Minna Wäljas

Persistent symptoms in mild to moderate traumatic brain injury associated with executive dysfunction

In order to improve detection of subtle cognitive dysfunction and to shed light on the etiology of persistent symptoms after mild-to-moderate traumatic brain injury (TBI), we employed an experimental executive reaction time (RT) test, standardized neuropsychological tests, and diffusion tensor imaging (DTI). The Executive RT-Test, an Executive Composite Score from standardized neuropsychological tests, and DTI-indices in the midbrain differentiated between patients with persistent symptoms from those fully recovered after mild-to-moderate TBI. We suggest that persistent symptoms in mild-to-moderate TBI may reflect disrupted fronto-striatal network involved in executive functioning, and the Executive RT-Test provides an objective and novel method to detect it.

Outcome from Complicated versus Uncomplicated Mild Traumatic Brain Injury

Objective. To compare acute outcome following complicated versus uncomplicated mild traumatic brain injury (MTBI) using neurocognitive and self-report measures. Method. Participants were 47 patients who presented to the emergency department of Tampere University Hospital, Finland. All completed MRI scanning, self-report measures, and neurocognitive testing at 3-4 weeks after injury. Participants were classified into the complicated MTBI or uncomplicated MTBI group based on the presence/absence of intracranial abnormality on day-of-injury CT scan or 3-4 week MRI scan. Results. There was a large statistically significant difference in time to return to work between groups. The patients with uncomplicated MTBIs had a median of 6.0 days (IQR = 0.75–14.75, range = 0–77) off work compared to a median of 36 days (IQR = 13.5–53, range = 3–315) for the complicated group. There were no significant differences between groups for any of the neurocognitive or self-report measures. There were no differences in the proportion of patients who (a) met criteria for ICD-10 postconcussional disorder or (b) had multiple low scores on the neurocognitive measures. Conclusion. Patients with complicated MTBIs took considerably longer to return to work. They did not perform more poorly on neurocognitive measures or report more symptoms, at 3-4 weeks after injury compared to patients with uncomplicated MTBIs.

Recovery from Mild Traumatic Brain Injury in Previously Healthy Adults.

This prospective longitudinal study reports recovery from mild traumatic brain injury (MTBI) across multiple domains in a carefully selected consecutive sample of 74 previously healthy adults. The patients with MTBI and 40 orthopedic controls (i.e., ankle injuries) completed assessments at 1, 6, and 12 months after injury. Outcome measures included cognition, post-concussion symptoms, depression, traumatic stress, quality of life, satisfaction with life, resilience, and return to work. Patients with MTBI reported more post-concussion symptoms and fatigue than the controls at the beginning of recovery, but by 6 months after injury, did not differ as a group from nonhead injury trauma controls on cognition, fatigue, or mental health, and by 12 months, their level of post-concussion symptoms and quality of life was similar to that of controls. Almost all (96%) patients with MTBI returned to work/normal activities (RTW) within the follow-up of 1 year. A subgroup of those with MTBIs and controls reported mild post-concussion-like symptoms at 1 year. A large percentage of the subgroup who had persistent symptoms had a modifiable psychological risk factor at 1 month (i.e., depression, traumatic stress, and/or low resilience), and at 6 months, they had greater post-concussion symptoms, fatigue, insomnia, traumatic stress, and depression, and worse quality of life. All of the control subjects who had mild post-concussion-like symptoms at 12 months also had a mental health problem (i.e., depression, traumatic stress, or both). This illustrates the importance of providing evidence-supported treatment and rehabilitation services early in the recovery period.

Mild Traumatic Brain Injury: Tissue Texture Analysis Correlated to Neuropsychological and DTI Findings

RATIONALE AND OBJECTIVES The aim of this study was to evaluate whether texture analysis (TA) can detect subtle changes in cerebral tissue caused by mild traumatic brain injury (MTBI) and to determine whether these changes correlate with neuropsychological and diffusion tensor imaging (DTI) findings. MATERIALS AND METHODS Forty-two patients with MTBIs were imaged using 1.5T magnetic resonance imaging within 3 weeks after head injury. TA was performed for the regions corresponding to the mesencephalon, centrum semiovale, and corpus callosum. Using DTI, the fractional anisotropic and apparent diffusion coefficient values for the same regions were evaluated. The same analyses were performed on a group of 10 healthy volunteers. Patients also underwent a battery of neurocognitive tests within 6 weeks after injury. RESULTS TA revealed textural differences between the right and left hemispheres in patients with MTBIs, whereas differences were minimal in healthy controls. A significant correlation was found between scores on memory tests and texture parameters (sum of squares, sum entropy, inverse difference moment, and sum average) in patients in the area of the mesencephalon and the genu of the corpus callosum. Significant correlations were also found between texture parameters for the left mesencephalon and both fractional anisotropic and apparent diffusion coefficient values. CONCLUSIONS The data suggest that heterogeneous texture and abnormal DTI patterns in the area of the mesencephalon may be linked with verbal memory deficits among patients with MTBIs. Therefore, TA combined with DTI in patients with MTBIs may increase the ability to detect early and subtle neuropathologic changes.

