Overview ventricular system Snapshot A 22-year-old male presents with altered mental status, fever, and headache. The patient is able to sluggishly answer questions. Passive flexion of the neck leads to spontaneous contraction of the hips. Pain is elicited when attempting to fully extend the knee while his hips are at a 90 degree angle. A skin finding is shown to the right. Introduction Function serves as a mechanical cushion for the CNS protects the brain against concussive injury removal of metabolites CSF flow is one-way hormone and hormone-releasing factor transportation homeostasis CSF pH affects ventilation and cerebral blood flow Production produced by the choroid plexus epithelial cells within ventricles found in lateral, third, and fourth ventricles reabsorbed into circulation by arachnoid granulations enters dural venous sinuses entire volume of CSF is recycled 2-3 times per 24 hours Ventricular system communications lateral ventricle → 3rd ventricle via the interventricular foramen of Monro 3rd ventricle → 4th ventricle via the cerebral aqueduct (Aqueduct of Sylvius) 4th ventricle → subarachnoid space via foramina of Luschka (lateral) foramen of Magendie (medial) Compared to the serum: ↓↓ protein ↓ glucose ↓ pH ↓ K+, HCO3-, Ca2+ ↑ Cl-, Mg2+ Presentation Cerebrospinal Fluid Analysis Test Normal Bacterial Viral Fungal/TB Opening pressure ≤ 20 cm H2O ↑ normal or slightly ↑ ↑ Color Clear Cloudy Clear Cloudy Cell count 0-5 cells/µL ↑ (PMN) ↑ (Lymphocytes) ↑ (Lymphocytes) Protein < 45 mg/dL ↑ Slighty ↑ ↑ CSF:Serum glucose > 0.6 ↓ Normal ↓ Hydrocephalus dilated ventricles via several types communicating login to view 4 more bullets noncommunicating/obstructive login to view 5 more bullets normal pressure (NPH) login to view 10 more bullets ex vacuo login to view 3 more bullets