Cerebrospinal Fluid (CSF)

Cerebrospinal fluid (CSF) is a clear, colorless fluid that surrounds the brain and spinal cord. It plays critical roles in mechanical protection, metabolic support, and intracranial pressure regulation.

• Mechanical cushion: protects brain and spinal cord from trauma.
• Buoyancy: reduces the effective weight of the brain.
• Metabolic exchange: removes waste and delivers nutrients.
• Intracranial pressure (ICP) buffer.
• Immune surveillance.

1. Produced in the choroid plexus of the lateral, third, and fourth ventricles.
2. Flows:
   1. Lateral ventricles → Foramina of Monro →
   2. Third ventricle → Aqueduct of Sylvius →
   3. Fourth ventricle → Foramina of Luschka and Magendie →
   4. Subarachnoid space → Arachnoid villi → Superior sagittal sinus.

• Diagnostic tool for infection, bleeding, or demyelinating disease.
• Normal pressure: 10–20 cmH₂O in lateral decubitus position.
• Contraindicated in patients with raised ICP and midline shift.

• Excess accumulation of CSF.
• Classified as:
  1. Communicating
  2. Non-communicating (obstructive)
  3. Normal pressure hydrocephalus

• Types: Ventriculoperitoneal (VP), ventriculoatrial, lumboperitoneal
• Indications: hydrocephalus, CSF pseudocysts, Dandy-Walker malformation

• Can be spontaneous or traumatic/post-surgical.
• Clinical signs: rhinorrhea, otorrhea, low-pressure headache.
• Diagnosed via beta-2 transferrin test and imaging (CT/MRI cisternography).

• intracranial_pressure_monitoring
• hydrocephalus
• lumbar_puncture
• shunt_malfunction