The objectives of this study were to elucidate the normal anatomy of middle cerebral artery (MCA) bifurcations and to analyze the differences in patients with MCA aneurysms. In the present study, 62 patients underwent three-dimensional magnetic resonance angiography, and no intracranial lesions were noted. The widths of M1 and the superior and inferior M2 branches, as well as their respective lateral angles, were measured. These values were used to calculate the daughter artery ratio (DA ratio; width of larger M2/width of smaller M2) and the lateral angle ratio (LA ratio; lateral angle between M1 and larger M2/lateral angle between M1 and smaller M2). The DA and LA ratios of 54 MCA aneurysm patients (34 with ruptured aneurysms, 20 with unruptured aneurysms) were also calculated, using three-dimensional digital subtraction angiography, and compared with the normal values. In normal patients, the widths of M1 and the branches of M2, the lateral angles, and the LA and DA ratios were not significantly different between the right and left sides. The bilateral superior and inferior lateral angles of normal MCAs were significantly wider than those of MCAs with aneurysms. The DA ratio was 1.5 ± 0.4 in normal MCAs and 1.7 ± 0.7 in MCAs with aneurysms; this difference was significant (p < 0.05). The LA ratio was 1.3 ± 0.4 in normal MCAs and 2.1 ± 1.4 in MCAs with aneurysms; these values were also significantly different (p < 0.01). Normal cerebral artery bifurcations show close to symmetric structure in the M2 branches and the lateral angles, whereas aneurysmal MCAs do not show this symmetry.

Type C and equality of the diameters of two daughter arteries, together with high AP ratios, seem to be morphological factors that associate with aneurysmal rupture.

Chronic subdural hematoma patients with frailty had a poorer prognosis than those without (median modified Rankin Scale: 4 and 2, P < 0.001; proportions of patients discharged to home: 35% and 91%, P < 0.001, respectively). After adjusting for patients' background, the patients' modified Rankin Scale scores at 3 months after surgery were found to be associated with age, controlling nutritional status score and recurrence, but not with frailty. However, receiver operating characteristic curves of the model with the Clinical Frailty Scale were more accurately correlated with prognosis than those of the model without this scale (area under the curve 0.98, 95% confidence interval 0.96-0.99; and 0.87, 95% confidence interval 0.82-0.91, respectively.) CONCLUSIONS: Chronic subdural hematoma patients with frailty had poorer prognosis than those without. The evaluation of the presence of frailty on admission can be an important factor in the prediction of the prognosis of chronic subdural hematoma patients. Geriatr Gerontol Int 2018; 18: 1173-1176.

A 77-year-old man presented with a metastatic brain tumor 15 years after nephrectomy for a renal cell carcinoma. Neurological examination showed recent memory disturbance and slight right hemiparesis. Magnetic resonance imaging revealed a round well-demarcated mass extending from the left thalamus to the left trigone of the lateral ventricle. Preoperative angiography showed tumor staining. Surgery was performed by opening the inferior temporal sulcus. Only biopsy could be performed because of extensive bleeding from the tumor. Histological examination identified metastatic renal cell carcinoma. Gamma knife surgery was performed which resulted in resolution of his hemiparesis. Metastatic renal cell carcinoma should be considered even if nephrectomy was performed 10 or more years before presentation.