The Factor Structure of the Boston Diagnostic Aphasia Examination, Third Edition.

OBJECTIVE: The Boston Diagnostic Aphasia Examination (BDAE) is one of the most commonly used aphasia batteries. The newest edition has undergone significant revisions since its original publication in 1972, but existing evidence for its validity is lacking. We examined the construct validity of BDAE-3 and identified the factor structure of this battery. METHOD: A total of 355 people with aphasia of various types and severity completed neuropsychological evaluations to assess their patterns of language impairment. A principal component analysis with varimax rotation was conducted to examine the components of BDAE-3 subtests. RESULTS: Five components accounting for over 70% of the BDAE-3 total variance were found. The five language factors identified were auditory comprehension/ideomotor praxis, naming and reading, articulation-repetition, grammatical comprehension, and phonological processing. CONCLUSIONS: Our results show that the BDAE-3 demonstrates good construct validity, and certain language functions remain primary, distinct language domains (i.e., receptive vs. expressive language) across severities of aphasia. Overall, our findings inform clinical practice by outlining the inherent structure of language abilities in people with aphasia. Clinicians can utilize the findings to select core BDAE-3 tests that are most representative of their respective functions, thereby reducing the total testing time while preserving diagnostic sensitivity. (JINS, 2019, 25, 772-776).

Predicting Cognitive Functioning, Activities of Daily Living, and Participation 6 Months after Mild to Moderate Stroke.

OBJECTIVE: Predicting neurocognitive and functional outcomes in stroke is an important clinical task, especially in rehabilitation settings. We assessed acute predictors of cognitive and functional outcomes 6 months after mild to moderate stroke. METHODS: We conducted a retrospective analysis of acute clinical data and 6-month follow-up telephone interviews for 498 mild to moderate stroke patients. Predictors were sociodemographic variables, the National Institute of Health Stroke Scale (NIHSS), basic physical measures, the Mesulam Cancellation Test, the Short Blessed Test (SBT), Trails A/B, and the Boston Naming Test. The outcome variables were the Communication, Memory and Thinking, ADL/IADLs, and Participation subscales from the Stroke Impact Scale. We conducted four hierarchical multiple regression analyses with demographic variables and the NIHSS score entered into the first step, followed by physical variables in the second step, and neuropsychological variables in the final step. RESULTS: Physical variables explained more variance in ADL/IADLs and Participation outcomes than in Communication and Memory and Thinking outcomes, while cognitive predictors exhibited the opposite trend. The SBT was the only significant independent predictor of Communication and Memory and Thinking (p's < .001), while the NIHSS was the only measure that significantly predicted ADL/IADLs (p < .001) and Participation (p = .002). Poorer performance on screening measures predicted worse cognitive and functional outcomes 6 months post-stroke. CONCLUSIONS: These results support the clinical utility of administering brief screening instruments during acute recovery from mild to moderate stroke. Neuropsychologists should prioritize performance on screening measures assessing acute neurologic status and cognitive dysfunction when making recommendations for post-stroke rehabilitation.

Utility of Serum Biomarkers in the Diagnosis and Stratification of Mild Traumatic Brain Injury.

