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See detailReduced gating of middle-latency auditory evoked potentials (P50) in migraine patients: another indication of abnormal sensory processing?
Ambrosini, A.; De Pasqua, Victor ULg; Afra, J. et al

in Neuroscience Letters (2001), 306(1-2), 132-4

Habituation of cortical evoked responses to repetitive stimuli is reduced in migraine between attacks. To explore another aspect of information processing, we measured auditory sensory gating. The ... [more ▼]

Habituation of cortical evoked responses to repetitive stimuli is reduced in migraine between attacks. To explore another aspect of information processing, we measured auditory sensory gating. The amplitude of the P50 response to the second of two homologous stimuli was significantly less reduced in migraineurs than in healthy volunteers. This lack of auditory sensory gating may be due to a hypofunction of monoaminergic subcortico-cortical pathways, which is also supposed to cause the interictal deficit of cortical habituation to repetitive stimuli. [less ▲]

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See detailProphylactic Treatment of Migraine with Beta-Blockers and Riboflavin: Differential Effects on the Intensity Dependence of Auditory Evoked Cortical Potentials
Sandor, P. S.; Afra, J.; Ambrosini, A. et al

in Headache (2000), 40(1), 30-5

OBJECTIVE: To investigate the influence of different pharmacological treatments on the intensity dependence of auditory evoked cortical potentials in migraineurs. BACKGROUND: Between attacks, patients ... [more ▼]

OBJECTIVE: To investigate the influence of different pharmacological treatments on the intensity dependence of auditory evoked cortical potentials in migraineurs. BACKGROUND: Between attacks, patients with migraine show abnormalities in cortical information processing and decreased brain mitochondrial energy reserve. Both are most probably relevant for migraine pathogenesis, and they could be differentially modified by prophylactic drug therapy. Design.-The intensity dependence of the auditory evoked cortical potentials is, on average, increased in migraine. We have studied this intensity dependence in 26 patients before and after a 4-month period of prophylaxis with beta-blockers (n = 11, all migraine without aura; metoprolol or bisoprolol) or riboflavin (n = 15, migraine without aura: 13, migraine with aura: 2). Recordings were performed at least 3 days before or after an attack. RESULTS: After the treatment with beta-blockers, the intensity dependence of the auditory evoked cortical potentials was significantly decreased (before: 1.66+/-1.02 microV/10 dB; after: 0.79+/-1.06 microV/10 dB, P=.02). The decrease in intensity dependence was correlated significantly with clinical improvement (r = .69, P = .02). There was no change in intensity dependence after riboflavin treatment (before: 1.80+/-0.81 microV/10 dB; after: 1.56+/-0.83 microV/10 dB, P = .39), although the majority of patients showed improvement. CONCLUSIONS: These results confirm that beta-blockers and riboflavin act on two distinct pathophysiological mechanisms. Combining both treatments might enhance their efficacy without increasing central nervous system side effects. [less ▲]

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See detailFrom neurophysiology to genetics: cortical information processing in migraine underlies familial influences--a novel approach
Sandor, P. S.; Afra, J.; Proietti Cecchini, A. P. et al

in Functional Neurology (2000), 15(Suppl 3), 68-72

Migraine patients show impaired cortical information processing between attacks with deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory ... [more ▼]

Migraine patients show impaired cortical information processing between attacks with deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory cortical evoked potentials (IDAP). This could be a genetic trait as certain genetic patterns are known for evoked potentials in healthy subjects. VEP-habituation and IDAP were studied in 40 migraine patients, i.e. pairs of 20 parents and their children. We developed a novel approach based on Monte Carlo statistics to selectively assess vertical familial influences. Both groups, parents and children, were characterized by abnormal VEP-habituation and IDAP. However, similarity between related pairs was far more pronounced than similarity between unrelated pairs. Assessed with a novel statistical approach, familial influences proved to be highly significant in determining cortical information processing in migraineurs, thus supporting the important role of genetic factors. [less ▲]

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See detailInfluence of colors on habituation of visual evoked potentials in patients with migraine with aura and in healthy volunteers.
Afra, J; Ambrosini, A; Génicot, Roger ULg et al

in Headache (2000), 40(1), 36-40

OBJECTIVE: To investigate whether colored glasses influence the habituation of visual evoked potentials. BACKGROUND: We have previously shown that during pattern-reversal stimulations lasting 2 minutes ... [more ▼]

