Neurophysiologie clinique = Clinical neurophysiology
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The retrospective electroclinical evaluation of anoxia by near-drowning in 23 children observed between 1985 and 1989 revealed 2 groups, each with a distinct evolution: the first group, with good prognosis of 17 children, which recovered consciousness without neurological complications between 2 d and 1 wk after the accident. The second group of 6 children with a poor outcome--either i), death; or ii), state of permanent injury; or iii), a high level of clinical deficits. The gravity of the early clinical state, the estimated duration of cardiorespiratory arrest, the severity of the hypothermia, the seizures and the paroxysmic activity, do not determine the severity of near-drowning encephalopathy. ⋯ A bad outcome was defined by: high voltage, rhythmic delta waves; biphasic sharp waves; monotonous EEG, "burst-suppression" pattern, absence of beta rhythms. The importance of EEG recordings is emphasized performed as early as possible and until 3 or 7 d after the near-drowning. Any modification in the EEG, with attenuation or disappearance of fast frequencies and painful reactivity, appearance or enhancement of slow and biphasic sharp waves, are ominous signs and may be accompanied by the appearance of cerebral oedema and decerebration.
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In the first part of this report a methodology is described which allows an objective and specific exploration of experimental pain in man by using some electrophysiological features of cutaneous reflexes. This method can be summarized as follows: in normal and trained volunteers, we studied simultaneously the recruitment curves of the nociceptive flexion reflex of a knee-flexor muscle (biceps femoris muscle) and that of pain sensation elicited by electrical stimulation of the ipsilateral sural nerve at the ankle. In this procedure, we found that the reflex threshold (Tr) was closely related to that of pain threshold (Tp) around a similar value (10 mA). ⋯ On the other hand, data also show that the spinal level is one of the main important sites of the mechanisms of morphine-induced analgesia since this drug is found to strongly depress selectively the nociceptive transmission directly at the spinal level. Finally, this method is applied for investigating the nociceptive reactions in patients affected either with a pathological lack of pain sensation or, by contrast, in patients complaining of acute or chronic pain from various origins. Since the nociceptive flexion reflex can be considered as a specific and objective physiological correlate of a pain sensation, it can be successfully employed as a useful tool for investigating some aspects of the human nociceptive reactions in both experimental and pathological situations.