The Japanese Journal of Psychiatry and Neurology, Vol. 46, No. 2, 1992
Intraoperative Measurement of rCBF in Epileptic Foci Using Laser Doppler Flowmetry in 5 Patients with Intractable Posttraumatic Epilepsy Hirotsune Kawamura, M.D., Keiichi Amano, M.D., Tatsuya Tanikawa, M.D., Hiroko Kawabatake, M.D., Hiroshi Iseki, M.D., Yukiya Iwata, M.D., Takaomi Taira, M.D. and Toshihiko Shimizu, M.D. Department of Neurosurgery, Neurological Institute, Tokyo Women’s Medical College, Tokyo Introduction Recently, interest has grown in the potential of single photon emission computerized tomography (SPECT) for the study of brain function in epilepsy.’” SPECT findings in epilepsies have often corresponded to the epileptic focus as defined by the scalp EEG. Decreased-rCBF and inoccurs at the focus interictally’ creased flow at the focus ictally’ ‘. However, these SPECT findings have been variable, with 30-70% of cases showing areas of reduced or increased rCBF. In the present study, we measured the rCBF in the epileptic foci intraoperatively by a laser-doppler flowmetry in 5 patients with medically refractory posttraumtic epilepsy.
’,
Subjects and Methods Of the five patients operated on for in-
549
tractable posttraumatic epilepsy, the relevant clinical, diagnostic, CT and/or MRI findings and EEG data on the all the patients are summarized in Table l. For precise determination of the epileptic focus, electrocorticogram was recorded using newly-devised multielectrodes which can be easily fixed to the surface of the brain cortex only by a surface tension of physical saline dripped on the electrodes and the cortical surface (Fig. l).’ The regional cerebral blood flow (rCBF) was measured by a laser doppler flowmeter (Laserflo Model BPM403, TSI INC) and with a P430-type probe in the epileptic foci, comparing to the value in other areas of the cerebral cortex (Fig. 2 ) . Results The values of the rCBF in each area (in the spike foci, in the necrotic scar, in the gliotic area without spike discharges, and in the normal cortex) in all the 5 cases are summarized in Table 2. The rCBF in the epileptic focus ranged from 40 to 58 ml/ 100 ml/min. The mean value was 52.2 ml/ 100 ml/min. that decreased up to 30% as compared with the mean value of 76.4 ml/ 100 ml/min. in the normal brain cortex. On the other hand, the mean rCBF increased up to 13.4 ml in the epileptic foci rather than in the gliotic area without any epileptic activity. The amount of rCBF in the epileptic foci, however, was not closely related to the epileptic activities on the electrocorticogram (Table 3).
Table 1 : Clinical Summary of 5 Patients with Medically Refractory Posttraumatic Epilepsy Case No.
Name
Age, Sex
1 2 3 4 5
N.N. T.Y.
28 M 31 M 47 F 15 F 43 M
S.H. S.K. T.N.
Seizure Type CPS
PS CPS CPS PS
Localization of Lesions on CT, MRI Lt-parietooccipital Rt-frontal Rt-parietal Lt-parietotemporal Lt-frontal base
Scalp EEG
Interval to Surnerv
SP in Lt-P-Post T SP, SW in Rt-F SP, SW in Rt-P-Post T SP in Lt-F-T SP. SW in Lt-F
10 Y
10 Y 15 Y 8 Y 3v
PS: partial seizure, CPS: complex partial seizure, SP: spike, SW: slow wave, Lt: left, Rt: right, F: frontal, P: parietal, T: temporal, Y : year,
550
Selected Papers: Seizure-Related Phenomena
Discussion
In the Present study, we have shown that the rCBF in the epileptic foci measured intraoPerativelY by a laser doPPler flowmeter in 5 patients with intactable post-
traumatic epilepsy had significantly decreased (30% of nearly normal cortex). These results are supported by the SPECT findings with significantly decreased rCBF in the epileptic foci interictally.' Laser doppier flowmetry is based on the direct detec-
'
Fig. 1: The electrocorticogram is recorded by our special multichannel electrode arranged in the international 10-20 system.