OBJECTIVE: The objective was to compare test characteristics of a single serum concentration of glial fibrillary acidic protein (GFAP), S-100ß, and ubiquitin carboxyl terminal hydrolase L1 (UCH-L1), obtained within 6 hours of head injury, to diagnose mild traumatic brain injury (mTBI) in head-injured subjects. METHODS: Adults aged 18 to 80 years who presented to one of seven EDs with a blunt closed head injury underwent head CT within 4 hours of injury and had blood drawn for biomarker analysis within 6 hours of injury were eligible. Subjects were considered to have mTBI if they had an initial Glasgow Coma Scale (GCS) > 13 and met one or more of the following criteria: loss of consciousness (LOC), posttraumatic amnesia, or confusion. Subjects with mTBI and an abnormal head computed tomography (CT) scan were categorized as complicated mTBI; those with a normal head CT were categorized as uncomplicated mTBI; and subjects with a GCS = 15, no LOC, no posttraumatic amnesia, and no confusion were considered to not have a mTBI. Biomarker concentration measurements for GFAP and UCH-L1 were performed using an enzyme-linked immunosorbent assay. S-100ß concentration was determined using an electrochemiluminescence immunoassay. Median biomarker concentration for each group was compared using the Kruskal-Wallis test. Logistic regression was used to determine area under the receiver operating curve (AUC) for each of the three biomarkers. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and negative and positive likelihood ratios (LRs) for the three biomarkers to differentiate between complicated mTBI, uncomplicated mTBI, and no mTBI were calculated. RESULTS: A total of 247 subjects were enrolled and had adequate clinical and biomarker information for analysis. A total of 188 met criteria for mTBI, with 34 (18.1%) having an acute abnormality on CT (complicated mTBI). The mean (±SD) age of the study population was 45.8 (±17.3) years, and 59.9% were male. Median serum concentrations for all biomarkers were significantly different between groups, lowest in the no mTBI group, and progressively increasing in the uncomplicated and complicated mTBI groups (p < 0.0001). All three biomarkers were significant classifiers of mTBI versus no mTBI, with the following AUCs: GFAP, 0.70; S-100ß, 0.69; and UCH-L1, 0.65 (p = 0.17). Sensitivity for mTBI was highest for S-100ß (96.5%). NPVs ranged from 31% for UCH-L1 to 35% for GFAP. PPVs ranged from 75.5% for S-100ß to 96.5% for GFAP. Negative LR ranged from 0.59 for GFAP to 0.71 for UCH-L1, with positive LR ranging from 1.0 for both UCH-L1 and S-100ß to 8.7 for GFAP. CONCLUSION: A single serum concentration of GFAP, UCH-L1, or S-100ß within 6 hours of head injury may be useful in identifying and stratifying the severity of brain injury in emergency department patients with head trauma, but cannot reliably exclude a diagnosis of concussion. A positive GFAP was associated with the presence of concussion.

Exploratory factor analysis of the reintegration to normal living index in a stroke population.

BACKGROUND: The reintegration to normal living index (RNLI) is a global assessment of patient quality of life often utilized in stroke populations. Previous studies in various general disability samples have consistently reported a two-factor solution for the RNLI. Despite its common use with stroke patients, the RNLI has not been psychometrically evaluated in an exclusively stroke sample. This study is believed to represent the first factor analysis of the RNLI using a sample comprised exclusively of individuals who have survived cerebral infarct. OBJECTIVE: The aim of this study is to evaluate the psychometric properties of the RNLI in assessing quality of life of stroke survivors. METHODS: We retrospectively examined RNLI scores of 928 adults with strokes of varying severities as part of a multidisciplinary, interinstitutional collaboration across an academic medical center, acute care hospital, and rehabilitation center. We utilized a principal component factor analysis to evaluate the factor structure of the RNLI. RESULTS: Mean RNLI scores ±SD for the sample were 75.26 ± 19.85, ranging between 20 and 100. The Cronbach α was .94. A scree test for factor retention strongly suggested a single factor solution, explaining 64.50% of the total variance. CONCLUSIONS: Previous factor analyses on the RNLI utilizing general disability samples commonly report a two-factor solution. Our data support the presence of a single factor solution across the RNLI within a large sample comprised exclusively of stroke survivors. This suggests that the RNLI acts as more of a unitary measure of quality of life within a stroke sample relative to other disabled samples.

Multivariable Prediction of Return to Work at 6-Month Follow-Up in Patients With Mild to Moderate Acute Stroke.

