- Email: [email protected]
Visual evoked responses in children with migraine: a diagnostic test
75
17. Mills BG, Masuoka LS, Graham CC, Singer FR, Waxman AD. Gallium-67 citrate localization in osteoclast nuclei of Paget’s disease of
bone. J Nucl Med 1988; 29:
1083-67.
18. Krakoff IH, Newman RA, Goldberg RS. Clinical toxicologic and pharmacologic studies of gallium nitrate. Cancer 1979; 44: 1722-27. 19. Warrell RP, Bockman RS, Coonley CJ, Isaacs M, Staszewski H. Gallium nitrate inhibits calcium resorption from bone and is effective treatment for cancer-related hypercalcaemia. J Clin Invest 1984; 72: 1487-90. 20. Warrell RP, Israel R, Frisone M, Snyder T, Gaynor JJ, Bockman RS. Gallium nitrate for acute treatment of cancer related hypercalcaemia. Ann Intern Med 1988; 108: 669-74. 21. Dudley HC, Marrer HH. Studies of the metabolism of gallium. III. Deposition in and clearance from bone. J Pharmacol Exp Ther 1952; 106: 129-34. 22. Walton RJ, Preston CJ, Bartlett M, Smith R, Russell GG. Biochemical measurements in Paget’s disease of bone. Eur J Clin Invest 1977; 7: 37-39. 23. Goverde BC, Veenkamp FJN. Routine assay of total urinary hydroxyproline based on resin-catalysed hydrolysis. Clin Chim Acta 1972; 41: 29-40. 24. Nussbaum SR, Zahradnik RJ, Lavigne JR, et al. Highly sensitive two-site immunoradiometric assay of parathyrin, and its clinical utility in evaluating patients with hypercalcaemia Clin Chem 1987; 33: 1364-67. 25. Walton RJ, Bijvoet OLM. Nomogram for derivation of renal threshold phosphate concentration. Lancet 1975; i: 309-10.
Papapoulos SE, Frolich M, Mudde AH, Harinck HIJ, Berg HVD, Bojvoet OLM. Serum osteocalcin in Padget’s disease of bone: bone concentrations and response to bisphosphonate treatment., J Endocrinol Metab 1987; 65: 89-94. 27. Bockman RS, Boskey AL, Blumenthal NC, Alcock NW, Warrell RP. Gallium increases bone calcium and crystallite perfection of hydroxyapatite. Calcif Tissue Int 1986; 39: 376-81. 28. Blumenthal NC, Cosma V, Levine S. Effect of gallium on the in vitro formation, growth, and solubility of hydroxyapatite. Calcif Tissue Int 1989; 45: 81-87. 29. Donnelly R, Boskey A. The effect of gallium on seeded hydroxyapatite growth. Calcif Tissue Int 1989; 44: 138-42. 30. Chitambar CR, Matthaeus WG, Antholine WE, Graff K, O’Brien WJ. Inhibition of leukemic HL60 cell growth by transferrin-gallium: effects on ribonucleotide reductase and demonstration of drug synergy with hydroxyurea. Blood 1988; 72: 1930-36. 31. Larson SM, Rasey JS, Allen DR, et al. Common pathway for tumor cell uptake of gallium-67 and iron-59 via a transferrin receptor. J Natl 26.
Cancer Inst 1980; 64: 41-53.
Anghileri LJ, Crone-Escanye M-C, Thouvenot P, Brunotte F, Robert J. Mechanisms of gallium-67 accumulation by tumors: role of cell membrane permeability. J Nucl Med 1988; 29: 663-68. 33. Pioli G, Girasole G, Pedrazzoni M, et al. Spontaneous release of interleukin-1 (IL-1) from medullary mononuclear cells of pagetic subjects. Calcif Tissue Int 1989; 45: 257-59. 32.
Visual evoked responses in children with a
migraine:
diagnostic test
The visual evoked responses (VERs) to both flash and pattern stimulation were recorded in 44 children with migraine, with or without aura, and 8 with periodic syndrome. The controls were 50 age and sex matched children. VERs of 50 sex matched adults with migraine were also recorded. The fast wave amplitude in children with migraine was higher than that in controls. The amplitude was higher in younger children with migraine (under 13 years) than that in older children or adults with migraine. Children with periodic syndrome had VERs similar to those of children with migraine. The VER, especially in children, may prove to be a useful test in the diagnosis of migraine.
