g., flickering of fluorescent lights), "food allergies", benefits from similar diets, and the role of nitric oxide. Abdominal migraine therefore stands as a falsifiable hypothesis with added importance accrued to potential therapeutic interventions.
Bruno PP. Carpino F. Carpino G. Zicari A. An overview on immune system and migraine. [Review] [23 refs] European Review for Medical & Pharmacological Sciences. 11(4):245-8, 2007. The pathogenesis of migraine is still unclear, but much evidence led us hypothesize that it can be associated with immune system modification, so that a role for cytokines has been suggested. Cytokines are important mediators of the immune and inflammatory pathways and their receptors are widely express in central nervous system (CNS) by all cell types, including neurons, indicating that they can act on neuronal receptors. Cytokines are now considered to be the pain mediators in neurovascular inflammation. Furthermore cytokines may be a cause of the migraine pain: in fact an high levels of chemokines could stimulate the activation of trigeminal nerves, the release of vasoactive peptides or other biochemical mediators, such as nitric oxide, and then to cause inflammation. In this scenario, many studies on humans have focused the attention on peripheral and central levels of cytokines, but data obtained are highly controversial. Since at the moment there is not a conclusive evidence of the role played by cytokines in migraine, the authors present and comment the latest reports regarding cytokine modification and the role of the immune system in migraine.
Bigal ME. Lipton RB. Holland PR. Goadsby PJ. Obesity, migraine, and chronic migraine: possible mechanisms of interaction. [Review] [99 refs] Neurology. 68(21):1851-61, 2007. Migraine and obesity are associated in several ways. First, both are prevalent and disabling disorders influenced by genetic and environmental risk factors. Second, migraine with aura, as obesity, seems to be a risk factor for cardiovascular events. Finally, large population-based studies suggest that obesity is a risk factor for chronic migraine after adjusting for comorbidities. In this article, we discuss plausible mechanisms that may account for this association. Several of the inflammatory mediators that are increased in obese individuals are important in migraine pathophysiology, including interleukins and calcitonin gene-related peptide (CGRP). These mediators may increase the frequency, severity, and duration of migraine attacks per se, which in turn would cause central sensitization. Repeated central sensitization may be associated with permanent neuronal damage close to the periaqueductal gray area, with poor modulation to pain. Obesity is also a state of sympathetic activation, which may contribute to increase in headache frequency. Furthermore, the levels of adiponectin are decreased in obesity. At low but not normal levels, adiponectin is nociceptive. Shared biologic predisposition may also play a major role. Orexins modulate both pain and metabolism. Dysfunction in the orexins pathways seems to be a risk factor for both conditions. Finally, conditions that are comorbid to both states (e.g., depression, sleep apnea) may also make the relationship between both diseases more complex.
Tassorelli C. Greco R. Armentero MT. Blandini F. Sandrini G. Nappi G. A role for brain cyclooxygenase-2 and prostaglandin-E2 in migraine: effects of nitroglycerin. International Review of Neurobiology. 82:373-82, 2007. Cyclooxygenase-2 (COX-2) may increase prostaglandin E(2) (PGE(2)) production in central nervous system (CNS) and contribute to the severity of pain responses in inflammatory pain. In this chapter, we sought to evaluate the possible role of COX-2 induction and prostaglandins (PGs) synthesis within neuronal areas proposed to be involved in migraine genesis in the animal model of migraine based on the administration of systemic nitroglycerin (NTG). Male Sprague-Dawley rats were injected with NTG (10mg/kg, i.p.) or vehicle and sacrificed 2 and 4h later. The hypothalamus and the lower brain stem were dissected out and utilized for the evaluation of COX-2 expression by means of Western blotting and for the determination of PGE(2) levels by means of ELISA immunoassay. COX-2 expression increased in the hypothalamus at 2h and in the lower brain stem at 4h. PGE(2) levels showed an opposite pattern of change with a decrease in PGE(2) levels at 2h in the hypothalamus and an increase at 4h in the lower brain stem. These data support the hypothesis that NTG administration is capable of activating the COX-2 pathway within cerebral areas. This activity may explain the pronociceptive effect of NTG described in animal and human models of pain. Most importantly, these findings point to mediators and areas that may be relevant for migraine pathogenesis and treatment.
