Often there is a history of trauma 3-6 weeks prior to presenting to the emergency room or the doctor’s office.  The presumption is, there was either a trauma or a bleeding event caused by blood thinners.  This then led to a brain bleed.  But, instead of the blood being completely absorbed by the brain, it starts to form a membrane of vessels, a “balloon.”  Over the next 3-4 weeks, this “balloon” expands and pushes the brain, causing micro-injuries.

Even after evacuation of this bleed, this subdural hematoma can re-form.

The surgery is simple.  However, there is a recurrence rate (due to the underlying pathophysiology of the subdural membrane) and brain irritation rate that can cause micro-seizures or overt seizures.