Introduction The aetiology of migraine (vasculogenic or neurogenic) has been debated for years. Peatfield1 has stated that "migrainous headache is believed to be initiated within the brainstem, expressed in the external carotid circulation and then perceived back in the brain stem, thalamus and cortex". The pathogenesis of migraine may involve the opening of arteriovenous anastomoses in the carotid circulation ;2 this theory is supported by the finding that a new 5hydroxytryptamine-like receptor agonist, a selective vasoconstrictor of this circulation in animals, relieves migraine in adults.3 Migraine headache affects 2.7% of children by the age of 7 and 10-6% by age 14.4,5 Because there have been no
diagnostic tests for migraine, most epidemiological data has been based on questionnaires.6 Many attempts have been made to find an objective marker.7 The diagnosis of migraine, with and without aura, and migraine equivalents is made from clinical history, physical examination, and elimination of alternatives;.8,9 the differential diagnosis is multiple and complex."* Despite the view that childhood periodic syndromes are migraine equivalents without headache they are not included in the International Headache Society classification of migraine.8,9 Electrophysiological techniques have been used to analyse the hypothalamic content of a migraine attack. Differences in both electroencephalograms (EEGs) and visual evoked responses (VERs) have been found between groups of children with migraine and controls,l1-13 but, to date, there has not been an electrophysiological test for diagnostic use. In an earlier study of adults, 14 we found that there was a difference in background fast wave activity of the VER between those with migraine and controls. We have studied VERs, with frequences over 14 Hz, in children with migraine and controls, and looked at the possible use of this test in the diagnosis of migraine.
ADDRESS: Birminghamand Midland Eye Hospital, Birmingham B32NS, UK (M. J. Mortimer, MRCGP, P A. Good, BSc, J. B. Marsters, PhD, D P. Addy, FRCP). Correspondence to Mr P. A Good.
76
Patients and methods 52 children, attending the Birmingham Migraine clinic, were assessed clinically; 44 had migraine with aura or migraine without aura,8 and 8 had periodic syndrome (paroxysmal abdominal pain with nausea and/or vomiting, but no headache). The district ethical committee approved the study. With informed parental consent, we recorded VERs for each child.
The 44 children with migraine headache were separated into two (10 boys and 12 girls) under 13 yr (range 3-12 yr, mean 9-2 yr), and 22 (5 boys and 17 girls) aged 13-16 yr (mean 14-11 yr). 13 yr was chosen as an approximation of puberty. In the younger group, 7 had migraine with aura and 15 had no aura. In the older children, 15 had experienced aura and 7 had not. All the children with periodic syndrome were 12 yr or younger (range 4-12 yr); 4 were girls and 4 boys. age groups: 22
A control group of 50 children, who were age and sex matched with the migraine subgroups, were volunteers from general practice; they had no history of migraine, and no ophthalmological or neurological abnormality. The adult migraine control group consisted of 50 sex-matched patients with migraine over 16 yr, selected at random from a group of adults with migraine referred from the Birmingham Migraine Clinic for investigation. 25 of these patients had migraine with aura and 25 migraine without aura. All controls were investigated under exactly the same conditions as the children with migraine.
The VERs were recorded to both diffuse flash and pattern stimulation (reversing checkerboard). Flash stimulation was generated by a Grass P5 22 photic stimulator with a blue/white light source of intensity 200 candella/m2 and with peak wavelength 510 nm. The stimulus rate was 2 Hz. Pattern stimulation was provided by a 2 Hz reversing black and white checkerboard displayed on a television screen. The pattern subtended an angle of 1°at the eye. The stimulus field size was 16°, contrast 90%, and mean luminance 350 candella/m2. Sources of both flash and pattern stimuli were 50 cm from the children’s eyes. Both eyes were stimulated at the same time. The recording electrodes were bipolar silver,/silver chloride electrodes put on the scalp at positions Fz and Oz, in accordance with international convention. Frequencies in the EEG &bgr; range, 10-50 Hz, were recorded (Nicolet C4 clinical averager). Analysis time was 500 ms. The amplitude and frequency of at least four different waveforms from five consecutive stimuli were used to calculate the means. The amplitudes of waves with frequency greater than 16 Hz occurring in the last 250 ms of the recording (fastwaves) were used to calculate the mean amplitude of fast wave activity. No child had a migraine at the time the VER was recorded.
