by Marie de Manacéïne

Below is the English translation of a seminal paper by Marie de Manacéïne, dated 1880. The original writing, in French, appeared as “Quelques observations sur l’influence de l’insomnie absolue. Arch. ital. de Biol., p. 322, 1894, aussi Congrès de Rome, vol II, p 174” and it is available here as PDF. A biography of Marie de Manacéïne can be found here. Translation by Giorgio Gilestro.

While observations on normal (2) and artificial sleep are becoming increasingly numerous, absolute insomnia or complete sleep deprivation has not yet been the subject of experimental research. However, to fully understand the role of sleep in organic life, it would also be necessary to know the influence of complete sleep deprivation. It is known that in China and in antiquity, among the different types of torture, there was death caused by sleep deprivation, that is to say, the condemned was kept from sleeping and was awakened each time he began to fall asleep. Facts of this kind clearly demonstrate that sleep deprivation produces one of the most harmful influences.

On the other hand, observations collected in clinics and in private medical practice have shown that most patients suffering from insomnia do not present a total lack of sleep, but that they only have very fleeting and short sleep (Hammond), and that this insufficient sleep is already capable of seriously disturbing the general health of people who are subject to it. Dr. Renaudin (3) observed that this partial insomnia is already sufficient to cause the development of more or less serious disorders of psychic life. Complete or absolute insomnia is extremely rare, and according to the observations of Prof. Hammond (4), it quickly ends in death; in fact, in an experiment where he observed absolute insomnia for 9 days, death occurred precisely during the 9th day.

All these facts demonstrate how important the experimental study of the influence of a complete lack of sleep must be, and this is what decided me to attempt an experimental study of absolute insomnia. My experiments were conducted on young dogs aged two, three and four months. All these dogs were still mainly feeding on their mother’s milk, and this circumstance was very useful for experiments of this nature, as the presence of their mother was much more effective than all other manipulations in keeping them awake. The number of these experiments was very limited, as they are extremely painful for the experimenter; indeed, he must constantly pay the utmost attention to the animals, which have a tendency to fall asleep at any moment and even in the most uncomfortable positions. I experimented only on ten young dogs; but, as the results obtained were absolutely identical in all cases, I thought that these experiments could suffice and that it was unnecessary to make more of these poor beasts perish.

The experiments carried out on young dogs have shown that the complete absence of sleep is much more fatal for animals than the absolute absence of food. One can hope to save animals that have undergone complete starvation for 20-25 days and even for a longer time, one can save them even after they have lost more than 50% of their weight, while in cases of absolute insomnia the animals were irreparably lost, even after sleep deprivation of 120 to 96 hours. No matter how much they were warmed up and artificially fed all the time and given the full possibility to sleep comfortably – they would still die. Out of ten dogs, I left four without sleep until death, while for the other six I tried to save them after insomnia of 120-96 hours. The first four dogs died after complete sleep deprivation for 92 to 143 hours. Older dogs endured the lack of sleep longer than younger dogs, – which is quite natural, because everyone knows that the younger an organism is, the more it needs sleep. The temperature of young dogs deprived of sleep begins to drop in the second 24 hours of insomnia, where it shows a decrease of 0.5 to 0.9 C; then the decrease becomes more and more rapid, and towards the final hours of life, the animals’ temperature is already 4° to 5° and even 5.8°C below normal. With the first drops in temperature, we notice very pronounced changes in reflex movements, which become slower and weaker and, at the same time, show a certain periodicity, appearing more or less absent, sometimes on one side of the body, sometimes on the other. The reaction of the pupils to light and darkness shows the same changes and the same periodicity as other reflex muscle movements. We sometimes notice, in sleep-deprived dogs, a pronounced inequality of the pupils. The number of red blood cells shows marked changes: after 48, 55, 96 and 110 hours of insomnia, the number of red blood cells was found to be reduced from 5,000,000 to 3,000,000 and even to 2,000,000 in a cubic millimeter.

Towards the end of life, that is, during the last 24 or 36 hours, we observe an apparent increase in red blood cells and hemoglobin; but this apparent increase depends on the fact that the animals refuse to eat or drink during the last 48 hours, and as their kidneys continue to function, they lose more and more water, and consequently the liquids in their body become increasingly concentrated. At the same time, we notice in the blood an increasingly pronounced hardening of the white blood cells, which depends on an arrest of these cells in the lymphatic pathways, as was verified during autopsies.

The histological examination of different organs of dogs that died from absolute insomnia demonstrated to me, in the most evident way, that the brain had undergone the greatest changes: a quantity of ganglia were in a state of fatty degeneration, the cerebral blood vessels were very often surrounded by a thick layer of white blood cells; one was tempted to say that the perivascular channels were filled with white blood cells, and in certain places, the blood vessels appeared as if compressed. Small capillary hemorrhages were encountered on the entire surface of the gray matter of the hemispheres, and larger hemorrhages around the optic nerves and in the substance of the optic lobes. The spinal cord appeared abnormally dry and anemic. The cardiac muscle was pale, the coronary vessels were filled with blood and contained, in most of these dogs, gas bubbles, which were also found in the large veins of the neck and in some cerebral vessels. The cardiac muscle fibers showed a finely granular degeneration. The spleen was in a state of hyperemia and appeared increased in volume, but I cannot prove it, as I did not make exact measurements. Another gap that I have left is that I did not observe the changes in the weight of different organs in dogs that died from insomnia.

I determined the weight of the dogs at the beginning of the experiment, then after their death; and in all cases, without exception, there was a weight loss, but it was not large and varied from 5% to 13%. As, in my life, I have been obliged to take part in experiments on starvation in different animals, I know very well the picture that animals that died of hunger present at autopsy; I know that the most surprising phenomenon in these animals is precisely the state of conservation of the brain, which loses the least of its weight and which preserves its normal state almost up to the moment of starvation where all the other organs and tissues of the body have already undergone profound changes and a more or less great loss of their weight. In animals that died of insomnia, on the contrary, we observe a diametrically opposed state, that is to say that, in them, the brain appears to be the site of predilection for the most profound and irreparable changes.

If my health permitted, I would very much like to undertake another series of experiments on the influence of insomnia on adult dogs and other animals; I would also try to obtain more exact data concerning the weight loss in relation to the different organs of the animal body.

But, however incomplete my experiments on absolute insomnia may be, they nevertheless provide us with conclusive proof of the profound importance of sleep for the organic life of animals with a cerebral system, and they also give us the right to consider as somewhat paradoxical, and even quite unfounded, the strange opinion that regards sleep as a useless, stupid and even harmful habit, as Girondeau does (5).

1. As communicated at the International Medical Conference in Rome, 1894
2. Marie De Manaceine, Sleep as one third of one’s lifetime, 1892 (Russian) Note: this book was later translated to English and became an absolute reference for Sleep science in the early 1900s. A digitised PDF copy can be found here.
3. Renaudin, Observations on the pathological effects of insomnia (Annales medico-psychologiques, 1857)
4. Hammond. On Sleep. Gaillard’s Medical Journal, 1880 and Journal of Psychological medicine 1870
5. Girondeau. On brain circulation and its relationship with sleep. Paris 1868