A chronic subdural intracranial hematoma is a blood clot on the surface of the brain, between the brain and the dura or thick outer lining. This is a chronic condition as the clot forms slowly over the course of several days.
A headache which gets gradually worse over several days. The patient may have loss of memory and confusion. Other symptoms include lethargy, nausea, vomiting and behavioral changes as well as weakness, impaired vision or even seizures.
Chonric subdural intracranial hematoma's usually occur in those over the age of 60. Most often it is due to brain atrophy or wasting / shrinkage which can happen in old age or due to other medical conditions. The shrinkage can cause tearing of minor blood vessels on the brains surface, which then bleed into the space. Other causes include blood thinning medications, alcohol abuse and seizures.
If this condition is suspected, seek medical attention as soon as possible. CT or MRI scans can be used to diagnose the condition and confirm the extent of the bleed. In most cases, the blood can be drained and so pressure released by drilling a small hole in a the skull. 80-90% of cases show considerable improvement after drainage, with few long-term side-effects.