OBJECTIVE: To investigate predictors of return to work (RTW) in a poststroke sample. DESIGN: Retrospective investigation of archival data from an inception cohort; acute care records and 6-month follow-up telephone interview data were obtained for analysis. SETTING: The Brain Recovery Core, a collaborative interinstitutional endeavor among an academic medical center, an acute care hospital, and a rehabilitation center. PARTICIPANTS: Data from patients with stroke from the Brain Recovery Core (N=298). Excluded cases included those with nontraditional and/or nonpaid job status, no National Institute of Health Stroke Scale (NIHSS) score, and an NIHSS score >16. Our final sample included 244 individuals (age range, 25-87y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Sociodemographic variables, stroke severity (NIHSS), and physical and neurocognitive measures. RESULTS: Adding predictor variables to our logistic regression model increased accuracy by approximately 18%. Greater independence in the FIM sit-to-stand movement predicted improved RTW rates (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.0-3.1), whereas nonwhite race (OR, 2.52; 95% CI, 1.16-5.47) and greater impairment on the NIHSS (OR, .88; 95% CI, .77-.99) predicted attenuated RTW rates. CONCLUSIONS: Valid measures of stroke severity and a clinician-rated sit-to-stand movement have utility in the acute prediction of later RTW in patients with mild to moderate stroke. Given the complexity of the RTW construct and the acute measurement of these variables, we believe that our findings can be used to inform clinical decisions and appropriately tailor rehabilitative strategies that improve quality of life for stroke survivors.

Family Ratings of Communication Largely Reflect Expressive Language and Conversation-Level Ability in People With Aphasia.

PURPOSE: Family ratings of communication and social interactions represent an important source of information about people with aphasia. Because of the reliance on family/partner ratings as an outcome measure in many aphasia treatment studies and in the clinic, there is a great need for the validation of commonly used family/partner rating measures, and a better understanding of predictors of family ratings of communication. METHOD: The communication ability of 130 individuals with aphasia due to neurologic illness was rated by family members/partners on the Communicative Effectiveness Index (CETI; Lomas et al., 1989). Information on aphasia severity, mood, quality of life, nonverbal cognitive functioning, and various demographic factors was collected. RESULTS: Principal component analysis confirmed a 2-factor model best represents the relationships among CETI rating items, and this model largely consists of a conversation-level ability factor. Family ratings were largely predicted by the patient's expressive (not receptive) language but also patient self-perceived quality of communication life. CONCLUSIONS: Family/partners typically rate the effectiveness of communication based largely on expressive language, despite the fact that other aspects of the aphasia (e.g., listening comprehension) are as important for everyday communication.

Common behavioral clusters and subcortical anatomy in stroke.

A long-held view is that stroke causes many distinct neurological syndromes due to damage of specialized cortical and subcortical centers. However, it is unknown if a syndrome-based description is helpful in characterizing behavioral deficits across a large number of patients. We studied a large prospective sample of first-time stroke patients with heterogeneous lesions at 1-2 weeks post-stroke. We measured behavior over multiple domains and lesion anatomy with structural MRI and a probabilistic atlas of white matter pathways. Multivariate methods estimated the percentage of behavioral variance explained by structural damage. A few clusters of behavioral deficits spanning multiple functions explained neurological impairment. Stroke topography was predominantly subcortical, and disconnection of white matter tracts critically contributed to behavioral deficits and their correlation. The locus of damage explained more variance for motor and language than memory or attention deficits. Our findings highlight the need for better models of white matter damage on cognition.

Descriptive data analysis examining how standardized assessments are used to guide post-acute discharge recommendations for rehabilitation services after stroke.