Vanmolkot FH. de Hoon JN. Increased C-reactive protein in young adult patients with migraine. Cephalalgia. 27(7):843-6, 2007. Interictal serum C-reactive protein (CRP) was measured in 50 young adult patients with migraine and compared with 50 controls. The median CRP level was 1.42 mg/l in patients with migraine and 0.90 mg/l in controls (P = 0.03). This finding supports the role of inflammation in migraine, but needs confirmation in larger controlled studies. Prospective studies may establish whether measurements of CRP can identify patients with migraine at risk for cardiovascular events.
The biochemical origin of pain: the origin of all pain is inflammation and the inflammatory response. Part 2 of 3 - inflammatory profile of pain syndromes. Omoigui S. Medical Hypotheses. 69(6):1169-78, 2007. Every pain syndrome has an inflammatory profile consisting of the inflammatory mediators that are present in the pain syndrome. The inflammatory profile may have variations from one person to another and may have variations in the same person at different times. The key to treatment of Pain Syndromes is an understanding of their inflammatory profile. Pain syndromes may be treated medically or surgically. The goal should be inhibition or suppression of production of the inflammatory mediators and inhibition, suppression or modulation of neuronal afferent and efferent (motor) transmission. A successful outcome is one that results in less inflammation and thus less pain. We hereby briefly describe the inflammatory profile for several pain syndromes including arthritis, back pain, neck pain, fibromyalgia, interstitial cystitis, migraine, neuropathic pain, complex regional pain syndrome/reflex sympathetic dystrophy (CRPS/RSD), bursitis, shoulder pain and vulvodynia. These profiles are derived from basic science and clinical research performed in the past by numerous investigators and serve as a foundation to be built upon by other researchers and will be updated in the future by new technologies such as magnetic resonance spectroscopy. Our unifying theory or law of pain states: the origin of all pain is inflammation and the inflammatory response. The biochemical mediators of inflammation include cytokines, neuropeptides, growth factors and neurotransmitters. Irrespective of the type of pain whether it is acute or chronic pain, peripheral or central pain, nociceptive or neuropathic pain, the underlying origin is inflammation and the inflammatory response. Activation of pain receptors, transmission and modulation of pain signals, neuro plasticity and central sensitization are all one continuum of inflammation and the inflammatory response. Irrespective of the characteristic of the pain, whether it is sharp, dull, aching, burning, stabbing, numbing or tingling, all pain arise from inflammation and the inflammatory response. We are proposing a re-classification and treatment of pain syndromes based upon their inflammatory profile.
The biochemical origin of pain--proposing a new law of pain: the origin of all pain is inflammation and the inflammatory response. Part 1 of 3--a unifying law of pain. Omoigui S. Medical Hypotheses. 69(1):70-82, 2007. We are proposing a unifying theory or law of pain, which states: the origin of all pain is inflammation and the inflammatory response. The biochemical mediators of inflammation include cytokines, neuropeptides, growth factors and neurotransmitters. Irrespective of the type of pain whether it is acute or chronic pain, peripheral or central pain, nociceptive or neuropathic pain, the underlying origin is inflammation and the inflammatory response. Activation of pain receptors, transmission and modulation of pain signals, neuro plasticity and central sensitization are all one continuum of inflammation and the inflammatory response. Irrespective of the characteristic of the pain, whether it is sharp, dull, aching, burning, stabbing, numbing or tingling, all pain arise from inflammation and the inflammatory response. We are proposing a re-classification and treatment of pain syndromes based upon their inflammatory profile. Treatment of pain syndromes should be based on these principles: 1. Determination of the inflammatory profile of the pain syndrome; 2. Inhibition or suppression of production of the appropriate inflammatory mediators, e.g. with inflammatory mediator blockers or surgical intervention where appropriate; 3. Inhibition or suppression of neuronal afferent and efferent (motor) transmission, e.g. with anti-seizure drugs or local anesthetic blocks; 4. Modulation of neuronal transmission, e.g. with opioid medication. At the L.A. Pain Clinic, we have successfully treated a variety of pain syndromes by utilizing these principles. This theory of the biochemical origin of pain is compatible with, inclusive of, and unifies existing theories and knowledge of the mechanism of pain including the gate control theory, and theories of pre-emptive analgesia, windup and central sensitization.
