Midcervical central cord syndrome: numb and clumsy hands due to midline cervical disc protrusion at the C3-4 intervertebral level.

Eight patients with midline cervical disc protrusion at the C3-4 intervertebral level showed unusual clinical signs: numbness in the finger tips and palms, clumsiness of the hands, and a tightening sensation at the midthoracic level. The proprioceptive and cutaneous sensory afferents essential for motor control of the upper limbs were preferentially involved, tactile discrimination of passively given stimuli being spared. Somatosensory evoked potentials subsequent to median nerve stimulation showed conduction failure through the fasciculus cuneatus, as evidenced by absent or delayed and attenuated medullary and scalp potentials. The potential originating in the lower cervical cord (N13a) had a low amplitude, indicative of the caudal extension of the lesion. On the basis of the functional anatomy of the intraspinal pathways, especially of the dorsal columns, it is concluded that involvement of the central cord at the C3-4 intervertebral level and its caudal extension is responsible for the syndrome.