BACKGROUND: Use of standardized assessments in acute rehabilitation is continuing to grow, a key objective being to assist clinicians in determining services needed postdischarge. OBJECTIVE: The purpose of this study was to examine how standardized assessment scores from initial acute care physical therapist and occupational therapist evaluations contribute to discharge recommendations for poststroke rehabilitation services. DESIGN: A descriptive analysis was conducted. METHODS: A total of 2,738 records of patients admitted to an acute care hospital with a diagnosis of stroke or transient ischemic attack were identified. Participants received an initial physical therapist and occupational therapist evaluation with standardized assessments and a discharge recommendation of home with no services, home with services, inpatient rehabilitation facility (IRF), or skilled nursing facility (SNF). A K-means clustering algorithm determined if it was feasible to categorize participants into the 4 groups based on their assessment scores. These results were compared with the physical therapist and occupational therapist discharge recommendations to determine if assessment scores guided postacute care recommendations. RESULTS: Participants could be separated into 4 clusters (A, B, C, and D) based on assessment scores. Cluster A was the least impaired, followed by clusters B, C, and D. In cluster A, 50% of the participants were recommended for discharge to home without services, whereas 1% were recommended for discharge to an SNF. Clusters B, C, and D each had a large proportion of individuals recommended for discharge to an IRF (74%-80%). There was a difference in percentage of recommendations across the clusters that was largely driven by the differences between cluster A and clusters B, C, and D. LIMITATIONS: Additional unknown factors may have influenced the discharge recommendations. CONCLUSIONS: Participants poststroke can be classified into meaningful groups based on assessment scores from their initial physical therapist and occupational therapist evaluations. These assessment scores, in part, guide poststroke acute care discharge recommendations.

Clinician adherence to a standardized assessment battery across settings and disciplines in a poststroke rehabilitation population.

OBJECTIVES: (1) To examine clinician adherence to a standardized assessment battery across settings (acute hospital, inpatient rehabilitation facilities [IRFs], outpatient facility), professional disciplines (physical therapy [PT], occupational therapy, speech-language pathology), and time of assessment (admission, discharge/monthly), and (2) to evaluate how specific implementation events affected adherence. DESIGN: Retrospective cohort study. SETTING: Acute hospital, IRF, and outpatient facility with approximately 118 clinicians (physical therapists, occupational therapists, speech-language pathologists). PARTICIPANTS: Participants (N=2194) with stroke who were admitted to at least 1 of the above settings. All persons with stroke underwent standardized clinical assessments. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Adherence to Brain Recovery Core assessment battery across settings, professional disciplines, and time. Visual inspections of 17 months of time-series data were conducted to see if the events (eg, staff meetings) increased adherence ≥5% and if so, how long the increase lasted. RESULTS: Median adherence ranged from .52 to .88 across all settings and professional disciplines. Both the acute hospital and the IRF had higher adherence than the outpatient setting (P≤.001), with PT having the highest adherence across all 3 disciplines (P<.004). Of the 25 events conducted across the 17-month period to improve adherence, 10 (40%) resulted in a ≥5% increase in adherence the following month, with 6 services (60%) maintaining their increased level of adherence for at least 1 additional month. CONCLUSIONS: Actual adherence to a standardized assessment battery in clinical practice varied across settings, disciplines, and time. Specific events increased adherence 40% of the time with those gains maintained for >1 month 60% of the time.

Prediction of discharge walking ability from initial assessment in a stroke inpatient rehabilitation facility population.

OBJECTIVES: To (1) determine which clinical assessments at admission to an inpatient rehabilitation facility (IRF) most simply predict discharge walking ability, and (2) identify a clinical decision rule to differentiate household versus community ambulators at discharge from an IRF. DESIGN: Retrospective cohort study. SETTING: IRF. PARTICIPANTS: Two samples of participants (n=110 and 159) admitted with stroke. INTERVENTIONS: A multiple regression determined which variables obtained at admission (age, time from stroke to assessment, Motricity Index, somatosensation, Modified Ashworth Scale, FIM, Berg Balance Scale, 10-m walk speed) could most simply predict discharge walking ability (10-m walk speed). A logistic regression determined the likelihood of a participant achieving household (<0.4m/s) versus community (≥0.4-0.8m/s; >0.8m/s) ambulation at the time of discharge. Validity of the results was evaluated on a second sample of participants. MAIN OUTCOME MEASURE: Discharge 10-m walk speed. RESULTS: Admission Berg Balance Scale and FIM walk item scores explained most of the variance in discharge walk speed. The odds ratio of achieving only household ambulation at discharge was 20 (95% confidence interval [CI], 6-63) for sample 1 and 32 (95% CI, 10-96) for sample 2 when the combination of having a Berg Balance Scale score of ≤20 and a FIM walk item score of 1 or 2 was present. CONCLUSIONS: A Berg Balance Scale score of ≤20 and a FIM walk item score of 1 or 2 at admission indicates that a person with stroke is highly likely to only achieve household ambulation speeds at discharge from an IRF.

