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P894: Thermal pain thresholds in migraineurs do not change with migraine phase
Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339
Conclusion: Our study showed that administration of Nifedipine as a Ca2+ channel-blockers could not significantly reduce the level of memory impairments, which naturally followed by repetitive spreading depression.
P893 Association between promoter region of the uPAR (rs344781) gene polymorphism in genetic susceptibility to migraine without aura in Iranian population A. Zandifar 1,2 , S. Soleimani 1 , N. Iraji 1 , F. Haghdoost 1 , M. Tajaddini 2 , S.H. Javanmard 2 1 Isfahan University of Medical Sciences, Medical Student Research Center, Isfahan, Islamic Republic of Iran; 2 Isfahan University of Medical Sciences, Physiology Research Center, Isfahan, Islamic Republic of Iran Introduction: Migraine is a chronic neurological disorder. Inflammation has a key role in migraine pathophysiology. Urokinase plasminogen activator receptor (uPAR) directly involves in inflammatory conditions by facilitating migration of inflammatory cells to different tissues. The aim of this study was investigation whether uPAR rs344781, common genetic polymorphism in the uPAR promoter region, might be associated with migraine without aura susceptibility in Iranian population. Methods: We enrolled 103 newly diagnosed patients with migraine and 100 healthy controls. Peripheral blood sample was used for DNA extraction and uPAR rs344781 gene polymorphism was determined. Patients filled HIT-6 as a tool to evaluate headache severity. Results: The genotype frequency of uPAR is significantly different between migraine patients and control subjects. Heterozygote genotype (AG) was statistically more frequent in the patients than the controls (P=0.001; OR=2.67, 95% CI = 1.51–4.7). Also G allele was more frequent in the patients. Total HIT-6 score was not significantly different between heterozygote and homozygote patients (55.50±2.22 vs. 49.60±3.68 respectively, P=0.075). Conclusion: In conclusion, our study showed a significant association between uPAR rs344781 gene promoter polymorphism and migraine without aura susceptibility but not with headache severity.
P894 Thermal pain thresholds in migraineurs do not change with migraine phase M. Uglem 1 , P.M. Omland 1 , T. Sand 1,2 1 Norwegian University of Science and Technology, Department of Neuroscience, Trondheim, Norway; 2 St. Olavs Hospital, Department of Neurology and Clinical Neurophysiology, Trondheim, Norway Question: Peripheral and central sensitisation may be important for the development of migraine attacks. Previous studies have shown lower thermal pain thresholds between, before and during migraine attacks. Can these findings be confirmed in a longitudinal study? Methods: Pain thresholds (PT) for cold (CPT) and heat (HPT) were recorded on the forehead and the volar hand. Forty-nine migraineurs (17 with aura) and 31 headache-free controls were analysed in this longitudinal study. The migraineurs were tested on 4 different days. The examiner was blinded for diagnosis on the migraineurs’ first session, and for migraine phase the next three sessions. Headache diaries were used to determine the migraine phase for each recording, defined by a 24 hours limit before/after the examination day. Interictal PTs were compared with preattack (23 pairs), attack (16 pairs) and postattack (10 pairs) PTs using Wilcoxon Signed-Rank Test. PTs of interictal recordings from 45 migraineurs and 31 controls were compared using Mann-Whitney U Test. Pain threshold definitions: CPTd = 32°C − CPT and HPTd = HPT − 32°C. Results: – Cold pain thresholds on the hand were lower in the postattack phase (18.8±7.1) compared to the interictal phase (20.3±7.4) (p=0.037). No other phase comparisons differed significantly (p>0.156). – Cold pain thresholds on the hand were lower in interictal migraineurs (20.0±6.0) compared to controls (22.6±5.3) (p=0.022). Conclusions: This longitudinal study could not confirm the previously reported lowered PTs in the preattack phase. However, a slight postattack allodynia was observed. Also, migraine patients had lower CPT than controls in the hand. Cold allodynia may accordingly be the more robust thermal pain feature that reflects a slight generalized hypersensitivity in migraine patients. Larger groups, investigated closer to attack onset, may be necessary to reliably quantify the previously reported preattack heat
S285
allodynia in migraine. Because of the large interindividual variation in the measurements, future studies should ideally apply a longitudinal design.
