Normal Imaging after Concussion Studies
“Computed tomography, magnetic resonance imaging, electroencephalogram, or routine neurological evaluations may be normal.”*
Normal imaging after concussion is not unheard of. It happens all of the time and creates a real problem with those who have suffered a TBI. If the injury is to the cells it is virtually impossible for those to show up on the imaging equipment that we have today. There are no pictures to show subtle brain injury.
Subtle brain injury can only be identified by a triangulated evaluation of these three things:
- The patients acute history,
- The patients long term symptomatology; and
- A detailed neuropsychological assessment.
Thus, when considering the relevancy of scanning in the diagnosis of brain injury, it is important to understand what each of the below diagnostic tests can tell us about brain damage.
*Source: Definition of Mild Traumatic Brain Injury Developed by the Mild Traumatic Brain Injury Committee of the Head Injury Interdisciplinary Special Interest Group of the American Congress of Rehabilitation Medicine.
J Head Trauma Rehabil 1993:8(3):86-87
Normal CT and MRI scans do not rule out brain injury.
Both of these tests are macroscopic. Axonal and neuronal brain injury are microscopic. In other words the images presented will show damage to the axons.
50% of those who are in a coma have normal MRI and CT scans.
In such cases, “it is usually concluded that the patient has sustained diffuse brain damage, but even with improved imaging, its precise type may not be identifiable during life.”
Greenfield’s Neuropathology, page 209
Again there isn’t any visible image on a scan to show traumatic brain injury and can go undiagnosed.
This is with patients who are in a Coma!
Computerized Tomography – CT