The Unusually Shaped Bifrontal Hematoma
To the Editor:
We present a rare case of bifrontal hematoma resulting in death caused by a spontaneously ruptured aneurysm of the anterior communicating artery (ACoA). The hematoma was in the shape of a thick crescent, and the aneurysm was revealed on computerized tomography (CT) and CT angiography.
A 60-year-old man suffering from hypertension and diabetes mellitus was admitted to the emergency service after having lost consciousness following vomiting and urinary incontinence. Examination revealed a systolic blood pressure of 220 mm Hg and a diastolic blood pressure of 120 mm Hg. He had a tachypneic and irregular respiration. His score on the Glasgow Coma Scale was 5 (E1M3V1). Both of his pupils were middilated, and direct and indirect light reflexes were decreased; deep tendon reflexes were decreased in all extremities, and he had a bilateral positive Babinski sign. He was admitted directly to the intensive care unit (ICU) from the emergency department. In the ICU, cardiopulmonary arrest developed. He was intubated, and a ventilator maintained his respiration. His radiological evaluation including CT revealed a thick, crescent-shaped bifrontal hematoma measuring 90 cm3 (Figure). He was grade 5 according to the World Federation of Neurological Surgeons grading scale. Conventional angiographic examination could not be performed because there was no indication of surgical approach and the patient’s clinical condition was not appropriate for transporting him to the angiography unit. On the second day of admission, the patient underwent a control CT and CT angiography. It demonstrated a 0.5-cm-diameter berry-shaped hyperdensity on coronal reformat images. Upper slices also showed cerebrospinal fluid and hematoma levels in posterior horns of the lateral ventricles. Since the patient’s neurological status had been poor, a digital substraction angiography was not performed. His operation was postponed until his status was stabilized. His neurologic and metabolic status quickly worsened, and his blood pressure decreased. He died on the third day of admission to the hospital.
Twenty-four percent of nontraumatic frontal lobe hematomas are caused by ruptured aneurysms of the anterior cerebral or ACoA. The frontal lobe hematoma is generally unilateral and it may be round, ovoid, triangular, linear, or rectangular.1 On the other hand, bilaterally frontal hematomas are less common than unilateral hematomas, and they present in a bilobed or butterfly shape. According to the literature, the known cause of bifrontal hematoma is ruptured aneurysm of the ACoA.1 Unilateral or bilateral frontal hematoma extending inward from the pericallosal cistern, caval-septal region, or interhemispheric fissure is most characteristic of ACoA aneurysm rupture. This kind of extension is also seen in the glial tumors and is called a butterfly tumor.2,3⇓ Yock and Larson have classified CT findings of ruptured ACoA aneurysms including asymmetric subarachnoid hemorrhage, subarachnoid hemorrhage involvement of the anterior interhemispheric fissure, and septal hematoma. They also observed non–giant aneurysms and occasionally negative scans.2 We detected the hematoma symmetrically in bifrontal localization opening to the ventricle.
Weisberg and Stazio reported 2 patients with bifrontal hemorrhage. One was butterfly shaped and the other was bilobed.1 The bifrontal hematoma in our case, however, was in the shape of a thick crescent.
General symptoms of frontal lobe hematomas include headache, vomiting, neck stiffness, seizures, and transient focal neurologic deficits. Neurologic signs are altered consciousness, motor deficits, gaze preference, nuchal rigidity, and sometimes aphasia. Our patient presented with loss of consciousness after vomiting.1 According to Pasqualin et al, the presence of a large hematoma, ventricular hemorrhage, and shift of ventricles is associated with poor prognosis.4 But Benoit et al concluded that the survival of the patient with intracerebral hematomas caused by aneurysmal rupture was more closely linked to the size and the localization of the hematoma than the localization of aneurysm or degree of midline shift.5 Tokuda et al reported that there had been a close correlation between the site of hematoma and that of the ruptured aneurysm. They found that poor outcome in patients with intracerebral hematoma seemed to be related to severity of clinical grade on admission.6 In our patient, we believe that the poor prognosis depended on the severity of the grade, which was caused by the bifrontal hematoma approximately 90 cm3 in volume.
In conclusion, bilateral frontal hematomas due to ruptured ACoA aneurysms may also appear in an unusual shape (eg, a thick crescent) in addition to the bifrontal butterfly shape.