Spike-Dome Complex in the Human Electroencephalogram

Abstract

THE SPIKE-DOME complex is a primary electric correlate of the clinical convulsive disorders. Because of its clinical importance, its striking contour, and its remarkable paroxysmal quality, the spike-dome discharge has been extensively studied in man* and, as far as is applicable, in experimental animals.1 This communication treats of the physical characteristics and the time relations of these complexes as derived from the intact scalp of man. Many complexes were recorded by relatively high-speed photography of cathode ray traces, obtained through conventional (A.C.) amplification in order to obtain sufficient resolution of the complexes to allow time measurements within 2 msec. Other complexes were recorded by low-speed direct-writing oscillographs with direct-coupled (D.C.) amplifiers. METHODRecordings were taken from more than 100 patients with various types of clinical epilepsy for the purposes of this investigation; these subjects ranged from 4\ m=1/ 2\ to 29 years of age. The sex distribution was predominantly female. In all A. C., and in some D. C., recordings the electrodes consisted of solder disks with a bentonite-Cambridge conducting paste. The electrodes were fixed to the head with collodion. For some of the D. C. recordings calomel (mild mercurous chloride U. S. P.) electrodes were also used. The calomel electrodes were modifications of those described by Bishop and his associates.! From the intact scalp it was observed that the D. C. tracings derived through the two types of electrodes were identical in all measured char¬ acteristics ; consequently, in the excerpts of the D. C. recordings the electrode type is not usually designated. For the A. C. records, Grass (Fig. 1) and Offner (all other Figures) amplifiers were used ; the direct-current recordings were made with the Offner Type 142 D. C. amplifier operating into the Offner dynograph.All cathode ray pictures were obtained from Electronic Tube Corporation multiple gun oscilloscopes. The A. C. amplifiers, except those used for Figure 1, were operated essentially flat between /2 and 10,000 cps. For Figure 1 the amplifiers were flat between 2 and 2,300 cps.The majority of the cathode ray oscillograph tracings were recorded on continuous moving film, at the rate of 25 to 50 cm. per second (Fairchild-DuMont Camera Type 314). These speeds gave resolutions of 8 to 20 times that ordinarily used in clinical recordings. RESULTSThe spike component of the full complex ranged between 40 and 70 msec, in duration ; the slow-wave component ranged between 250 and 290 msec. Individual spikes, although maintaining a general similarity in contour, showed, when they were From the United States

A Newly Described Ictal Pattern: The Initial Ictal Slow Shift

“…One other difference is that our records showed a prominent positivity after the end of the S+W complexes, up to 600μV lasting for up to 5 sec, and Chatrian et al 10 reported that they did not find the shifts after the end of the complexes. On the other hand, Cohn 11 showed a similar positive shift after the end of the S+W complexes that continued for 5–6 sec, just as we described. The former author speculated that this shift may have been a psychogalvanic sweat potential, appearing to us as unlikely.…”

A Newly Described Ictal Pattern: The Initial Ictal Slow Shift

“…One other difference is that our records showed a prominent positivity after the end of the S+W complexes, up to 600μV lasting for up to 5 sec, and Chatrian et al 10 reported that they did not find the shifts after the end of the complexes. On the other hand, Cohn 11 showed a similar positive shift after the end of the S+W complexes that continued for 5–6 sec, just as we described. The former author speculated that this shift may have been a psychogalvanic sweat potential, appearing to us as unlikely.…”

DC Changes recorded Transcranially during “Typical” Three per Second Spike and Wave Discharges in Man

“…Our findings confirm the occurrence in man of enduring shifts in potential accompanying the manifestation of bisynchronous typical 3/sec spike and wave complexes in the EEG, which has been known since the early work of Cohn (8). The notion of negative DC shifts associated with spike and wave activity was challenged by Bates ( I ) who contended that this type of discharge represents "a unidirectional vertex-negative disturbance without significant shift of the baseline, save possibly that there is a slight shift toward negativity of the baseline at the beginning of some attacks".…”