The brain recovery core: building a system of organized stroke rehabilitation and outcomes assessment across the continuum of care.

This Special Interest article describes a multidisciplinary, interinstitutional effort to build an organized system of stroke rehabilitation and outcomes measurement across the continuum of care. This system is focused on a cohort of patients who are admitted with the diagnosis of stroke to our acute facility, are discharged to inpatient and/or outpatient rehabilitation at our free-standing facility, and are then discharged to the community. This article first briefly explains the justification, goals, and purpose of the Brain Recovery Core system. The next sections describe its development and implementation, with details on the aspects related to physical therapy. The article concludes with an assessment of how the Brain Recovery Core system has changed and improved delivery of rehabilitation services. It is hoped that the contents of this article will be useful in initiating discussions and potentially facilitating similar efforts among other centers.

The role of postoperative neurocognitive dysfunction on quality of life for postmenopausal women 6 months after cardiac surgery.

BACKGROUND: Women are prone to neurological complications after cardiac surgery. We have previously reported that treatment perioperatively with the neuroprotectant steroid 17beta-estradiol did not improve neurocognitive end-points 4 to 6 wk after surgery for elderly women. In this study, we evaluated the influence of early postoperative neurocognitive dysfunction on quality of life in postmenopausal women undergoing cardiac surgery and whether it is impacted by perioperative 17beta-estradiol treatment. METHODS: One hundred seventy-four postmenopausal women randomly received 17beta-estradiol or placebo in a double-blind manner beginning the day before surgery and continued until the fifth postoperative day. The patients underwent psychometric testing using a standard battery before surgery and again 4 to 6 wk and 6 mo postoperatively. Quality of life was assessed at baseline and 6 mo after surgery with the SF-36 questionnaire and the Lawton instrumental activities of daily living scale. RESULTS: Complete data were available from 108 women of whom 13% demonstrated postoperative neurocognitive dysfunction. Based on multiple logistic regression analysis, a neurocognitive deficit 4 to 6 wk after surgery was an independent predictor of a lower SF-36 physical component score (P = 0.004) and lower Lawton instrumental activities of daily living scale 6 mo postoperatively (P = 0.026). Treatment with 17beta-estradiol (P = 0.003) and smoking status (P = 0.015) were predictors of worse SF-36 mental health component rating. Preoperative lower scores were independently associated with low quality of life postoperatively for all measurements. CONCLUSIONS: Postoperative neurocognitive dysfunction is associated with impaired quality of life in women after cardiac surgery. Perioperative treatment with 17beta-estradiol provides no benefits to postoperative quality of life. The relationship between low preoperative and postoperative self-rated health status suggests that some aspects of quality of life in postmenopausal women are not amenable to improvements with cardiac surgery.

Risk factors for neurocognitive dysfunction after cardiac surgery in postmenopausal women.

