Abstract
An 80-year-old male with a history of hypertension presented with chronic subdural hematoma manifesting as progressive consciousness disturbance and left hemiparesis. T1-weighted and fluid attenuation inversion recovery (FLAIR) magnetic resonance imaging showed a fresh hematoma in the right subdural space with a midline shift of 15 mm. FLAIR and diffusion-weighted imaging showed a hyperintense area in the right paraventricular white matter compressed by the hematoma. Apparent diffusion coefficients (ADCs) corresponding to the hyperintense area in the central area of the affected cerebral hemisphere on FLAIR images were measured before and one month after the operation. The motion probing gradient was applied in the right-left direction to the body axis. Since the central area in the cerebrum includes nerve fibers perpendicular to the direction of the gradient, the measured ADC appeared to be anisotropic. Preoperative ADC in the right paraventricular white matter was anisotropic and greater than in age-matched normal subjects, so the edema was identified as the vasogenic type. The edema in the right paraventricular white matter resolved promptly with improvement of the midline shift and normalization of the ADC.
