- Email: [email protected]
OPL179 Lifting the burden: the global campaign to reduce the burden of headache worldwide
OralPlatform Abstracts Federico H University, Naples, Italy; 3Laboratory of Neurogenetics, U.O. Neuromuscular and Neurodegenerative Disease, Istituto Gaslini, University of Genova, Italy; 4Laboratory of Human Genetics, E.O. Ospedali Galliera, Genova, Italy We report a fantily with four affected brothers presenting with the progressive myoclonic epilepsy caused by Lafora Disease (LD). In all patients, the clinical manifestations were myoclonus, generalized tonic-clonic seizures and mild cognitive impairment starting at the ages of 17-21 years. The clinical diagnosis o f LD was confirmed by the identification of PAS positive inclusions (Lafora bodies) in samples from skin biopsy. All the patients presented a slow progression of the disease, being not dependent in their third decade. Genetic study revealed a missense (DI46N) mutation in the NHCLR1 gene. We conclude that this mutation is associated with slow progression of LD. The study of LD fantilies with several affected members is important to investigate the role of specific mutations in phenotypic variability.
H e a d a c h e S e s s i o n 2 - Clinical Perspective OP1- 175 Tile role of Homocysteine in the pathogenesis and development of ufigraine de Tommaso, M, Losito, L, Livrea P. Neurological and Psychiatric
Sciences Department, University of Bari, Italy Background: Migraine, with and without aura (MA and MO), is a
prevalent and complex neurovascular disorder that may also be affected by genetically influenced hyper-homocysteinaenfia. Objective: To determine whether the C677T variant in the M T H F R gene is associated with migraine susceptibility and severity and increased vascular risk, by the evaluation of the clinical features, the Contingent Negative Variation (CNV) habituation pattern, the steady state visual evoked potentials (SSVEPs) and Magnetic Resonance imaging (MRI) and spectroscopy. Methods: Ninety migraine patients were studied: the M T H F R C677T variant was genotyped in 75 MO, 15 M A patients and 100 controls. In all cases the CNV habituation and SSVEPs to medium and high frequency stimulation patterns were evaluated. Eighty patients were also submitted to MRI study. Results: we observed an over-representation of the 677T allele in migraine patients compared to controls, more evident for the M A subtype: the M T H F R variant was also associated with reduced habituation pattern of CNV. The high levels o f homocysteine was linked with earlier onset of migraine, higher frequency of headache and multiple gliotic peri-ventricular areas at MRI. Conclusion: The M T H F R gene variant seemed to enhance the susceptibility to migraine and to worsen its evolution. Keywords: migraine, genetic variant, homocysteine. OP1- 176
Altitude Headache: Therapeutic approach (Altitude: 3.600 meters above
Thursday, November 10, 2005
$91
Method: Subjects with higher than 55% hemacrito were selected, who
showed cephalea (120), dizziness (15), low concentration (12), peripheral cyanosis (18), and insomnia (114), excluding respiratory, cardiac, renal or subjacent metabolic pathologies. Each subject underwent one-hour sauna daily session, for a period of three months, while avoiding exhaustion, exercise and dehydration. Cardiac frequency, arterial pressure, respiratory frequency, body weight, hematocrito and hemoglobin were controlled. The presence, intensity and duration of the synthoms presented by the subjects were recorded. Results: Headache disappeared in all subjects within the first and third week; dizziness and low concentration disappeared within the second and third week; insomnia disappeared beginning the third week; and peripheral cyanosis gradually diminished beginning the first month to disappear by mid third month. Hematocrito shows an average lowering of 6%, and hemoglobin of 2 mg/dl within three months. Conclusions: The exposure of the organism to a hot envirotmtent (sauna), mdeashes adaptive responses with an increase o f cardiac frequency, peripheral vasodilatation and sweating, allowing a greater oxygen capture and facilitating its liberation; these changes determine the disappearance of synthoms and signs of misadaptation to altitude, (3.600 meters above sea level) specially the rapid disappearance of cephalea. OPL177 Levetiraeetarrl in the Trealment of "Alice in Wonderland Syndrome": A Prospective Study
