aetiology
Last reviewed 06/2023
Communicating hydrocephalus most commonly results from deficient reabsorption of CSF absorption due to thickening of the leptomeninges - pia-mater and arachnoid - and / or damage to the arachnoid granulations. Causes include:
- post-meningitis:
- bacterial - pneumococcus more than meningococcus
- tuberculosis
- fungal
- subarachnoid haemorrhage - 80% of cases develop some degree of hydrocephalus
- trauma
- neoplastic infiltration in the subarachnoid space
- dural sinus thrombosis - not generally considered as a major cause of hydrocephalus
Less common mechanisms include:
- increased CSF viscosity - high protein content
- excess CSF production - choroid plexus papilloma