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mycotic aneurysms are rare inflammatory neurovascular lesions first described in 1855.6 ) mycotic aneurysms account for approximately 2.5 ~ 4.5% of all intracranial aneurysms and are unique in their natural history , pathologic findings , location and common multiplicity.6)8)26)27)34 ) their spontaneous rupture mostly results in subarachnoid and intracerebral hemorrhage , accompanied by morbidity and mortality as high as 60 ~ 90% in older case reports , and 12 ~ 32% in more recent reports.17)29 ) ruptured mycotic aneurysm manifesting as subdural hematoma ( sdh ) is extremely rare ; only 10 cases have been reported.2 - 4)13 - 15)20)26)31)34 ) we present a case of mycotic aneurysm associated with sdh , which was resolved with medical treatment .
he slipped and suffered from blunt traumas to his head 10 days before his visit to the hospital .
he showed right hemiparesis with a motor power of grade iv / v in the right upper and lower limbs .
the initial glasgow coma scale score was 12 ( eye response - 3 , verbal response - 4 , motor response - 5 ) .
he had no extracranial wounds and the vital signs were stable , but his body temperature was mildly elevated .
the patient had a history of type 2 diabetes mellitus and hypertension , and he was a heavy alcoholic .
enhanced computer tomography ( ct ) of the brain showed subacute subdural hematomas on both fronto - parietal areas and an enhancing nodule in the left parietal area ( fig .
ct angiography revealed that the enhancing nodule was a saccular aneurysm located at the m4 segment of the left middle cerebral artery ( mca ) .
cerebral angiogram showed 2 aneurysms ; one located at the distal left mca and the other at the bifurcation of the left mca ( fig .
2 ) . laboratory studies revealed an elevated erythrocyte sedimentation rate ( esr , 49 mm / hr ) , white blood cell count ( wbc , 12,990/l ) and c - reactive protein ( crp , 9.28 mg / l ) , but other hematological and biochemical parameters were within normal range .
blood cultures were negative and there was no evidence of infective endocarditis in the echocardiography .
the enhanced ct 10 days after admission revealed disappearance of the aneurysm located at the m4 segment and partial resolution of sdh ( fig .
antibiotics were continuously given for 4 weeks with moderate improvement of his symptoms and the patient was discharged . because the aneurysm located at the bifurcation of the left mca was small and had no interval change , we decided to observe it in our outpatient department .
mycotic aneurysms are rare inflammatory neurovascular lesions , comprising 0.7 - 5.4% of all intracranial aneurysms.1 ) sixty five percent of patients of mycotic aneurysms have underlying endocarditis.1 ) other common sources of infection are intravenous drug abuse ( 6.3% ) , bacterial meningitis ( 5.2% ) , poor dental hygiene ( 4.2% ) and cavernous sinus thrombosis ( 2.8%).1 ) in this case , no infective endocarditis or infectious diseases were found . however , the patient was old , a heavy alcoholic and had a history including diabetes mellitus .
this can increase the risk of infectious diseases , but the origin of the mycotic aneurysm was not found .
there are several limitations in diagnosing mycotic aneurysms , because the infectious pathological lesions can be identified histopathologically only in resected specimens .
it is possible to diagnose mycotic aneurysm when the lesion was resolved completely under treatment .
the recently published diagnostic criteria enable early diagnosis of mycotic aneurysm ( table 1).12 ) these criteria are easy to apply and have 96% sensitivity and 100% specificity to differentiate mycotic aneurysm from a noninfectious aneurysm.12 ) in our case , the patient had a fever at presentation , multiplicity and distal location of the aneurysm .
the distal mca aneurysm completely disappeared in angiography after antibiotic therapy . following the criteria mentioned above
, the aneurysm located at the m4 segment of left mca can be diagnosed with a mycotic aneurysm .
the rupture of mycotic aneurysm causes intraparenchymal ( 28% ) , subarachnoid ( 22% ) and intraventricular hemorrhage ( 5%).1 ) a mycotic aneurysm associated with sdh is a rare case.16 ) only 10 cases have been reported.2 - 4)14 - 16)20)26)31)34 ) in this case , his head trauma may have caused the rupture of the underlying mycotic aneurysm .
on the other hand , the trauma could directly cause bilateral subdural hematomas and the mycotic aneurysm could be found incidentally .
ct angiography is a useful non - invasive tool in the diagnosis of mycotic aneurysms and detecting intracranial hemorrhage and edema.1 ) cerebral angiography is the gold standard for the diagnosis of mycotic aneurysms and is often used in determining treatment method and prognosis.5 ) laboratory studies are typically suggestive of an underlying inflammatory process and may include leukocytosis , elevated esr , crp , and anemia.6 ) elevated esr , crp and leukocytosis provide supporting evidences of mycotic aneurysms.35 ) blood cultures are positive in only 35.6% of patients.1 ) in our case , wbc count , esr and crp were elevated but blood cultures were negative . there is no randomized controlled trial or prospective cohort study evaluating treatment approaches to mycotic aneurysms . because there is no standard recommendation about clinical decision making , treatment of mycotic aneurysms is highly individualized and varied.18 ) treatment approach is usually dependent on the rupture status . in the case of unruptured mycotic aneurysms ,
the treatment was generally initiated with antibiotic therapy alone.1 ) antibiotic therapy should be guided by culture results obtained from blood or cerebrospinal fluid samples , but if cultures are negative , empirical antibiotics should be initiated according to the suspected predisposing infection .
the existing literature generally supports a minimum of 4 to 6 weeks of antibiotic therapy.18 ) serial ct scan or angiography should be followed to monitor the status of the aneurysm during conservative care . in the case of ruptured mycotic aneurysms , definitive treatment relies on surgical clipping , endovascular coiling , or trapping of the aneurysm .
frazee recommended antibiotic therapy as the first line of treatment for mycotic aneurysm.9 ) some studies suggested that standard recommendations of treatment were to initiate intravenous antibiotics on an empirical basis.7)28)30 ) in kanoth 's study , 25 patients were treated with medical , surgical and endovascular method , and some cases with intracranial hemorrhage were completely resolved by antibiotic therapy alone.24 ) some cases required surgery because the lesions were not resolved or enlarged.24 ) in our case , the treatment was started with antibiotics alone because he did n't have significant mass effect from the subdural hematomas and no signs of tentorial herniation .
the subdural hematomas in initial ct were subacute types and there was no presence of midline shift .
both subdural hematomas were resolved in later ct and the follow - up cerebral angiography revealed disappearance of the distal mca aneurysm .
we experienced a rare case of ruptured mycotic aneurysm associated with sdh without infective endocarditis and any other infectious disease .
after treatment with antibiotics for 4 weeks , the patient was nearly relieved of symptoms .
mycotic aneurysms are rare inflammatory neurovascular lesions . ruptured mycotic aneurysm manifesting as 
 subdural hematoma is extremely rare . 
 a 72-year - old male patient was admitted to our hospital with headache and drowsiness . 
 computer tomography ( ct ) of brain and ct angiography revealed subdural hematoma and an aneurysm located at the m4 segment of the left middle cerebral artery ( mca ) . 
 cerebral angiogram revealed 2 aneurysms ; one located at the left distal mca and the other at the bifurcation of left mca . 
 laboratory studies showed leukocytosis and elevated inflammatory factors . 
 the patent was treated with antibiotic therapy for 4 weeks . 
 the follow - up ct and cerebral angiography showed that the mycotic aneurysm was completely resolved , and the patient was nearly free of symptoms .