Perceived migraine triggers: do dietary factors play a role?

The present cross-sectional study was designed to assess the frequency of 36 possible triggering factors precipitating a migraine crisis (hormonal, environmental, and dietary) in adult outpatients suffering from migraine attacks. A group of 123 migraine sufferers, aged 43.2 ± 13.9 (mean ± SD) years, including 114 (92.7%) women, 68.3% having migraine without aura, 68.3% reporting pain severe enough to require drug prophylaxis, and 29.3% presenting with hypertension, were evaluated. The most common triggers were stress and fasting, and environmental and hormonal factors were frequently found to precipitate a crisis. More than 90% of the patients reported susceptibility to 5 or more factors, and only 2.4% did not complain about any dietary factor. The large number of triggers detected in the present study emphasises the importance of awareness and avoidance of these factors in the management of patients with migraine.

Guanosine and GMP prevent seizures induced by quinolinic acid in mice.

In the mammalian CNS, glutamate and GABA are the principal neurotransmitters mediating excitatory and inhibitory synaptic events, respectively, and have been implicated in the neurobiology of seizures. Guanine-based purines, including the nucleoside guanosine and the nucleotide GMP, have been shown to antagonize glutamatergic activity at the receptor level and the other purine nucleoside adenosine is a well-known modulator of seizure threshold. In the present study we investigated the anticonvulsant effect of i. p. guanosine and GMP against seizures induced by the glutamate agonist quinolinic acid (QA) or the GABA(A) antagonist picrotoxin in mice. Animals were pretreated with an i.p. injection of saline, guanosine or GMP 30 min before either an i.c.v. injection of 4 microliter QA (36.8 nmol) or a subcutaneous injection of picrotoxin (3.2 mg/kg). All animals pretreated with vehicle followed by QA or picrotoxin presented seizures, which were completely prevented by the NMDA antagonist MK-801 and the GABA agonist phenobarbital, respectively. Guanosine and GMP dose-dependently protected against QA-induced seizures, up to 70 and 80% at 7.5 mg/kg, with ED(50)=2. 6+/-0.4 and 1.7+/-0.6 mg/kg, respectively. Conversely, neither guanosine, GMP nor MK-801 affected picrotoxin-induced seizures, indicating some degree of specificity towards the glutamatergic system. This study suggests anticonvulsant properties of i.p. guanosine and GMP, which may be related with antagonism of glutamate receptors.