A Healthy Brain is a Joy Forever
Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, griefs and tears. […]
And by the same organ we become mad and delirious, and fears and terrors assail us […]
All these things we endure from the brain, when it is not healthy
(c. 460 B.C. – c. 370 B.C.)
Long before we knew what it was for, we already knew things could be wrong in the brain. We have archeological evidence of brain surgery performed “since prehistoric times“: people had holes drilled in their skull and survived. The skulls not only have large holes in them with signs of having been made by tools, there is also evidence of healing and regrowth of the bone. While some of the trepanations might have been made for “ritual purposes“, this still requires the development of anatomical knowledge and surgical tools.
We even found evidence of trepanning on a “prehistoric cow“, which might be one of the earliest examples of experimentation on animals. So, even without knowing exactly what the function of the brain was, prehistoric humans already understood that something could be wrong with it and that something could be done about that.
This was a widespread practice, both medical as well as spiritual. We found skulls in south America and in Asia with clear evidence of ritual trepanning as well as evidence of cranial surgery and neurosurgery several centuries BCE in Egypt, China, India, “Greece“, etc.
And so on ….
We have extensive evidence of Arabic surgeons, such as “Avicenna” and “Abulcasis” conducting brain surgery on tumors, aneurysms, hydrocephalus, etc. as well as detailed descriptions and illustrations of tools and procedures.
Still, while ancient and medieval authors were able to describe in detail the location of various nerves and even able to determine their function through”trial and error“, they still did have no idea as to how these nerves or the brain worked exactly.
From Galen, through Avicenna, and up to Descartes, nerves were generally considered as hollow conduits, like blood vessels, not for fluids, but for “animal spirits“.
It was only after early experiments with electricity in the 18th century (by Luigi “Galvani“) and the observation and description of neurons in the 19th century (by “Purkinje” ,”Golgi“, and “ Cajal “) that we started understanding how something wrong in the brain might be connected to something wrong in the body. Step by step we started localizing bodily functions in the brain (after i.a. Flourens, Broca, Ferrier): sensation, movement, speech, etc. and coming up with ways to address the problems in increasingly sophisticated ways. While we still do not fully understand how the brain makes us conscious, we’ve always somehow known that the brain is something special, and that if something is wrong with it we can try to heal it.