A study of persistent post-concussion symptoms in mild head trauma using positron emission tomography

Complaints of persistent cognitive deficits following mild head trauma are often uncorroborated by structural brain imaging and neuropsychological examination.

To investigate, using positron emission tomography (PET), the in vivo changes in regional cerebral uptake of 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG) and regional cerebral blood flow (rCBF) in patients with persistent symptoms following mild head trauma.

Five patients with mild head trauma and five age and education matched healthy controls were imaged using FDG-PET to measure differences in resting regional cerebral glucose metabolism. Oxygen-15 labelled water (H(2)(15)O)-PET was also used to measure group differences in rCBF changes during a spatial working memory task. In addition, neuropsychological testing and self report of dysexecutive function and post-concussion symptoms were acquired to characterise the sample.

There was no difference between patients and controls in normalised regional cerebral FDG uptake in the resting state in frontal and temporal regions selected a priori. However, during the spatial working memory task, patients had a smaller increase in rCBF than controls in the right prefrontal cortex.

Persistent post-concussive symptoms may not be associated with resting state hypometabolism. A cognitive challenge may be necessary to detect cerebral changes associated with mild head trauma.