Bosio, A. Neurology Department, S. Camillo Hospital, Brescia, Italy Background: The tetan "Alice in Wonderland Syndrome" has been
used to account for certain hallucinations peculiar to migraine. Levetiracetam (LEV) is a new antiepileptic drug with an excellent tolerability profile. LEV exerts inhibitory effects on N-type calcium channels, and may modulate neurotransmitter release through synaptic vesicle SV2A protein binding. We evaluated the use of LEV treatment over one year in the prophylaxis of migraine with aura showing complex dimorptfisms characteristic of "Alice in Wonderland Syndrome". Methods: Nineteen subjects; 10 male, 9 female; aged 23-39 (mean 28) years; suffering from migraine with aura with complex dimorphism were treated with LEV 1500 mg/day (500 mg in the morning and 1000 mg in the evening) for one year. Electroencephalogram (EEG) readings at baseline showed temporal slow patterns in all patients. Visits were scheduled at Day 0, 15, 30, 60, 90, 180 and 360. Results: After 15 days, 5/19 patients (26.3%) were free of migraine attacks and at final evaluation 16/19 patients (84.2?,'8) were free of attacks. Attack fiequency was reduced by > 50"/0 in the 3 remaining patients. EEG patterns notmalised in 15/19 patients. In 4 patients, EEG patterns did not improve and 3 of these patients continued to suffer migraine attacks at evaluation. Side effects were few and light in severity. No patients discontinued treatment and no relapses were observed. Conclusion: In this preliminary study, LEV was well tolerated and effective as prophylactic treatment for migraine associated with "Alice in Wonderland Syndrome", warranting further investigation.
sea level: La Paz - Bolivia) Duran Qniroz, JC, Limachi Chuqnimia, ME, Limachi Pabon, LD,
Lopez Lazaro, HG, Lopez Mamani, JS, Lopez oporto, E, Loza Condori, E, Loza Vargas, C, Loza Vargas, LA, Calla Magne, J.
Universidad Mayor De San Andres, Bolivia Justification: Altitude eritrocitosis is a physiologic misadaptation phenomenon, and the factors that cause it have not been studied; possibly environmental modifications induce changes in the peripheral vascular dynamics, opening pre-capillary shunts and closing capillaries, consequently lowering oxygen liberation to tissues. Eritrocitosis manifests itself by headache, dizziness, low concentration, and peripheral cyanosis.
O PL 178 Could Silent Brain Isehemia Cause Chronic Headache? Unno, y~,2, Iwaslfita, T a, Stfimizu, H 1. 1Department of Internal
Medicine, Kawakita General Hospital, Tokyo, Japan," 2Department of ~l,fedicine, Kitasato University, Kanagawa, ,)'apart Background: Whether the so-called "silent brain infarction" may cause
chronic headache is not yet eluddated. It is also not known if the pathogenesis of lacunar infarction such as hypertension, arterial sclerosis and cerebral ischenfia may become the cause of chronic headache. The purpose of this study is to investigate the possible role of chronic cerebral hypoperfusion in the mechanism o f headache.
$92
Friday, November l 1, 2005
Methods: In serial 160 patients (69 men, 91 women, 60.1 years) who underwent brain MRI were evaluated. Results: Fifty-three of 160 patients suffered from headache. Tile patients with headache (14 men, 39 women, 49.5 years) were siguificantly yomlger than tile patients without headache (55 men, 52 women, 65.3 years). In 113 of 160 patients, neurological findings were negative. One or more risk factors of cerebrovascular disease (CVD) existed in 77 of 160 patients. Fourteen of 53 patients with headache and 63 of 107 patients without headache had one or more risk factors for CVD, and that difference was statistically siguificant. Brain MRI showed prior cerebrovascular disease in 14 of 53 patients with headache and in 64 of 107 patients without headache. Among patients without risk factors for CVD, the difference of the ratio of ischemic lesions on MRI was not significant between the patients with headache (17.5%) and tile patients without headache
(30.2%). Con¢lusiOllS: There was no univariate correlation between cerebral ischemic lesion and headache. However, among patients with ischemic lesions, headache sufferers were younger, more women, and with less atherosclerotic risk factors than non-headache sufferers. These results suggested there was a correlation between asymptomatic CVD and headache.