Fig 1-Examples of VER recordings
to flash and pattern
stimulation. Note increased fast
wave
activity
in
patients.
Statistical analysis of the data was by analysis of (ANOVA) and Bonferroni’s procedure was applied.
variance
Results The visual evoked responses for control groups and migraine groups are shown in the table. Children with migraine or periodic syndrome who were younger than 13 and lower years had higher fast wave amplitude (p <0’01) < controls in the fast wave frequency (p 0-01) than same age groups. In older children the fast wave amplitude was higher in the children with migraine than in controls (p < 0-01), but the difference in fast wave frequency was not
significant. VISUAL EVOKED RESPONSE: FAST WAVE AMPLITUDE AND FREQUENCY
Analysis of fast wave amplitude data There was no significance difference in fast wave amplitudes between the two control groups for either flash pattern stimulation. None of the control children had fast wave amplitudes over 2 uV to either flash or pattern stimulation. Fast wave amplitude after flash stimulation was greater than 2pV in 47 (90%) of the 52 children with migraine. Only 1 child had a value less than 2 µV. After pattern stimulation 45 (87%) of the 52 children with migraine had a fast wave amplitude over 2 uV. 1 child had a value less than 2 µV. or
Mean (standard error of the mean) M migraine without aura, MA = migraine with aura, =
Mig
=
migraine
The younger children with migraine had higher fast wave amplitudes than the older children with migraine for both flash and pattern stimulation (p<0001). Children with had similar fast wave periodic syndrome amplitudes to the older children children with whereas the younger migraine with migraine had fast wave amplitudes resembling those of
77
The fast wave activity recorded for children with migraine under 13 years of age was characteristic-high fast wave amplitude and low fast wave frequency. The explanation for the low frequency may be related to developmental EEG changes; beta rhythm does not become fully developed until puberty." Children with periodic syndrome had high fast wave
frequency with superimposed intermittent high amplitude sharp waves after flash stimulation, a response pattern that has been reported in adults with acephalgic migraine." Furthermore, the amplitude and frequency ranges of the fast wave activity in periodic syndrome are similar to those seen in acephalgic migraine. The focal neurological symptoms in periodic syndrome and acephalgic migraine8,9,16 may have a common hypothalamic aetiology. The finding of similar VERs in migraine and periodic syndrome supports the inclusion of the latter in the international classification.8 This study has shown that the VER differentiates children with migraine from controls. When responses to both flash and pattern stimulation are taken into account, and a cut-off value of 2 uV is used, the specificity is high (96%). Our study suggests that the VER can be used as a diagnostic test for migraine. We thank Dr G. Bissenden, consultant paediatrician, for allowing us to assess his patients with periodic syndrome.
REFERENCES 1. Peatfield R.
Medical 2-3. 2.
Fig 2-Distribution of VER fast wave amplitude data after flash
(A) and pattern (B) stimulation. Note increased amplitude
in
patients.
the adult migraine group. In the younger children there was no significant difference in fast wave amplitude between those with a history of migraine with aura and those without aura. In the older children the fast wave amplitudes were higher in children who had migraine with aura than in those who had migraine without aura. The same was true of the adult migraine group (flash and pattern amplitude, both
p<0001).
after pattern stimulation in the younger controls were lower than those in the older controls (p < 001), but there was no significant difference after flash stimulation. The fast wave frequencies, to both flash and pattern stimulation, were lower in younger children with migraine than in any other group studied (all control groups, p < 0-001; all other migraine groups, p < 0 01, and periodic
syndrome group, p < 0-05). Discussion
The differences in fast wave activity between the migraine groups and control groups suggests that the VER might be used as a diagnostic test for migraine in children.
Spierings ELH, Saxena PR. The action of ergotamine on the distribution of carotid blood flow-the migraine shunt theory revisited. Headache 1980; 20: 143-45.