Return to work following mild traumatic brain injury.

Objective:To examine factors relating to return to work (RTW) following mild traumatic brain injury (mTBI). Participants:One hundred and nine patients (Age: M = 37.4 years, SD = 13.2; 52.3% women) who sustained an mTBI. Design:Inception cohort design with questionnaires and neuropsychological testing completed approximately 3 to 4 weeks postinjury. Setting:Emergency Department of Tampere University Hospital, Finland. Main Outcome Measures:Self-report (postconcussion symptoms, depression, fatigue, and general health) and neurocognitive measures (attention and memory). Results:The cumulative RTW rates were as follows: 1 week = 46.8%, 2 weeks = 59.6%, 3 weeks = 67.0%, 4 weeks = 70.6%, 2 months = 91.7%, and 1 year = 97.2%. Four variables were significant predictors of the number of days to RTW: age, multiple bodily injuries, intracranial abnormality at the day of injury, and fatigue ratings (all P < .001). The largest amount of variance accounted for by these variables in the prediction of RTW was at 30 days following injury (P < .001, R2 = 0.504). Participants who returned to work fewer than 30 days after injury (n = 82, 75.2%) versus more than 30 days (n = 27, 24.8%) did not differ on demographic or neuropsychological variables. Conclusions:The vast majority of this cohort returned to work within 2 months. Predictors of slower RTW included age, multiple bodily injuries, intracranial abnormality at the day of injury, and fatigue.

Resilience is associated with outcome from mild traumatic brain injury

Resilient individuals manifest adaptive behavior and are better able to recover from adversity. The association between resilience and outcome from mild traumatic brain injury (mTBI) is examined, and the reliability and validity of the Resilience Scale and its short form in mTBI research is evaluated. Patients with mTBI (n=74) and orthopedic controls (n=39) completed the Resilience Scale at one, six, and 12 months after injury. Additionally, self-reported post-concussion symptoms, fatigue, insomnia, pain, post-traumatic stress, and depression, as well as quality of life, were evaluated. The internal consistency of the Resilience Scale and the short form ranged from 0.91 to 0.93 for the mTBI group and from 0.86 to 0.95 for controls. The test-retest reliability ranged from 0.70 to 0.82. Patients with mTBI and moderate-to-high resilience reported significantly fewer post-concussion symptoms, less fatigue, insomnia, traumatic stress, and depressive symptoms, and better quality of life, than the patients with low resilience. No association between resilience and time to return to work was found. Resilience was associated with self-reported outcome from mTBI, and based on this preliminary study, can be reliably evaluated with Resilience Scale and its short form in those with mTBIs.

To exclude or not to exclude: White matter hyperintensities in diffusion tensor imaging research

Objective: A practical methodological issue for diffusion tensor imaging (DTI) researchers is determining what to do about incidental findings, such as white matter hyperintensities (WMHI). The purpose of this study was to compare healthy control subjects with or without WMHIs on whole brain DTI. Method: Participants were 30 subjects (age = 37.7, SD = 11.3, Range = 18–60; 70% female) who had no known developmental, general medical, neurological or psychiatric condition that could have had an adverse affect on brain morphology. Results: MRI (3 Tesla) revealed, at minimum, a WMHI in eight subjects (26.7%). Fractional anisotropy (FA) was calculated for 19 regions of interest (ROI). Frequency distributions of FA scores for the 19 ROIs were calculated. The 10th percentile for each ROI was selected as a cut-off score. Having four or more low FA scores occurred in 16.7%. More subjects with incidental findings met criterion for low FA scores (37.5%), compared to 9.1% of subjects with no findings. When subjects with minor WMHIs were retained and only those with multiple incidental findings were excluded, 8.3% of the retained subjects met criterion for low FA scores compared to 50.0% of the excluded subjects. Conclusions: The decision to include or exclude subjects who have incidental findings can influence the results of a study.

