Review Neuropsychobiology 2015;71:49–62 DOI: 10.1159/000368118
Received: December 18, 2013 Accepted after revision: August 24, 2014 Published online: February 27, 2015
Topographic Analysis of Electroencephalographic Changes during Photic Driving Responses in Patients with Migraine Ryotaro Takashima Hideaki Tanaka Kazuhito Kimoto Yuka Watanabe Koichi Hirata Department of Neurology, Dokkyo Medical University, Mibu-machi, Japan
Abstract Objective: Migraineurs demonstrate abnormal information processing such as photic hypersensitivity. The photic driving response to photic stimulation (PS) is a reaction to the visual stimulation of electroencephalography (EEG). Both the photic driving response and photic hypersensitivity appear during light stimulation. We considered that evaluation of a migraineur’s photic driving response may help to elucidate the mechanism of the migraineur’s sensitive condition. Our study aimed to investigate EEG photic driving responses with a source-localizing method. Methods: We recorded spontaneous resting EEG with eyes closed from 20 electrodes on the scalp during the interictal phase. After recording, each PS was separately selected. We also analyzed EEG by fast Fourier transform and observed the spectrum frequency peaks and topographies in response to PS. Results: The photic driving response could be observed at a flashing rate of >15 Hz. Patients with photic hypersensitivity tended to show more photic driving regardless of the migraine subtype. Moreover, in topographies, their activated areas were shifted anteriorly from fundamental driving to harmonic driving for each photic frequency. This anterior shift was
© 2015 S. Karger AG, Basel 0302–282X/15/0711–0049$39.50/0 E-Mail [email protected] www.karger.com/nps
more evident with a longer duration of illness, although no significant differences were seen between migraine subtypes. The global field power value had a positive correlation with the duration of illness. Conclusion: Photic hypersensitivity and photic driving responses were increased in migraineurs. Photic hypersensitivity might result in sensitization of the limbic system. © 2015 S. Karger AG, Basel
Introduction
Migraine is a condition with a prevalence rate higher than that of essential hypertension. A pulsatile headache appears spasmodically several times per month, and the condition is generally serious. Migraine is accompanied by nausea, vomiting and photic hypersensitivity in the ictal phase. Photophobia is an aggravation factor for migraine attacks and is included in the diagnostic criteria of the 2nd edition of the international classification of headache disorders (ICHD-II) [1]; however, its underlying mechanisms are unknown. Photophobia is caused by the existence of hypersensitivity to light. Photic hypersensitivity is one index that increases a migraineur’s brain hypersensitivity, and physiological evaluation of this mechanism is thought to be important. Both the photic driving response and photic hyperRyotaro Takashima Department of Neurology, Dokkyo Medical University 880 Kitakobayashi Mibu-machi, Shimotsuga-gun, Tochigi 321-0293 (Japan) E-Mail hakutaka683kei @ yahoo.co.jp
Downloaded by: John Rylands Library 130.88.90.140 - 5/25/2015 9:07:03 PM
Key Words Electroencephalography · Gravity center · Migraine · Photic driving · Topography
GFP =
Electrodes
1
n
0.5 – 2
Ʒ (ui – u)
ni=1
1 Reference elctrodes (n = 4)
2 Topography of average potential
No. 1
No. 2
14
–2
9
–7
No. 3
No. 4
8
0
3
–5
3 Calculate GFP from 2
92 + (–7)2 + 32 + (–5)2
0.5
4 = 6.40
Average potential = 5
Fig. 1. Details of GFP calculation.
Patients and Methods Patients We recruited 28 patients [9 males and 19 females; age, 20–50 years; 11 had migraine with aura (MWA) and 17 migraine without aura (MWOA)]; migraine was diagnosed according to the diagnostic criteria of the ICHD-II. All participants continued medications for the prevention and abortion (e.g. triptans) of migraine attacks.
