A.R. Cananzi

Platelet Glycine, Glutamate and Aspartate in Primary Headache

Platelet levels of glutamic and aspartic acid and glycine were measured in patients with migraine with aura, migraine without aura, tension headache and cluster headache. High levels of these amino acids were found in patients with migraine with aura compared to normal subjects and other headache groups. During headache, glutamate levels further increased in migraine with aura patients. These findings may have relevance to the neurological symptoms of migraine with aura.

Platelet and Plasma Levels of Glutamate and Glutamine in Migraine With and Without Aura

We evaluated plasma and platelet glutamate and glutamine levels in migraine with and without aura during headache-free periods and compared the results with those of normal controls. The plasma and platelet levels of glutamine in migraine with and without aura were normal. Migraine without aura patients had higher glutamate levels in plasma, and normal platelet levels. In migraine with aura patients, glutamate levels were high in platelets, but not in plasma. This suggests different profiles of excitatory amino acid metabolism in migraine with and without aura.

Acute confusional migraine: clinical and electroencephalographic aspects.

Twelve patients with episodes of acute confusional migraine (ACM) are reported. Prolonged agitation and mental confusion characterized the headache attacks, occurring mostly among adolescents. The ictal EEG showed diffuse, slow abnormalities and a peculiar pattern known as FIRDA (frontal intermittent rhythmic delta activity). Neuroradiologic examinations and laboratory tests were unremarkable. After the acute stage, EEG gradually tended to show normalization. Apart from the noticeable similarities to the “juvenile head trauma syndrome”, the authors assume that ACM represents a peculiar clinical form among the different types of migraine associated with disorders of higher mental functions.

Platelet models and their possible usefulness in the study of migraine pathogenesis

Platelets may be linked to migraine. On the one hand they are activated during the migraine attack and thus may participate in the pathogenesis of the disorder (the nature of this activation is still unknown). In order to understand this platelet anomaly, we discuss the data available in the literature. In particular, we review recent in vitro studies of a-granules and dense bodies secretion, and aggregation induced by collagen and PAF. On the other hand, platelets share many metabolic characteristics with serotonergic neurons and endothelial cells. Accordingly, platelets have been used to investigate the possible role of serotonin turnover and nitric oxide function in migraine. In both cases, the data obtained have shown peculiar abnormalities that may explain pathogenetic and clinical aspects of primary headache.

Personality and Memory in Childhood Migraine

A series of neuropsychological tests were administered to a group of healthy children and another group suffering from common migraine. The tests demonstrated that children with common migraine do not have definitely abnormal personality traits even though inhibition of aggressivity and greater anxiety levels following certain environmental stimuli were seen. We also observed a decreased short- and long-term memory function in children with common migraine.

Decreased Collagen-Induced Platelet Aggregation and Increased Platelet Arginine Levels in Migraine: A Possible Link With The NO Pathway

We studied whole blood platelet aggregation induced by collagen, platelet activating factor (PAF) and measured basal platelet L-arginine (L-arg) levels, as an indirect index of the nitric oxide (NO) pathway in migraine. Migraine, both with and without aura groups, showed a reduced aggregation to collagen, but not to PAF, compared with control subjects. Platelet L-arg levels were significantly increased in migraine with aura sufferers, whereas the plasma levels were in the same range in migraineurs and controls. Platelet hyperesponsiveness to collagen stimulation in migraine may be linked to an increased availability of the amino acid precursor and an abnormal NO synthesis.

Nimodipine versus Flunarizine in Common Migraine: A Controlled Pilot Trial

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The Effect of Dopamine Receptor Agonists on Prolactin Secretion in Childhood Migraine

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Platelet activity in cluster headache

Platelets are known to be activated in common or classic migraine both during the attack and in headache-free periods. Platelet behavior is less well known in cluster headache. We have investigated beta-thromboglobulin (b-TG) and platelet factor four (PF4) plasma levels, markers of in vivo platelet activation, in patients during remission and during bouts of cluster headache with and without pain. The results indicated that statistically significantly higher levels of b-TG and PF4 occur in the patients during the remission period when compared with the control subjects. Such high levels seemed to persist between paroxysmal episodes in cluster periods. However, during the attacks of cluster headache b-TG and PF4 plasma levels decreased by 42% and 50%, respectively, in comparison with plasma concentrations measured outside of attack. Thus, although platelet activation also occurs in patients with cluster headache, the attack as such seems to be characterized by a marked reduction in platelet activation.

Platelet Function in Acute Ischemic Stroke: Relevance of Granule Secretion

We studied platelet aggregation and secretion in 48 patients with ischemic stroke, within 24 h of onset of symptoms, and 17 healthy controls. Aggregation was studied in platelet-rich plasma with the impedance method. As markers of dense and α-granule secretion we used adenosine triphosphate (ATP) and platelet factor 4 (PF4), respectively. Furthermore, we determined the basal platelet serotonin levels as an indicator of previous in vivo platelet activation. Platelet aggregation and secretion of ATP and PF4 were significantly increased in the patients in response to 1.0 and 2.0 µg/ml collagen. Similarly, the patients exhibited significantly increased platelet aggregation and PF4 secretion induced by 1.0 and 10 µmol/l adenosine diphosphate. Platelet aggregation in response to 1.0 µmol/l of platelet-activating factor was similar in patients and controls, but the parallel ATP secretion was significantly higher in patients. Platelets in patients thus exhibited an enhanced responsiveness to all three agonists, suggesting a general lower threshold for activation. The basal platelet levels of serotonin were significantly decreased in patients, indicating a previous in vivo platelet activation. Our data suggest that platelets are hyperaggregable with an increased secretion in the acute phase of cerebral infarct. Apart from the established importance of platelet hyperaggregatability in clot formation, platelet hypersecretion of serotonin and α-granule proteins may be of significance in the pathophysiology of ischemic stroke.