Recovery of an Injured Cingulum via the Lateral Cholinergic Pathway in a Patient with Traumatic Brain Injury.

We report on a patient with traumatic brain injury who showed recovery of an injured cingulum via the lateral cholinergic pathway, using diffusion tensor tractography (DTT). A 63-year-old man underwent craniotomy for subarachnoid hemorrhage and subdural hemorrhage in both frontotemporal lobes, which occurred by hitting his head against a floor after falling from approximately 2 m. The Wechsler Intelligence Scale and the Seoul neuropsychological screening battery were used for evaluation of cognitive function. At 4 weeks after onset, the patient exhibited mild cognitive impairment (total IQ, 85; verbal immediate recall, 26.76 percentile; visual immediate recall, 29.81 percentile; verbal delayed recall, 24.51 percentile; visual delayed recall, 11.70 percentile). By contrast, at the 9-month evaluation, the cognitive impairment had improved as much as total IQ, 96; verbal immediate recall, 56.75 percentile; visual immediate recall, 89.49 percentile; verbal delayed recall, 78.23 percentile; and visual delayed recall, 89.07 percentile. On 4-week DTT, discontinuations were observed superior to the genu of the corpus callosum in both cingula. However, on 9-month DTT, the discontinued anterior part of the right cingulum was elongated inferoposteriorly through an unusual neural tract, which ran through the external capsule and the white matter of the temporo-occipital lobes. The results of this study seem to suggest a mechanism for recovery of an injured cingulum after brain injury.