3. Doenicke A, Brand J, Perrin VL. Possible benefit of GR43175, a novel 5-HT1-like receptor agonist for the acute treatment of severe migraine. Lancet 1988; i: 1309-11. 4. Bille B. Migraine 51: 13451.
in school children. Acta Paediatr Scand (suppl 36) 1962;
Sillanpaa M. Changes in the prevalence of migraine and other headaches during the first seven school years. Headache 1983; 23: 15-19. 6. Waters WE. Epidemiology of migraine. In: Pierce J, Heinneman W, eds. Modem topics in migraine. London: Medical books, 1967: 12-13. 7. Edmeades J. Migraine markers. Headache 1988; 28: 568. 5.
8. Headache. Classification Committee of the International Headache Society. Classification and diagnostic criteria for headache disorders, neuralgias and facial pain. Cephalalgia 1988; 8: 7 (suppl). 9.
Analysis of fast wave frequencies The fast wave frequencies recorded
Migraine pathophysiology: an update. In: Piercy V, ed. dialogue. Brussels: Information medical express, 1988; 192:
Hockaday JM. Migraine and its equivalents in childhood. Dev Med Child
Neurol 1987; 29: 258-70. Prensky AR. Migraine in children. In: Blan JN, ed. Migraine: clinical conceptual and research aspects. London: Chapman and Hall, 1988: 43-44. 11. Simon RH, Zimmerman AW, Sanderson P, Tasman A. EEG markers of migraine in children and adults. Headache 1983; 23: 201-05. 12. Jay GW. Epilepsy, migraine and EEG abnormalities in children: a review and hypothesis. Headache 1982; 22: 110-14. 13. Brinciotti M, Cerquiglini V, Guidetti M, Matricardi M, et al. Multimodality evoked potentials in childhood migraine. Proc 7th 10.
Migraine Trust International Symposium. 1988, (suppl) 39. 14. Marsters JB, Good PA, Mortimer MJ. A diagnostic test for migraine using the visual evoked potential. Headache 1988; 28: 526-30. 15. Mortimer MJ, Good PA, Marsters JB. Acephalgic migraine (migraine aura without headache), demyelinating disease and the visual evoked potential. Headache (in press). 16. O’Connor PS, Tredici TJ. Acephalgic migraine: fifteen years experience. Ophthalmologica 1981; 88: 999-1003.
17. Mills BG, Masuoka LS, Graham CC, Singer FR, Waxman AD. Gallium-67 citrate localization in osteoclast nuclei of Paget’s disease of
bone. J Nucl Med 1988; 29:
1083-67.
18. Krakoff IH, Newman RA, Goldberg RS. Clinical toxicologic and pharmacologic studies of gallium nitrate. Cancer 1979; 44: 1722-27. 19. Warrell RP, Bockman RS, Coonley CJ, Isaacs M, Staszewski H. Gallium nitrate inhibits calcium resorption from bone and is effective treatment for cancer-related hypercalcaemia. J Clin Invest 1984; 72: 1487-90. 20. Warrell RP, Israel R, Frisone M, Snyder T, Gaynor JJ, Bockman RS. Gallium nitrate for acute treatment of cancer related hypercalcaemia. Ann Intern Med 1988; 108: 669-74. 21. Dudley HC, Marrer HH. Studies of the metabolism of gallium. III. Deposition in and clearance from bone. J Pharmacol Exp Ther 1952; 106: 129-34. 22. Walton RJ, Preston CJ, Bartlett M, Smith R, Russell GG. Biochemical measurements in Paget’s disease of bone. Eur J Clin Invest 1977; 7: 37-39. 23. Goverde BC, Veenkamp FJN. Routine assay of total urinary hydroxyproline based on resin-catalysed hydrolysis. Clin Chim Acta 1972; 41: 29-40. 24. Nussbaum SR, Zahradnik RJ, Lavigne JR, et al. Highly sensitive two-site immunoradiometric assay of parathyrin, and its clinical utility in evaluating patients with hypercalcaemia Clin Chem 1987; 33: 1364-67. 25. Walton RJ, Bijvoet OLM. Nomogram for derivation of renal threshold phosphate concentration. Lancet 1975; i: 309-10.