O PL 179 Lifting The Burden: the Global Campaign to Reduce the Burden of Headache Worldwide Sleiner, T J 1 on behalf of tile Global Canlpaign Committee. ~Imperial
Oral Platform Abstracts Methods: 15 patients (112 men and 3 women) between 20 to 44 years old are reported with the diagnosis of pseudomigraine with pleocytosis between Agoust- 1993 to February-2005 in Madrid Area-5. Tests: brain CT, lunlbar punction, serologic and inmlmlOlogic determinations, brain MRI and EEG. SPECT test was realised in 11 patients, Arteriography in 5 patients, echocardiography and carotid ultrasound test in 4 patients and angiography-MR[ in 2 patients. Results: Personal antecedent of migraine was reported in 4 patients, Non-migraine headache in 1 patient and a infectious disease in 5 patients. 13 patients had sensitive symptoms, 5 of them were ascendant symptoms. 6 patients had motor symptoms, 9 patients had aphasia and 3 patients had disarthria. Headache was predominantly bifrontal, of pulsating quality and moderate-severe pain intensity. CSF had 10-360 cells (55-95% mononuclear cell). Regions of high signals were seen in 3 patients in brain MRI. Temporal or fi'ont-temporal unspecific alterations were reported in EEG. Normal metabolism (4 patients), hyperperfusion (12 patients) or hypoperfusion could be present in SPECT. Other tests did not present significant alterations. Conclusions: Male gender is predominant in pseudomigraine with pleocytosis (3er-4th decade). Sensitive symptoms were the most fiequent neurological symptoms (86'67%) being ascendant symptoms tile 38% of them. Migraine antecedent was presented in some cases (26'67%).
Friday 11 November 2005
Clinical Neurophysiology
College London, London, UK Background: The World Health Orgauization ([WHO) ranks migraine 19th amongst causes of worldwide disability. Tension-type headache and chronic daily headache impose at least a similar disability burden on the world's populations. Lifting The Burden (LTB) is a response to this public health calanlity. Method: LTB has three phases. Firstly it is collating tile evidence of headache burden in all world regions in order to know its scale and scope. Secondly it is exploiting this evidence to raise awareness of the need for action in every country to relieve this burden. Thirdly, it will work with govertmlents to plan and implement local solutions to locally-assessed needs, and evaluate them for success. Results: WHO, the lay World Headache Alliance and tile professional Interuational Headache Society and European Headache Federation have committed to partnership in action taking the form of a Global Campaign. A network o f other partners, academic and commercial, is in the stages o f being built. Burden data have been gathered on migraine for much o f tile world, but are generally poor for other headache disorders and require supplenlentation through new epidemJological studies wlffch are being plamted. Education will be a pillar of LTB's later phases, aimed at governments through Regional Declarations on Headache, at health-care providers through a training-the-trainers program and at the public utilizing the media. Headache-related health-care interventional projects will follow. Conclusion: LTB is anlbitious and global. Its implementation requires substantial resources but it promises relief from disability that affects the entire world, with huge savings in recovered productivity. OPLIS0 Pseudonfigraine with Pleocytosis. A Report of 15 Cases Maxlin Balbuena S 1, Arpa j l Coya J 2 Frank A 1, Vivancos F 1, Marfinez p 1 Rodrlguez de Rivera FJ 1. ZDepartment Of Neurology.
