Abnormal whole-brain functional networks in homogeneous acute mild traumatic brain injury
Shumskaya E et al. – The authors proved that whole–brain functional connectivity is altered early (within 4 weeks) after mild traumatic brain injury (MTBI), suggesting that changes in functional networks underlie the cognitive deficits and postconcussive complaints reported by patients with MTBI.Methods
- Thirty-five patients with acute MTBI and 35 healthy control subjects, matched in age, gender, handedness, and education, underwent resting-state fMRI, susceptibility weighted imaging, neuropsychological, and postconcussive symptom assessments.
- The authors ensured the homogeneity of the patient group by limiting the injury mechanism to fronto-occipital impacts.
- Alterations in functional connectivity were analyzed by using data-driven independent component analysis, which is not biased by a priori region selection.
- They found a decrease in functional connectivity within the motor-striatal network in the MTBI group.
- At the same time, patients showed deficits in psychomotor speed as well as in speed of information processing.
- They propose that although disorders in motor function after MTBI are rarely reported, injury still has an effect on motor functioning, which in its turn may also explain the reduction in speed of information processing.
- Further, they found a cluster of increased functional connectivity in the right frontoparietal network in the MTBI group.
- They suggest that this abnormal increased connectivity might reflect increased awareness to external environment and explain excessive cognitive fatigue reported by patients with MTBI.
- It might also underlie the physical postconcussive symptoms, such as headache and increased sensitivity to noise/light.