Change of ascending reticular activating system with recovery from vegetative state to minimally conscious state in a stroke patient

RATIONALE We report on a stroke patient who showed change of the ascending reticular activating system (ARAS) concurrent with recovery from a vegetative state (VS) to a minimally conscious state (MCS), which was demonstrated on diffusion tensor tractography (DTT). PATIENT CONCERNS A 59-year-old male patient underwent CT-guided stereotactic drainage 3 times for management of intracerebral hemorrhage and intraventricular hemorrhage. DIAGNOSIS After 4 months from onset, when starting rehabilitation, the patient showed impaired consciousness, with a Glasgow Coma Scale (GCS) score of 6 and a Coma Recovery Scale-Revised score of 2. At 10 months after onset, his GCS score had recovered to 11 with a GRS-R score of 20, and he was able to perform rock-scissors-paper using his right hand according to verbal command. INTERVENTIONS On 10-month DTT, marked increased neural connectivity of the thalamic intralaminar nucleus (ILN) to the cerebral cortex was observed in both prefrontal cortexes and the right thalamus compared with 4-month DTT. However, no significant change was observed in the lower dorsal ARAS between the pontine reticular formation (PRF) and the thalamic ILN. In addition, the reconstructed lower ventral ARAS between the PRF and hypothalamus had disappeared in both hemispheres on 10-month DTT. OUTCOMES Change of the ARAS was demonstrated in a stroke patient who showed recovery from a VS to an MCS. LESSONS It appeared that the prefrontal cortex and thalamus, which showed increased neural connectivity, contributed to recovery from a VS to an MCS in this patient.