Differences in the thalamocortical tract of the ascending reticular activating system in disorders of consciousness after hypoxic-ischemic brain injury: A pilot study

This study purposed to investigate differences in the thalamocortical tract of the ascending reticular activating system between vegetative state (VS) and minimally conscious state (MCS) patients with hypoxic-ischemic brain injury (HI-BI). Fourteen patients with disorders of consciousness following HI-BI (VS group: 7 patients, MCS group: 7 patients) and 12 normal subjects were recruited. The 5 parts of reconstructed thalamocortical tract were prefrontal cortex (PFC), premotor cortex, primary motor cortex (M1), primary somatosensory cortex (S1), and posterior parietal cortex (PPC). The fractional anisotropy (FA) value and tract volume (TV) in each part of the thalamocortical tract were estimated. The FA values and TV of all parts of the thalamocortical tract in the VS group and the FA values of all parts and TV of PFC, premotor cortex, and PPC parts in the MCS group were lower than the control group (P < .05). In addition, the FA values of PFC and PPC parts were significantly lower in the VS group than the MCS group (P < .05). The results of our pilot study indicate that PFC and PPC parts of the thalamocortical tract are important areas to assess for differentiation of VS and MCS after HI-BI.