Papapoulos SE, Frolich M, Mudde AH, Harinck HIJ, Berg HVD, Bojvoet OLM. Serum osteocalcin in Padget’s disease of bone: bone concentrations and response to bisphosphonate treatment., J Endocrinol Metab 1987; 65: 89-94. 27. Bockman RS, Boskey AL, Blumenthal NC, Alcock NW, Warrell RP. Gallium increases bone calcium and crystallite perfection of hydroxyapatite. Calcif Tissue Int 1986; 39: 376-81. 28. Blumenthal NC, Cosma V, Levine S. Effect of gallium on the in vitro formation, growth, and solubility of hydroxyapatite. Calcif Tissue Int 1989; 45: 81-87. 29. Donnelly R, Boskey A. The effect of gallium on seeded hydroxyapatite growth. Calcif Tissue Int 1989; 44: 138-42. 30. Chitambar CR, Matthaeus WG, Antholine WE, Graff K, O’Brien WJ. Inhibition of leukemic HL60 cell growth by transferrin-gallium: effects on ribonucleotide reductase and demonstration of drug synergy with hydroxyurea. Blood 1988; 72: 1930-36. 31. Larson SM, Rasey JS, Allen DR, et al. Common pathway for tumor cell uptake of gallium-67 and iron-59 via a transferrin receptor. J Natl 26.
Cancer Inst 1980; 64: 41-53.
Anghileri LJ, Crone-Escanye M-C, Thouvenot P, Brunotte F, Robert J. Mechanisms of gallium-67 accumulation by tumors: role of cell membrane permeability. J Nucl Med 1988; 29: 663-68. 33. Pioli G, Girasole G, Pedrazzoni M, et al. Spontaneous release of interleukin-1 (IL-1) from medullary mononuclear cells of pagetic subjects. Calcif Tissue Int 1989; 45: 257-59. 32.
Visual evoked responses in children with a
migraine:
diagnostic test
The visual evoked responses (VERs) to both flash and pattern stimulation were recorded in 44 children with migraine, with or without aura, and 8 with periodic syndrome. The controls were 50 age and sex matched children. VERs of 50 sex matched adults with migraine were also recorded. The fast wave amplitude in children with migraine was higher than that in controls. The amplitude was higher in younger children with migraine (under 13 years) than that in older children or adults with migraine. Children with periodic syndrome had VERs similar to those of children with migraine. The VER, especially in children, may prove to be a useful test in the diagnosis of migraine.
Introduction The aetiology of migraine (vasculogenic or neurogenic) has been debated for years. Peatfield1 has stated that "migrainous headache is believed to be initiated within the brainstem, expressed in the external carotid circulation and then perceived back in the brain stem, thalamus and cortex". The pathogenesis of migraine may involve the opening of arteriovenous anastomoses in the carotid circulation ;2 this theory is supported by the finding that a new 5hydroxytryptamine-like receptor agonist, a selective vasoconstrictor of this circulation in animals, relieves migraine in adults.3 Migraine headache affects 2.7% of children by the age of 7 and 10-6% by age 14.4,5 Because there have been no
diagnostic tests for migraine, most epidemiological data has been based on questionnaires.6 Many attempts have been made to find an objective marker.7 The diagnosis of migraine, with and without aura, and migraine equivalents is made from clinical history, physical examination, and elimination of alternatives;.8,9 the differential diagnosis is multiple and complex."* Despite the view that childhood periodic syndromes are migraine equivalents without headache they are not included in the International Headache Society classification of migraine.8,9 Electrophysiological techniques have been used to analyse the hypothalamic content of a migraine attack. Differences in both electroencephalograms (EEGs) and visual evoked responses (VERs) have been found between groups of children with migraine and controls,l1-13 but, to date, there has not been an electrophysiological test for diagnostic use. In an earlier study of adults, 14 we found that there was a difference in background fast wave activity of the VER between those with migraine and controls. We have studied VERs, with frequences over 14 Hz, in children with migraine and controls, and looked at the possible use of this test in the diagnosis of migraine.
ADDRESS: Birminghamand Midland Eye Hospital, Birmingham B32NS, UK (M. J. Mortimer, MRCGP, P A. Good, BSc, J. B. Marsters, PhD, D P. Addy, FRCP). Correspondence to Mr P. A Good.
76
Patients and methods 52 children, attending the Birmingham Migraine clinic, were assessed clinically; 44 had migraine with aura or migraine without aura,8 and 8 had periodic syndrome (paroxysmal abdominal pain with nausea and/or vomiting, but no headache). The district ethical committee approved the study. With informed parental consent, we recorded VERs for each child.
