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15 mars 2009
Proceedings of the Royal Society of Medicine
Discussion on faints and fits
Charles Symonds
2 february 1950


This has been a digression from the main theme of our discussion. Vaso-vagal attacks are not faints, nor are they in any ordinary sense fits, but the observations which I have put forward support Kinnier Wilson's argument that they may be epileptic.
Perhaps the most important distinction between faint and fit is the setting of the attack. Faints very rarely occur except in the erect posture. If an attack occurs after long unaccustomed standing, or as the result of sudden emotion or pain, in a hot and stuffy atmosphere, or aftet loss of blood, it may be presumed to be a faint unless there is evidence to the contrary. If it occurs without any of these causes it is probably a fit. Yet again, however, the distinction is imperfect. Epileptic attacks may be precipitated by various causes of which emotion is one. The malaise of infection may be another. In the following case both precipitants were evident.
The patient was a man of 61, whom I saw for an entirely different complaint, and the details which follow were obtained from his past history. He had as he said "fainted" on many occasions. The first was in his teens when he was taken to the doctor with influenza, the second at 19 after a cycle accident. He was not injured, but very much upset, and lost his senses suddenly fifteen minutes later. The next occasion was a year afterwards when he went to have a tooth out, and, feeling, as he said, in a blue funk, lost his senses and fell before getting into the dentist's chair. In this attack he passed urine. There was a similar episode at the dentist's a year later. Again he passed water. There were no more attacks precipitated by emotion, but on about a dozen occasions he had fainted at the onset of a febrile illness, influenza or bronchitis. The sequence was always the same. He would begin to yawn and continue yawning for ten to twenty minutes. If he could keep walking about this might end without further incident, but if he gave way and sat down his vision would suddenly become grey and he would lose his senses for a minute. In almost all these attacks he passed urine.
These attacks, I believe, were epileptic for two reasons. The first is the occurrence of involuntary micturition in nearly all the attacks. This may occur in a faint if the bladder happens to be full at the time, but its regular occurrence always suggests an epileptic discharge involving the centres for micturition. The second reason is the prodromal yawning, recognized by Gowers (1901) and again by Kinnier Wilson (1928) as a precursor of epileptic attacks. I have several examples of this in my own notes of undoubted epileptics.
There is next to be considered a rare but important group of patients who begin by having attacks in childhood or adolescence which we diagnose confidently as faints, but who go on to have attacks which we are sure, are epileptic. The earlier attacks have the usual causes for a faint, but the liability appears èxcessive, the attacks are more frequent than usual and continue to a later age and when they have continued long enough we are not altogether surprised when we are confronted 'With the story of an attack this time without cause and characteristic of epilepsy. In these cases then we observe excessive liability to fainting followed by an excessive liability to epilepsy. The word excessive may be equally applied to both. Anyone may faint or have a fit with sufficient cause. Why do some persons have faints or fits with so little cause or no apparent cause? The answer in the case of the epileptic is that there are nervous centres which are unstable. This is the trigger mechanism for the attack. Of the causes that operate to pull the trigger we know very little. In the case of the fainter on the other hand we know a good deal about the causes that pull the trigger, and we know that when the trigger is pulled there is bradycardia or fall of blood pressure to explain the symptoms that follow. But where is the trigger itself? Probably in the central nervous system. Fainting in response to emotion clearly suggests this localization. Again in a faint which results from prolonged or unaccustomed standing what is it that gives, way? Surely the reflex mechanisms responsible for maintenance of heart-rate and blood pressure, and where are these except in the central nervous system? In the syndrome of postural hypotension, which provides the extreme example of postural fainting, there is a good deal of evidence for the existence of a trigger mechanism at or near the hypothalamus (East and Brigden, 1946). It seems probable, therefore, that for faints as well as fits an essential link in the chain of causation is an unstable nervous mechanism. If this be so it would not be surprising if we sometimes found both kinds of instability present in the same person. Nor I think would it be surprising to find that with the passage of time the instability responsible for fainting became less and that responsible for epilepsy greater. This kind of thing sometimes happens in persons who have migraine in their youth and as they grow older exchange it for epilepsy.
The carotid sinus syndrome is also of interest in relation to the occurrence of faints and fits in the same person. In this malady pressure upon the sinus, according to Ferris and others (1935), may produce faints, with bradycardia or fall of blood pressure sufficiently abrupt to cause loss of consciousness and sometimes convulsions: or it may cause these symptoms without any adequate cardiovascular derangement to explain them. Thus it would appear that the specific stimulus in this syndrome may produce either reflex fainting or reflex epilepsy.
The general trend of these remarks has been towards the conclusions, first, that there is no absolute means of distinguishing between a fit and a faint unless the attack can be observed in detail with estimations of pulse-rate and blood pressure before and during the episode, and second, that even though fits and faints may be clinically distinguishable they are closely related in their dependence upon the instability of nervous mechanisms.