Diffuse Axonal Injury

Excerpt

Diffuse axonal injury (DAI) is a type of traumatic brain injury (TBI) that results from a blunt injury to the brain. In the United States, traumatic brain injury is a leading cause of death and disability among children and young adults. The Center for Disease Control and Prevention (CDC) estimates that there are over 1.5 million reported cases of traumatic brain injury every year in the United States. Traumatic brain injury is classified as mild, moderate, and severe based on the Glasgow coma scale (GCS). Traumatic brain injury patients with GCS of 13 to 15 are classified to be mild, which includes the majority of traumatic brain injury patients. Patients with a GCS of nine to 12 are considered to have a moderate traumatic brain injury, while patients with a GCS below eight are classified as having a severe traumatic brain injury.

The GCS measures the following three functions:

1. Eye Opening (E): 4-spontaneous, 3-to voice, 2-to pain, 1-none

2. Verbal Response (V): 5-normal conversation, 4-oriented conversation, 3-words, but not coherent, 2-no words, only sounds, 1-none

3. Motor Response (M): 6-normal, 5-localized to pain, 4-withdraws to pain, 3-decorticate posture, 2-decerebrate

Diffuse axonal injury (DAI) primarily affects the white matter tracts in the brain. Clinically, patients with DAI can present in a spectrum of neurological dysfunction. This can range from clinically insignificant to a comatose state. However, most patients with DAI are identified to be severe and commonly have a GCS of less than 8. A diffuse axonal injury is a clinical diagnosis.