Localization and Identification of Brain Microstructural Abnormalities in Paediatric Concussion.

In the United States, approximately 2.53 million people sustain a concussion each year. Relative to adults, youth show greater cognitive deficits following concussion and a longer recovery. An accurate and reliable imaging method is needed to determine injury severity and symptom resolution. The primary objective of this study was to characterize concussions with diffusion tensor imaging (DTI). This was performed through a normative Z-scoring analysis of DTI metrics, fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD), to quantify patient-specific injuries and identify commonly damaged brain regions in paediatric concussion patients relative to healthy controls. It was hypothesized that personalizing the detection analysis through normative Z-scoring would provide an understanding of trauma-induced microstructural damage. Concussion patients were volunteers recruited from the Emergency Department of the McMaster Children's Hospital with a recent concussion (n = 26), 9 males and 17 females, mean age 14.22 ± 2.64, while healthy paediatric brain DTI datasets (25 males and 24 females, mean age 13.52 ± 1.03) were obtained from an MRI data repository. Significant abnormalities were commonly found in the longitudinal fasciculus, fronto-occipital fasciculus, and corticospinal tract, while unique abnormalities were localized in a number of other areas reflecting the individuality of each child's injury. Total injury burden, determined by the number of regions containing outliers per DTI metric per patient, was used as the metric to quantify the overall injury severity of each patient. The primary outcome of this analysis found that younger patients experienced a significantly greater injury burden when measured using fractional anisotropy (p < 0.001). These results show that DTI was able to detect microstructural changes caused by concussion, on a per-person basis, and has the potential to be a useful tool for improving diagnostic accuracy and prognosis of a concussion.

Post-concussive depression: evaluating depressive symptoms following concussion in adolescents and its effects on executive function.

Background: Post-concussive depression describes an elevation of depressive symptoms following concussion that occurs in conjunction with other symptoms of concussion. Children with concussion are more likely to diagnosed with depression. The overlapping symptoms between clinical depression and concussion make the diagnosis of depression difficult. The purpose of this study is to explore how post-concussive depression relates to post-concussion symptoms and cognition by investigating symptom-reporting in youth with post-concussive depression and executive function.Methods: Adolescents (age 10-17 years) diagnosed with concussion were divided into two groups based on depression scores on the Children's Depression Inventory (post-concussion depression; non-depression groups). Symptom reporting on the Post-Concussion Symptom Inventory and performance on Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) were compared.Results: Participants with post-concussive depression had heightened emotionality, irritability, and nervousness. Sadness and fatigue were reported by both groups. ImPACT was unable to distinguish between groups but the group overall demonstrated severe neurocognitive deficits.Conclusion: Reports of greater emotionality, irritability, and nervousness on concussion symptom scales may be indicators of post-concussion depression. It is important for clinicians to take note when an adolescent with concussion scores high on these three emotional symptoms as they may be indicative of greater emotional distress.

An Emotional Go/No-Go fMRI study in adolescents with depressive symptoms following concussion.

BACKGROUND: Following concussion, adolescents may experience both poor inhibitory control and increased depressive symptoms. fMRI research suggests that adolescents with major depressive disorder have abnormal physiological responses in the frontostriatal pathway, and exhibit poorer inhibitory control in the presence of negatively-aroused images. The scarcity of information surrounding depression following concussion in adolescents makes it difficult to identify patients at risk of depression after injury. This is the first study to examine neural activity patterns in adolescents with post-concussive depressive symptoms. PURPOSE: To explore the effect of depressive symptoms on inhibitory control in adolescents with concussion in the presence of emotional stimuli using fMRI. METHODS: Using a prospective cohort design, 30 adolescents diagnosed with concussion between 10 and 17years were recruited. The Children's Depression Inventory questionnaire was used to divide participants into two groups: average or elevated levels of depressive symptoms. Participants completed an Emotional Go/No-Go task involving angry or neutral faces in a 3Telsa MRI scanner. RESULTS: Eleven participants had elevated depressive symptoms, of which 72% were hit in the occipital region of the head at the time of injury. fMRI results from the Emotional Go/No-Go task revealed activity patterns in the overall sample. Faces activated regions associated with both facial and cognitive processing. However, frontal regions that are usually associated with inhibitory control were not activated. Adolescents with elevated levels of depressive symptoms engaged more frontal lobe regions during the task than the average group. They also showed a trend towards worse symptoms following MRI scanning. CONCLUSIONS: Adolescents with elevated depressive symptoms engaged brain regions subserving evaluative processing of social interactions. This finding provides insight into the role the environment plays in contributing to the cognitive demands placed on adolescents recovering from concussion.