Associations among civilian mild traumatic brain injury with loss of consciousness, posttraumatic stress disorder symptom trajectories, and structural brain volumetric data.

Posttraumatic stress disorder (PTSD) is prevalent and associated with significant morbidity. Mild traumatic brain injury (mTBI) concurrent with psychiatric trauma may be associated with PTSD. Prior studies of PTSD-related structural brain alterations have focused on military populations. The current study examined correlations between PTSD, acute mTBI, and structural brain alterations longitudinally in civilian patients (N = 504) who experienced a recent Criterion A traumatic event. Participants who reported loss of consciousness (LOC) were characterized as having mTBI; all others were included in the control group. PTSD symptoms were assessed at enrollment and over the following year; a subset of participants (n = 89) underwent volumetric brain MRI (M = 53 days posttrauma). Classes of PTSD symptom trajectories were modeled using latent growth mixture modeling. Associations between PTSD symptom trajectories and cortical thicknesses or subcortical volumes were assessed using a moderator-based regression. mTBI with LOC during trauma was positively correlated with the likelihood of developing a chronic PTSD symptom trajectory. mTBI showed significant interactions with cortical thickness in the rostral anterior cingulate cortex (rACC) in predicting PTSD symptoms, r = .461-.463. Bilateral rACC thickness positively predicted PTSD symptoms but only among participants who endorsed LOC, p < .001. The results demonstrate positive correlations between mTBI with LOC and PTSD symptom trajectories, and findings related to mTBI with LOC and rACC thickness interactions in predicting subsequent chronic PTSD symptoms suggest the importance of further understanding the role of mTBI in the context of PTSD to inform intervention and risk stratification.

Acute Effects of Concussion in Youth With Pre-existing Migraines.

OBJECTIVE: To examine associations between pre-existing migraines and postconcussion symptoms and cognitive performance acutely (within 72 hours) after a suspected concussion. DESIGN: Nested case-control study. SETTING: High schools in Maine, USA. PARTICIPANTS: From a sample of 39 161 adolescent athletes who underwent baseline preseason testing, 633 were assessed within 3 days of a suspected concussion. Of these, 59 reported a history of treatment for migraines at baseline (9.3%). These athletes were individually matched to 2 athletes who had a suspected concussion but denied preinjury migraines (total N = 177; age: M = 15.8, SD = 1.3). ASSESSMENT OF RISK FACTORS: Self-reported history of treatment for migraines by a physician. MAIN OUTCOME MEASURES: Post-Concussion Symptom Scale total score, ImPACT composite scores, and individual symptom endorsement. RESULTS: Individuals with a pre-existing migraine disorder endorsed greater symptom severity (M = 8.4, SD = 9.9) compared with controls (M = 4.5, SD = 6.5; Cohen's d = 0.47) at preinjury baseline and acutely after suspected injury (migraine: M = 26.0, SD = 25.5; controls: M = 16.7, SD = 15.4; d = 0.44). Acutely after a suspected concussion, greater proportions of athletes with migraine disorders reported mental fogginess (49.2% vs 33.9%) and memory problems (39.0% vs 24.6%; P < 0.05). Baseline ImPACT composite scores were similar between migraine and control groups (d = 0.04-0.13). Adolescents with pre-existing migraine disorders performed worse after a suspected concussion compared with the control participants on verbal memory (F = 4.32, P = 0.041) and visual memory (F = 3.95, P = 0.049). CONCLUSIONS: Individuals with pre-existing migraine disorders may be at higher risk for worse outcomes, including greater overall burden of symptoms and worse cognitive functioning in the memory domain, in the first 72 hours after concussion.

Serum Neurofilament Light Is Elevated Differentially in Older Adults with Uncomplicated Mild Traumatic Brain Injuries.

Neurofilament light (NF-L) might have diagnostic and prognostic potential as a blood biomarker for mild traumatic brain injury (mTBI). However, elevated NF-L is associated with several neurological disorders associated with older age, which could confound its usefulness as a traumatic brain injury biomarker. We examined whether NF-L is elevated differentially following uncomplicated mTBI in older adults with pre-injury neurological disorders. In a case-control study, a sample of 118 adults (mean age = 62.3 years, standard deviation [SD] = 22.5, range = 18-100; 52.5% women) presenting to the emergency department (ED) with an uncomplicated mTBI were enrolled. All participants underwent head computed tomography in the ED and showed no macroscopic evidence of injury. The mean time between injury and blood sampling was 8.3 h (median [Md] = 3.5; SD = 13.5; interquartile range [IQR] = 1.9-6.0, range = 0.8-67.4, and 90% collected within 19 h). A sample of 40 orthopedically-injured trauma control subjects recruited from a second ED also were examined. Serum NF-L levels were measured and analyzed using Human Neurology 4-Plex A assay on a HD-1 Single Molecule Array (Simoa) instrument. A high correlation was found between age and NF-L levels in the total mTBI sample (r = 0.80), within the subgroups without pre-injury neurological diseases (r = 0.76) and with pre-injury neurological diseases (r = 0.68), and in the trauma control subjects (r = 0.76). Those with mTBIs and pre-injury neurological conditions had higher NF-L levels than those with no pre-injury neurological conditions (p < 0.001, Cohen's d = 1.01). Older age and pre-injury neurological diseases are associated with elevated serum NF-L levels in patients with head trauma and in orthopedically-injured control subjects.