Acute-on-Chronic Subdural Hematoma: Not Uncommon Events.
OBJECTIVE
Patients with asymptomatic chronic subdural hematoma (SDH) are prone to fall or slip. Acute trauma on these patients may develop acute subdural bleeding over the chronic SDH. We recently experienced 9 patients with acute-on-chronic SDH. We report the clinical and radiological features of this lesion.


METHODS
We retrospectively examined the computed tomographic (CT) scans of 107 consecutive patients who diagnosed as chronic SDH from January 2008 to December 2010. All cases of CSDH were diagnosed on CT with or without MRI scan.


RESULTS
Acute-on-chronic SDH is not rare, being 8% of chronic SDH. The most common cause of trauma was a slip in drunken state. Alcoholism with multiple episodes of trauma was one of the prominent histories. Acute-on-chronic SDH appeared as a hyperdense layer of clot with irregular blurred margin or lumps in liquefied hematoma. Single or two burr holes was usually effective to remove the hematoma.


CONCLUSIONS
Repeated trauma may cause acute bleeding over the chronic SDH. It will be helpful to understand the role of repeated trauma as a mechanism of hematoma enlargement.
Department of Neurosurgery, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
Kyeong-Seok
KS
Lee
Jae-Jun
JJ
Shim
Seok-Mann
SM
Yoon
Jae-Won
JW
Doh
Il-Gyu
IG
Yun
Hack-Gun
HG
Bae