Cerebrospinal Fluid

Cerebrospinal fluid (from Latin liquor cerebrospinalis) is a clear, colorless biological medium that continuously circulates within the cavities of the brain and spinal cord and bathes them externally. It is a vital component of the protective and metabolic systems of the central nervous system.

Etiology and pathophysiology

This fluid is continuously produced by specialized vascular plexuses located deep within the brain (in the cerebral ventricles). In a day, the human adult body produces about half a liter of cerebrospinal fluid, although only about 150 ml is present in the system at any one time.

Cerebrospinal fluid performs three critical functions. Firstly, it acts as an ideal hydrodynamic shock absorber. The brain literally floats in it, losing part of its weight, which protects the delicate neural tissue from being crushed against the bones of the cranium during movements and impacts. Secondly, the cerebrospinal fluid delivers nutrients to neurons. Thirdly, it continuously washes and carries away toxic metabolic by-products into the venous system, functioning as a cleansing system.

Clinical significance

In trauma medicine, the condition of cerebrospinal fluid serves as a crucial diagnostic indicator. In cases of brain contusion and subarachnoid hemorrhage, the cerebrospinal fluid becomes tinged with blood, which can be detected by performing a lumbar (spinal) puncture.

Disruption of normal circulation of this fluid leads to severe complications. If, after an injury, blood clots obstruct its outflow, the constantly produced cerebrospinal fluid begins to accumulate and distend the brain from the inside, causing hydrocephalus (brain edema). Furthermore, fluid accumulation in the subdural space leads to the formation of subdural hygromas, which require surgical drainage.