Fidan I. Yuksel S. Ymir T. Irkec C. Aksakal FN. The importance of cytokines, chemokines and nitric oxide in pathophysiology of migraine. Journal of Neuroimmunology. 171(1-2):184-8, 2006. The certain etiology migraine is unknown. The study was aimed at determining to the efficiency of cytokines, chemokines and nitric oxide (NO) to the pathophysiology of migraine. The levels of cytokines, chemokines and NO in serum of 25 patients with migraine during attacks and attack-free periods and 25 healthy controls were investigated. The levels of cytokines and chemokines were determined by enzyme-linked immunosorbent assay. NO concentrations were determined by a nitrate/nitrite colorimetric assay kit. In attack groups, IL-10 levels were found higher than in attack-free groups and healthy controls (p<0.05). IL-6 levels in migraine patients were significantly higher than in healthy controls. The levels of RANTES were high in attacks groups. There was an increase NO concentrations in migraine attacks. The study's results reflect that the etiology of migraine is multifactorial and probably related to immunological changes.
Ahn AH. Basbaum AI. Tissue injury regulates serotonin 1D receptor expression: implications for the control of migraine and inflammatory pain. Journal of Neuroscience. 26(32):8332-8, 2006. The anti-migraine action of "triptan" drugs involves the activation of serotonin subtype 1D (5-HT1D) receptors expressed on "pain-responsive" trigeminal primary afferents. In the central terminals of these nociceptors, the receptor is concentrated on peptidergic dense core vesicles (DCVs) and is notably absent from the plasma membrane. Based on this arrangement, we hypothesized that in the resting state the receptor is not available for binding by a triptan, but that noxious stimulation of these afferents could trigger vesicular release of DCVs, thus externalizing the receptor. Here we report that within 5 min of an acute mechanical stimulus to the hindpaw of the rat, there is a significant increase of 5-HT1D-immunoreactivity (IR) in the ipsilateral dorsal horn of the spinal cord. We suggest that these rapid immunohistochemical changes reflect redistribution of sequestered receptor to the plasma membrane, where it is more readily detected. We also observed divergent changes in 5-HT1D-IR in inflammatory and nerve-injury models of persistent pain, occurring at least in part through the regulation of 5-HT1D-receptor gene expression. Finally, we found that 5-HT1D-IR is unchanged in the spinal cord dorsal horn of mice with a deletion of the gene encoding the neuropeptide substance P. This result differs from that reported for the partial differential-opioid receptor, which is also sorted to DCVs, but is greatly reduced in preprotachykinin mutant mice. We suggest that a "pain"-triggered regulation of 5-HT1D-receptor expression underlies the effectiveness of triptans for the treatment of migraine. Moreover, the widespread expression of 5-HT1D receptor in somatic nociceptive afferents suggests that triptans could, in certain circumstances, treat pain in nontrigeminal regions of the body.
Tronvik E. Stovner LJ. Schrader H. Bovim G. Involvement of the renin-angiotensin system in migraine. [Review] [36 refs] Journal of Hypertension - Supplement. 24(1):S139-43, 2006. Migraine is a common episodic headache that predominantly affects young adults, particularly women in their most productive years. Many of the prophylactic agents available today have side-effects that are not compatible with long-term use. The discovery that drugs influencing the renin-angiotensin system (RAS), which have few side-effects, were effective in some patients with migraine led to several studies investigating a possible link between the angiotensin system and migraine pathophysiology. Clinical trials indicated that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are effective in the prophylactic treatment of migraine. These findings are further supported by pharmacoepidemiological, genetic, and physiological studies. In addition, it is known that the RAS has neurophysiological, chemical, and immunological effects that are of relevance in migraine pathophysiology. On the basis of evidence presented in this review, we find it likely that the RAS has a clinically important role in migraine pathophysiology. The effect of ARBs and ACEIs on migraine is probably not attributable to their effect on blood pressure. The RAS has several actions that may be relevant in migraine pathophysiology, but the reason for the prophylactic effect of ARBs/ACEIs in migraine remains a matter of speculation.
