Jared M. Bruce

Diffusion-weighted imaging predicts cognitive impairment in multiple sclerosis

Following a previous study with diffusion tensor imaging, we investigated the correlation between diffusion-weighted imaging (DWI) and cognitive dysfunction in multiple sclerosis (MS). We studied 60 MS patients (mean age 45.8±9.0 years) using 1.5-T MRI. Disease course was RR=40 and SP = 20. Mean disease duration was 12.8±8.7 years. Mean EDSS was 3.4±1.7. Whole brain, gray and white matter normalized volumes were calculated on 3D SPGR T1-WI using a fully automated Hybrid SIENAX method. Parenchymal mean diffusivity (PMD) maps were created after automated segmentation of the brain parenchyma and cerebrospinal fluid using T2-WI and DW images. Histogram analysis was performed and DWI indices of peak position (PP), peak height (PH), mean parenchymal diffusivity (MPD) and entropy were obtained. Neuropsychological (NP) evaluation emphasized auditory/verbal and visual/spatial memory, as well as processing speed and executive function. We found significant correlations between DWI and performance in all cognitive domains. Overall, stronger correlations emerged for MPD and entropy than other DWI measures, although all correlations were in the expected direction. The strongest association was between DWI entropy and performance on the Symbol Digit Modalities Test, which assesses processing speed and working memory (r = -0.54). Fisher r to z transformations revealed that DWI, gray matter (GMF) and whole brain (BPF) atrophy, T1-lesion volume (LV) and T2-LV all accounted for similar amounts of variance in NP testing. Stepwise regression models determined whether multiple MRI measures predicted unique additive variance in test performance. GMF (R2 = 0.35, F =30.82, P <0.01) and entropy (ΔR2 =0.06, ΔF=5.47, P <0.05) both accounted for unique variance in processing speed. Our data make a stronger case for the clinical validity of DWI in MS than heretofore reported. DWI has very short acquisition times, and the segmentation method applied in the present study is reliable and fully automated. Given its overall simplicity and moderate correlation with cognition, DWI may offer several logistic advantages over more traditional MRI measures when predicting the presence of NP impairment. Multiple Sclerosis 2007; 13: 722-730. http://msj.sagepub.com

The Utility of Post-Concussion Neuropsychological Data in Identifying Cognitive Change Following Sports- Related MTBI in the Absence of Baseline Data

Neuropsychological tests have become commonplace in the assessment of sports-related concussion. Typically, post-injury test data are compared to pre-injury “baselines.” Baseline testing can be expensive and logistically challenging, yet the usefulness of neuropsychological baseline testing has not been tested empirically. This paper examines the extent to which baseline testing is useful for detecting neurocognitive deficits following sports concussion in a college-age population. A total of 223 collegiate athletes from multiple sports who sustained concussions and had both baseline and post-injury testing using Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) were included in the study. Reliable change (RC) in scores was determined by two approaches, the Jacobson and Truax (JT) and the Gulliksen-Lord-Novick (GLN) methods. The 90% confidence interval was used for both. Classification using these methods was compared to standard normative methods that compared post-concussion performance to baseline population means. Agreement between reliable change and normative methods was examined using Cohens Kappa scores to determine whether post-injury scores alone could identify reliable cognitive decline. Mean time from concussion to post-injury testing was 3.40 days. The percentage of athletes who declined when using the JT method was similar to the percentage that would be expected to decline due to chance alone. Although the GLN and JT methods demonstrated moderate to substantial agreement, the GLN method consistently identified more cognitively compromised athletes than the JT method. Post-injury scores alone identified a significant majority of athletes with a reliable decline on ImPACT. Although preliminary and in need of replication across age groups and instruments, these findings suggest that the majority of collegiate athletes who experience clinically meaningful post-concussion cognitive decline can be identified without baseline data.

Brain Responses to Food Logos in Obese and Healthy Weight Children

OBJECTIVE To evaluate brain activation in response to common food and nonfood logos in healthy weight and obese children. STUDY DESIGN Ten healthy weight children (mean body mass index in the 50th percentile) and 10 obese children (mean body mass index in the 97.9th percentile) completed self-report measures of self-control. They then underwent functional magnetic resonance imaging while viewing food and nonfood logos. RESULTS Compared with the healthy weight children, obese children showed significantly less brain activation to food logos in the bilateral middle/inferior prefrontal cortex, an area involved in cognitive control. CONCLUSION When shown food logos, obese children showed significantly less brain activation than the healthy weight children in regions associated with cognitive control. This provides initial neuroimaging evidence that obese children may be more vulnerable to the effects of food advertising.

