Quantitative and qualitative analysis of ambulatory electroencephalography during mild traumatic brain injury

Arch Neurol. 2011 Dec;68(12):1595-8. doi: 10.1001/archneurol.2011.1080.

Abstract

Objectives: To characterize the neurophysiological changes in a patient with mild traumatic brain injury (mTBI) and to compare these changes with a small cohort of patients with neurocardiogenic syncope, an analogous cause of transient neurological dysfunction.

Design: Case report and quantitative analysis of a small electroencephalography (EEG) cohort.

Setting: University-affiliated teaching hospital.

Patients: A 64-year-old man with mTBI recorded on ambulatory EEG. The comparison group was 4 patients with spontaneous neurocardiogenic syncope during continuous video EEG recording.

Intervention: Quantitative and qualitative analysis of EEG.

Main outcome measures: Changes in quantitative EEG measurements between the patient with mTBI and the comparison group.

Results: In the patient with mTBI, there was an abrupt decrease in high-frequency (beta) power and alpha-delta ratio immediately after the injury and a corresponding increase in lower-frequency (alpha, theta, delta) power. The change in beta power resolved within 5 minutes of the injury, but the increases in low-frequency power persisted up to 20 minutes after the injury before resolving. Similar but smaller changes were seen in the patients with syncope, but these changes resolved within 5 minutes, with no intermediate or long-term changes.

Conclusions: The quantitative EEG changes in mTBI are initially similar to those in syncope, suggesting acute transient cortical dysfunction. However, there are longer-lasting increases in low-frequency power during mTBI, suggesting ongoing disruption of cortical-thalamic circuits.

Publication types

  • Case Reports
  • Comparative Study

MeSH terms

  • Accidents, Traffic*
  • Astrocytoma / surgery
  • Brain Injuries / physiopathology*
  • Brain Neoplasms / surgery
  • Electroencephalography*
  • Epilepsy / etiology
  • Humans
  • Male
  • Middle Aged
  • Syncope, Vasovagal / physiopathology*