Geppetti P. Capone JG. Trevisani M. Nicoletti P. Zagli G. Tola MR. CGRP and migraine: neurogenic inflammation revisited. [Review] [81 refs] Journal of Headache & Pain. 6(2):61-70, 2005. For more than a century neurogenic inflammation has been proposed to have a role in various human diseases. The present review will cover the conceptual steps of the itinerary that has led to the conclusion that neurogenic inflammation is important in migraine. Of particular relevance for the object of this article is the observation that tachykin-independent neurogenic inflammatory responses are evident in rodents, but much less pronounced or absent in other mammal species, including man, whereas neurogenic vasodilatation, most likely mediated by CGRP, occurs in most mammalian species and also in man. Recent evidence that a CGRP receptor antagonist was effective in the treatment of migraine attack supports the hypothesis that neurogenic vasodilatation is a major underlying mechanism of migraine.
Peroutka SJ. Neurogenic inflammation and migraine: implications for the therapeutics. [Review] [85 refs] Molecular Interventions. 5(5):304-11, 2005. Significant recent advances in molecular pharmacology have elucidated the molecular pathways involved in neurogenic inflammation (NI). The release of tachykinins and endothelin-3 (ET-3) from trigeminal neurons induces dural vascular permeability and vasodilatation via activation of tachykinin receptor 1 (Tacr1) and endothelin receptor type B (Ednrb) on endothelial cells. Endothelial cell receptor stimulation results in cellular contraction, leading to plasma protein extravasation (PPE), which is the most recognized physiological hallmark of NI, and nitric oxide-induced vasodilatation. By contrast, the release of calcitonin gene-related peptide (CGRP) from trigeminal neurons--also a key physiological component of NI--does not affect vascular permeability but does induce neurogenic vasodilatation (NV) via the direct, (i.e., endothelium-independent) relaxation of vascular smooth muscle. The molecular pharmacology of NI is discussed within the context of migraine research and assesses the putative role of the two key physiological components of NI (i.e., PPE and NV) in migraine pathophysiology. The data indicate that the PPE component of NI plays no significant role in migraine but that NV is likely to be involved in migraine pathophysiology.
Buzzi MG. Moskowitz MA. The pathophysiology of migraine: year 2005. [Review] [85 refs] Journal of Headache & Pain. 6(3):105-11, 2005. Migraine is a complex patholophysiology in which both central and peripheral components of the trigeminal pain pathway probably play a significant role, both in the symptoms and signs of the attack and in the mechanisms of action of antimigraine compounds, such as triptans, which constitute the most important therapy for aborting migraine pain and possess several mechanisms on 5-HT receptor-mediated actions. The experimental neurogenic inflammation model represents a simple procedure to obtain preliminary information on well characterized receptortargeted drugs. The apparent paradox observed with certain drugs that are shown to be effective in this model but not in clinical trials offers the opportunity to better manipulate structure-activity to obtain the best pharmacological profile using an array of experimental models. The observation that nitric oxide donors induce migraine-like pain in migraineours and that nitric oxide plays a pivotal role in the control of several functions in the central nervous system, has prompted the use of such molecules for better understanding the pathophysiology of migraine attacks. A link between central and peripheral components of the trigeminal pain pathway is provided by the observation that cortical spreading depression in the rat activates trigeminovascular afferents and induces a series of cortical meningeal and brainstem events consistent with the development of headache. Studies in humans support the hypothesis that cortical spreading depression underlies migraine.aura. Therefore, tt is possible that visual, motor or sensory aura might be responsible for the generation of the pain through the above mechanisms.