The 44 children with migraine headache were separated into two (10 boys and 12 girls) under 13 yr (range 3-12 yr, mean 9-2 yr), and 22 (5 boys and 17 girls) aged 13-16 yr (mean 14-11 yr). 13 yr was chosen as an approximation of puberty. In the younger group, 7 had migraine with aura and 15 had no aura. In the older children, 15 had experienced aura and 7 had not. All the children with periodic syndrome were 12 yr or younger (range 4-12 yr); 4 were girls and 4 boys. age groups: 22
A control group of 50 children, who were age and sex matched with the migraine subgroups, were volunteers from general practice; they had no history of migraine, and no ophthalmological or neurological abnormality. The adult migraine control group consisted of 50 sex-matched patients with migraine over 16 yr, selected at random from a group of adults with migraine referred from the Birmingham Migraine Clinic for investigation. 25 of these patients had migraine with aura and 25 migraine without aura. All controls were investigated under exactly the same conditions as the children with migraine.
The VERs were recorded to both diffuse flash and pattern stimulation (reversing checkerboard). Flash stimulation was generated by a Grass P5 22 photic stimulator with a blue/white light source of intensity 200 candella/m2 and with peak wavelength 510 nm. The stimulus rate was 2 Hz. Pattern stimulation was provided by a 2 Hz reversing black and white checkerboard displayed on a television screen. The pattern subtended an angle of 1°at the eye. The stimulus field size was 16°, contrast 90%, and mean luminance 350 candella/m2. Sources of both flash and pattern stimuli were 50 cm from the children’s eyes. Both eyes were stimulated at the same time. The recording electrodes were bipolar silver,/silver chloride electrodes put on the scalp at positions Fz and Oz, in accordance with international convention. Frequencies in the EEG &bgr; range, 10-50 Hz, were recorded (Nicolet C4 clinical averager). Analysis time was 500 ms. The amplitude and frequency of at least four different waveforms from five consecutive stimuli were used to calculate the means. The amplitudes of waves with frequency greater than 16 Hz occurring in the last 250 ms of the recording (fastwaves) were used to calculate the mean amplitude of fast wave activity. No child had a migraine at the time the VER was recorded.
Fig 1-Examples of VER recordings
to flash and pattern
stimulation. Note increased fast
wave
activity
in
patients.
Statistical analysis of the data was by analysis of (ANOVA) and Bonferroni’s procedure was applied.
variance
Results The visual evoked responses for control groups and migraine groups are shown in the table. Children with migraine or periodic syndrome who were younger than 13 and lower years had higher fast wave amplitude (p <0’01) < controls in the fast wave frequency (p 0-01) than same age groups. In older children the fast wave amplitude was higher in the children with migraine than in controls (p < 0-01), but the difference in fast wave frequency was not
significant. VISUAL EVOKED RESPONSE: FAST WAVE AMPLITUDE AND FREQUENCY
Analysis of fast wave amplitude data There was no significance difference in fast wave amplitudes between the two control groups for either flash pattern stimulation. None of the control children had fast wave amplitudes over 2 uV to either flash or pattern stimulation. Fast wave amplitude after flash stimulation was greater than 2pV in 47 (90%) of the 52 children with migraine. Only 1 child had a value less than 2 µV. After pattern stimulation 45 (87%) of the 52 children with migraine had a fast wave amplitude over 2 uV. 1 child had a value less than 2 µV. or
Mean (standard error of the mean) M migraine without aura, MA = migraine with aura, =
Mig
=
migraine
The younger children with migraine had higher fast wave amplitudes than the older children with migraine for both flash and pattern stimulation (p<0001). Children with had similar fast wave periodic syndrome amplitudes to the older children children with whereas the younger migraine with migraine had fast wave amplitudes resembling those of
77
The fast wave activity recorded for children with migraine under 13 years of age was characteristic-high fast wave amplitude and low fast wave frequency. The explanation for the low frequency may be related to developmental EEG changes; beta rhythm does not become fully developed until puberty." Children with periodic syndrome had high fast wave
frequency with superimposed intermittent high amplitude sharp waves after flash stimulation, a response pattern that has been reported in adults with acephalgic migraine." Furthermore, the amplitude and frequency ranges of the fast wave activity in periodic syndrome are similar to those seen in acephalgic migraine. The focal neurological symptoms in periodic syndrome and acephalgic migraine8,9,16 may have a common hypothalamic aetiology. The finding of similar VERs in migraine and periodic syndrome supports the inclusion of the latter in the international classification.8 This study has shown that the VER differentiates children with migraine from controls. When responses to both flash and pattern stimulation are taken into account, and a cut-off value of 2 uV is used, the specificity is high (96%). Our study suggests that the VER can be used as a diagnostic test for migraine. We thank Dr G. Bissenden, consultant paediatrician, for allowing us to assess his patients with periodic syndrome.