BACKGROUND: Women are at higher risk than men for neurologic complications from cardiac operations. This study identified risk factors for neurocognitive dysfunction after cardiac operations in elderly women. METHODS: One hundred thirteen postmenopausal women undergoing primary coronary artery bypass grafting, with or without valve operation, underwent psychometric testing and neurologic evaluation the day before operation and 4 to 6 weeks postoperatively. Risk factors assessed for neurologic complications included atherosclerosis of the ascending aorta and apolipoprotein epsilon4 genotype. Postoperative neurocognitive dysfunction was defined as the composite end point of a one standard deviation decrement from baseline on two or more psychometric tests or a new neurologic deficit. RESULTS: Neurocognitive dysfunction was present in 25% of the women 4 to 6 weeks postoperatively. Women with a neurocognitive deficit tended to be older than those without a deficit (72.1 +/- 8.1 vs 69.4 +/- 8.9 years, p = 0.144) and were more likely to have mild atherosclerosis of the ascending aorta, a history of congestive heart failure, longer duration of cardiopulmonary bypass (CPB) and aortic cross-clamping, lower nadir blood pressure during CPB, higher rates of postoperative atrial fibrillation, and longer postoperative hospitalization. Mild atherosclerosis of the ascending aorta, duration of CPB, duration of aortic cross-clamping (p = 0.051), and length of postsurgical hospitalization were independently associated with postoperative neurocognitive dysfunction. CONCLUSIONS: Mild atherosclerosis of the ascending aorta, duration of CPB, aortic cross-clamping time, and length of hospitalization, but not apolipoprotein epsilon4 genotype, identified risk for neurocognitive dysfunction after cardiac operation in postmenopausal women.

Assessment of patients with mild concussion in the emergency department.

OBJECTIVES: (1) To test the validity of the Standardized Assessment of Concussion (SAC) in characterizing the early evolution of concussion-related symptoms and mental status changes in the emergency department (ED) setting and (2) to compare it to the Conner's Continuous Performance Test 2nd Edition (CPT-II). DESIGN: Prospective within-subject (repeated measures) design. PARTICIPANTS: Sixty-two persons with concussion (Glasgow Coma Scale = 15) and negative head computed tomographic scan results were examined on arrival in the ED and 3 and 6 hours later. SETTING: A large urban, tertiary medical center ED. MAIN OUTCOME MEASURES: SAC; CPT-II; Post-Concussion Symptom Scale-Revised (PCS-R). RESULTS: SAC and CPT-II scores improved significantly over the time course in the ED. Symptoms did not correlate with improvement, with many subjects complaining of headache or nausea after their scores improved. The average initial score on the SAC was 21 +/- 5.4/30. CONCLUSION: The SAC appears sensitive to the acute changes following concussion. It may be a useful tool for clinicians in detecting mental status changes after a concussion, when Glasgow Coma Scale and radiologic findings are normal.

Neurocognitive outcomes are not improved by 17beta-estradiol in postmenopausal women undergoing cardiac surgery.

BACKGROUND AND PURPOSE: Neurocognitive dysfunction is an important source of patient morbidity and mortality after cardiac surgery that may disproportionately affect postmenopausal women. 17beta-Estradiol limits the extent of ischemic neuronal injury in a variety of experimental models. The purpose of this study was to evaluate whether perioperative administration of 17beta-estradiol to postmenopausal women reduces the frequency of neurocognitive dysfunction after cardiac surgery. METHODS: One hundred seventy-four postmenopausal women not on estrogen replacement therapy who were undergoing primary coronary artery bypass graft surgery and/or valve surgery with cardiopulmonary bypass were prospectively randomized to receive in a double-blinded manner either 17beta-estradiol or placebo beginning the day before surgery and continuing for 5 days postoperatively. The patients were evaluated before and after surgery with the National Institutes of Health Stroke Scale and a psychometric test battery. RESULTS: There were no differences in the frequency of neurocognitive dysfunction (primary outcome) between patients randomized to perioperative 17beta-estradiol (n=86) and those randomized to placebo (n=88) 4 to 6 weeks after surgery (17beta-estradiol, 22.4% versus placebo, 21.4%, P=0.45). The mean scores on tests of psychomotor speed were worse in women in the 17beta-estradiol group than in the placebo group at the 4- to 6-week (P=0.005) postoperative testing sessions. CONCLUSIONS: Perioperative treatment with 17beta-estradiol did not result in improved neurocognitive outcomes in postmenopausal women undergoing cardiac surgery.

Preexisting cognitive impairment in women before cardiac surgery and its relationship with C-reactive protein concentrations.