Hospital Universitario La Paz. Madrid Spain; 2Department of Nuclear Medicine. Hospital Universitario La Paz. Madrid Spain Objectives: Pseudomigraine with pleocytosis is a rare neurological disease which is characterized by temporary neurological symptoms and lymphocytic pleocytosis in tile CSF. 15 cases are reported.
OPL181 P~e-Ictal Desyncbxol6zafion in a Model of Temporal Lobe Epilepsy: Application of Non-Stalionary Amplitude and Phase Co~rdalion Techniques Stiliyan Kalitzin~, Miron D e r c h a n s k u"7.3, Peter C.arlen2&4, Fernando Lopes da Silva ~. 1Dutch Epilepsy Clinics Foundation "Meet
en Bosch," Heemstede; Department of Medical Physics, The Netherlands; 2Division of Cellular and Molecular Biology, Toronto Western Research Institute, Toronto, Canada; 3Department of Physiology, University of Toronto, Toronto, Canada," 4Krembil Neuroscience Centre, Toronto Western Hospital, University of Toronto, Toronto, Canada; SSwammerdam Institute for Life Sciences, University of Amsterdam, The Netherlands In tiffs study we investigated the phenomenon of a decrease in correlation between nmltisite electrophysiological recordings during ictal onsets in a model of temporal lobe epilepsy (TLE). We used the intact isolated mouse hippocampus, exposed to low-magnesium artificial cerebral spinal fluid (ACSF), to obtain recurrent, spontaneous seizures. Synchronization between nmltisite recordings along tile septotemporal lffppocanlpal axis is quantified using four different methods. Local (complex) anlplitudes obtained by multiscale Gaborwavelet transforms were used to determine linear and non-lniear correlations between the magnitudes and the phase synehrony among the various frequency bands at multiple sites. We found that during seizure onset, Gabor magnitudes becanle uncorrelated in the high beta and ganmla frequency bands. However, local phase synchrony monotonically increased at the onset of a seizure. Using a non-linear association technique, we further examined the relationship between the synehrony and magnitudes of the various epileptiform rhythms. We found that phase synehrony was related to the wavelet magnitude for frequencies in the ganmla range in a uuidirectional mamler; increased magnitude leads to synchrony but not vice-versa. In conclusion, this observation may limit the use of nmltivariate (i~hase) correlation techniques for seizure prediction and suggests that application of paradigms aimed at increasing the magnitude of neuronal oscillations by external stimulation might be advantageous.
H e a d a c h e S e s s i o n 2 - Clinical Perspective OP1- 175 Tile role of Homocysteine in the pathogenesis and development of ufigraine de Tommaso, M, Losito, L, Livrea P. Neurological and Psychiatric
Sciences Department, University of Bari, Italy Background: Migraine, with and without aura (MA and MO), is a
prevalent and complex neurovascular disorder that may also be affected by genetically influenced hyper-homocysteinaenfia. Objective: To determine whether the C677T variant in the M T H F R gene is associated with migraine susceptibility and severity and increased vascular risk, by the evaluation of the clinical features, the Contingent Negative Variation (CNV) habituation pattern, the steady state visual evoked potentials (SSVEPs) and Magnetic Resonance imaging (MRI) and spectroscopy. Methods: Ninety migraine patients were studied: the M T H F R C677T variant was genotyped in 75 MO, 15 M A patients and 100 controls. In all cases the CNV habituation and SSVEPs to medium and high frequency stimulation patterns were evaluated. Eighty patients were also submitted to MRI study. Results: we observed an over-representation of the 677T allele in migraine patients compared to controls, more evident for the M A subtype: the M T H F R variant was also associated with reduced habituation pattern of CNV. The high levels o f homocysteine was linked with earlier onset of migraine, higher frequency of headache and multiple gliotic peri-ventricular areas at MRI. Conclusion: The M T H F R gene variant seemed to enhance the susceptibility to migraine and to worsen its evolution. Keywords: migraine, genetic variant, homocysteine. OP1- 176
