acute subdural hemorrhage ( asdh ) needs emergent neurosurgery or close observation because it associated with a 60 - 80% mortality rate . sometimes , it is treated with emergent surgical decompression , patients may be managed conservatively when they are neurologically intact or the hematoma is small . rapid spontaneous resolution of asdh has rarely been reported because it takes several weeks or months for spontaneous resolution without neurosurgical interventions.1,3,5 ) moreover , the true incidence of rapid spontaneous resolution of asdh is underestimated due to the routine use of emergency decompression . the underlying pathophysiology is not well understood , but probably more than one mechanism is responsible for this phenomenon . two possible mechanisms for spontaneous resolution of asdh have been put forward to explain this phenomenon including redistribution of subdural blood and dilution by cerebral spinal fluid ( csf).10 ) herein , we present a patient with liver cirrhosis who show - ed an unexpected rapid resolution of asdh spontaneously within 1 day after mild head injury and discuss the mechanism related to the coagulopathy contributed to the spontaneous resolution of the hematoma . a 67-year - old male patient presented with deterioration of mental status following fall down less than 1 meter . he has the underlying disease , such as alcoholic liver cirrhosis , diabetes mellitus and hypertension . initially , the patient was comatose with a score of five on the glasgow coma scale and had a right hemiparesis with a dilated left pupil . brain computed tomography ( ct ) revealed an asdh with a thickness of 25 mm in the left frontotemporoparietal region . a hypodense band was also observed between the inner table of the skull and the hyperdense collection ( figure 1 ) . we decided to perform craniotomy for hematoma removal but significant findings on blood work were revealed platelet count of 51000 and an international normalized ratio ( inr ) of 2.17 . under the consideration of post - operation complication and familial opinion , we decided to perform conservative care in intensive unit care . was performed 24 after the initial scan , and showed redistribution of hematoma to the tentorium and posterior inter hemispheric fissure ( figure 2 ) . the mass effect to the ipsilateral lateral ventricle had resolved and the adjacent sulci reappeared . another brain ct scan was performed on the next 3 days , ct scan showed complete resolution of the subdural hematoma ( sdh ) over the left cerebral hemisphere ( figure 3 ) . asdh is a frequent brain insult resulting from head injury and asdh is a neurosurgical emergency requiring immediate therapeutic intervention . most of these patients undergo urgent hematoma evacuation via a craniotomy except for those with poor general condition or with irreversible brain damage . interestingly , there are a number of case reports in the literature describing the event of spontaneous asdh resolution.6,10 ) the mechanism of the spontaneous resolution of asdh has been attributed to intracranial redistribution of the hematoma rather than disappearance in the subdural space.8 ) two possible mechanisms have been proposed for this infrequent phenomenon . first , the hematoma may be diluted by flow of cerebrospinal fluid through the arachnoid tear , followed by retrograde flow into the subarachnoid space . this process is explained by the presence of a low density band between the sdh and inner table of the skull and it may be a useful sign for cases with good prognosis.8 ) second , brain swelling , caused by cerebral contusion , compresses the hematoma and may contribute the redistribution of hematomas resulting in rapid resolution of sdhs.8 ) some authors have demonstrated the finding of redistribution and dispersal of blood in the cerebellar tentorium or inter hemispheric subdural space with follow - up magnetic resonance imaging.7,9 ) in addition , the accompanying fracture might have facilitated the redistribution of the asdh and improvement of the brain shift . this process may be explained by the prolapse of dura mater into the fracture sites by the force of the sdh.2 ) in this case , two mechanisms have been put forward to explain the rapid resolution of asdh . first , this patient had a brain atrophy and the presence of a low density band between the sdh and inner table of the skull . the specificity of our case was the presentation of low density component and cerebral atrophy with widening of subarachnoid space . the combination effect of cerebral atrophy and csf leakage may favor both redistribution and dilution of asdh . second , in follow - up imaging , there is an increasing of layer of a hyperintense component consistent with acute blood along the tentorium ( figure 2 ) suggesting blood redistribution . additionally , the unique aspect of the case presented above is that the patient had a coagulopathy . in the present case , we were concerned as to why spontaneous resolution of asdh happened to this patient with liver cirrhosis . to date , only one case of similar phenomenon has been reported . chaudhary et al.4 ) described a similar case of resolution of large sdh in a 73-year - old male with myelodysplastic syndrome . healthy individuals possess adequate amounts of clotting factors , regulatory proteins , and platelets to achieve optimal clot formation , clot limitation , and dissolution . patients with liver disease , on the other hand , have a disturbed balance of pro - coagulant and anti - coagulant factors deviating from the normal coagulation cascade . in this case , our patient had a known chronic liver disease , liver cirrhosis . one is a formation of a " platelet plug " which requires sufficient quantity of functional platelets working in an intact blood vessel . the other is a production of a " fibrin clot " which needs adequate and functional clotting factors . in this patient , as noted above , multiple factors can result in a hypocoagulable state because of liver cirrhosis . decreased levels of all liver synthesized pro - coagulant factors , including the vitamin k dependent clotting factors ( ii , vii , ix , and x ) , indicated by the prolonged inr . additionally , platelet dysfunction is also a contributing aspect of decreased clot formation , including thrombocytopenia . these conditions acts like the face and back of a coin for causing an asdh with minor trauma in this patient , they may have also concerned to redistribution of hematoma by the preventing the well - organized hematoma formation . summing up , this coagulopathic status is more susceptible for hematoma to wash out or redistribute via the csf dilution route . the pathophysiologic mechanisms that are responsible for this phenomenon are dilution by csf and redistribution of the asdh in patients with cerebral atrophy . in this case , coagulopathy , as a new factor , may contribute to the spontaneous resolution of the hematoma .
acute subdural hematoma ( asdh ) constitutes one of the most critical emergencies in neurosurgery and rapid spontaneous resolution of asdh is an infrequent phenomenon . 
 several mechanisms have been attributed to explain this phenomenon including redistribution of subdural blood , dilution by cerebral spinal fluid and brain atrophy . 
 rapid resolution of asdh related to coagulopathy is a rare phenomenon ; to our knowledge , only one case has been reported . 
 we report on a patient who showed rapid resolution of asdh with coagulopathy and also discuss such a rare case with speculation of the coagulopathy as a factor to promote this phenomenon .