OBJECTIVE: To investigate whether colored glasses influence the habituation of visual evoked potentials. BACKGROUND: We have previously shown that during pattern-reversal stimulations lasting 2 minutes the amplitude of the visual evoked potential increases in migraine with and without aura between attacks, whereas it decreases in healthy volunteers. Red light was found to increase visually evoked EEG fast activity only in children with migraine with aura. Wearing rose-tinted glasses for 4 months decreased attack frequency in parallel with a reduction of the visually evoked EEG fast activity. METHODS: We compared the change in amplitude of the visual evoked potential using five different tinted glasses in 12 patients with migraine with aura and in 10 healthy volunteers. During continuous stimulation at 3.1 Hz, five blocks of 50 responses were sequentially averaged using red, yellow, green, blue, and grey glasses and without glasses in a random order and analyzed in terms of latencies and N1-P1 amplitudes. Amplitude changes were calculated for each block by comparison with the first block in every condition and analyzed statistically using Zerbe's method. RESULTS: In healthy volunteers, the visual evoked potential amplitude increased with red glasses compared to without glasses (P = .05) or with green glasses (P = .03). In patients with migraine with aura, no significant difference was detected using colored glasses. Our findings in healthy volunteers are in line with earlier reports of increased excitability of the human visual cortex when exposed to red light. The lack of such a pattern in patients with migraine with aura suggests that the visual cortex is interictally hypoexcitable rather than hyperexcitable, which is consistent with studies of transcranial magnetic stimulation. [less ▲]

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See detailComparison of visual and auditory evoked cortical potentials in migraine patients between attacks.
Afra, J.; Proietti Cecchini, A.; Sandor, P. S. et al

in Clinical Neurophysiology (2000), 111(6), 1124-9

OBJECTIVE: As both habituation of pattern reversal visual evoked potentials (PR-VEP) (Schoenen J, Wang W, Albert A, Delwaide PJ. Potentiation instead of habituation characterizes visual evoked potentials ... [more ▼]

OBJECTIVE: As both habituation of pattern reversal visual evoked potentials (PR-VEP) (Schoenen J, Wang W, Albert A, Delwaide PJ. Potentiation instead of habituation characterizes visual evoked potentials in migraine patients between attacks. Eur J Neurol 1995;2:115-122) and intensity dependence of auditory evoked cortical potentials (IDAP) (Wang W, Timsit-Berthier M, Schoenen J. Intensity dependence of auditory evoked potentials in migraine: an indication of cortical potentiation and low serotonergic neurotransmission? Neurology 1996;46:1404-1409) were found abnormal in migraine between attacks, we have searched for intraindividual correlations between both tests in 59 migraine patients (22 with aura [MA], 37 without aura [MO]) and in 23 healthy volunteers (HV). METHODS: Amplitude change of the PR-VEP N1-P1 was measured between the 1st and 5th block of 50 sequential averagings during continuous stimulation at 3.1 Hz. IDAP was computed from N1-P2 amplitudes of 100 averagings during stimulations at 40, 50, 60 and 70 dB SL. Amplitude-stimulus intensity function (ASF) slopes and amplitude changes between 40 and 70 dB were calculated. MO and MA differed from HV in PR-VEP amplitude change (P=0.007) and IDAP slope (P = 0.0004). RESULTS: There was no significant correlation between VEP amplitude changes and IDAP slopes, nor between the latter two and attack frequency or disease duration. A negative correlation was found between the amplitude of the first block of averaged responses and potentiation of VEP in all subject groups (P = 0.03) as well as between the amplitude of the auditory evoked potential, at 40 dB, and the percentage of amplitude increase between 40 and 70 dB in MO (P = 0.004) and MA (P = 0.007). ASF slopes and 40 dB amplitudes were significantly correlated only in the MA group (P = 0.002). These results confirm the interictal deficit of habituation in cortical processing of repetitive visual and auditory information in migraine. Since there is no intraindividual correlation between the cortical responses to these sensory modalities they are complementary tools for the study of migraine and may help to identify subgroups of patients with distinct pathophysiological mechanisms. CONCLUSIONS: The strong negative correlation between the initial amplitude of evoked potentials and their amplitude increase during subsequent averaging confirms that the response potentiation in migraine is likely to be due to a reduced preactivation level of sensory cortices. [less ▲]