50
Neuropsychobiology 2015;71:49–62 DOI: 10.1159/000368118
Conduct of the Study This study protocol was approved by the Human Ethics Review Committee of the Dokkyo Medical University. All procedures were handled in accordance with the ethical standards of the Declaration of Helsinki. Written informed consent was obtained from each patient participating in the study. Data Acquisition and Analysis We evaluated the patients’ clinical background using a questionnaire that analyzed the duration of illness, age at onset and presence of photic hypersensitivity in the interictal phase. Spontaneous resting electroencephalography (EEG) with eyes closed during the interictal phase was performed using silver/silver chloride electrodes attached to 20 locations of the international 10/20 system (Fp1/2, Fz, F3/4, F7/8, C3/4, Cz, P3/4, Pz, T3/4, T5/6, O1/2 and Oz) with a ground electrode attached to linked earlobes. We used a digital EEG system (NeuroFax 1518; Nihon Kohden Corp., Tokyo, Japan) with a band pass filter of 0.53–120 Hz and sampling performed at 200 Hz. The resistance of each electrode was
Received: December 18, 2013 Accepted after revision: August 24, 2014 Published online: February 27, 2015
Topographic Analysis of Electroencephalographic Changes during Photic Driving Responses in Patients with Migraine Ryotaro Takashima Hideaki Tanaka Kazuhito Kimoto Yuka Watanabe Koichi Hirata Department of Neurology, Dokkyo Medical University, Mibu-machi, Japan
Abstract Objective: Migraineurs demonstrate abnormal information processing such as photic hypersensitivity. The photic driving response to photic stimulation (PS) is a reaction to the visual stimulation of electroencephalography (EEG). Both the photic driving response and photic hypersensitivity appear during light stimulation. We considered that evaluation of a migraineur’s photic driving response may help to elucidate the mechanism of the migraineur’s sensitive condition. Our study aimed to investigate EEG photic driving responses with a source-localizing method. Methods: We recorded spontaneous resting EEG with eyes closed from 20 electrodes on the scalp during the interictal phase. After recording, each PS was separately selected. We also analyzed EEG by fast Fourier transform and observed the spectrum frequency peaks and topographies in response to PS. Results: The photic driving response could be observed at a flashing rate of >15 Hz. Patients with photic hypersensitivity tended to show more photic driving regardless of the migraine subtype. Moreover, in topographies, their activated areas were shifted anteriorly from fundamental driving to harmonic driving for each photic frequency. This anterior shift was
© 2015 S. Karger AG, Basel 0302–282X/15/0711–0049$39.50/0 E-Mail [email protected] www.karger.com/nps
more evident with a longer duration of illness, although no significant differences were seen between migraine subtypes. The global field power value had a positive correlation with the duration of illness. Conclusion: Photic hypersensitivity and photic driving responses were increased in migraineurs. Photic hypersensitivity might result in sensitization of the limbic system. © 2015 S. Karger AG, Basel
Introduction
Migraine is a condition with a prevalence rate higher than that of essential hypertension. A pulsatile headache appears spasmodically several times per month, and the condition is generally serious. Migraine is accompanied by nausea, vomiting and photic hypersensitivity in the ictal phase. Photophobia is an aggravation factor for migraine attacks and is included in the diagnostic criteria of the 2nd edition of the international classification of headache disorders (ICHD-II) [1]; however, its underlying mechanisms are unknown. Photophobia is caused by the existence of hypersensitivity to light. Photic hypersensitivity is one index that increases a migraineur’s brain hypersensitivity, and physiological evaluation of this mechanism is thought to be important. Both the photic driving response and photic hyperRyotaro Takashima Department of Neurology, Dokkyo Medical University 880 Kitakobayashi Mibu-machi, Shimotsuga-gun, Tochigi 321-0293 (Japan) E-Mail hakutaka683kei @ yahoo.co.jp
Downloaded by: John Rylands Library 130.88.90.140 - 5/25/2015 9:07:03 PM
Key Words Electroencephalography · Gravity center · Migraine · Photic driving · Topography
GFP =
Electrodes
1
n
0.5 – 2
Ʒ (ui – u)
ni=1
1 Reference elctrodes (n = 4)
2 Topography of average potential
No. 1
No. 2
14
–2
9
–7
No. 3
No. 4
8
0
3
–5
3 Calculate GFP from 2
92 + (–7)2 + 32 + (–5)2
0.5
4 = 6.40
Average potential = 5
Fig. 1. Details of GFP calculation.
Patients and Methods Patients We recruited 28 patients [9 males and 19 females; age, 20–50 years; 11 had migraine with aura (MWA) and 17 migraine without aura (MWOA)]; migraine was diagnosed according to the diagnostic criteria of the ICHD-II. All participants continued medications for the prevention and abortion (e.g. triptans) of migraine attacks.
50
Neuropsychobiology 2015;71:49–62 DOI: 10.1159/000368118
Conduct of the Study This study protocol was approved by the Human Ethics Review Committee of the Dokkyo Medical University. All procedures were handled in accordance with the ethical standards of the Declaration of Helsinki. Written informed consent was obtained from each patient participating in the study. Data Acquisition and Analysis We evaluated the patients’ clinical background using a questionnaire that analyzed the duration of illness, age at onset and presence of photic hypersensitivity in the interictal phase. Spontaneous resting electroencephalography (EEG) with eyes closed during the interictal phase was performed using silver/silver chloride electrodes attached to 20 locations of the international 10/20 system (Fp1/2, Fz, F3/4, F7/8, C3/4, Cz, P3/4, Pz, T3/4, T5/6, O1/2 and Oz) with a ground electrode attached to linked earlobes. We used a digital EEG system (NeuroFax 1518; Nihon Kohden Corp., Tokyo, Japan) with a band pass filter of 0.53–120 Hz and sampling performed at 200 Hz. The resistance of each electrode was