Fig. 2: Actual measurement of the rCBF in the epileptic focus by the P430 probe.
The Japanese Journal of Psychiatry and Neurology, Vol. 46, No. 2, 1992
55 1
Table 2: Microtissue Blood Flow Measured by LASERFLO (m1/100 ml/min) No.
Name
Spike Focus
Necrotic Scar
Gliosis
Nearly Normal
S / N (%)
1 2 3 4 5
N.N. T.Y.
58 40 76 42 45 52.2
3.5 2.8 16.0 5.0 3.2 6.1
21 32 49 36 50 38.8
80 16 86 68 12 76.4
72 * 5% 52.6% 88.4% 61.8% 62.5% 68.3%
S.H. S.K. T.N. Averaged
S/N: spike focus/normal tissue
Table 3: Comparison between the Change of Regional Blood Flow in Epileptic Focus and Its Epileptic Activity on Electrocorticogram Recorded during Surgical Treatment No.
Name
1
N.N.
2 3 4 5
T.Y.
ECoG
Blood Flow in Spike Focus
S.H. S.K. T.N.
58 (ml/l00 ml/min) 40 16 42 45
Spike Area
No. of Spikes/30 Sec
2X3cm
15-25
1x2
5-6 3-4 20-28 -66
1x1 2x3
1x1
ECoG : electrocorticogram
tion of the blood flow which is computed by determining the results of velocity and volume. Therefore, the flowmetry allows to assess the rCBF at a real time and also it can measure the blood flow in the small cerebral cortex4 of approximately 1 mm’. By using the laser doppler flowmetry, we have made it clear that the rCBF in the epileptic focus increases up to 25% of the area adjacent to the epileptic focus as defined by the corticogram. These findings could prove to be beneficial to understand the mechanism of hyperperfusion in the epileptic foci during clinical seizures. References
1. Konishi, T.: Regional cerebral blood flow in epileptic foci using [I-123] IMP-SPECT. Jpn J Psychiatry Neurol 43: 355-360, 1989 (in Japanese). 2. Lee, B.I., Markand, O.N., Wellman, H.N. Siddiqui, A.R., Park, H.M., Mock, B.,
Worth, R.M., Edwards, M.K. and Krepshaw, J.: HIPDM-SPECT in patients with medically intractable complex partial seizures: Ictal study. Arch Neurol 45 397-402, 1988. Magistretti, L., Uren, R.F., Parker, J.A., Royal, H.D., Front, D. and Kolodny, G.M.: Monitoring of regional cerebral blood flow by single photon emission tomography of 1231-N-isopropyl-iodoamphetaminein epileptics. Ann Radio1 26 68-71, 1983. Rosenblim, B.R., Bonner, R.F. and Oldfield, E.H.: Intraoperative measurement of cortical blood flow adjacent to cerebral AVM using laser doppler velocimetry. J Neurosurg 66: 396-399, 1987. Rowe, C.C., Berkovic, S.F., Sia, S.T.,DipApplSci, M.A., Mckay, W.J., Kalnins, P.M. and Bladin, P.F.: Localization of epileptic foci with postictal single photon emission computed tomography. Ann Neurol 126 660-668, 1989. Stefan, H.,Bauer, J., Feistel, H., Schulemann, H., Neubauer, U. Wenzel, B., Wolf,
Selected Papers: Seizure-Related Phenomena
552
F., Neundorfer, B. and Huk, W.J.: Regional cerebral blood flow during focal seizures of temporal and frontal onset. Ann Neurol 127: 162-166, 1990.
7. Taira, T., Amano, K., Kawamura, H., Tanikawa, T., Kawabatake, H., Iseki, H.,
Nagao, T., Iwata, Y., Umezawa, Y., Shimizu, T., Kawasaki, H., Arai, K. and Shimizu, T.: Experience of biologic brain atlas system. Proceedings of the 7th Japanese Conference of Topographic Electroencephalography, 1-5, 1988.