REFERENCES 1. Peatfield R.
Medical 2-3. 2.
Fig 2-Distribution of VER fast wave amplitude data after flash
(A) and pattern (B) stimulation. Note increased amplitude
in
patients.
the adult migraine group. In the younger children there was no significant difference in fast wave amplitude between those with a history of migraine with aura and those without aura. In the older children the fast wave amplitudes were higher in children who had migraine with aura than in those who had migraine without aura. The same was true of the adult migraine group (flash and pattern amplitude, both
p<0001).
after pattern stimulation in the younger controls were lower than those in the older controls (p < 001), but there was no significant difference after flash stimulation. The fast wave frequencies, to both flash and pattern stimulation, were lower in younger children with migraine than in any other group studied (all control groups, p < 0-001; all other migraine groups, p < 0 01, and periodic
syndrome group, p < 0-05). Discussion
The differences in fast wave activity between the migraine groups and control groups suggests that the VER might be used as a diagnostic test for migraine in children.
Spierings ELH, Saxena PR. The action of ergotamine on the distribution of carotid blood flow-the migraine shunt theory revisited. Headache 1980; 20: 143-45.
3. Doenicke A, Brand J, Perrin VL. Possible benefit of GR43175, a novel 5-HT1-like receptor agonist for the acute treatment of severe migraine. Lancet 1988; i: 1309-11. 4. Bille B. Migraine 51: 13451.
in school children. Acta Paediatr Scand (suppl 36) 1962;
Sillanpaa M. Changes in the prevalence of migraine and other headaches during the first seven school years. Headache 1983; 23: 15-19. 6. Waters WE. Epidemiology of migraine. In: Pierce J, Heinneman W, eds. Modem topics in migraine. London: Medical books, 1967: 12-13. 7. Edmeades J. Migraine markers. Headache 1988; 28: 568. 5.
8. Headache. Classification Committee of the International Headache Society. Classification and diagnostic criteria for headache disorders, neuralgias and facial pain. Cephalalgia 1988; 8: 7 (suppl). 9.
Analysis of fast wave frequencies The fast wave frequencies recorded
Migraine pathophysiology: an update. In: Piercy V, ed. dialogue. Brussels: Information medical express, 1988; 192:
Hockaday JM. Migraine and its equivalents in childhood. Dev Med Child
Neurol 1987; 29: 258-70. Prensky AR. Migraine in children. In: Blan JN, ed. Migraine: clinical conceptual and research aspects. London: Chapman and Hall, 1988: 43-44. 11. Simon RH, Zimmerman AW, Sanderson P, Tasman A. EEG markers of migraine in children and adults. Headache 1983; 23: 201-05. 12. Jay GW. Epilepsy, migraine and EEG abnormalities in children: a review and hypothesis. Headache 1982; 22: 110-14. 13. Brinciotti M, Cerquiglini V, Guidetti M, Matricardi M, et al. Multimodality evoked potentials in childhood migraine. Proc 7th 10.
Migraine Trust International Symposium. 1988, (suppl) 39. 14. Marsters JB, Good PA, Mortimer MJ. A diagnostic test for migraine using the visual evoked potential. Headache 1988; 28: 526-30. 15. Mortimer MJ, Good PA, Marsters JB. Acephalgic migraine (migraine aura without headache), demyelinating disease and the visual evoked potential. Headache (in press). 16. O’Connor PS, Tredici TJ. Acephalgic migraine: fifteen years experience. Ophthalmologica 1981; 88: 999-1003.