Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The first International Headache Society classification defined tension-type headaches (TTHs) by itemising those characteristics of migraines TTHs did not possess [1]. As a result, TTHs, both episodic and chronic, remain the most nonspecific of all the commonly observed primary headaches. Until recently, there has been little impetus on the part of the pharmaceutical industry to investigate TTHs; many of the potentially useful drugs are now generic and unprofitable. In addition, few investigators have pursued the study of TTHs in lieu of its more glamorous neighbour, migraine. As a result, there are few well-designed studies on the pharmacotherapy of TTHs. The few studies that exist support the use of age-old standard drug classes, the tricyclic antidepressants and the NSAIDs. New research is now emerging that points to the potential utility of botulinum toxin type A, NMDA-receptor antagonists including Mg(2+) and nitric oxide synthase inhibitors. More scientifically rigorous clinical studies are needed.
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PMID:New developments in the pharmacotherapy of tension-type headaches. 1464 Sep 22

(1) The standard treatment for mild to moderately severe Alzheimer's disease is donepezil, an anticholinesterase with some beneficial effects (progression is slowed in about 10% of patients, by six months on average) and mainly gastrointestinal adverse effects. (2) Memantine, a drug first developed several decades ago, belongs to the family of NMDA glutamate receptor inhibitors. Marketing authorisation was recently granted for memantine in moderately severe and severe Alzheimer's disease. (3) The clinical evaluation dossier on memantine is poor. Marketing approval was obtained thanks to only one placebo-controlled trial. It included only 252 patients treated for 28 weeks. Patients with moderately severe Alzheimer's disease were not analyzed separately from those with severe forms, even though the response criteria are different for the two categories of patients. (4) According to the chosen endpoint, 5% to 19% of patients were clinically improved by memantine. It is not known whether this benefit persists beyond six months. (5) The report of a trial comparing memantine + donepezil with placebo + donepezil does not analyse the response rate. Use of this combination is not currently justified. (6) In clinical trials the main adverse effects of memantine were neurological (dizziness and headache). Fairly lengthy pharmacovigilance data from Germany are relatively reassuring. (7) In practice, donepezil remains the reference option for moderately severe Alzheimer's disease. Memantine is a second-line option, as its adverse effects differ from those of anticholinesterases. There is still no drug offering a clear benefit for patients with severe forms of the disease.
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PMID:Memantine: new preparation. Poor evaluation and uncertain benefit in Alzheimer's disease. 1498 82

Topiramate is a neuromodulatory compound with stabilizing properties that was initially introduced for the management of partial seizures. Topiramate has been demonstrated to modify several receptor-gated and voltage-sensitive ion channels, including voltage-activated Na+ and Ca2+ channels and non-NMDA receptors. These receptors have been implicated in the pathophysiology of both epilepsy and migraine. The pharmacological mechanisms of action for topiramate that may explain its antiepileptic and migraine preventive activities will be discussed in this review. In addition, the potential relationship between the molecular activities of topiramate and its efficacy in epilepsy and migraine prevention will be emphasized.
Headache 2005 Apr
PMID:Molecular pharmacology of topiramate: managing seizures and preventing migraine. 1583 90

Retigabine [D23129; N-(2-amino-4-(4-fluorobenzylamino)-phenyl)carbamic acid ethyl ester] is an antiepileptic drug with a recently described novel mechanism of action that involves opening of neuronal K(V)7.2-7.5 (formerly KCNQ2-5) voltage-activated K(+) channels. These channels (primarily K(V)7.2/7.3) enable generation of the M-current, a subthreshold K(+) current that serves to stabilize the membrane potential and control neuronal excitability. In this regard, retigabine has been shown to have a broad-spectrum of activity in animal models of electrically-induced (amygdala-kindling, maximal electroshock) and chemically-induced (pentylenetetrazole, picrotoxin, NMDA) epileptic seizures. These encouraging results suggest that retigabine may also prove useful in the treatment of other diseases associated with neuronal hyperexcitability. Neuropathic pain conditions are characterized by pathological changes in sensory pathways, which favor action potential generation and enhanced pain transmission. Although sometimes difficult to treat with conventional analgesics, antiepileptics can relieve some symptoms of neuropathic pain. A number of recent studies have reported that retigabine can relieve pain-like behaviors (hyperalgesia and allodynia) in animal models of neuropathic pain. Neuronal activation within several key structures within the CNS can also be observed in various animal models of anxiety. Moreover, amygdala-kindled rats, which have a lowered threshold for neuronal activation, also display enhanced anxiety-like responses. Retigabine dose-dependently reduces unconditioned anxiety-like behaviors when assessed in the mouse marble burying test and zero maze. Early clinical studies have indicated that retigabine is rapidly absorbed and distributed, and is resistant to first pass metabolism. Tolerability is good in humans when titrated up to its therapeutic dose range (600-1200 mg/day). No tolerance, dependence or withdrawal potential has been reported, although adverse effects can include mild dizziness, headache, nausea and somnolence. Thus, retigabine may prove to be useful in the treatment of a diverse range of disease states in which neuronal hyperexcitability is a common underlying factor.
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PMID:Retigabine: chemical synthesis to clinical application. 1586 50