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See detailFamilial influences on cortical evoked potentials in migraine.
Sandor, P S; Afra, J; Proietti-Cecchini, A et al

in Neuroreport (1999), 10(6), 1235-8

Cortical information processing in migraine patients is impaired between attacks, showing deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of ... [more ▼]

Cortical information processing in migraine patients is impaired between attacks, showing deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory cortical evoked potentials (IDAP). This could be a genetic trait as certain genetic patterns are known for evoked potentials in healthy subjects. We investigated VEP habituation and IDAP in 20 pairs of migraineurs made up of parents and their children. Using a Monte-Carlo statistical method, we selectively assessed vertical familial influences. VEP habituation and IDAP were abnormal in both parents and children. However, similarity was far more pronounced between related pairs than between unrelated pairs. Familial influences are highly significant in determinants of cortical information processing in migraineurs, hence supporting the important role of genetic factors. [less ▲]

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See detailDopamine and Migraine: A Review of Pharmacological, Biochemical, Neurophysiological, and Therapeutic Data
Mascia, A.; Afra, J.; Schoenen, Jean ULg

in Cephalalgia : An International Journal of Headache (1998), 18(4), 174-82

The dopamine theory of migraine pathogenesis, first proposed by F. Sicuteri in 1977, has attracted renewed interest after an increased frequency of the dopamine D2 receptor (DRD2) gene allele NcoI C was ... [more ▼]

The dopamine theory of migraine pathogenesis, first proposed by F. Sicuteri in 1977, has attracted renewed interest after an increased frequency of the dopamine D2 receptor (DRD2) gene allele NcoI C was found in patients with migraine with aura. [less ▲]

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See detailCraniometric Measures in Cluster Headache Patients
Afra, J.; Cecchini, A. P.; Schoenen, Jean ULg

in Cephalalgia : An International Journal of Headache (1998), 18(3), 143-5

Blockade of venous drainage in the cavernous sinus, which may play a pivotal role in the pathophysiology of cluster headache (CH), could be triggered by local inflammation. It could also be favored by a ... [more ▼]

Blockade of venous drainage in the cavernous sinus, which may play a pivotal role in the pathophysiology of cluster headache (CH), could be triggered by local inflammation. It could also be favored by a constitutional narrowness of the cavernous sinus region. Before exploring the latter with magnetic resonance imaging (MRI), we determined whether external morphometric skull measures are different among CH patients (n = 25), healthy volunteers (n = 21), and migraine patients (n = 20). All subjects were males of comparable age distribution. Six measures were taken: inion-nasion perimeter, inion-nasion distance over the vertex; distance between the upper ends of tragus; diameter at the level of the temporal fossa; diameter at mid inion-nasion perimeter at ear level; and inion-nasion diameter. CH patients had significantly smaller values than healthy subjects and/or migraine patients in all but one measure (ANOVA and Duncan's post-hoc analysis). This may suggest that they have a narrower anterior/middle cranial fossa, and possibly a narrower cavernous sinus loggia, which needs to be confirmed by a quantitative MRI study. [less ▲]

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See detailVisual evoked potentials during long periods of pattern-reversal stimulation in migraine.
Afra, J; Cecchini, A P; DE PASQUA, Victor ULg et al

in Brain : A Journal of Neurology (1998), 121(2), 233-41

We have previously shown that during repetitive pattern-reversal stimulation, lasting 2 min, the amplitude of the visual evoked potential (PR-VEP) increases in migraineurs when tested interictally whereas ... [more ▼]

