December 28, 2007
Schematic Drawing of Cerebrospinal Fluid Circulation.
Elevated CSF pressure is transmitted around the brain and along the optic nerve (sub-arachnoid space) producing papilledema.
Cerebrospinal fluid flows from the choroid plexus through the brain’s four, interconnecting ventricles before finally entering the sub-arachnoid space, which surrounds the brain and spinal cord. The fluid then flows over the brain and spinal cord and is eventually absorbed into the venous blood system through tiny, one-way channels called arachnoid granulations or villi.
When this continuous cycle of CSF production, circulation and absorption functions normally, it regulates the volume of CSF in the skull and the fluid pressure remains at a constant level. In other words, the CSF production rate remains equal to the CSF absorption rate.
But when the body cannot effectively absorb or drain CSF, intracranial pressure increases within the fixed space of the skull. And since the brain and the vasculature can only be compressed so far, intracranial pressure must rise. Intracranial hypertension in adults is generally defined as intracranial pressure that reaches 250mmH2O or above.
Schematic Drawing of Cerebrospinal Fluid Circulation.
Elevated CSF pressure is transmitted around the brain and along the optic nerve (sub-arachnoid space) producing papilledema.
Cerebrospinal fluid flows from the choroid plexus through the brain’s four, interconnecting ventricles before finally entering the sub-arachnoid space, which surrounds the brain and spinal cord. The fluid then flows over the brain and spinal cord and is eventually absorbed into the venous blood system through tiny, one-way channels called arachnoid granulations or villi.
When this continuous cycle of CSF production, circulation and absorption functions normally, it regulates the volume of CSF in the skull and the fluid pressure remains at a constant level. In other words, the CSF production rate remains equal to the CSF absorption rate.
But when the body cannot effectively absorb or drain CSF, intracranial pressure increases within the fixed space of the skull. And since the brain and the vasculature can only be compressed so far, intracranial pressure must rise. Intracranial hypertension in adults is generally defined as intracranial pressure that reaches 250mmH2O or above.