Delayed-Onset Central Pain due to Degeneration of Ischemic Transcallosal Fibers After Corpus Callosum Hemorrhage.

Abstract

A patient developed delayed-onset central pain due to degeneration of the spinothalamic tract resulting from degeneration of the ischemic transcallosal fibers, in the aftermath of a corpus callosum (CC) hemorrhage. The detection and diagnosis of these lesions using diffusion tensor tractography are described. A 59-yr-old man underwent conservative management for hemorrhages in the CC and lateral ventricle that resulted from hitting his head against a wall while falling. He began to feel pain in his right upper and lower extremities approximately 1½ yrs after the initial injury. The pain was characterized as constant tingling, numb, and cool sensation without allodynia or hyperalgesia (visual analogue scale score, 5). Disruption of transcallosal fibers in the genu and isthmus of the CC was observed on diffusion tensor tractography 1 mo after the initial injury. By 3 yrs, the diffusion tensor tractography showed that transcallosal fibers in the isthmus (67.8%-77.9%) of the CC had disappeared, and the left spinothalamic tract had become thinner. The results suggest that central pain can occur without direct injury of the spinothalamic tract and point up the need for evaluation of the spinothalamic tract and transcallosal fibers in patients with a CC lesion who complain of central pain.