Segmental or spinal myoclonus is an uncommon involuntary movement in infancy which has been attributed to sepsis, degenerative and developmental diseases of the spinal cord, birth trauma, and sclerosing panencephalitis. A premature infant presenting with segmental myoclonus associated with extreme hyperglycorrhachia secondary to the administration of parenteral nutrition through a femoral percutaneous indwelling central catheter that had inadvertently migrated into a paravertebral vein is reported. We recommend a lateral abdominal radiograph in addition to the usual anteroposterior view to confirm the correct placement of femoral catheters.