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The Electroencephalographic Study on Adult‐Type Lennox‐Gastaut Syndrome
Author(s) -
Higano Harufusa,
Ohtaka Tadashi
Publication year - 1976
Publication title -
psychiatry and clinical neurosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.609
H-Index - 74
eISSN - 1440-1819
pISSN - 1323-1316
DOI - 10.1111/j.1440-1819.1976.tb02268.x
Subject(s) - tonic (physiology) , rhythm , lennox–gastaut syndrome , electroencephalography , psychology , seizure types , anesthesia , audiology , medicine , neuroscience
SUMMARY Polygraphic recordings were performed 22 times during a period of about two years on a 25–year‐old man with the Lennox‐Gastaut syndrome of the adult type. He had several generalized convulsions initially when he was eight years old, and had the Lennox‐Gastaut syndrome since the age of 17 years. The paroxysmal fast rhythm shown 214 times in the recordings, which appeared only in the light stage of sleep, was analyzed. The pattern of the paroxysms, and the relationship between the pattern and the clinical seizures was studied. The paroxysms were composed of a series of spikes and slow spike and wave. They appeared diffuse and bilaterally synchronous. And so, we classified these paroxysms into four types, A through D, from the differences of basic activity before appearance of the paroxysms, amplitude, frequency and fluctuation of amplitude and frequency. Consequently D type was thought to be different from the other types on the ground of elec‐trophysiological viewpoint. But types A through C were clinicoencephalographically the same type of the pattern in spite of the differences in frequency, fluctuation of that and duration of the discharge. All of the clinical seizures which appeared with these paroxysmal fast rhythms was local tonic spasm in the lip. But D type never failed to associate with local tonic spasms and usually developed generalized tonic seizure. Except for D type, it was shown obviously that the same local tonic spasm appeared when the duration of the paroxysm was longer than 4.9 sec. We proposed the paroxysmal fast rhythm of a name “tonic seizure discharge” on the basis of the findings on this patient.