―Case Reports― Atypical Radiological and Intraoperative Findings of Acute Cerebral Hemorrhage Caused by Ruptured Cerebral Aneurysm in a Patient with Severe Chronic Anemia Fumihiro Matano1, Yasuo Murai1, Shunsuke Nakagawa1, Taisei Kato1, Takayuki Kitamura1, Tetsuro Sekine2, Ryo Takagi2 and Akira Teramoto1 1 Department of Neurosurgery, Nippon Medical School 2 Department of Radiology, Nippon Medical School Abstract Acute intracerebral hemorrhage (ICH) associated with mild anemia is commonly observed on radiological examination, and there are several reports of ruptured aneurysms occurring with ICH but without accompanying subarachnoid hemorrhage. However, the relationship among computed tomography (CT), magnetic resonance imaging (MRI), and intraoperative findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia has been rarely reported and is poorly understood. Here, we report atypical radiological and intraoperative findings of acute ICH caused by ruptured cerebral aneurysm in a patient with severe chronic anemia. A 64-year-old man with anemia was admitted to our hospital after he experienced left hemiparesis and a disturbance of consciousness. At a referring institution, he showed evidence of macrocytic anemia (white blood cell count, 9,000! μL; red blood cell count, 104 104! μL; hemoglobin, 4.0 g! dL; hematocrit, 12.2%; and platelet count, 26.6 104! μL). Both CT and MRI showed a right frontal ICH. The outer ring of the hematoma appeared as low-density area on CT, a low-intensity area on T1-weighted MRI, and a high-intensity area on T2weighted MRI with a serous component. The patient received a blood transfusion and underwent surgical removal of the hematoma the following day. The white serous effusion visualized with CT and MRI was identified as a blood clot in the hematoma cavity. The blood that leaks from blood vessels appears as a high-intensity area on CT because it undergoes plasma absorption in a solidification shrinkage process, and is, therefore, concentrated. Although we did not examine the white effusion to determine if serous components were present, we speculated that the effusion may have contained serous components. Therefore, we removed the part of the effusion that appeared as a low-density area on CT. The presence of ICH without subarachnoid hemorrhage suggested the possible adhesion and rupture of a previous aneurysm. Therefore, ICH appeared as a mixed density area on CT because bleeding may have occurred several times. Because radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia are similar to those of ICH and cerebral edema, we suggest that the atypical radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia should be carefully evaluated, especially when surgery is indicated. (J Nippon Med Sch 2014; 81: 264―268) Key words: intracerebral hemorrhage, anemia, intraoperative finding, computed tomography, magnetic resonance imaging Correspondence to Fumihiro Matano, MD, Department of Neurosurgery, Nippon Medical School, 1―1―5 Sendagi, Bunkyo-ku, Tokyo 113―8603, Japan E-mail: s00-078@nms.ac.jp Journal Website (http:! ! www.nms.ac.jp! jnms! ) 264 J Nippon Med Sch 2014; 81 (4) Cerebral Hemorrhage Caused by Ruptured Cerebral Aneurysm in Severe Anemia noted in periodic medical examinations but had not been evaluated. The patient was discovered in an Introduction unconsciousness state at his residence; however, his Acute intracerebral hemorrhage (ICH) associated with slight anemia is commonly observed on wellness had been confirmed earlier. The episode of headache with aura was unclear. radiological examination, and there are several Physical examination showed a blood pressure of reports of ruptured aneurysms occurring in ICH 110! 59 mmHg. At a referring institution, hematologic without accompanying subarachnoid hemorrhage examinations showed evidence of macrocytic anemia (SAH). However, the relationship among findings of (white blood cell count, 9,000! μL; red blood cell computed tomography (CT) and magnetic resonance count, 104 104! μL; hemoglobin, 4.0 g! dL; hematocrit, imaging (MRI) and intraoperative findings in cases of 12.2%; and platelet count, 26.6 104! μL), but other acute ICH caused by ruptured cerebral aneurysm in results were normal. Both CT (Fig. 1) and MRI (Fig. patients with severe chronic anemia has been rarely 2a, 2b, 2c) almost 12 hours after the ictus revealed a reported and is poorly understood. right frontal ICH without SAH. The outer ring of Here, we report atypical radiological and the hematoma showed low density on CT, low intraoperative findings in a case of acute ICH caused intensity on T1-weighted MRI, and high intensity on by ruptured cerebral aneurysm in a patient with T2-weighted severe chronic anemia. Magnetic resonance angiography (Fig. 2d) and 3- MRI with a serous component. dimensional CT angiography (Fig. 2e) revealed a Case Report right middle cerebral artery aneurysm. On the basis of these images, a ruptured aneurysm was believed A 64-year-old man with anemia was admitted to to have caused the ICH. our hospital after experiencing left hemiparesis and The patient received a blood transfusion and a disturbance of consciousness. Anemia had been underwent surgical clipping and removal of the Fig. 1 a: Computed tomography reveals a right frontal intracerebral hemorrhage. b: Postoperative computed tomography reveals almost complete removal of the hematoma and the presence of an outer ring of the hematoma, which was a low-intensity lesion. J Nippon Med Sch 2014; 81 (4) 265 F. Matano, et al Fig. 2 a: T1WI magnetic resonance imaging reveals a right frontal intracerebral hemorrhage. b: T2WI magnetic resonance imaging reveals a right frontal intracerebral hemorrhage. c: Fluid-attenuated inversion recovery magnetic resonance imaging reveals no subarachnoid hemorrhage. d: Magnetic resonance angiography reveals a right middle cerebral artery aneurysm (white arrow). e: Three-dimensional computed tomography angiography reveals a right middle cerebral artery aneurysm (white arrow). hematoma the following day. A right frontotemporal aspiration, but the cause of anemia still could not be craniotomy determined. The appropriate management of anemia was performed with a pterional approach to expose the aneurysm. The aneurysmal is a blood transfusion neck was successfully clipped, and the hematoma hematologist. was evacuated with a transcortical approach. A another hospital for rehabilitation. The as patient suggested was by a transferred to white serous effusion in the hematoma cavity Discussion (Fig. 3a) was identified as a blood clot (Fig. 3b). Postoperative CT revealed near-complete removal of the hematoma and the absence of any low-density patientʼs uneventful. He recovery showed this study, we have reported atypical radiological and intraoperative findings in a case of area around the hematoma (Fig. 1b). The In surgery was acute ICH caused by ruptured cerebral aneurysm in improvement of a patient with severe chronic anemia. The potential after consciousness and could communicate; however, the reasons for these findings are discussed below. Digital Rupture of a cerebral aneurysm resulted in SAH. subtraction angiography performed after surgery In 35% of cases of SAHs caused by ruptured showed that the aneurysm had been clipped cerebral aneurysms, ICH is also present1. Ruptured completely. After the patientʼs general condition aneurysms resulting in ICH often do not cause improved, we consulted the hematology department SAH2,3. However, the relationship among the findings of of CT and MRI and intraoperative findings in cases hemiparesis internal 266 showed medicine no improvement. regarding bone marrow J Nippon Med Sch 2014; 81 (4) Cerebral Hemorrhage Caused by Ruptured Cerebral Aneurysm in Severe Anemia component of the acute phase of ICH appears as a low-density area on CT, as a low-intensity area on T1-weighted MRI, and as a high-intensity area on T2-weighted MRI. In the present case, the presence of ICH without SAH suggested the possible adhesion and rupture of a previous aneurysm7. Therefore, ICH showed mixed density because bleeding may have occurred several times. The image intensity of the outer ring of the acute hematoma was similar to that of the perihematomal edema, which exhibited low density on CT, low intensity on T1-weighted MRI, and high intensity on T2-weighted MRI. However, the morphology of the outer ring of the hematoma differed from that of the brain edema around the acute phase of the ICH because of the well-circumscribed and round outer ring of the hematoma. In addition, the intraoperative observation revealed a low-density area in the outer ring of the hematoma on CT, which suggested that the low-density area was white effusion of the hematoma with a serous component. New and Aronow8 have concluded that the high-density areas of hematomas on CT are dependent on hemolysis, Fig. 3 a: Intraoperative observation of the white effusion indicates a peripheral hematoma that appeared as a low-density area on computed tomography. b: Intraoperative observation showed a hematoma that appeared as a high-density area on computed tomography. hemoglobin, and hematocrit. Furthermore, New and Aronow have reported that hematomas appear as isodensity lesions on CT in patients with anemia (hemoglobin, 9―11 g! dL). Bergstrom et al.9 have reported that areas of higher and lower attenuation may exist within a single hematoma, and the existence of both types of attenuation may be due to of acute ICH caused by ruptured cerebral aneurysm clot retraction or the age of the hematoma. In other in patients with severe chronic anemia has been words, the blood that leaks from blood vessels rarely reported and is poorly understood. appears as a high-intensity lesion on CT because it During the acute phase ICH appears as a high- undergoes plasma absorption in a solidification density area on CT and as a isointensity area on shrinkage process, and therefore, is concentrated10―12. both T1-weighted and T2-weighted MRI; brain Although we did not examine the white effusion to edema appears as a low-density area on CT, as a determine low-intensity area on T1-weighted MRI, and as a present, we speculate that the effusion may contain 4,5 whether serous components were high-intensity area on T2-weighted MRI ; and these perihematomal edema volume increases during the decreasing low-density areas, and because usually first 24 hours after hyperacute spontaneous ICH6. there is no edema immediately after ICH, we Findings in the present case suggest that coagulated concluded that the low-density area on CT was not blood cell components (blood clots) in the acute due to brain edema but rather due to the serum phase of ICH appear as high-density lesions on CT components; thus, we removed this area. components. Postoperative CT revealed and as isointensity lesions on T1-weighted and T2- Because radiological findings of ICH caused by weighted MRI and that the perihematomal serum ruptured cerebral aneurysm in patients with severe J Nippon Med Sch 2014; 81 (4) 267 F. Matano, et al chronic anemia are similar to those of ICH and cerebral edema, we suggest that atypical radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia need to be carefully evaluated, particularly if surgery is indicated. A study with larger numbers of patients with ICH caused by ruptured cerebral aneurysm and with severe chronic anemia would be helpful to obtain additional evidence in support of these findings. Conflict of Interest: The authors declare no conflict of interest. References 1.Pasqualin A, Bazzan A, Cavazzani P: Intracranial hematomas following aneurysmal rupture: experience with 309 cases. 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(Received, June 2, 2013) (Accepted, September 11, 2013) J Nippon Med Sch 2014; 81 (4)