Commentary: The Epilepsy Diathesis

“…The term “generalized” was based on ink‐written EEG tracings with limited time resolution and channel capacity. It was shown early on, however, that in absence seizures, the hallmark of “generalized” seizures and “generalized epilepsy,” latencies of the discharges in the millisecond range can occur between the two hemispheres, and that a spread across the cortex can be demonstrated (Cohn, 1954; Petsche, 1962). These findings have been subsequently confirmed with digital technology (Rodin & Ancheta, 1987; Rodin, 1999; Holmes et al., 2004).…”

A Newly Described Ictal Pattern: The Initial Ictal Slow Shift

“…One other difference is that our records showed a prominent positivity after the end of the S+W complexes, up to 600μV lasting for up to 5 sec, and Chatrian et al 10 reported that they did not find the shifts after the end of the complexes. On the other hand, Cohn 11 showed a similar positive shift after the end of the S+W complexes that continued for 5–6 sec, just as we described. The former author speculated that this shift may have been a psychogalvanic sweat potential, appearing to us as unlikely.…”

DC Changes recorded Transcranially during “Typical” Three per Second Spike and Wave Discharges in Man

“…Our findings confirm the occurrence in man of enduring shifts in potential accompanying the manifestation of bisynchronous typical 3/sec spike and wave complexes in the EEG, which has been known since the early work of Cohn (8). The notion of negative DC shifts associated with spike and wave activity was challenged by Bates ( I ) who contended that this type of discharge represents "a unidirectional vertex-negative disturbance without significant shift of the baseline, save possibly that there is a slight shift toward negativity of the baseline at the beginning of some attacks".…”

Commentary: The Epilepsy Diathesis

“…The term “generalized” was based on ink‐written EEG tracings with limited time resolution and channel capacity. It was shown early on, however, that in absence seizures, the hallmark of “generalized” seizures and “generalized epilepsy,” latencies of the discharges in the millisecond range can occur between the two hemispheres, and that a spread across the cortex can be demonstrated (Cohn, 1954; Petsche, 1962). These findings have been subsequently confirmed with digital technology (Rodin & Ancheta, 1987; Rodin, 1999; Holmes et al., 2004).…”

A Newly Described Ictal Pattern: The Initial Ictal Slow Shift

“…One other difference is that our records showed a prominent positivity after the end of the S+W complexes, up to 600μV lasting for up to 5 sec, and Chatrian et al 10 reported that they did not find the shifts after the end of the complexes. On the other hand, Cohn 11 showed a similar positive shift after the end of the S+W complexes that continued for 5–6 sec, just as we described. The former author speculated that this shift may have been a psychogalvanic sweat potential, appearing to us as unlikely.…”

DC Changes recorded Transcranially during “Typical” Three per Second Spike and Wave Discharges in Man

“…Our findings confirm the occurrence in man of enduring shifts in potential accompanying the manifestation of bisynchronous typical 3/sec spike and wave complexes in the EEG, which has been known since the early work of Cohn (8). The notion of negative DC shifts associated with spike and wave activity was challenged by Bates ( I ) who contended that this type of discharge represents "a unidirectional vertex-negative disturbance without significant shift of the baseline, save possibly that there is a slight shift toward negativity of the baseline at the beginning of some attacks".…”

Commentary: The Epilepsy Diathesis

“…The term “generalized” was based on ink‐written EEG tracings with limited time resolution and channel capacity. It was shown early on, however, that in absence seizures, the hallmark of “generalized” seizures and “generalized epilepsy,” latencies of the discharges in the millisecond range can occur between the two hemispheres, and that a spread across the cortex can be demonstrated (Cohn, 1954; Petsche, 1962). These findings have been subsequently confirmed with digital technology (Rodin & Ancheta, 1987; Rodin, 1999; Holmes et al., 2004).…”