Several years ago, there appeared in the Journal of the American Medical Association a provocative article with the arresting title, “Brain Fever,” written by Louis Cassamajor.[1] The author is to be commended for his courage in choosing this unusual title, and the Journal to be congratulated for publishing it. Although I welcome the term “brain fever,” I did rub my eyes, because I had not seen it employed for a long time. In my youth the term was used commonly, but was dismissed from my mind when I commenced the study of medicine. It was relegated to the same limbo as the old expression “typhoid malaria.”

In order that I may develop my thesis, a brief review of Cassamajor’s article is in order. The author points out that, in the early part of the past century, considerable literature appeared describing a disease known as “brain fever” (called also “hydrocephalic fever” and sometimes “encephalitis”). For the main part, it occurred in children. The illness subsided after a few days to a couple of weeks, and the patient usually recovered.

The author brings out further that, although the disease was apparently accompanied by fever, there are no recorded temperatures, for the modern clinical thermometer was not invented until 1868. It is emphasized, also, that no neurological signs appeared in the case reports. It was only after the writings of Erb and of Westphal in 1875 that neurological examination, as we now know it, began to develop. For some unknown reason, about 1850 mention of the disease disappeared from medical literature. The author, however, makes the statement: “Undoubtedly the condition does exist today.”

Following a brief historical introduction, the author gives in some detail the case histories of four children, the youngest six and one-half and the oldest eleven years of age, whom he had rather recently diagnosed as suffering from “brain fever.” It is highly gratifying that they all made a complete recovery. The disease is characterized by signs and symptoms indicating a considerable brain involvement, “including convulsions, comas, paralyses, cerebellar asynergy and a sort of bulbar palsy.” The onset is irregular, except when head trauma has been previously sustained, when it may be sudden.

One reason, among others, why this stimulating article especially interested me was that the term “brain fever” called to my mind the immortal stories of Sherlock Holmes. In them several individuals are described as suffering from this condition. It is of nostalgic interest to examine the circumstances which surrounded these victims when they were stricken.

We find in one of the stories that a housemaid, with an unstable Celtic temperament, “had a sharp touch of brain fever.” She had had a violent love affair with a handsome but perfidious butler, who had thrown her over for another girl. Following her partial recovery, she had taken a terrible vengeance and was directly responsible for her faithless lover’s death. When questioned about him by the master of the household, she became hysterical and unmanageable: “For two days [she] had been so ill, sometimes delirious, sometimes hysterical...” (The Musgrave Ritual). She evidently made a rapid recovery, for on the third night she disappeared and her whereabouts were never discovered.

In another story, a young girl whose mother had died was treated cruelly by her father, who had remarried. She had an income of her own which she generously allowed her father to use. When she fell in love with a young man, her father tried desperately to make her sign a contract providing that, in the event of marriage, he could still use her money. This she refused to do. He placed her in solitary confinement so that she could not see her lover, and treated her inhumanly in other ways: “... he kept on worrying her until she got brain fever, and for several weeks was at death’s door” (The Adventure of the Copper Beeches). It is pleasant to relate that she recovered and succeeded in eloping with her lover and presumably lived happily ever after.

In still another story, in which Sherlock Holmes attempted to gain an audience with a middle-aged spinster, he was informed that she was too ill to be interviewed. Her doctor said: “She has been suffering since yesterday from brain symptoms of great severity. As her medical adviser, I cannot possibly take the responsibility of allowing anyone to see her. I should recommend you to call again in ten days” (The Adventure of the Cardboard Box). This illness, somewhat later in the story, is referred to specifically as “brain fever.”

The illness had developed when this spinster heard that conscientious diplomat. Through his own carelessness, how-her younger sister had been foully murdered by her husband. It was the spinster who, by wicked machinations, had been largely responsible for her sister’s death. It is noteworthy that Holmes was advised to come back ten days later. This indicates that the disease was not of long duration.

One of Dr. Watson’s former schoolfellows, Percy Phelps, wrote him, “I have only just recovered from nine weeks of brain fever and am still exceedingly weak.” In his letter, he further informed Dr. Watson that he wished to consult with Sherlock Holmes, and asked his friend to bring him, since he was in deep trouble. This able young man was an earnest and ever, he had lost an important state document. In narrating his story to Sherlock Holmes and Dr. Watson, the patient gave a vivid description of his distressing illness: “Here I have lain, Mr. Holmes, for over nine weeks, unconscious, and raving with brain fever ... in my mad fits I was capable of anything. Slowly my reason has cleared, but it is only during the last three days that my memory has quite returned” (The Naval Treaty).