Resilience is associated with fatigue after mild traumatic brain injury.

Objective:To examine resilience as a predictor of change in self-reported fatigue after mild traumatic brain injury (MTBI). Participants:A consecutive series of 67 patients with MTBI and 34 orthopedic controls. Design: Prospective longitudinal study. Main Measures:Resilience Scale, Beck Depression Inventory–Second Edition, and Pain subscale from Ruff Neurobehavioral Inventory 1 month after injury and Barrow Neurological Institute Fatigue Scale 1 and 6 months after injury. Results:Insomnia, pain, and depressive symptoms were significantly correlated with fatigue, but even when these variables were controlled for, resilience significantly predicted the change in fatigue from 1 to 6 months after MTBI. In patients with MTBI, the correlation between resilience and fatigue strengthened during follow-up. In controls, significant associations between resilience and fatigue were not found. Conclusion:Resilience is a significant predictor of decrease in self-reported fatigue following MTBI. Resilience seems to be a relevant factor to consider in the management of fatigue after MTBI along with the previously established associated factors (insomnia, pain, and depressive symptoms).

Reliability, validity and clinical usefulness of the BNI fatigue scale in mild traumatic brain injury

Objectives: The purpose of this study was to examine the reliability, validity and clinical usefulness of the Barrow Neurological Institute Fatigue Scale (BNI-FS) in patients with mild traumatic brain injuries (MTBI). Methods and procedure: Participants were 125 patients enrolled from the Emergency Department (ED) of Tampere University Hospital, Finland who had sustained an MTBI. The average number of days from injury to the interview and questionnaires was 24.1 (SD = 5.4, Range = 8–38). The patients were compared to a healthy control sample. Patients completed the Barrow Neurological Institute Fatigue Scale, Fatigue Impact Scale (FIS), Beck Depression Inventory-Second Edition (BDI-II), Rivermead Post-concussion Symptom Questionnaire (RPSQ) and the health assessment measure EuroQol five Dimension (EQ-5D) Visual Analogue Scale (VAS). Results: The MTBI group had significantly greater total scores on the BNI-FS than the control group (p < 0.005, Cohens d = 0.40). The internal consistency reliability for the BNI-FS, as measured by Cronbachs alpha, was 0.96 for the MTBI group and 0.87 for the control group. The 10 items were submitted to an exploratory principal components factor analysis with varimax rotation in the MTBI group. A one-factor solution, accounting for 73.3% of the total variance, appropriately summarized the data. The correlation between the BNI-FS and other measures was rs = 0.68 (p < 0.001) for the BDI-II, rs = 0.68 (p < 0.001) for the RPSQ, rs = −0.39 (p < 0.001) for the EQ-5D VAS and rs = 0.84 (p < 0.001) for the FIS. Fatigue ratings correlated positively with number of days post-injury before returning to work (rs = 0.27, p < 0.006). Conclusion: The BNI-FS is a relatively new, brief and highly reliable measure of fatigue.

Clinical correlates of retrograde amnesia in mild traumatic brain injury

Abstract Primary objective: The purpose of this study was to examine the clinical significance of retrograde amnesia (RA) in patients with acute mild traumatic brain injuries (MTBI). Methods and procedures: An emergency department sample of patients (n = 75), aged 18–60 years, with no pre-morbid medical or psychiatric conditions, who met the WHO criteria for MTBI were enrolled in this prospective, descriptive, follow-up study. This study examined the presence and duration of RA in relation to socio-demographics, MTBI severity markers including neuroimaging (CT, MRI) and clinical outcomes (Rivermead post-concussion symptoms questionnaire, post-concussion syndrome (PCS) diagnosis and return to work (RTW) status) at 2 weeks, 1 month and 6 months post-injury. Main outcomes and results: GCS scores and duration of post-traumatic amnesia (PTA) were related to RA. Those with GCS scores of 14 vs. 15 were more likely to have RA (χ2(1) = 13.70, p < 0.0001) and a longer duration (Mann-Whitney U = 56.0, p < 0.0001, d = 1.15) of RA. The duration of RA and PTA correlated positively (Spearman ρ(75) = 0.42, p < 0.0001) and those with RA had longer durations of PTA (Mann-Whitney U = 228.5, p = 0.001, d = 1.21). During the follow-up, the presence and duration of RA were not significantly associated with PCS diagnosis or time to RTW. Conclusions: In this study, the presence and duration of RA was not associated with outcome.