What If the MRI Brain Looks Normal but cognition is not?

It’s a common scenario in personal injury cases: A client with a mild Traumatic Brain Injury (mTBI) reports significant cognitive difficulties—memory lapses, slowed thinking, attention problems—yet their MRI or CT scan is completely normal. Does that mean the cognitive issues aren’t real? Not at all.

Traditional MRI is excellent at detecting structural damage like bleeding or lesions, but it can’t detect subtle microstructural changes that can disrupt cognitive function. Until recently, neuropsychological assessment was the only way to prove the existence of these changes.

Now, advanced imaging techniques are emerging that can detect these subtle changes, even in mTBI cases where conventional imaging is clear:
🔹 Diffusion Tensor Imaging (DTI) – Examines the integrity of white matter tracts that connect different parts of the brain, revealing disruptions linked to slowed processing speed and memory issues.
🔹 Neurite Orientation Dispersion and Density Imaging (NODDI) – Measures neurite density and organisation, detecting microstructural changes associated with impaired attention and executive function.

Research shows that even when cognitive function appears normal on the surface, these imaging techniques can reveal subtle white matter disorganisation that correlates with cognitive difficulties.

However, these tools are currently only available in research settings and are not yet used in standard clinical practice. Their legal acceptance is also limited—especially in Australia, where as far as I am aware, they have not yet been presented in court. In the US, DTI has been admitted in some mTBI cases, but its use remains controversial due to debates about methodological reliability and admissibility standards.

This makes neuropsychological assessment essential for determining how these brain changes affect daily life—something no imaging technique can fully capture.

Have you encountered cases where MRI didn’t explain cognitive complaints? Let’s discuss how advanced imaging and neuropsychology can provide a clearer picture.

Some References:
Anderson JFI, Oehr LE, Chen J, Maller JJ, Seal ML and Yang JY-M (2023) The relationship between cognition and white matter tract damage after mild traumatic brain injury in a premorbidly healthy, hospitalised adult cohort during the post-acute period. Front. Neurol. 14:1278908.

Huang, S., Huang, C., Li, M., Zhang, H., & Liu, J. (2022). White Matter Abnormalities and Cognitive Deficit After Mild Traumatic Brain Injury: Comparing DTI, DKI, and NODDI. Frontiers in Neurology, 13, 803066.