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The effect of arousal mechanisms on various forms of abnormality in the electroencephalogram

1952; Elsevier BV; Volume: 4; Issue: 4 Linguagem: Inglês

10.1016/0013-4694(52)90084-9

1872-6380

Choh‐Luh Li, Herbert H. Jasper, Luke A. Henderson,

Functional Brain Connectivity Studies

1. The effect of arousal mechanisms upon various forms of EEG abnormality was studied in 59 cases, which included: (a) petit mal epilepsy, (b) seizures following diffuse encephalopathy with involvement of subcortical structures, (c) coma, (d) encephalities, (e) narcolepsy, (f) lesions in the diencephalon or brain stem, (g) lesions of cerebral cortex with localized slow waves, sharp wave and spike discharges, and (h) lesions involving both cortical and subcortical structures. 2. In general it seems that stimuli or mental activities which arouse mental alertness may have different effects upon the electrical activity of the cortex, depending upon the cortical excitatory state existing at the time of the stimulation. Thus, the effect of arousal is not always that of desynchronization; under some conditions the opposite effect (or synchronization) may be produced. 3. From a clinical point of view destructive or discharging lesions producing epileptiform activity are most commonly affected by arousal when they involve the diencephalon or brain stem; but when the lesions or focal discharge was clearly of cortical origin the abnormality tends to continue relatively independent of the arousal stimuli. There are, however, exceptions to this rule. 4. The study of arousal responses is of value in the understanding of electroencephalographic abnormalities.