High cervical chordotomy has been performed for the past few years following Foerster's demonstration that pain and temperature fibers cross over immediately or at most ascend one segment before crossing over to form the spinothalamic tract. Foerster1advocated section of the spinothalamic tract as high as the second cervical segment and was the first to produce a unilateral analgesia nearly to that dermatome. This has proved to be an important contribution to Spiller's operation. Bilateral chordotomy in the upper cervical segments should not be performed because of the danger of respiratory paralysis. The phrenic nerves arise chiefly from cells in the fourth cervical segment. The exact location of the tracts descending to these cell bodies is unknown. Theoretically, at least, edema following section of the anterolateral tracts might involve these descending fibers or the phrenic cells in the anterior horns as well as the motor tracts of the intercostal