Stimulation of the greater occipital nerve produces excitation of second order neurons in the trigeminocervical complex. Given that neck pain is very common in primary headache disorders, this convergent excitation may play a role in pain referral from cervical structures. While previous studies have demonstrated a physiological model for this convergence, this study sought an anatomical approach to examine the distribution of second order neurons in the trigeminocervical complex receiving greater occipital nerve input. In addition, the role of glutamatergic NMDA receptor activation within the trigeminocervical complex in response to cervical afferents was studied. Noxious stimulation of the occipital muscle in rat using mustard oil and mineral oil produced significantly altered Fos expression in the trigeminocervical complex compared with the surgical control (H(4)=31.3, P<0.001, Kruskal-Wallis). Baseline expression was 11 (median, range 4, 17) fos positive cells in the trigeminocervical complex, occipital muscle treated with mustard oil produced 23 (17, 33) and mineral oil a smaller effect of 19 (15, 25) fos positive cells, respectively (P=0.046). The effects of both mustard and mineral oil were reversed by the NMDA-receptor antagonist MK801. This study introduces a model for examining trigeminocervical complex activity after occipital afferent stimulation in the rat that has good anatomical resolution and demonstrates involvement of glutamatergic NMDA receptors at this important synapse.
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PMID:Occipital afferent activation of second order neurons in the trigeminocervical complex in rat. 1673 Jan 24

Autoantibodies (aAB) to AMPA (Glu R1 subunit) and NMDA (NR 2A subunit) glutamate receptors were studied in blood serum of 60 children, aged 7-16 years, with chronic posttraumatic headache after mild skull injury. All the children were divided into 2 groups: group 1 included 48 children with concussion of the brain, group 2--12 children with brain contusion. Group 1 was divided into 2 subgroups: subgroup 1a comprised 34 children with single concussion and subgroup 1b--14 children with repeated concussion. The aAB level was determined 6 months and 1 year after skull injury. The aAB concentration was expressed in percents to the control level being considered significant if the increase was higher than 120%. The increased NMDA aAB level was observed during the first year after skull injury. In the la subgroup, the NR2 aAB level in blood serum was 145 +/- 12,6%, in the 1b one--108 +/- 12,4%, in group 2--165 +/- 34%. The content of aAB to AMPA receptors was elevated only in children of lb subgroup and group 2 (150 +/- 16,8% and 167 +/- 31,3%, respectively). The EEG examination of this group revealed the nonspecific paroxysmal discharges in 18% of cases and epileptiform activity in 6% of children. The results obtained suggest that children with posttraumatic headache have elevated levels of aAB to glutamate receptors, hyperstimulation of which reflects hypoxic processes in the brain, and are in need of metabolic therapy.
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PMID:[Autoantibodies to glutamate receptors in children with chronic posttraumatic headache]. 1697 97

Seizures are a common complication of metastatic brain tumors (MBT), affecting approximately 27-50% of all patients during the course of their illness. Treatment of tumor-induced seizures is often inadequate with traditional antiepileptic drugs (AED) due to a variety of factors, including activation of glutamatergic NMDA receptors, alterations of neuronal input pathways, and tumor growth. Levetiracetam (LEV) is a 2nd generation non-enzyme inducing AED with a novel mechanism of action, binding to neuronal synaptic vesicle protein SV2A, that has been previously shown to reduce seizure activity in patients with primary brain tumors. Due to its unique mechanism of action, it has been postulated that LEV may also be effective in controlling seizures from MBT. A retrospective chart review was performed of all Neuro-Oncology Center patients with MBT who had received LEV for seizure control. Thirteen patients were reviewed with a median age of 55.1 years (range: 34-70). Six patients had breast cancer, five had lung cancer, and two had melanoma. LEV was used as an add-on AED in seven patients (54%) and as monotherapy in six patients (46%), with a median dose of 1,000 mg/day (range: 500-3,000). The baseline median seizure frequency was one ictal event every other day. After the addition of LEV, the median seizure frequency was reduced to 0 per week. The seizure frequency was reduced to less than 50% of the pre-LEV baseline in 100% of patients (P=0.0002, Sign test), with 10 patients (77%; confidence interval: 46-95%) noting complete seizure control. The most common adverse event was somnolence and headache, noted in 3 of 13 patients (23%). LEV was very effective and well tolerated in MBT patients with seizures and should be considered for add-on therapy or as a substitute AED for monotherapy.
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PMID:Retrospective analysis of the efficacy and tolerability of levetiracetam in patients with metastatic brain tumors. 1743 42

