Ann Rehabil Med.  2019 Feb;43(1):106-110. 10.5535/arm.2019.43.1.106.

Global Synchronization Index as an Indicator for Tracking Cognitive Function Changes in a Traumatic Brain Injury Patient: A Case Report

  • 1Department of Physical Medicine and Rehabilitation, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea.


Traumatic brain injury is a main cause of long-term neurological disability, and many patients suffer from cognitive impairment for a lengthy period. Cognitive impairment is a fatal malady to that limits active rehabilitation, and functional recovery in patients with traumatic brain injury. In severe cases, it is impossible to assess cognitive function precisely, and severe cognitive impairment makes it difficult to establish a rehabilitation plan, as well as evaluate the course of rehabilitation. Evaluation of cognitive function is essential for establishing a rehabilitation plan, as well as evaluating the course of rehabilitation. We report a case of the analysis of electroencephalography with global synchronization index and low-resolution brain electromagnetic tomography applied, for evaluation of cognitive function that was difficult with conventional tests, due to severe cognitive impairment in a 77-year-old male patient that experienced traumatic brain injury.


Electroencephalography; Cognition; Traumatic brain injuries

MeSH Terms

Brain Injuries*
Cognition Disorders


  • Fig. 1. Experimental design. Brain computed tomography taken at emergency room revealed subdural hemorrhage (A) and brain magnetic resonance imaging (MRI) taken at 8 months after trauma revealed prefrontal contusion (B). The patient received cognitive rehabilitation including cognitive therapy, medications, and transcranial direct current stimulation (tDCS). The cognitive function was assessed using Rancho Los Amigos (RLA) scale, Korean version of the Mini-Mental State Examination (K-MMSE), and electroencephalography (EEG) at the date that the brain MRI was taken and followed up after 20 days.

  • Fig. 2. LORETA analysis comparing the first and second EEG. Increased activities in the second EEG compared to the first EEG are highlighted in blue. Meanwhile, decreased activities between are highlighted in yellow-red. Each of the bands is composed of delta (1.5–4 Hz), theta (4–8 Hz), alpha1 (8–10 Hz), alpha2 (10–13 Hz), beta1 (13–18 Hz), beta2 (18–21 Hz), and beta3 (21–30 Hz) in ranges. LORETA, low resolution brain electromagnetic tomography; EEG, electroencephalography.


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