Cerebrospinal Fluid 1764 – A Clear, Colorless Fluid

Cerebrospinal fluid (CSF) is a clear, colorless fluid that fills the brain's ventricles, which connect to the central canal of the spinal cord. CSF also surrounds the brain and spinal cord, reducing friction and acting as a cushion against shocks. 

CSF is produced in the brain's ventricles (by cells in the ventricular choroid plexus) and carries waste products away from the brain and spinal cord into the bloodstream. About 500 milliliters (17 ounces) are produced daily, and all the fluid is replaced approximately every seven hours. 

Physicians can obtain and examine a CSF sample by inserting a needle or catheter in the lumbar (lower-back) region. Cloudy CSF may indicate meningitis, inflammation of the membranes surrounding the brain or spinal cord. Causes of meningitis (such as bacteria, viruses or fungi) can be distinguished through detailed examination of proteins, glucose and white blood cells or through staining. 

Blood in CSF may indicate bleeding inside or around the brain, while certain proteins may indicate Alzheimer's disease. CSF can also be used to diagnose possible brain tumors, syphilis and multiple sclerosis, a disease in which the myelin sheath surrounding nerve axons is damaged.

A Spiritual Fluid, Vapor or Water?

In 1736, the Swedish scientist, philosopher, theologian and mystic Emanuel Swedenborg described CSF as “spiritual lymph” and “a highly capable water”.

In 1764, the Italian physician Domenico Cotugno described CSF in the ventricles and surrounding the brain and spinal cord, believing that it was continually renewed. For a time, CSF was called “Liquor Cotunnii” in honor of his work. Before Cotugno's research, many physicians wrongly believed that the brain's ventricles were filled with vapor, which sometimes condensed into water as bodies cooled rapidly before examination.

Many earlier anatomists had not even observed CSF, because the head was brutally separated from the body before dissection, draining fluids from both the spine and skull. 

About the Article Image: The brain's ventricles (yellow), from Andreas Vesalius's “De Humani Corporis Fabrica” (1543). In Vesalius's time, some physicians believed that the ventricles housed both the soul and spirits responsible for the body's motor and sensory activity.

Historical Figures Mentioned in the Article: Emanuel Swedenborg (1688–1772), Domenico Felice Antonio Cotugno (1736–1822)

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