Skip to main content
. 2021 Aug 24;42(16):5477–5494. doi: 10.1002/hbm.25630

TABLE 1.

Summary of mTBI studies using task‐based fMRI

Author Participants Task Major findings (activity alterations in mTBI patients)
Saluja et al. (2015) 15 mTBI pediatric patients, up to 3 months postinjury Spatial navigation task Diminished activation in the retrosplenial, thalamic, and parahippocampal areas bilaterally, along with the right dorsolateral prefrontal cortex and left precuneus; increased activation in the left hippocampus and right middle temporal gyrus.
Astafiev et al. (2015) 45 mTBI patients, 3 months to 5 years postinjury Visual tracking tasks Decrease in the right anterior internal capsule and right superior longitudinal fasciculus.
Hsu et al. (2015) 30 mTBI patients

  1. Within 1 month postinjury

  2. 6 weeks after (1)

 The N‐back

Increased activation of the bilateral frontal and parietal regions: In mTBI patients, decreased activation in 2‐back, 1‐back conditions were observed in female patients compared with female control subjects at the initial imaging study; increased activation in 2‐back, 1‐back conditions was observed in male patients compared with male control subjects.

At the 6‐week follow‐up study, female patients showed persistent hypoactivation, male patients showed a regression of hyperactivation to the level of activation similar to control subjects.
Wylie et al. (2015) 27 mTBI patients

  1. <72 hr post‐injury

  2. 1 week later

 The N‐back task Changes from time 1 to time 2 showed an increase in posterior cingulate activation; activation was increased greater in those mTBI subjects without cognitive recovery; in increased workload, activation increased in cortical regions in the right hemisphere.
Mayer et al. (2015) 46 mTBI patients within 3 weeks of injury; follow‐up examination 4 months postinjury Multisensory (audiovisual) cognitive control task Abnormal activation within different regions of visual cortex that depended on whether attention was focused on auditory or visual information streams: Increased activation within bilateral inferior parietal lobules during higher cognitive/perceptual loads. Functional abnormalities within the visual cortex and inferior parietal lobules were only partially resolved at 4 months postinjury.
Westfall et al. (2015) 19 adolescents with mTBI, 3–12 months postinjury Auditory–verbal N‐back task Increased activation during the most difficult part of the task was observed in cluster 1 (left sublobar insula, left middle temporal gyrus, and left superior temporal gyrus), cluster 2 (left precentral gyrus and left sublobar insula), and cluster 3 (right frontal lobe subgyral region and right medial frontal gyrus).
Van der Horn et al. (2016) 55 mTBI patients, 4 weeks postinjury The N‐back task Reduced activation within the medial prefrontal cortex; postconcussive complaints (PCC)‐absent patients showed stronger deactivation of the DMN compared with PCC‐present patients and HCs, especially during difficult task conditions; functional connectivity between the DMN and FEN was lower in PCC‐absent patients compared with PCC‐present patients.
Chen et al. (2016) 13 younger (21–30 years) and 13 older (51–68 years) mTBI patients

  1. Within 1 month postinjury

  2. 6 weeks after

 The N‐back task

Younger patients: Initial hyperactivation in the right precuneus and right inferior parietal gyrus in 2‐back > 1‐back conditions compared with younger HCs.

Older patients: Hypoactivation in the right precuneus and right inferior frontal gyrus compared with older HCs.
Wang et al. (2017) 44 mTBI patients, within 2 weeks postinjury Shifted‐attention emotion appraisal task (SEAT) Decreased activation in the response to fearful faces in clusters in the left superior parietal gyrus and left medial orbitofrontal gyrus, and bilaterally in the lateral orbitofrontal gyri.
Sullivan et al. (2018) 17 individuals with blast‐related mTBI Flanker task

Incongruent trials: Increased activation in the left superior parietal lobe, left dorsal anterior cingulate cortex, right supramarginal gyrus, and right lateral occipital cortex.

Error trials: Greater deactivation in the areas of the default mode network including the left dorsomedial prefrontal cortex (DLPFC) and left posterior cingulate cortex, precuneus.
Sours, Kinnison, Padmala, Gullapalli, and Pessoa (2018) 30 mTBI patients during chronic phase The N‐back task Decreased segregation between the DMN and task‐positive networks, elevation in functional connectivity within the DMN regions.
Holmes et al. (2019) 27 mTBI pediatric patients, high‐symptom and low‐symptom groups Spatial navigation task Low‐symptom group had an elevated activity in the frontal and occipital cortices; high‐symptom group had broader increased activity in the frontal region and in the cerebellum.
Khetani, Rohr, Sojoudi, Bray, and Barlow (2019) 60 individuals with PPCS and 30 recovered after mTBI, ~14 years old, 38 days after mTBI Visuospatial N‐back task Children with persistent postconcussive symptoms (PPCS) had decreased activation relative to the children with typical recovery in the posterior cingulate and precuneus during the one‐back working memory condition, despite similar task performance.
Ramage, Tate, New, Lewis, and Robin (2019) 60 individuals, 3–24 months postconcussion Constant effort task (CE) Hyper‐connectivity increased with an effort level but diminished quickly when maintaining the effort; connectivity between the left anterior insula, rostral anterior cingulate cortex, and right‐sided inferior frontal regions, correlated with effort‐level and state fatigue in mTBI participants.
Cook et al. (2020) Meta‐analysis of 7 studies: 174 patients, acute to subacute phase Memory and attention tasks Reduced activation within the right middle frontal gyrus (MFG).