P895 Trigeminal somatosensorial evoked potentials in migraine F. Karaali-Savrun, Y. Gulen-Abanoz, Y. Abanoz, A. Gunduz Istanbul University, Cerrahpasa School of Medicine, Department of Neurology, Istanbul, Turkey Introduction: Migraine pathogenesis is suggested to involve many structures in cerebral cortex, brainstem and trigeminovascular system. Electrophysiologic studies revealed loss of habituation, decreased cortical preactivation, segmental hypersensitivity and decrease in control of inhibitory descending pathways. Given these information we aimed to evaluate the excitability changes of the trigeminal pathway in the cortex, and brainstem in migraine using trigeminal nerve somatosensory evoked potentials (TSEP). Patients and method: Fifty-one women with migraine without aura and 25 age-matched healthy women were included. TSEP were recorded in migraine patients during interictal period and in healthy volunteers. The latencies of P1, N2, P2 and N3 waves as well as N2/P1 and N2/P2 amplitudes were measured. Results: TSEP stimulation thresholds were bilaterally higher in migraine group. Other parameters including latencies and amplitudes did not show significant difference between patients and healthy volunteers. There were no differences of TSEP parameters considering the localization of headache and attack frequency in migraine group. However, patients with long disease duration had longer latencies of right N3, left P2 and left N3. Conclusion: Our study did not show difference between migraine patients and healthy volunteers which may be attributed to the interictal design of the study similar to the limited previous studies. However, migraine with long duration even affects the excitability of the cortical and brainstem trigeminal pathways during interictal periods.
P897 Acute and prophylactic treatment with inhibitory transcranial electrical current stimulation of the visual cortex: which method is better? A. Antal, F. Wickmann, C. Stephani, D. Czesnik, F. Klinker, C. Timaeus, L. Chaieb, W. Paulus University Medical Center, Clinical Neurophysiology, Goettingen, Germany Background and purpose: The present study aimed to investigate the efficacy of 140 Hz alternating current stimulation (tACS) and consecutive repetitive cathodal direct current stimulation (rc-tDCS) over the visual cortex (V1) as acute and prophylactic treatments in migraine. Method: 56 patients participated in this double-blind, randomized and placebo-controlled study and were assigned to active or to sham stimulation. In the prophylactically treated group 20 patients received rc-tDCS or sham stimulation with 2 mA intensity for 20 minutes for five days. In the acute treatment group 36 patients were treated during the migraine attacks using tACS for 10 minutes with 0.4 mA intensity or with sham stimulation. The stimulation was done by the patients at home, using a preprogrammed stimulator. The frequency, duration of attacks and the intensity of pain were recorded during the study periods. Results: A significantly decrease in the number of migraine attacks was observed during rc-tDCS compared to sham stimulation in the prophylactically treated group. 140 Hz tACS did not decrease the occurrence of the attacks compared to placebo stimulation. Conclusion: The results suggest that cathodal stimulation applied over the visual cortex has a prophylactic effect and might be a promising tool as an alternative or additional treatment option in migraine, although more challenging and time consuming compared to drug intake. Though previous studies reported that 140 Hz tACS with 0.4 mA intensity applied over the motor cortex has an inhibitory effect, in this study it did not affect the duration or the frequency of the migraine attacks, probably due to the too low intensity.
Conclusion: Our study showed that administration of Nifedipine as a Ca2+ channel-blockers could not significantly reduce the level of memory impairments, which naturally followed by repetitive spreading depression.
P893 Association between promoter region of the uPAR (rs344781) gene polymorphism in genetic susceptibility to migraine without aura in Iranian population A. Zandifar 1,2 , S. Soleimani 1 , N. Iraji 1 , F. Haghdoost 1 , M. Tajaddini 2 , S.H. Javanmard 2 1 Isfahan University of Medical Sciences, Medical Student Research Center, Isfahan, Islamic Republic of Iran; 2 Isfahan University of Medical Sciences, Physiology Research Center, Isfahan, Islamic Republic of Iran Introduction: Migraine is a chronic neurological disorder. Inflammation has a key role in migraine pathophysiology. Urokinase plasminogen activator receptor (uPAR) directly involves in inflammatory conditions by facilitating migration of inflammatory cells to different tissues. The aim of this study was investigation whether uPAR rs344781, common genetic polymorphism in the uPAR promoter region, might be associated with migraine without aura susceptibility in Iranian population. Methods: We enrolled 103 newly diagnosed patients with migraine and 100 healthy controls. Peripheral blood sample was used for DNA extraction and uPAR rs344781 gene polymorphism was determined. Patients filled HIT-6 as a tool to evaluate headache severity. Results: The genotype frequency of uPAR is significantly different between migraine patients and control subjects. Heterozygote genotype (AG) was statistically more frequent in the patients than the controls (P=0.001; OR=2.67, 95% CI = 1.51–4.7). Also G allele was more frequent in the patients. Total HIT-6 score was not significantly different between heterozygote and homozygote patients (55.50±2.22 vs. 49.60±3.68 respectively, P=0.075). Conclusion: In conclusion, our study showed a significant association between uPAR rs344781 gene promoter polymorphism and migraine without aura susceptibility but not with headache severity.
