Background Basilar-type Migraine (BM) and Familial Hemiplegic Migraine (FHM) are phenotypically similar subtypes of migraine with aura, differentiated only by motor symptoms, which characterize FHM. The latter is thus far the only migraine subtype in which mutations have been found in the CACNA1A and ATP1A2 genes. Methods We looked for mutations in CACNA1A and ATP1A2 in members of a family with BM. Screening was performed by direct sequencing on blood genomic DNA.Results No mutations were found in CACNA1A. However, we identified a novel point mutation in exon 12 of the ATP1A2 gene resulting in replacement of arginine 548 with histidine (R548H). Four individuals of this family carried the mutation, which was absent in 400 control chromosomes and in 174 chromosomes from unrelated migraineurs. "A posteriori" genotyping was consistent with linkage to the FHM2 locus. Conclusions In this study we report a novel mutation in the ATP1A2 gene (R548H) in a family with Basilar-type Migraine, a subtype of migraine with aura phenotypically close to FHM. This is the first report of an ATP1A2 gene mutation in a form of migraine other than FHM. This finding suggests that BM and FHM may be allelic disorders. Marinis, A. Pujia, F. Randi, N. Panella Department of Neurological Sciences, University La Sapienza, Rome, Italy; e-mail: m.de.marinis@mclink.it Objectives Activation of the trigeminovascular system as well as of brainstem trigeminal nuclei are thought to play an important role in migraine. The aim of this study was to investigate the habituation phenomenon of the blink reflex in "chronic migraine". Patients and methods An EMG device with a specific habituation test program was used to elicit and record blink reflex responses on both the right and left sides, and to randomly repeat the stimulations at different time intervals in order to induce habituation. We studied 15 patients suffering from "chronic migraine" (diagnosed according to the IHS classification criteria) and 15 control subjects. Results Whereas the R1 and R2 latencies, amplitudes and areas in the basal assessment were similar in patients and control subjects, the blink reflex habituation responses were markedly reduced in patients with "chronic migraine". In these patients, the differences between the R2 areas, obtained when stimuli were delivered at subsequent time intervals ranging between 10-5, 5-4, 4-3 and 3-2 seconds, were statistically different (p<0.001) from those of controls subjects. Conclusions Our data suggest that the brainstem pathways involved in the blink reflex may be activated in chronic migraine, probably through mechanisms that involve dopaminergic function.
THE BLINK REFLEX IN CHRONIC MIGRAINE
M. De
CUTANEOUS ALLODYNIA AND CEREBROSPINAL FLUID GLUTAMATE LEVELS IN CHRONIC MIGRAINE PATIENTSP. Sarchielli, C. Rossi, F. Coppola, A. Baldi, P. Calabresi Neurologic Clinic, Department of Medical and Surgical Specialties and Public Health, University of Perugia; Italy; e-mail: headache@unipg.it Introduction Cutaneous allodynia has been desc...