We have previously shown that during repetitive pattern-reversal stimulation, lasting 2 min, the amplitude of the visual evoked potential (PR-VEP) increases in migraineurs when tested interictally whereas it decreases in healthy control subjects. According to Sappey-Marinier et al. (J Cereb Blood Flow Metab 1992; 12: 584-92) habituation of the PR-VEP in normal subjects is maxima after 12 min, at a time when there is a decrease of stimulation-enhanced lactate levels in the occipital cortex. We have therefore compared PR-VEP during long periods of repetitive stimulation in healthy control subjects (n = 25) and in patients suffering from migraine without (n = 25) and with aura (n = 15) between attacks. During uninterrupted stimulation at 3.1 Hz VEPs were sequentially averaged in blocks of 100 responses for a total duration of 15 min and analysed in terms of latencies and peak-to-peak amplitudes of N1-P1 and P1-N2 peaks. Amplitude changes from the baseline were calculated for each block, by comparison with the first block, and analysed statistically using Zerbe's method. The N1-P1 and P1-N2 amplitudes in the first block tended to be lower in migraineurs than in healthy control subjects. During the 15 min of stimulation, amplitudes of both components progressively decreased in control subjects, but remained stable in both groups of patients. The difference between patients and control subjects proved to be significant (P < 0.05). The neurophysiological data were not correlated with clinical features such as attack frequency or duration of illness. These results are yet another demonstration in migraine of an interictal habituation deficit in cortical information processing, which might favour lactate accumulation in sensory cortices during sustained activation. [less ▲]

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See detailNeurophysiological approach to primary headache pathophysiology.
Lozza, A.; Proietti Cecchini, A.; Afra, J. et al

in Cephalalgia : An International Journal of Headache (1998), 18 Suppl 21

Electroencephalography (EEG), evoked potentials (EP), and electromyography (EMG) techniques are useful tools in the clinical assessment of headache and in understanding the pathophysiological mechanisms ... [more ▼]

Electroencephalography (EEG), evoked potentials (EP), and electromyography (EMG) techniques are useful tools in the clinical assessment of headache and in understanding the pathophysiological mechanisms of these pathologies. EEG and EP studies in migraine revealed functional abnormalities in cortical electrical activity and in sensory processing. EMG studies resulted in pain syndromes involving nerves or myofascial structures such as tension-type headache and cluster headache. Moreover, it was possible to test the effect of old and new drugs with the help of these neurophysiological techniques. An updated review is reported of the literature. [less ▲]

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See detailIntensity Dependence of the Cortical Auditory Evoked Potentials as a Surrogate Marker of Central Nervous System Serotonin Transmission in Man: Demonstration of a Central Effect for the 5ht1b/1d Agonist Zolmitriptan (311c90, Zomig)
Proietti-Cecchini, A.; Afra, J.; Schoenen, Jean ULg

in Cephalalgia : An International Journal of Headache (1997), 17(8), 849-54799

As shown in animal studies, 5HT1B/D agonists can inhibit activity in the trigeminal nucleus caudalis, which may be advantageous for their antimigraine effect. To demonstrate a possible central nervous ... [more ▼]

As shown in animal studies, 5HT1B/D agonists can inhibit activity in the trigeminal nucleus caudalis, which may be advantageous for their antimigraine effect. To demonstrate a possible central nervous system (CNS) action of these compounds in man we studied their effect on the intensity dependence of the cortical auditory evoked potentials (IDAPs), thought to be inversely related to central serotonergic transmission. An amplitude/stimulus intensity function (ASF) slope was computed in healthy volunteers and migraine patients between attacks before and 2 h after oral 311C90 (zolmitriptan "Zomig") 10 mg (n=14), 311C90 5 mg (n=7), sumatriptan 100 mg (n=14), dexfenfluramine 15 mg (n=4), lorazepam 1.25 mg (n=4) and placebo (n=14). 311C90 10 mg and, to a lesser degree, 5 mg significantly increased the mean ASF slope (p=0.007 and 0.05 vs placebo). There was a significant positive correlation between plasma levels of 311C90 and ASF slope changes. Sumatriptan and lorazepam had little effect, but dexfenfluramine produced a significant ASF slope decrease. 311C90 is able to modify a CNS activity that is modulated by serotonin, i.e. the IDAP. This effect is probably the consequence of its superior lipophilicity compared to sumatriptan and of activation of prejunctional 5HT1B/D autoreceptors, which lowers central serotonin release and thus the preactivation level of sensory cortices. [less ▲]

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