Altitude Headache: Therapeutic approach (Altitude: 3.600 meters above
Thursday, November 10, 2005
$91
Method: Subjects with higher than 55% hemacrito were selected, who
showed cephalea (120), dizziness (15), low concentration (12), peripheral cyanosis (18), and insomnia (114), excluding respiratory, cardiac, renal or subjacent metabolic pathologies. Each subject underwent one-hour sauna daily session, for a period of three months, while avoiding exhaustion, exercise and dehydration. Cardiac frequency, arterial pressure, respiratory frequency, body weight, hematocrito and hemoglobin were controlled. The presence, intensity and duration of the synthoms presented by the subjects were recorded. Results: Headache disappeared in all subjects within the first and third week; dizziness and low concentration disappeared within the second and third week; insomnia disappeared beginning the third week; and peripheral cyanosis gradually diminished beginning the first month to disappear by mid third month. Hematocrito shows an average lowering of 6%, and hemoglobin of 2 mg/dl within three months. Conclusions: The exposure of the organism to a hot envirotmtent (sauna), mdeashes adaptive responses with an increase o f cardiac frequency, peripheral vasodilatation and sweating, allowing a greater oxygen capture and facilitating its liberation; these changes determine the disappearance of synthoms and signs of misadaptation to altitude, (3.600 meters above sea level) specially the rapid disappearance of cephalea. OPL177 Levetiraeetarrl in the Trealment of "Alice in Wonderland Syndrome": A Prospective Study
Bosio, A. Neurology Department, S. Camillo Hospital, Brescia, Italy Background: The tetan "Alice in Wonderland Syndrome" has been
used to account for certain hallucinations peculiar to migraine. Levetiracetam (LEV) is a new antiepileptic drug with an excellent tolerability profile. LEV exerts inhibitory effects on N-type calcium channels, and may modulate neurotransmitter release through synaptic vesicle SV2A protein binding. We evaluated the use of LEV treatment over one year in the prophylaxis of migraine with aura showing complex dimorptfisms characteristic of "Alice in Wonderland Syndrome". Methods: Nineteen subjects; 10 male, 9 female; aged 23-39 (mean 28) years; suffering from migraine with aura with complex dimorphism were treated with LEV 1500 mg/day (500 mg in the morning and 1000 mg in the evening) for one year. Electroencephalogram (EEG) readings at baseline showed temporal slow patterns in all patients. Visits were scheduled at Day 0, 15, 30, 60, 90, 180 and 360. Results: After 15 days, 5/19 patients (26.3%) were free of migraine attacks and at final evaluation 16/19 patients (84.2?,'8) were free of attacks. Attack fiequency was reduced by > 50"/0 in the 3 remaining patients. EEG patterns notmalised in 15/19 patients. In 4 patients, EEG patterns did not improve and 3 of these patients continued to suffer migraine attacks at evaluation. Side effects were few and light in severity. No patients discontinued treatment and no relapses were observed. Conclusion: In this preliminary study, LEV was well tolerated and effective as prophylactic treatment for migraine associated with "Alice in Wonderland Syndrome", warranting further investigation.
sea level: La Paz - Bolivia) Duran Qniroz, JC, Limachi Chuqnimia, ME, Limachi Pabon, LD,
Lopez Lazaro, HG, Lopez Mamani, JS, Lopez oporto, E, Loza Condori, E, Loza Vargas, C, Loza Vargas, LA, Calla Magne, J.
Universidad Mayor De San Andres, Bolivia Justification: Altitude eritrocitosis is a physiologic misadaptation phenomenon, and the factors that cause it have not been studied; possibly environmental modifications induce changes in the peripheral vascular dynamics, opening pre-capillary shunts and closing capillaries, consequently lowering oxygen liberation to tissues. Eritrocitosis manifests itself by headache, dizziness, low concentration, and peripheral cyanosis.