HISTORY OF MULTIPLE SELF-REPORTED CONCUSSIONS IS NOT ASSOCIATED WITH REDUCED COGNITIVE ABILITIES

OBJECTIVEThe long-term impact of sports-related concussion is uncertain. Several studies using traditional neuropsychological measures have found a relationship between a previous history of concussion and reduced cognitive abilities. In contrast, studies using computerized neuropsychological measures have typically found no relationship between concussion history and cognition. In the present study, we examined the association between a self-reported concussion history and cognition using traditional and computer-based neuropsychological tests. METHODSA computerized neuropsychological battery was administered to a sample of 858 collegiate male athletes. Of this sample, 298 athletes reported a history of concussion. A traditional neuropsychological battery was administered to a separate sample of 479 male collegiate athletes, 187 of whom reported a history of concussion. Finally, both a computerized and a traditional neuropsychological battery were administered to a third distinct sample of 175 male collegiate athletes, 57 of whom reported a history of concussion. Concussion history was assessed via self-report. None of the athletes had been concussed in the 6 months before testing. RESULTSNo significant association was found between self-reported concussion history and performance on either computerized or traditional neuropsychological tests. CONCLUSIONFindings suggest that athletes who report a distant history of concussion have minimal enduring neurocognitive deficits. Given conflicting findings in the literature, prospective studies that attempt to identify moderating factors are necessary to help determine who is at risk for long-term cognitive difficulties after concussion.

Robust relation between temporal discounting rates and body mass

When given the choice between

Burden among spousal and child caregivers of patients with mild cognitive impairment.

100 today and

Objective adherence monitoring in multiple sclerosis: initial validation and association with self-report

110 in 1 week, certain people are more likely to choose the immediate, yet smaller reward. The present study examined the relations between temporal discounting rate and body mass while accounting for important demographic variables, depressive symptoms, and behavioral inhibition and approach. After having their heights and weights measured, 100 healthy adults completed the Monetary Choice Questionnaire, the Beck Depression Inventory-II, and the Behavioral Inhibition Scale/Behavioral Approach Scale. Overweight and obese participants exhibited higher temporal discounting rates than underweight and healthy weight participants. Temporal discounting rates decreased as the magnitude of the delayed reward increased, even when other variables known to impact temporal discounting rate (i.e., age, education level, and annual household income) were used as covariates. A higher body mass was strongly related to choosing a more immediate monetary reward. Additional research is needed to determine whether consideration-of-future-consequences interventions, or perhaps cognitive control interventions, could be effective in obesity intervention or prevention programs.

Concussion history predicts self-reported symptoms before and following a concussive event

Background/Aims: Patients with mild cognitive impairment (MCI) experience cognitive declines and often report significant emotional/behavioral changes. Despite this, few studies have examined the impact of MCI on caregiver burden. The purpose of this study was to confirm the presence of caregiver burden in MCI and examine the relationship between burden and patients’ neuropsychological, behavioral and emotional functioning. Methods: The current study included 51 individuals who had been diagnosed as having MCI using Petersen’s criteria. The patients underwent a thorough neuropsychological evaluation and completed the Beck Depression Inventory and Cognitive Difficulties Scale. The caregivers completed the Zarit Burden Interview and the Revised Memory and Behavior Checklist. Results: More than 30% of the caregivers reported clinically significant burden. Increased caregiver burden was associated with a longer course of cognitive symptoms, patient reports of worse depression and greater cognitive difficulties, and informant reports of patients having more behavior, mood and memory problems. Caregiver burden was not significantly associated with patients’ neuropsychological test performance. Conclusion: The results highlight the importance of addressing patients’ behavioral and emotional difficulties, as well as caregiver burden, as part of the clinical exam in MCI.

Self-reported everyday memory and depression in patients with multiple sclerosis.

Poor adherence to medication is commonplace and contributes to poor health outcomes among numerous patient populations. Studies that have examined treatment adherence in multiple sclerosis focus exclusively on retrospective self-reports and/or imprecise measures of treatment discontinuation. To help address these methodological limitations, the present longitudinal study compared adherence outcomes for patients with multiple sclerosis using retrospective self-reports, adherence diaries, and a novel electronic monitoring device. Sixty-seven patients with relapsing—remitting multiple sclerosis were followed for a period of eight weeks during which they used a medication diary and a sharps container that captured electronically the time and date of each needle disposal. The patients also reported at the outset and conclusion of the study how frequently they missed doses. All measures of adherence were highly correlated. Patients reported better adherence than was indicated by medication diaries and electronic monitoring of needle disposals. Nearly one-fifth of the sample exhibited poor adherence, missing more than 20% of their prescribed medication. The results support the validity of electronic monitoring of needle disposal as an effective means of measuring adherence to disease modifying therapies in multiple sclerosis. In contrast, studies employing only self-report may underestimate poor adherence. Larger scale studies that employ prospective objective methods are necessary to gain a better understanding of adherence patterns in multiple sclerosis.

Changes in brain activation to food pictures after adjustable gastric banding

The authors evaluated how history of concussion affects symptom reporting prior to and after sustaining a concussion. At baseline, athletes with a positive concussion history reported more current symptomatology than athletes who had never been concussed. At 2 hours postinjury, concussed athletes with a history of previous concussion (PC) reported fewer symptoms than concussed athletes with no previous concussion history (NPC). By 1 week postinjury, however, PC athletes reported more symptoms than NPC athletes.