We report on a 38-year-old female patient with acute proprioceptive sensory impairment and pseudoathetosis in the four limbs, particularly in the fingers of both hands. She had great difficulty in buttoning, unbuttoning, using chopsticks and writing, because she was no longer able to feel her fingers in space. There was a profound loss of position and vibration sensation in all limbs, especially in both hands. Pseudoathetoid movement, a rare presentation of multiple sclerosis, was observed in the outstretched hands and extended fingers. T1- and T2-weighted magnetic resonance imaging (MRI) of the spinal cord revealed an inactive intramedullary lesion in the C2-C5 segments. Gadolinium-enhanced MRI revealed an active lesion in the posterior columns of the cervical cord at the C3 vertebral level, which is very likely responsible for pseudoathetoid movement. Based on the disseminated lesions in the spinal cord verified by MRI the four neurologic manifestations, and the abnormal somatosensory-evoked potentials, we made a definitive diagnosis of multiple sclerosis of the spinal cord.