Did you know that a clear fluid layer called the cerebrospinal fluid (CSF) surrounds the vicinity of the brain and spinal cord? The CSF is a multifaceted marvel, able to continuously support the nervous system throughout our life. It acts as a shock absorber, cushioning and preventing rubbing of brain and spinal cord against the skull and spine. Moreover, the CSF supplies nutrients to both of them and flushes away metabolic waste products and any excess neurotransmitters.
Cerebrospinal fluid is produced from the blood by an ultra-filtering mechanism. A network of blood capillaries lined by specialized cells (choroid plexus) in the brain churn out 500-700 milli-litres of the fluid per day. At any given time, the total volume circulating is 150 mL.
The filtered fluid keeps circulating in the space surrounding the brain and spinal cord until it gets re-absorbed into the blood again (at subarachinoid space).
Cerebrospinal fluid is 99 per cent water. Proteins, ions, neurotransmitters, and glucose make up the remaining one per cent. While normally, the composition, quantity and pressure of CSF remain constant, analysing changes in these parameters gives valuable clues in diagnosing hydrocephalus, cerebral oedema, amyotrophic lateral sclerosis, meningitis, encephalitis, multiple sclerosis and idiopathic intracranial hypertension.
For example, Dr T R Raju, neurophysiologist and director-research, Sankara Academy of Vision, Bengaluru, says that “The level and activity of a potential biomarker Chitotriosidase (CHIT-1) is significantly increased in cerebrospinal fluid [in people with] amyotrophic lateral sclerosis.”
The following infographic gives a pictorial representation of CSF and its effect in health conditions.
Read More: When muscle falter: understanding amyotrophic lateral sclerosis
Read More: When sodium levels plunge: the hidden peril of brain swelling
