No abstract

The aim of this study was to test the function of the diffuse noxious inhibitory control system (DNIC) in chronic and episodic migraine, exploring the blink reflex (BR) modifications induced by topical application of capsaicin on the hand. We evaluated 11 migraine without aura (MA) and nine chronic migraine (CM) patients during the not symptomatic phase; they were compared with 14 non-headache subjects (N). The BR was elicited by weak electrical stimuli delivered to the right supraorbital nerve; it was obtained 10 min and 20 min after the application of 1 ml of 3% capsaicin in a cream base (Teofarma) on the skin of the dorsum of the right hand, and 60 min after capsaicin removal. The subjective pain sensation induced by capsaicin was significantly increased in CM with respect to both MA patients and normal subjects; the R2 area was increased in CM patients during capsaicin application, with respect to controls and MA patients, who did not exhibit any reflex alterations. These results may suggest a failure of DNIC and a disturbed control of the trigeminal reflex at the central level, linked with migraine frequency.

The association between estrogens “withdrawal” and attacks of migraine without aura is well-known. The aim of the study was to examine the features of laser evoked potentials (LEPs), including habituation, in women suffering from migraine without aura versus healthy controls, during the pre-menstrual and late luteal phases. Nine migraine without aura and 10 non-migraine healthy women, were evaluated during the pre-menstrual phase and late luteal phase. The LEPs were recorded during the inter-critical phase. The right supraorbital zone and the dorsum of the right hand were stimulated. Three consecutive series of 20 laser stimuli were obtained for each stimulation site. Laser pain perception was rated by a 0–100 VAS after each stimulation series. Migraine patients exhibited increased LEPs amplitude and reduced habituation compared to normal subjects. Laser-pain perception was increased during the pre-menstrual phase in both patients and controls. Migraine patients and controls showed increased P2 and N2–P2 amplitude in the pre-menstrual phase, on both stimulation sites. During the pre-menstrual phase the N2–P2 habituation appeared to be reduced in both migraine and healthy women. The estrogen withdrawal occurring during the menstrual cycle may favor reduced habituation of nociceptive cortex, which may facilitate pain symptoms and migraine in predisposed women.

Previously an amplitude enhancement of laser evoked potentials (LEPs) was detected during migraine attack: we further examined pain threshold to CO2 laser stimuli and LEPs during attacks, evaluating the effect of almotriptan, lysine-acetylsalicylate and placebo treatment on cutaneous hyperalgesia to thermal stimuli delivered by CO2 laser and on LEP components. Eighteen patients suffering from migraine without aura were analysed. They were divided into three groups of six patients each, randomly assigned to lysine acetyl-salicylate, almotriptan or placebo treatments. The supraorbital zones and the dorsum of the hand were stimulated on both the symptomatic and not symptomatic side in all patients. The LEPs were recorded by 25 scalp electrodes. During attacks, the P2 wave was significantly enhanced; the amplitude of the P2 component obtained by the stimulation of the supraorbital zone during the attack on the side of the headache was significantly correlated with the intensity of pain and the frequency of headache. Both almotriptan and lysine acetyl-salicylate significantly reduced the P2 amplitude but they showed no effects on hyperalgesia to laser stimulation; headache relief following therapy was correlated with the reduction of the P2 amplitude. The cortical elaboration of laser-induced experimental pain seemed increased during migraine attack, and the severity of headache was mainly related to the increase of the later LEPs components expressing the attentive and emotive compounds of suffering. Reversion of this process appeared to be primarily responsible for the efficacy of drugs in treating migraine, though both almotriptan and lysine-acetil salicilate seemed to have no effect in reducing sensitization at second and third order nociceptive neurons.

Generalized edema is the result of increased interstitial fluid volume due to altered Starling forces or capillary endothelial damage. The authors present a patient with severe Parkinson disease who presented with increasing dyspnea, bilateral pleural effusion, and peripheral edema that was refractory to diuretics. Common causes of the severe loss of fluid into the extravascular space were ruled out and pergolide was suspected. Upon discontinuation of pergolide therapy, all signs of fluid retention resolved. This report emphasizes that pergolide should be considered a cause of otherwise unexplained generalized edema in patients with Parkinson disease on this therapy.