O PL 178 Could Silent Brain Isehemia Cause Chronic Headache? Unno, y~,2, Iwaslfita, T a, Stfimizu, H 1. 1Department of Internal
Medicine, Kawakita General Hospital, Tokyo, Japan," 2Department of ~l,fedicine, Kitasato University, Kanagawa, ,)'apart Background: Whether the so-called "silent brain infarction" may cause
chronic headache is not yet eluddated. It is also not known if the pathogenesis of lacunar infarction such as hypertension, arterial sclerosis and cerebral ischenfia may become the cause of chronic headache. The purpose of this study is to investigate the possible role of chronic cerebral hypoperfusion in the mechanism o f headache.
$92
Friday, November l 1, 2005
Methods: In serial 160 patients (69 men, 91 women, 60.1 years) who underwent brain MRI were evaluated. Results: Fifty-three of 160 patients suffered from headache. Tile patients with headache (14 men, 39 women, 49.5 years) were siguificantly yomlger than tile patients without headache (55 men, 52 women, 65.3 years). In 113 of 160 patients, neurological findings were negative. One or more risk factors of cerebrovascular disease (CVD) existed in 77 of 160 patients. Fourteen of 53 patients with headache and 63 of 107 patients without headache had one or more risk factors for CVD, and that difference was statistically siguificant. Brain MRI showed prior cerebrovascular disease in 14 of 53 patients with headache and in 64 of 107 patients without headache. Among patients without risk factors for CVD, the difference of the ratio of ischemic lesions on MRI was not significant between the patients with headache (17.5%) and tile patients without headache
(30.2%). Con¢lusiOllS: There was no univariate correlation between cerebral ischemic lesion and headache. However, among patients with ischemic lesions, headache sufferers were younger, more women, and with less atherosclerotic risk factors than non-headache sufferers. These results suggested there was a correlation between asymptomatic CVD and headache.
O PL 179 Lifting The Burden: the Global Campaign to Reduce the Burden of Headache Worldwide Sleiner, T J 1 on behalf of tile Global Canlpaign Committee. ~Imperial
Oral Platform Abstracts Methods: 15 patients (112 men and 3 women) between 20 to 44 years old are reported with the diagnosis of pseudomigraine with pleocytosis between Agoust- 1993 to February-2005 in Madrid Area-5. Tests: brain CT, lunlbar punction, serologic and inmlmlOlogic determinations, brain MRI and EEG. SPECT test was realised in 11 patients, Arteriography in 5 patients, echocardiography and carotid ultrasound test in 4 patients and angiography-MR[ in 2 patients. Results: Personal antecedent of migraine was reported in 4 patients, Non-migraine headache in 1 patient and a infectious disease in 5 patients. 13 patients had sensitive symptoms, 5 of them were ascendant symptoms. 6 patients had motor symptoms, 9 patients had aphasia and 3 patients had disarthria. Headache was predominantly bifrontal, of pulsating quality and moderate-severe pain intensity. CSF had 10-360 cells (55-95% mononuclear cell). Regions of high signals were seen in 3 patients in brain MRI. Temporal or fi'ont-temporal unspecific alterations were reported in EEG. Normal metabolism (4 patients), hyperperfusion (12 patients) or hypoperfusion could be present in SPECT. Other tests did not present significant alterations. Conclusions: Male gender is predominant in pseudomigraine with pleocytosis (3er-4th decade). Sensitive symptoms were the most fiequent neurological symptoms (86'67%) being ascendant symptoms tile 38% of them. Migraine antecedent was presented in some cases (26'67%).
