What causes low intracranial pressure?

Generally, there are many causes of intracranial hypotension, such as reduced cerebral vascular bed volume, decreased brain volume, and reduced cerebrospinal fluid (CSF).

1. Reduced cerebral vascular bed volume: When the partial pressure of carbon dioxide in the blood decreases, the volume of the cerebral vascular bed also decreases, leading to a reduction in intracranial pressure.

2. Decreased brain volume: Brain tissue damage due to various factors may lead to loss of parenchymal water, reduced CSF production, and increased blood osmotic pressure, ultimately resulting in brain volume reduction. This can trigger intracranial hypotension syndrome, presenting symptoms such as headache and vomiting.

3. Reduced cerebrospinal fluid: After lumbar puncture or spinal membrane surgery, CSF may leak through the needle puncture site, or reflexive spasm of local choroid plexus vessels and dysfunction of the hypothalamic center regulating CSF production may occur, all of which can lead to decreased CSF. Additionally, following traumatic brain injury or neurosurgery, reduced cerebral circulation, skull base fractures, and other conditions may cause CSF leakage and reflexive spasm of local choroid plexus vessels, also contributing to decreased CSF. Patients with meningeal herniation accompanied by CSF leakage are prone to developing intracranial hypotension syndrome.