This poor fellow had an illness of long duration and, according to the story, his strength came back but slowly. It will be recalled that Sherlock Holmes solved the mystery and was able to place the important state document again in the patient’s hands. As far as we know, he eventually made a complete recovery in spite of the severity of the attack.

In The Hound of the Baskervilles, it will be remembered that the heir, Sir Henry Baskerville, narrowly escaped death on the moor. The shock of the adventure with the hound, coupled with the fact that the woman with whom the heir was in love was actually the wife of the villainous Stapleton, his would-be murderer, was too much for our hero. Watson writes: “But the shock of the night’s adventure had shattered his nerves, and before morning he lay delirious in a high fever under the care of Dr. Mortimer. The two of them were destined to travel together round the world before Sir Henry had become once more the hale, hearty man that he had been before he became master of that ill-omened estate.”

In this last instance, Watson does not specifically state that the patient was afflicted with “brain fever,” but the implication is plainly there. It is, moreover, worthy of note that it took the victim a long time to regain his health.

The individuals whom Dr. Watson described as suffering from “brain fever” obviously had all passed through a terrific mental storm—in modern parlance, they had sustained “severe psychic traumata.” Whether this alone could cause “brain fever” is a moot question. The condition presumably is caused by a virus. That a severe brain storm could cause the lurking virus to become active seems unlikely.

Previously it has been mentioned that a head injury apparently is capable of hastening the onset of brain fever in children. (We will waive the fact that the cases Dr. Watson described are adults.) A physical injury presumably produces certain organic changes in the brain or in its meninges, which perhaps could precipitate an attack of encephalitis, assuming that the virus was present. There is no particular evidence that the patients mentioned in the tales had suffered a head injury.

It is true, of course, that great emotional upsets are often accompanied by marked vascular disturbances. These may manifest themselves in the brain as well as in other parts of the body. It is not conceivable that encephalitis would follow an emotional storm. Be that as it may, this can be said: It is generally agreed that anything which lowers the resistance of an individual may make him more susceptible to disease. In the cases described by Dr. Watson, the virus may have been present, and the shock produced by the emotional storm, which all these people experienced, might have precipitated an attack of encephalitis (brain fever).

If this seems too farfetched, and the reader cannot go along with me, I can say only that I am sorry. I will have to use the argument that one should allow a talented and imaginative writer like Dr. Watson a liberal degree of poetic license.

Dr. Watson may have used the term “brain fever” loosely, and perhaps as synonymous with extreme nervous exhaustion. He does, however, mention that some of the sufferers became delirious. This symptom is suggestive of encephalitis. Also, in one or two instances the victim recovered rather quickly, which points to an acute condition such as encephalitis rather than nervous exhaustion. I am cognizant that some may regard this as a specious argument.

The question could be raised whether the patients described by Dr. Watson suffered from hysteria. This condition cannot entirely be ruled out. Hysteria has protean manifestations, and may even be accompanied by fever. The great mental storms through which these patients passed are conducive to hysterical attacks. The fact, however, that these individuals ran a high fever and were dangerously ill would militate against a diagnosis of hysteria. It seems fairly safe to assume that the disease from which they suffered probably had an organic basis.

The reader should be reminded that Dr. Watson began the study of medicine only a short time after the researches of Erb and of Westphal on the nervous system had been published. Neurology had not yet come into its own, and it is likely that the medical profession did not make fine distinctions when dealing with diseases of the brain or its meninges. It probably is not charitable for me to suggest that the professors who taught the young Watson about nervous diseases in the year 1876 or thereabouts had not kept up with the literature in their field—a fault of which we are all more or less guilty.

Dr. Watson has been taken to task by some critics in the medical profession for using the term “brain fever,” and the implication has been made that his employment of a meaningless term was unworthy of a medically trained man. Now it appears that this criticism is unjustified. We might quarrel with Dr. Watson as to what brought on the attacks of “brain fever,” or whether the victims actually had the disease in the cases he so vividly described, but the term itself is acceptable.

The Holmesian enthusiast will rejoice that the term “brain fever” is again in good repute and is accepted by the medical fraternity. The very fact that the staid Journal of the American Medical Association has published an article bearing the title “Brain Fever” has stripped criticism of all weapons. The loyal Holmesian no longer needs to feel apologetic for the nomenclature Dr. Watson used to describe a rather unusual and fortunately rare clinical entity.