Friday 11 November 2005
Clinical Neurophysiology
College London, London, UK Background: The World Health Orgauization ([WHO) ranks migraine 19th amongst causes of worldwide disability. Tension-type headache and chronic daily headache impose at least a similar disability burden on the world's populations. Lifting The Burden (LTB) is a response to this public health calanlity. Method: LTB has three phases. Firstly it is collating tile evidence of headache burden in all world regions in order to know its scale and scope. Secondly it is exploiting this evidence to raise awareness of the need for action in every country to relieve this burden. Thirdly, it will work with govertmlents to plan and implement local solutions to locally-assessed needs, and evaluate them for success. Results: WHO, the lay World Headache Alliance and tile professional Interuational Headache Society and European Headache Federation have committed to partnership in action taking the form of a Global Campaign. A network o f other partners, academic and commercial, is in the stages o f being built. Burden data have been gathered on migraine for much o f tile world, but are generally poor for other headache disorders and require supplenlentation through new epidemJological studies wlffch are being plamted. Education will be a pillar of LTB's later phases, aimed at governments through Regional Declarations on Headache, at health-care providers through a training-the-trainers program and at the public utilizing the media. Headache-related health-care interventional projects will follow. Conclusion: LTB is anlbitious and global. Its implementation requires substantial resources but it promises relief from disability that affects the entire world, with huge savings in recovered productivity. OPLIS0 Pseudonfigraine with Pleocytosis. A Report of 15 Cases Maxlin Balbuena S 1, Arpa j l Coya J 2 Frank A 1, Vivancos F 1, Marfinez p 1 Rodrlguez de Rivera FJ 1. ZDepartment Of Neurology.
Hospital Universitario La Paz. Madrid Spain; 2Department of Nuclear Medicine. Hospital Universitario La Paz. Madrid Spain Objectives: Pseudomigraine with pleocytosis is a rare neurological disease which is characterized by temporary neurological symptoms and lymphocytic pleocytosis in tile CSF. 15 cases are reported.
OPL181 P~e-Ictal Desyncbxol6zafion in a Model of Temporal Lobe Epilepsy: Application of Non-Stalionary Amplitude and Phase Co~rdalion Techniques Stiliyan Kalitzin~, Miron D e r c h a n s k u"7.3, Peter C.arlen2&4, Fernando Lopes da Silva ~. 1Dutch Epilepsy Clinics Foundation "Meet
en Bosch," Heemstede; Department of Medical Physics, The Netherlands; 2Division of Cellular and Molecular Biology, Toronto Western Research Institute, Toronto, Canada; 3Department of Physiology, University of Toronto, Toronto, Canada," 4Krembil Neuroscience Centre, Toronto Western Hospital, University of Toronto, Toronto, Canada; SSwammerdam Institute for Life Sciences, University of Amsterdam, The Netherlands In tiffs study we investigated the phenomenon of a decrease in correlation between nmltisite electrophysiological recordings during ictal onsets in a model of temporal lobe epilepsy (TLE). We used the intact isolated mouse hippocampus, exposed to low-magnesium artificial cerebral spinal fluid (ACSF), to obtain recurrent, spontaneous seizures. Synchronization between nmltisite recordings along tile septotemporal lffppocanlpal axis is quantified using four different methods. Local (complex) anlplitudes obtained by multiscale Gaborwavelet transforms were used to determine linear and non-lniear correlations between the magnitudes and the phase synehrony among the various frequency bands at multiple sites. We found that during seizure onset, Gabor magnitudes becanle uncorrelated in the high beta and ganmla frequency bands. However, local phase synchrony monotonically increased at the onset of a seizure. Using a non-linear association technique, we further examined the relationship between the synehrony and magnitudes of the various epileptiform rhythms. We found that phase synehrony was related to the wavelet magnitude for frequencies in the ganmla range in a uuidirectional mamler; increased magnitude leads to synchrony but not vice-versa. In conclusion, this observation may limit the use of nmltivariate (i~hase) correlation techniques for seizure prediction and suggests that application of paradigms aimed at increasing the magnitude of neuronal oscillations by external stimulation might be advantageous.