Preoperative cognitive state is seldom considered when investigating the effects of cardiac surgery on cognition. In this study we sought to determine the prevalence of cognitive impairment in women scheduled for cardiac surgery using nonhospitalized volunteers as a reference group and to examine the relationship between C-reactive protein levels and cognitive impairment. Psychometric testing was performed in 108 postmenopausal women scheduled for cardiac surgery and in 58 nonhospitalized control women. High sensitivity C-reactive protein levels were measured in the surgical patients. Preoperative cognitive impairment was defined as >2 sd lower scores on > or =2 tests compared with the controls. Cognitive impairment was present in 49 of 108 (45%) patients. C-reactive protein levels were higher for patients with compared with those without cognitive impairment (median, 8.1 mg/L versus 4.7 mg/L; P = 0.04). Based on multivariate logistic regression analysis, patient age, lower attained level of education, type 2 diabetes mellitus, and prior myocardial infarction identified risk for cognitive impairment (P < 0.05) but C-reactive protein levels did not (P = 0.09). In conclusion, cognitive impairment is prevalent in women before cardiac surgery. C-reactive protein levels are increased in women with this condition but the relationship between this inflammatory marker and preexisting cognitive impairment is likely secondary to the acute phase reactant serving as a marker for other predisposing conditions.

Does the use of artificial turf contribute to head injuries?

BACKGROUND: A number of high-profile professional football players have suffered career-ending concussions. The purpose of this article is to test the surfaces used by a professional team to determine their impact-attenuating properties. METHODS: An accelerometer was dropped from a height of 48 inches onto three different playing fields in the St. Louis area: an indoor artificial turf practice field, a grass outdoor practice field, and the artificial turf field at a domed stadium. The accelerometer was dropped 20 times from a height of 48 inches onto each surface. RESULTS: Statistical analysis of the peak Gs for impacts onto each surface indicate all three are statistically different. The artificial surface of the domed stadium was the hardest surface, with an average peak acceleration of 261 Gs compared with 183 Gs for the indoor artificial turf practice field and 246 Gs for the outdoor grass field. CONCLUSION: The surface used to play league games has the least impact attenuation of any field tested and may contribute to the high incidence of concussion in football players.

Abnormalities in glucose regulation during antipsychotic treatment of schizophrenia.

BACKGROUND: Hyperglycemia and type 2 diabetes mellitus are more common in schizophrenia than in the general population. Glucoregulatory abnormalities have also been associated with the use of antipsychotic medications themselves. While antipsychotics may increase adiposity, which can decrease insulin sensitivity, disease- and medication-related differences in glucose regulation might also occur independent of differences in adiposity. METHODS: Modified oral glucose tolerance tests were performed in schizophrenic patients (n = 48) receiving clozapine, olanzapine, risperidone, or typical antipsychotics, and untreated healthy control subjects (n = 31), excluding subjects with diabetes and matching groups for adiposity and age. Plasma was sampled at 0 (fasting), 15, 45, and 75 minutes after glucose load. RESULTS: Significant time x treatment group interactions were detected for plasma glucose (F(12,222) = 4.89, P<.001) and insulin (F(12,171) = 2.10, P =.02) levels, with significant effects of treatment group on plasma glucose level at all time points. Olanzapine-treated patients had significant (1.0-1.5 SDs) glucose elevations at all time points, in comparison with patients receiving typical antipsychotics as well as untreated healthy control subjects. Clozapine-treated patients had significant (1.0-1.5 SDs) glucose elevations at fasting and 75 minutes after load, again in comparison with patients receiving typical antipsychotics and untreated control subjects. Risperidone-treated patients had elevations in fasting and postload glucose levels, but only in comparison with untreated healthy control subjects. No differences in mean plasma glucose level were detected when comparing risperidone-treated vs typical antipsychotic-treated patients and when comparing typical antipsychotic-treated patients vs untreated control subjects. CONCLUSION: Antipsychotic treatment of nondiabetic patients with schizophrenia can be associated with adverse effects on glucose regulation, which can vary in severity independent of adiposity and potentially increase long-term cardiovascular risk.