Intraoperative Measurement of rCBF in Epileptic Foci Using Laser Doppler Flowmetry in 5 Patients with Intractable Posttraumatic Epilepsy Hirotsune Kawamura, M.D., Keiichi Amano, M.D., Tatsuya Tanikawa, M.D., Hiroko Kawabatake, M.D., Hiroshi Iseki, M.D., Yukiya Iwata, M.D., Takaomi Taira, M.D. and Toshihiko Shimizu, M.D. Department of Neurosurgery, Neurological Institute, Tokyo Women’s Medical College, Tokyo Introduction Recently, interest has grown in the potential of single photon emission computerized tomography (SPECT) for the study of brain function in epilepsy.’” SPECT findings in epilepsies have often corresponded to the epileptic focus as defined by the scalp EEG. Decreased-rCBF and inoccurs at the focus interictally’ creased flow at the focus ictally’ ‘. However, these SPECT findings have been variable, with 30-70% of cases showing areas of reduced or increased rCBF. In the present study, we measured the rCBF in the epileptic foci intraoperatively by a laser-doppler flowmetry in 5 patients with medically refractory posttraumtic epilepsy.
’,
Subjects and Methods Of the five patients operated on for in-
549
tractable posttraumatic epilepsy, the relevant clinical, diagnostic, CT and/or MRI findings and EEG data on the all the patients are summarized in Table l. For precise determination of the epileptic focus, electrocorticogram was recorded using newly-devised multielectrodes which can be easily fixed to the surface of the brain cortex only by a surface tension of physical saline dripped on the electrodes and the cortical surface (Fig. l).’ The regional cerebral blood flow (rCBF) was measured by a laser doppler flowmeter (Laserflo Model BPM403, TSI INC) and with a P430-type probe in the epileptic foci, comparing to the value in other areas of the cerebral cortex (Fig. 2 ) . Results The values of the rCBF in each area (in the spike foci, in the necrotic scar, in the gliotic area without spike discharges, and in the normal cortex) in all the 5 cases are summarized in Table 2. The rCBF in the epileptic focus ranged from 40 to 58 ml/ 100 ml/min. The mean value was 52.2 ml/ 100 ml/min. that decreased up to 30% as compared with the mean value of 76.4 ml/ 100 ml/min. in the normal brain cortex. On the other hand, the mean rCBF increased up to 13.4 ml in the epileptic foci rather than in the gliotic area without any epileptic activity. The amount of rCBF in the epileptic foci, however, was not closely related to the epileptic activities on the electrocorticogram (Table 3).
Table 1 : Clinical Summary of 5 Patients with Medically Refractory Posttraumatic Epilepsy Case No.
Name
Age, Sex
1 2 3 4 5
N.N. T.Y.
28 M 31 M 47 F 15 F 43 M
S.H. S.K. T.N.
Seizure Type CPS
PS CPS CPS PS
Localization of Lesions on CT, MRI Lt-parietooccipital Rt-frontal Rt-parietal Lt-parietotemporal Lt-frontal base
Scalp EEG
Interval to Surnerv
SP in Lt-P-Post T SP, SW in Rt-F SP, SW in Rt-P-Post T SP in Lt-F-T SP. SW in Lt-F
10 Y
10 Y 15 Y 8 Y 3v
PS: partial seizure, CPS: complex partial seizure, SP: spike, SW: slow wave, Lt: left, Rt: right, F: frontal, P: parietal, T: temporal, Y : year,
550
Selected Papers: Seizure-Related Phenomena
Discussion
In the Present study, we have shown that the rCBF in the epileptic foci measured intraoPerativelY by a laser doPPler flowmeter in 5 patients with intactable post-
traumatic epilepsy had significantly decreased (30% of nearly normal cortex). These results are supported by the SPECT findings with significantly decreased rCBF in the epileptic foci interictally.' Laser doppier flowmetry is based on the direct detec-
'
Fig. 1: The electrocorticogram is recorded by our special multichannel electrode arranged in the international 10-20 system.