Spierings EL. Pathogenesis of the migraine attack. [Review] [30 refs] Clinical Journal of Pain. 19(4):255-62, 2003. BACKGROUND: There is clinical experimental evidence that extracranial arterial vasodilation, extracranial neurogenic inflammation, and decreased inhibition of central pain transmission are involved in the pathogenesis of the migraine headache. The migraine aura is likely caused by a neurophysiologic phenomenon akin to Leao's cortical spreading depression, a wave of short-lasting neuronal excitation that travels over the cerebral cortex, followed by prolonged depression of cortical neuronal activity. METHOD: A concept of the pathogenesis of the migraine attack is presented, in which the relation of the mechanism of the migraine aura and that of the migraine headache is considered parallel rather than sequential in nature. CONCLUSIONS: The process driving the pathogenesis of the migraine attack and susceptible to the migraine trigger factors may be located in the brain stem.
Fusco M. D'Andrea G. Micciche F. Stecca A. Bernardini D. Cananzi AL. Neurogenic inflammation in primary headaches. [Review] [27 refs] Neurological Sciences. 24 Suppl 2:S61-4, 2003. The headache in migraine is thought to result from neuronal nociceptive activity in the trigeminovascular system, that is, the meninges. In addition, trigeminal axons projecting to the meninges contain vasoactive neuropeptides, such as substance P, calcitonin gene-related peptide and neurokinin A, that may promote, when released, plasma protein leakage and vasodilation within dura mater, characteristic of neurogenic inflammation. Thus, it has been hypothesized that a sterile neurogenic inflammation in the meninges may be involved in generating or sustaining, via occurrence of a vicious cycle, the pain accompanying the migraine attacks. We here review the evidence in support of this hypothesis as well as its potential significance in better tailoring therapies in migraine or other types of primary headaches.
van der Kuy PH. Lohman JJ. The role of nitric oxide in vascular headache. [Review] [57 refs] Pharmacy World & Science. 25(4):146-51, 2003. Shortly after the invention of nitroglycerin (NTG), it was noticed that this substance is capable of inducing a violent headache. Only recently, it became known that this was due to the release of nitric oxide (NO) by NTG. As the molecular mechanism of migraine pain remains to be determined, NTG, being pro-drug for NO, has been used to study the aetiology and pathophysiology of migraine. Such studies with NTG- and also histamine-induced headaches, have led to propose that NO may be the causative molecule in migraine pain. The evidence supporting the role of NO in migraine is discussed, e.g. substances capable of inducing experimental vascular headache do so with NO as the common mediator, while drugs with antimigraine activity inhibit NO and the cascade of intracellular reactions triggered by NO. The importance of NO as a potential initiator of the migraine attack opens new directions for the pharmacological treatment of migraine and other vascular headaches.
Williamson DJ. Hargreaves RJ. Neurogenic inflammation in the context of migraine. [Review] [94 refs] Microscopy Research & Technique. 53(3):167-78, 2001. Despite considerable research into the pathogenesis of idiopathic headaches, such as migraine, the pathophysiological mechanisms underlying them remain poorly understood. Although it is well established that the trigeminal nerve becomes activated during migraine, the consequences of this activation remain controversial. One theory, based on preclinical observations, is that activation of trigeminal sensory fibers leads to a painful neurogenic inflammation within the meningeal (dural) vasculature mediated by neuropeptide release from trigeminal sensory fibres and characterized by plasma protein extravasation, vasodilation, and mast cell degranulation. Effective antimigraine agents such as ergots, triptans, opioids, and valproate inhibit preclinical neurogenic dural extravasation, suggesting that this activity may be a predictor of potential clinical efficacy of novel agents. However, several clinical trials with other agents that inhibit this process preclinically have failed to show efficacy in the acute treatment of migraine in man. Alternatively, it has been proposed that painful neurogenic vasodilation of meningeal blood vessels could be a key component of the inflammatory process during migraine headache. This view is supported by the observation that jugular plasma levels of the potent vasodilator, calcitonin gene-related peptide (CGRP) are elevated during the headache and normalized by successful sumatriptan treatment. Preclinically, activation of trigeminal sensory fibers evokes a CGRP-mediated neurogenic dural vasodilation, which is blocked by dihydroergotamine, triptans, and opioids but unaffected by NK1 receptor antagonists that failed in clinical trials. These observations suggest that CGRP release with associated neurogenic dural vasodilation may be important in the generation of migraine pain, a theory that would ultimately be tested by the clinical testing of a CGRP receptor antagonist.