P894 Thermal pain thresholds in migraineurs do not change with migraine phase M. Uglem 1 , P.M. Omland 1 , T. Sand 1,2 1 Norwegian University of Science and Technology, Department of Neuroscience, Trondheim, Norway; 2 St. Olavs Hospital, Department of Neurology and Clinical Neurophysiology, Trondheim, Norway Question: Peripheral and central sensitisation may be important for the development of migraine attacks. Previous studies have shown lower thermal pain thresholds between, before and during migraine attacks. Can these findings be confirmed in a longitudinal study? Methods: Pain thresholds (PT) for cold (CPT) and heat (HPT) were recorded on the forehead and the volar hand. Forty-nine migraineurs (17 with aura) and 31 headache-free controls were analysed in this longitudinal study. The migraineurs were tested on 4 different days. The examiner was blinded for diagnosis on the migraineurs’ first session, and for migraine phase the next three sessions. Headache diaries were used to determine the migraine phase for each recording, defined by a 24 hours limit before/after the examination day. Interictal PTs were compared with preattack (23 pairs), attack (16 pairs) and postattack (10 pairs) PTs using Wilcoxon Signed-Rank Test. PTs of interictal recordings from 45 migraineurs and 31 controls were compared using Mann-Whitney U Test. Pain threshold definitions: CPTd = 32°C − CPT and HPTd = HPT − 32°C. Results: – Cold pain thresholds on the hand were lower in the postattack phase (18.8±7.1) compared to the interictal phase (20.3±7.4) (p=0.037). No other phase comparisons differed significantly (p>0.156). – Cold pain thresholds on the hand were lower in interictal migraineurs (20.0±6.0) compared to controls (22.6±5.3) (p=0.022). Conclusions: This longitudinal study could not confirm the previously reported lowered PTs in the preattack phase. However, a slight postattack allodynia was observed. Also, migraine patients had lower CPT than controls in the hand. Cold allodynia may accordingly be the more robust thermal pain feature that reflects a slight generalized hypersensitivity in migraine patients. Larger groups, investigated closer to attack onset, may be necessary to reliably quantify the previously reported preattack heat
S285
allodynia in migraine. Because of the large interindividual variation in the measurements, future studies should ideally apply a longitudinal design.
P895 Trigeminal somatosensorial evoked potentials in migraine F. Karaali-Savrun, Y. Gulen-Abanoz, Y. Abanoz, A. Gunduz Istanbul University, Cerrahpasa School of Medicine, Department of Neurology, Istanbul, Turkey Introduction: Migraine pathogenesis is suggested to involve many structures in cerebral cortex, brainstem and trigeminovascular system. Electrophysiologic studies revealed loss of habituation, decreased cortical preactivation, segmental hypersensitivity and decrease in control of inhibitory descending pathways. Given these information we aimed to evaluate the excitability changes of the trigeminal pathway in the cortex, and brainstem in migraine using trigeminal nerve somatosensory evoked potentials (TSEP). Patients and method: Fifty-one women with migraine without aura and 25 age-matched healthy women were included. TSEP were recorded in migraine patients during interictal period and in healthy volunteers. The latencies of P1, N2, P2 and N3 waves as well as N2/P1 and N2/P2 amplitudes were measured. Results: TSEP stimulation thresholds were bilaterally higher in migraine group. Other parameters including latencies and amplitudes did not show significant difference between patients and healthy volunteers. There were no differences of TSEP parameters considering the localization of headache and attack frequency in migraine group. However, patients with long disease duration had longer latencies of right N3, left P2 and left N3. Conclusion: Our study did not show difference between migraine patients and healthy volunteers which may be attributed to the interictal design of the study similar to the limited previous studies. However, migraine with long duration even affects the excitability of the cortical and brainstem trigeminal pathways during interictal periods.
P897 Acute and prophylactic treatment with inhibitory transcranial electrical current stimulation of the visual cortex: which method is better? A. Antal, F. Wickmann, C. Stephani, D. Czesnik, F. Klinker, C. Timaeus, L. Chaieb, W. Paulus University Medical Center, Clinical Neurophysiology, Goettingen, Germany Background and purpose: The present study aimed to investigate the efficacy of 140 Hz alternating current stimulation (tACS) and consecutive repetitive cathodal direct current stimulation (rc-tDCS) over the visual cortex (V1) as acute and prophylactic treatments in migraine. Method: 56 patients participated in this double-blind, randomized and placebo-controlled study and were assigned to active or to sham stimulation. In the prophylactically treated group 20 patients received rc-tDCS or sham stimulation with 2 mA intensity for 20 minutes for five days. In the acute treatment group 36 patients were treated during the migraine attacks using tACS for 10 minutes with 0.4 mA intensity or with sham stimulation. The stimulation was done by the patients at home, using a preprogrammed stimulator. The frequency, duration of attacks and the intensity of pain were recorded during the study periods. Results: A significantly decrease in the number of migraine attacks was observed during rc-tDCS compared to sham stimulation in the prophylactically treated group. 140 Hz tACS did not decrease the occurrence of the attacks compared to placebo stimulation. Conclusion: The results suggest that cathodal stimulation applied over the visual cortex has a prophylactic effect and might be a promising tool as an alternative or additional treatment option in migraine, although more challenging and time consuming compared to drug intake. Though previous studies reported that 140 Hz tACS with 0.4 mA intensity applied over the motor cortex has an inhibitory effect, in this study it did not affect the duration or the frequency of the migraine attacks, probably due to the too low intensity.