chronic subdural hematoma ( csdh ) is a common disease in the neurosurgical field , particularly in the elderly . the most common cause of chronic subdural hematoma is head trauma ; other causes include coagulopathy , anticoagulant therapy , metastatic tumor , vascular malformations , and alcoholism210 ) . symptoms vary , including headache , motor weakness , amnestic deficit , and lack of concentration . surgical treatment of csdh in symptomatic patients is still the " gold standard " of therapy because it enables immediate decompression of the space - occupying lesion and significantly improves outcome . nonsurgical treatment of csdh could be administered in situations such as poor general condition or elderly patients who favor nonsurgical treatment . herein , we report on a case that showed spontaneous resolution of a large csdh and review the literatures on spontaneous resolution and nonsurgical treatment of csdh . an 87-year - old woman presented with confused mentality and right side weakness of motor grade ii for 10 days . after visiting a local hospital and undergoing computed tomographic ( ct ) scan , she was diagnosed as csdh and transferred to our hospital for surgery . when she visited our hospital , her glasgow coma scale score was 14 , mental state was light drowsy , motor grade was right hemiparesis of grade ii , and mini - mental state examination score was 11/30 . the initial ct scan showed a 22 mm thick low density lesion located in the left fronto - temporo - parietal region with 12 mm midline shift to the right ( fig . 1a ) . based on the ct scan and the patient 's status , it was a definite indication for surgical treatment . although we recommended surgical management to the patient 's family , they refused because of the patient 's old age and the risk of surgery . therefore , we prescribed anticonvulsant ( valproate sodium ) only and planned on close observation of the patient with follow up brain ct . follow up brain ct scan after 1 month showed a decreased amount of hematoma ( fig . the thickness of sdh in the left fronto - temporo - parietal convexity was 12 mm . the patient 's mental status was improved to alert and the right side hemiparesis symptom improved to motor grade 4 . the brain ct after 2 and 3 months showed a gradual subsiding of the sdh ( fig . follow up brain ct scan after 5 months showed disappearance of the csdh and the patient was neurologically normal ( fig . in the literature , spontaneous resolution of csdh has rarely been reported and the reason for spontaneous resolution of csdh remains unclear . however , several theories have been proposed to explain the mechanisms of resolution of csdh . according to nakamura et al.7 ) , the decreased fibrinolytic activity of the hematoma and its capsule might have caused spontaneous resolution . kawano and suzuki6 ) investigated the possibility that presence of smooth muscle cells in the outer membrane of hematoma might play a role in the resolution of csdh . glover and labadie1 ) demonstrated a reduced rate of membrane formation in an animal model with corticosteroid treatment in which the effect of dexamethasone was thought to be anti - inflammatory or antiangiogenic3 ) . several non - operative treatments have been described , including observation only , mannitol and ace inhibitors or corticosteroids , however justification for treatment using ace inhibitors or steroids has mainly been theoretical , and further research is clearly warranted11 ) . in a recent study , kageyama et al.5 ) suggested that tranexamic acid might simultaneously inhibit the fibrinolytic and inflammatory ( kinin - kallikrein ) systems , which might consequently lead to resolution of csdh . in our patient , we prescribed only anticonvulsant ( valproate sodium ) without other medication . some case reports on ct characteristics of spontaneous resolution of chronic subdural hematoma showed that the hematoma density becomes low with decreasing size4789 ) . nakamura et al.7 ) reported that every csdh that resolved without surgery showed low density on follow - up ct and these authors also indicated that the fibrinolytic activity of low density hematomas decreased with regression of the thickness of the cavity . in the previously reported cases , radiologic characteristics of spontaneously resolved csdh were small size of subdural hematoma , low or iso density of hematoma7 ) , and absence of mid - line shifting or severe mass effect4 ) , and its clinical characteristics were asymptomatic and mild transient headache410 ) . the radiologic and clinical characteristics of our case are completely different from those of the previously reported cases . in our case , this is a previously unreported rare case of spontaneous resolution of a large csdh which required surgical decompression with hemiparesis and severe midline shift . surgical treatment is still the gold standard and the first option in large csdh with ventricular compression with mid - line shift having a distinct neurologic deficit . the possibility of conservative treatment is not indicated , however , there is probably another chance of spontaneous recovery as in our case .
we report on a case of an 87-year - old woman who showed spontaneous resolution of a large chronic subdural hematoma which required surgical decompression . 
 she had suffered from confused mentality and right side weakness of motor grade ii for 10 days . 
 the initial brain ct scan showed a 22 mm thick low density lesion located in the left fronto - temporo - parietal region with midline shift ( 12 mm ) which required emergency decompression . 
 however , because she and her family did not want surgery , she was followed up in the outpatient clinic . 
 five months later , follow up brain ct showed that the csdh had disappeared and the patient became neurologically normal . 
 the reasons for spontaneous resolution of csdh remain unclear . 
 we discuss the possible relation between mechanisms of physio - pathogenesis and spontaneous resolution of a large chronic subdural hematoma ( csh ) in an elderly patient .