Introduction: DBS has been hypothesized to activate arousal input to the cortex to revive comatose patients. However, clinical trials have been inconsistent (Schiff, 2007). We hypothesize that minimally conscious state (MCS) represents regression of the brain’s default state (Buzsaki, 2011) that can no longer be perturbed by the normal ascending arousal input. We report our experience with rhythmic stimulation at EEG alpha frequency (Magnetic Resonant Therapy, MRT) to the frontal cortex to treat 2 comatose patients.
Methods: Two adolescent with TBI and MCS were treated with MRT. Case I: 19 yo male with initial GCS 3 and GCS 4t at 7 months. Case 2: 15 year old male with initial GCS 3, improving to E2M4Vt at 8 months. EEGs were recorded at treatment start, week 1 end, and each month’s end. MRT was delivered with a MagPro R30 (Mag Venture, Denmark) at stimulation intensity 80% motor threshold and rate determined by patients’ EEG, directed over the central frontal cortex for 6 sec/min, 30min/session/day.
Results: Case 1: Patient received 4 months of treatment as of report date. Patient responded to verbal commands at 2 weeks, continuing to improve. At four months, patient began walking and communicating verbally, performing simple calculations, and showing appropriate emotional responses.
Case 2: Patient received 6 weeks of treatment as of report date. After 4 weeks, patient could imitate manual movement and respond to simple verbal commands. At 6 weeks, patient could perform basic movements to cooperate with his care, with GCS improving to E4M5Vt.
Both Patients had increased posterior alpha activity and reduced delta activity by EEG.
Conclusions: MRT resulted in clinical improvements in TBI patients in MCS with positive EEG changes and similar improvement patterns, perhaps by recapitulating an arousal effect similar to subcortical input in the cortical/subcortical coupling model.
Patient Care: Understand options for coma patients.
Learning Objectives: Understand the cortical/subcortical coupling model of coma and neuromodulation for treatment.
References: Buzsaki G. “Rhythms of the Brain”. Oxford University Press, 2011.
Schiff ND, Giacino JT, Kalmar K, et al. Behavioural improvements with thalamic stimulation after severe traumatic brain injury. Nature. Aug 2 2007;448(7153):600-603.