Fig. 2: Actual measurement of the rCBF in the epileptic focus by the P430 probe.
The Japanese Journal of Psychiatry and Neurology, Vol. 46, No. 2, 1992
55 1
Table 2: Microtissue Blood Flow Measured by LASERFLO (m1/100 ml/min) No.
Name
Spike Focus
Necrotic Scar
Gliosis
Nearly Normal
S / N (%)
1 2 3 4 5
N.N. T.Y.
58 40 76 42 45 52.2
3.5 2.8 16.0 5.0 3.2 6.1
21 32 49 36 50 38.8
80 16 86 68 12 76.4
72 * 5% 52.6% 88.4% 61.8% 62.5% 68.3%
S.H. S.K. T.N. Averaged
S/N: spike focus/normal tissue
Table 3: Comparison between the Change of Regional Blood Flow in Epileptic Focus and Its Epileptic Activity on Electrocorticogram Recorded during Surgical Treatment No.
Name
1
N.N.
2 3 4 5
T.Y.
ECoG
Blood Flow in Spike Focus
S.H. S.K. T.N.
58 (ml/l00 ml/min) 40 16 42 45
Spike Area
No. of Spikes/30 Sec
2X3cm
15-25
1x2
5-6 3-4 20-28 -66
1x1 2x3
1x1
ECoG : electrocorticogram
tion of the blood flow which is computed by determining the results of velocity and volume. Therefore, the flowmetry allows to assess the rCBF at a real time and also it can measure the blood flow in the small cerebral cortex4 of approximately 1 mm’. By using the laser doppler flowmetry, we have made it clear that the rCBF in the epileptic focus increases up to 25% of the area adjacent to the epileptic focus as defined by the corticogram. These findings could prove to be beneficial to understand the mechanism of hyperperfusion in the epileptic foci during clinical seizures. References
1. Konishi, T.: Regional cerebral blood flow in epileptic foci using [I-123] IMP-SPECT. Jpn J Psychiatry Neurol 43: 355-360, 1989 (in Japanese). 2. Lee, B.I., Markand, O.N., Wellman, H.N. Siddiqui, A.R., Park, H.M., Mock, B.,
Worth, R.M., Edwards, M.K. and Krepshaw, J.: HIPDM-SPECT in patients with medically intractable complex partial seizures: Ictal study. Arch Neurol 45 397-402, 1988. Magistretti, L., Uren, R.F., Parker, J.A., Royal, H.D., Front, D. and Kolodny, G.M.: Monitoring of regional cerebral blood flow by single photon emission tomography of 1231-N-isopropyl-iodoamphetaminein epileptics. Ann Radio1 26 68-71, 1983. Rosenblim, B.R., Bonner, R.F. and Oldfield, E.H.: Intraoperative measurement of cortical blood flow adjacent to cerebral AVM using laser doppler velocimetry. J Neurosurg 66: 396-399, 1987. Rowe, C.C., Berkovic, S.F., Sia, S.T.,DipApplSci, M.A., Mckay, W.J., Kalnins, P.M. and Bladin, P.F.: Localization of epileptic foci with postictal single photon emission computed tomography. Ann Neurol 126 660-668, 1989. Stefan, H.,Bauer, J., Feistel, H., Schulemann, H., Neubauer, U. Wenzel, B., Wolf,
Selected Papers: Seizure-Related Phenomena
552
F., Neundorfer, B. and Huk, W.J.: Regional cerebral blood flow during focal seizures of temporal and frontal onset. Ann Neurol 127: 162-166, 1990.
7. Taira, T., Amano, K., Kawamura, H., Tanikawa, T., Kawabatake, H., Iseki, H.,
Nagao, T., Iwata, Y., Umezawa, Y., Shimizu, T., Kawasaki, H., Arai, K. and Shimizu, T.: Experience of biologic brain atlas system. Proceedings of the 7th Japanese Conference of Topographic Electroencephalography, 1-5, 1988.
