[MRI findings of posterior spinal artery syndrome--report of a case].

A 58-year-old woman presented with sudden onset of numbness and weakness of the lower limbs. She showed paraparesis associated with hyperreflexia and pathological reflexes in lower limbs. She showed decreased sensation of vibration and proprioception in lower limbs, as well as tingling sensation below Th11 level. Pinprick and thermal sensations were spared. Magnetic resonance imaging (MRI) of the spinal cord revealed a symmetric high signal intensity area at the posterior medial part of the spinal cord spanning Th9 to Th11 on T2-weighted and proton density images. On the basis of clinical findings as well as MRI findings, we made a diagnosis of posterior spinal artery syndrome. The MRI findings are considered to be highly useful for the diagnosis of PSAS.