Recurrence for chronic subdural hematoma is at around 15 percent.

The recurrence is not a sudden event, but unfolds over a short period of time.

My mother had a chronic subdural hematoma, and her neurosurgeon  told me that one of the risks of the draining procedure was a 15 percent recurrence rate.

He did not tell me how long, after the draining it typically takes for a recurrence of a chronic subdural hematoma to develop.

Or, to put it another way, how long after treatment the symptoms of a recurrence would start presenting.

Variability in How Long It Takes a Chronic Subdural Hematoma to Come Back

“The recurrence rate is somewhat variable and will range anywhere from 10-30 percent,” says Kangmin Daniel Lee, MD, a neurosurgeon with New Jersey Brain and Spine.

“There is some variability in technique from surgeon to surgeon and will depend on the location and size of the chronic subdural hematoma.

“Sometimes two vs. one burr holes are used, and small vs. large sized burr holes are also used.”

My mother had one burr hole for her procedure. Dr. Lee continues, “There is also some discussion regarding the utility of a subdural drain once the burr hole washout is completed.”

My mother had such a drain after her surgery, and gravity was used to continue the draining while she was recovering in her hospital bed.

“However, the general consensus is that larger burr holes and the routine use of a subdural drain will minimize the risk of recurrence,” says Dr. Lee.

The post-surgical drain tube does not guarantee against a recurrence, because 10 days after my mother’s procedure, she started showing peculiar symptoms.

And it turned out she had a recurrence of the chronic subdural hematoma, and had to have a second burr hole operation.

But what about a specific time window or “grace period” following drainage of a first chronic subdural hematoma, as far as potential development of a recurrence? My mother’s time window was (to our observation) 10 days.

But is there data on how long after treatment would a patient be clear of ever having a recurrence of the chronic subdural hematoma?

Dr. Lee explains, “There is some variability with this number depending on the technique, but most recurrences, when it does occur, will happen in the short term.  Most published reports range it from the 1-3 week period.”

]As you can see, my mother’s case clearly fits into what the published reports indicate.

Now, what usually causes the recurrence?

In my mother’s case, it didn’t seem related to the surgeon’s handiwork, because a CAT scan the morning after surgery was satisfactory to him, and the post-surgical drainage tube was ordered removed when it indicated that no more blood was coming out (though cerebral spinal fluid was, and the nurse told me that this was a sign that the drainage was nearing completion and that the tube should be removed).

I speculate that my mother’s recurrence of the chronic subdural hematoma was caused…believe it or not…by a second fall she took!

The first one was caused by striking her head on a bathtub after she fell. This fall was caused by blacking out while she was standing at the sink; she was experiencing frequent orthostatic hypotension.

The second fall occurred outside and I didn’t see it, but a witness said my mother did not hit her head.

The second fall apparently resulted from side effects of Keppra.

Though she didn’t hit her head, her neurosurgeon told me that the jarring from this second fall could have easily shaken things up in her brain and caused the recurrence of the chronic subdural hematoma.

The fall occurred the day after she was discharged from the hospital.

dr. lee

Dr. Lee focuses on minimally invasive techniques to treat traumatic and degenerative diseases of the spine and brain tumors. He’s been invited to speak at the regional and national levels on his research areas.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Shutterstock/Alexander Raths