Chronification of acute subdural hematoma
Chronification occurred in a third of all patients with conservatively treated acute subdural hematoma (aSDH), on average within 3 weeks. The probability of developing a cSDH is 0.96 times higher with every yearly increase in age, resulting in 56% chronification in patients ≥ 70 years. Hematoma thickness and impairment of the coagulation system such as anticoagulant medication (ASA, Coumadin, and Novel oral anticoagulants) or thrombocytopenia are further risk factors for chronification 1).
When managed conservatively, acute subdural hematomas can sometimes progress to chronic subdural hematoma formation, further enlargement, seizures, and progressive midline shift. Another potential difference in the young and the elderly is brain atrophy, which increases the potential space to accommodate a larger hematoma. It is not known if these two groups differ in other ways that might have implications for treatment or prognosis. In this paper, we investigate the clinical course of 80 patients admitted to our institution with acute subdural hematomas, to identify differences in patients above or below the age of 65 years. The natural progression/resolution of acute subdural hematomas was mapped by measuring volume expansion/regression over time. In this retrospective chart review, we investigated clinical baseline metrics and subsequent volumetric expansion outcomes between patients < 65 years old (N=44) and those > 65 years old (N=36). Volume was estimated by the ABC/2 method. We observed a statistically significant difference between groups in use of anticoagulants χ2 =40.305 with p < 0.001, corrective platelet administration χ2 =19.380 with p < 0.001, gender χ2 =14.573 with p < 0.001, and Glasgow Coma Scale with χ2 =23.125 (p=0.026). Overall outcomes were similar in the two groups. Younger patients on average had worse presenting GCS scores, but recovered comparable to older patients. No significant difference in rate of volume expansion, resolution time, or need for surgical treatment was seen between these two groups. We conclude that the initial volume, size, and severity of subdural hematoma determined by the Glasgow Coma Scale score is more likely to predict surgery or future expansion than age of the patient. Patients on oral anti-coagulants that are given appropriate medical reversal agents early do quite well and no impact on the eventual outcome could be demonstrated. Further work is needed to establish better predictors of future volume expansion, and progression to chronic subdural hematoma based on improved severity scales 2).
Among traumatic brain injuries, acute subdural hematoma (aSDH) is considered one of the most devastating still retaining poor surgical outcomes in a considerable percentage of affected patients. However, according to results drawn from published samples of aSDH patients, overall mortality and functional recovery have been progressively ameliorating during the last decades.
The mortality rate is 40% to 60%.
Two further stages, subacute subdural hematoma and chronic subdural hematoma, may develop with untreated acute subdural hematoma (SDH).
Spontaneous rapid resolution of acute subdural hematoma developing secondary to trauma has been reported in the literature, yet it is very rare in pediatric population 3).