Impairment rating for conditions that affect the spinal cord is discussed in the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, Section 4.3. Spinal cord lesions produce varied and characteristic patterns of neurologic loss, depending on the portion of the cord affected, and the AMA Guides divides them into six categories: station and gait, use of upper extremities, respiration, urinary bladder dysfunction, anorectal dysfunction, and sexual functioning. With respect to station and gait, the functional result of the disorder is rated, not the underlying pathology (infarct, contusion, or otherwise), so that different conditions with similar functional outcomes can have similar ratings. Because many activities of daily living depend on dexterous use of the dominant upper limb, loss or loss of use of that extremity usually results in greater impairment than if the contralateral limb were involved. Section 4.3c addresses breathing only in terms of neurologic limitations, and other aspects are covered in chapters that address the respiratory system; criteria for neurologic impairment of the bladder (used to rate bladder dysfunction related to neurologic pathology, based primarily on ability to control bladder emptying); impairment ratings associated with anorectal dysfunction; and rating sexual functioning.