CNS trauma: Imaging

Question 1

Dopaminergic abnormalities following traumatic brain injury (Brain vol 141(3) 2018)

Answer 1

• TBI can reduce striatal dopamine levels, thought to be due to damage to the nigrostriatal system
• Investigated pattern of abnormalities using SPECT scans in brain injury patients. MRI assessed the nigrostriatal system
• Dopamine transport abnormalities were associated with reduced SN volume.
• Small percentage of patients had evidence of macroscopic lesions and there was no relationship between presence of lesions and dopamine transporter specific binding ratio abnormalities. There was also no relationship between reduced volume in the striatal subregions and reduced dopamine transporter specific binding ratios.
• Results showed dopaminergic system is affected by a moderate-severe TBI, most commonly shown in the caudate

Question 2

What is diffusion tensor immaging?

Answer 2

• A way to image for diffuse axonal injury
• Tracks the diffusion of water
• In injury, water diffuses with much less direction

Question 3

DaT imaging uses

Answer 3

• Dopamine imaging

- Low levels of imaging are identified and can be given dopamine treatment for this

Question 4

List types of imaging in TBI

Answer 4

• CT scanning good at blood and fractures
• MRI damage within the brain
• Susceptibility weighted imaging and DTI are informative in subtle imaging
• Imaging biomarkers can be useful, allowing clinical trials