Folia Psychiatrica et Neurologica Japonica, Vol. 32, No. 3, 1978
EEG Activation by Ophthalmic Stimulation of the Epileptic Foci in the Frontal and Occipital Lobes Takeo Takahashi, M.D. Department of Neuropsychiatry, Tohoku University School of Medicine, Sendai
EEG activation by ophthalmic stimulation (ophthalmic activation) consists of visuo-sensory activation (VSA) and oculomotor activation (OMA). Using a visual stimulator', VSA was carried out. As a routine method, visual stimuli of paterns of a dot and crosshatched, flickering-pattern (crosshatched) and red-flicker of 15 Hz and 20cd/m2 were used. The stimuli were given for seven seconds each. When the generalized paroxysmal discharges were induced by red-flicker without apparent focal origin, a repeat examination with redflicker of 10 cd/m2 and of 5 cd/m2, if necessary, was made. OMA was carried out with the subject sitting in a dark room. They were instructed to close and open their eyes (five seconds each), and move their eyeballs upward, forward, downward, forward, rightward, forward, leftward and forward (five seconds each). The eye opening and closing and eye movements were repeated three times. Paroxysmal discharges were induced by ophthalmic activation in a total of 189 cases. Among them, 79 cases (first group) were induced by VSA, 55 cases (second group) by OMA, and another 55 cases (third group) by both VSA and OMA. Among the 79 cases of the first group, there were epilepsy (60), sequelae of head trauma ( 5 ) , mental retardation (3), breath holding spells ( 1 1, schizophrenia ( 1 ) , atypi-
Received for publication Apr. 30, 1978.
cal psychosis ( 1), hereditary tremor ( 11, cerebellar ataxia ( 1 ) , primary hypothyroidism ( 1), pubertas praecox ( 1) and normal healthy children (4). On the other hand, the cases in the second and third groups were all epileptics. Paroxysmal discharges induced by ophthalmic activation were focal (F-type) and generalized. Generalized paroxysmal discharges (GPDs) were further classified into the following three groups; posterior type (P-type: GPD was preceded by posterior spikes), generalized type (G-type: simultaneous occurrence of GPD over all the areas) and anterior type (A-type: GPD was preceded by anterior spike). The types of paroxysmal discharges induced by redflicker in 115 cases were P-type (64%), A-type (14%), G-type (13%), and posterior F-type (10%). Those induced by pattern and/or flickering-pattern in 97 cases were only P-type (92%) and posterior Ftype (7%). On the other hand, those induced by OMA were A-type (67%), P-type (14%), posterior F-type ( l l % ) , anterior F-type ( 9 % ) , and G-type (2%). Such an analysis in each of the three groups showed similar findings. These results are considered to be suggestive of the following: red-flicker tended to activate the epileptic foci in the occipital lobe and next in the so-called centrencephaIon; pattern and/or flickering-pattern was of the occipital lobe; OMA was of the frontal lobe and next of the occipital lobe. A com-
348
T. Takahashi
parison with the results of GPSs induced by ophthalmic activation in 30 cases: and discussion with regard to the above results were made. As the author has previously emphasized, ophthalmic activation is not only superior to simply making the subjects open and close their eyes and giving intermittent photic stimulation, but also the above results are very important from the view point of
treating the epileptic patients.$
REFERENCES 1 Electroenceph Clin Neurophysiol, 35: 333, 1973. Tohoku Exp Med, 115: 1, 1975. 3 Clin Pgychiat, 18: 720, 1976 (in Japanese).
EEG Activation by Ophthalmic Stimulation of the Epileptic Foci in the Frontal and Occipital Lobes Takeo Takahashi, M.D. Department of Neuropsychiatry, Tohoku University School of Medicine, Sendai
EEG activation by ophthalmic stimulation (ophthalmic activation) consists of visuo-sensory activation (VSA) and oculomotor activation (OMA). Using a visual stimulator', VSA was carried out. As a routine method, visual stimuli of paterns of a dot and crosshatched, flickering-pattern (crosshatched) and red-flicker of 15 Hz and 20cd/m2 were used. The stimuli were given for seven seconds each. When the generalized paroxysmal discharges were induced by red-flicker without apparent focal origin, a repeat examination with redflicker of 10 cd/m2 and of 5 cd/m2, if necessary, was made. OMA was carried out with the subject sitting in a dark room. They were instructed to close and open their eyes (five seconds each), and move their eyeballs upward, forward, downward, forward, rightward, forward, leftward and forward (five seconds each). The eye opening and closing and eye movements were repeated three times. Paroxysmal discharges were induced by ophthalmic activation in a total of 189 cases. Among them, 79 cases (first group) were induced by VSA, 55 cases (second group) by OMA, and another 55 cases (third group) by both VSA and OMA. Among the 79 cases of the first group, there were epilepsy (60), sequelae of head trauma ( 5 ) , mental retardation (3), breath holding spells ( 1 1, schizophrenia ( 1 ) , atypi-
Received for publication Apr. 30, 1978.
cal psychosis ( 1), hereditary tremor ( 11, cerebellar ataxia ( 1 ) , primary hypothyroidism ( 1), pubertas praecox ( 1) and normal healthy children (4). On the other hand, the cases in the second and third groups were all epileptics. Paroxysmal discharges induced by ophthalmic activation were focal (F-type) and generalized. Generalized paroxysmal discharges (GPDs) were further classified into the following three groups; posterior type (P-type: GPD was preceded by posterior spikes), generalized type (G-type: simultaneous occurrence of GPD over all the areas) and anterior type (A-type: GPD was preceded by anterior spike). The types of paroxysmal discharges induced by redflicker in 115 cases were P-type (64%), A-type (14%), G-type (13%), and posterior F-type (10%). Those induced by pattern and/or flickering-pattern in 97 cases were only P-type (92%) and posterior Ftype (7%). On the other hand, those induced by OMA were A-type (67%), P-type (14%), posterior F-type ( l l % ) , anterior F-type ( 9 % ) , and G-type (2%). Such an analysis in each of the three groups showed similar findings. These results are considered to be suggestive of the following: red-flicker tended to activate the epileptic foci in the occipital lobe and next in the so-called centrencephaIon; pattern and/or flickering-pattern was of the occipital lobe; OMA was of the frontal lobe and next of the occipital lobe. A com-
348
T. Takahashi
parison with the results of GPSs induced by ophthalmic activation in 30 cases: and discussion with regard to the above results were made. As the author has previously emphasized, ophthalmic activation is not only superior to simply making the subjects open and close their eyes and giving intermittent photic stimulation, but also the above results are very important from the view point of
treating the epileptic patients.$
REFERENCES 1 Electroenceph Clin Neurophysiol, 35: 333, 1973. Tohoku Exp Med, 115: 1, 1975. 3 Clin Pgychiat, 18: 720, 1976 (in Japanese).