We report here studies on the levels of autoantibodies (aAb) to AMPA glutamate receptors (GluR1 subunit) and NMDA glutamate receptors (NR2A subunit) in serum from 60 children aged 7-16 years with chronic posttraumatic headache (CPTHA) following mild craniocerebral trauma (CCT). The first group consisted of 48 children who had sustained cerebral concussion (CC), of which 34 had single-episode CC (subgroup 1a) and 14 had repeated CC (subgroup 1). The second group included 12 children with mild cerebral contusions (MCC). Serum glutamate receptor aAb levels were measured six months and one year after trauma. Increased aAb levels were expressed as percentages and were regarded as significant when increases were to 120% of the level seen in healthy children of the same age. The highest levels of aAb to NMDA receptors were seen in children with MCC (165 +/- 34%) and single CC (145 +/- 12.6%). Children with repeated CC had NMDA receptor aAb at normal levels (108 +/- 12.4%). Increases in NMDA receptor aAb were seen during the first year after trauma. Increases in AMPA receptor aAb were seen in children with repeated CC and MCC (150 +/- 16.8% and 167 +/- 31.3%). EEG studies showed that 18% of these children had nonspecific paroxysmal changes and 6% showed epileptiform activity. These results provide evidence that children with post-traumatic headache demonstrated hyperstimulation of glutamate receptors and overdevelopment of the autoimmune process. Increases in serum levels of aAb to NMDA glutamate receptors reflected hypoxic-ischemic brain lesions in children with CPTHA and dictate the need for these children to receive metabolic therapy.
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PMID:Glutamate receptor autoantibody concentrations in children with chronic post-traumatic headache. 1792 39

Migraine is a recurrent incapacitating neurovascular disorder characterized by unilateral and throbbing headaches associated with photophobia, phonophobia, nausea, and vomiting. Current specific drugs used in the acute treatment of migraine interact with vascular receptors, a fact that has raised concerns about their cardiovascular safety. In the past, alpha-adrenoceptor agonists (ergotamine, dihydroergotamine, isometheptene) were used. The last two decades have witnessed the advent of 5-HT(1B/1D) receptor agonists (sumatriptan and second-generation triptans), which have a well-established efficacy in the acute treatment of migraine. Moreover, current prophylactic treatments of migraine include 5-HT(2) receptor antagonists, Ca(2+) channel blockers, and beta-adrenoceptor antagonists. Despite the progress in migraine research and in view of its complex etiology, this disease still remains underdiagnosed, and available therapies are underused. In this review, we have discussed pharmacological targets in migraine, with special emphasis on compounds acting on 5-HT (5-HT(1-7)), adrenergic (alpha(1), alpha(2,) and beta), calcitonin gene-related peptide (CGRP(1) and CGRP(2)), adenosine (A(1), A(2), and A(3)), glutamate (NMDA, AMPA, kainate, and metabotropic), dopamine, endothelin, and female hormone (estrogen and progesterone) receptors. In addition, we have considered some other targets, including gamma-aminobutyric acid, angiotensin, bradykinin, histamine, and ionotropic receptors, in relation to antimigraine therapy. Finally, the cardiovascular safety of current and prospective antimigraine therapies is touched upon.
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PMID:Current and prospective pharmacological targets in relation to antimigraine action. 1862 30

Migraine attacks are characterized by unilateral throbbing, pulsating headache associated with nausea, vomiting, photophobia, phonophobia and allodynia. Peripheral sensitization is an acute, chemical-induced form of functional plasticity, which converts high-threshold nociceptors into low-threshold sensory neurons. This form of sensitization occurs when the nerve terminals (meningeal nociceptors) of the neurons of the trigeminal ganglion are soaked with the "inflammatory" soup (prostaglandin E2, bradykinin, serotonin and cytokines) along the vasculature of the cerebral dura mater. Peripheral sensitization in migraine attacks is explained clinically by intracranial hypersensitivity (the headache worsens during coughing or physical activity) and by a throbbing element in the pain of migraine (sensitized nociceptors become hyperresponsive to the otherwise innocuous and unperceived rhythmic fluctuation in intracranial pressure produced by normal arterial pulsation). The essence of central sensitization is that the second-order neurons in the trigeminocervical complex become hyperexcitable. The altered behavior of the second-order neurons is based on the increased glutamate sensistivity of the NMDA receptors and the neuronal nitric oxide synthase activity stimulated by nitric oxide. This process is explained clinically by face and scalp ollodynia and by neck stiffness (extracranial tenderness).
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PMID:[The mechanism of peripheral and central sensitization in migraine. A literature review]. 1973 14


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