Robotic training and clinical assessment of forearm and wrist movements after incomplete spinal cord injury: a case study.

The effectiveness of a robotic training device was evaluated in a 24-year-old male, cervical level four, ASIA Impairment Scale D injury. Robotic training of both upper extremities was provided for three hr/day for ten consecutive sessions using the RiceWrist, an electrically-actuated forearm and wrist haptic exoskeleton device that has been designed for rehabilitation applications. Training involved wrist flexion/extension, radial/ulnar deviation and forearm supination/pronation. Therapy sessions were tailored, based on the patient's movement capabilities for the wrist and forearm, progressed gradually by increasing number of repetitions and resistance. Outcome measures included the ASIA upper-extremity motor score, grip and pinch strength, the Jebsen-Taylor Hand Function test and the Functional Independence Measure. After the training, improvements were observed in pinch strength, and functional tasks. The data from one subject provides valuable information on the feasibility and effectiveness of robotic-assisted training of forearm and hand functions after incomplete spinal cord injury.

Apolipoprotein E genotype and memory in the sixth decade of life.

BACKGROUND: Virtually all adult studies of APOE genotypes and cognition have included individuals over 60. In older adults, epsilon 4 carriers may manifest greater cognitive asymmetries than non-epsilon 4 carriers even in the absence of overall mean differences. General cognitive ability may also be affected by aging and APOE genotype, but most studies have inadequately addressed this potential confound. The goals of this study were to examine, in middle age, the relationship of APOE genotype with episodic memory and verbal-visuospatial episodic memory asymmetries, after accounting for prior general cognitive ability. METHOD: We compared epsilon 4+ and epsilon 4- individuals in 626 male twins in their 50s. We examined verbal and visuospatial episodic memory and verbal-visual asymmetry scores after adjusting for cognitive ability at age 20. Analyses corrected for correlations between twin pair members. RESULTS: Compared with epsilon 4- individuals, epsilon 4 carriers performed significantly more poorly on verbal, but not visuospatial memory, manifested significantly greater cognitive asymmetry, and also had significantly more concerns about memory. At age 20, epsilon 4 carriers had higher general cognitive ability than epsilon 4- individuals, and current memory differences were enhanced after adjusting for age 20 cognitive ability. CONCLUSIONS: Small, but significant, APOE-epsilon 4-related memory deficits appear in the sixth decade of life in individuals who show no signs of preclinical dementia. The results partially support studies of older adults that suggest that increased cognitive asymmetries reflect risk for dementia and are associated with the APOE-epsilon 4 genotype. The results also highlight the potential problems of not having accurate data on prior cognitive ability.

Disruption of limbic pathways in a case of profound amnesia.

We report a case of episodic amnesia in which the anatomical basis of injury was investigated by diffusion tensor imaging (DTI). Two months after an adult male suffered severe closed head injury, conventional magnetic resonance imaging (CMRI) revealed only a right superior frontal lesion. However, 14 years later, DTI revealed structural anomalies not visible on CMRI involving limbic white matter tracts, notably the fornix, which could explain the amnesia.

Efficacy of early use of intrathecal baclofen therapy for treating spastic hypertonia due to acquired brain injury.

OBJECTIVE: To determine the efficacy and safety of early (<1 year post-disease onset) use of intrathecal baclofen (ITB). DESIGN: Consecutive case series of 14 individuals with spastic hypertonia due to trauma (5), anoxia (6) and stroke (3). MAIN OUTCOME MEASURES: Modified Ashworth (MAS) and Disability Rating (DRS) scales. INTERVENTIONS: ITB pump placement within 1 year of onset, after inadequate response to other previous treatment modalities. RESULTS: At follow-up after ITB pump implantation (mean = 13.9 months; mean daily dose = 591.5 microg per day), mean MAS scores improved from baseline by 1.0 and 2.1 points in the upper and lower limbs, respectively. DRS scores did not change significantly. Functional gains included decreased pain and improved gait speed and motor skills. The only complication was spinal leak in one subject. CONCLUSIONS: ITB therapy within 1 year of onset of acquired brain injury appears effective and safe in decreasing spastic hypertonia and does not appear to adversely affect recovery.

Neuropsychological outcome and community re-integration following traumatic brain injury: the impact of frontal and non-frontal lesions.

PRIMARY OBJECTIVE: To examine the relationship between cortical lesion location and brain injury outcome. It was hypothesized that focal frontal lesions after traumatic brain injury (TBI) would result in decreased executive and memory functioning and poor community participation outcome. RESEARCH DESIGN: Three quasi-experimental, prospective studies employed a total of 643 patients with focal frontal, fronto-temporal, non-frontal or no lesions in CT scans. METHODS AND PROCEDURES: CT scan analysis, neuropsychological assessment, the Neurobehavioural Functioning Inventory (NFI), the Community Integration Questionnaire (CIQ). MAIN RESULTS: In study 1, frontal and fronto-temporal groups performed worse in executive functioning and better in constructional ability. Study 2 found no differences in neuropsychological and community re-integration measures at 1-year follow-up. Study 3 found comparable neuropsychological test score improvement across groups over 1 year. CONCLUSIONS: Results are consistent with previous findings and document the potential for test score improvement with rehabilitation and suggest that lesion location needs to be considered when individual rehabilitation plans are being implemented in the post-acute stage of TBI.

Forty years of solitude: life-history divergence and behavioural isolation between laboratory lines of Drosophila melanogaster.

The study of the early stages of speciation can benefit from examination of differences between populations of known history that have been separated for a short time, such as a few thousands of generations. We asked whether two lines of Drosophila melanogaster that were isolated more than 40 years ago have evolved differences in life-history characters, or have begun to evolve behavioural or postzygotic isolation. One line, which is resistant to DDT, showed lower egg production and a shorter lifespan than a susceptible line. These differences are not a pleiotropic effect of resistance because they are not attributable to the chromosome that contains the resistance factors. The two lines have begun to become behaviourally isolated. Again, the isolation is not attributable to genes on the chromosome that contains resistance factors. The lines show only prezygotic isolation; there is no evidence of reduced fitness of F1 or F2 hybrids. These lines and others like them, should be excellent subjects for analyses of genetic changes that could lead to speciation.

The neurobehavioural rating scale-revised: sensitivity and validity in closed head injury assessment.

OBJECTIVES: To investigate the factor structure and psychometric properties of the neurobehavioural rating scale-revised (NRS-R) and to determine its usefulness in clinical trials. METHODS: A consecutive series of patients sustaining severe closed head injury were evacuated to one of 11 large regional North American trauma centres and entered into a randomised, phase III, multicentre clinical trial investigating the therapeutic use of moderate hypothermia. Acute care personnel were blinded to outcome and outcome personnel were blinded to treatment condition. The Glasgow outcome scale (GOS) was the primary outcome measure. Secondary outcome measures included the disability rating scale (DRS) and the NRS-R. RESULTS: Exploratory factor analysis of NRS-R data collected at 6 months after injury (n=210) resulted in a five factor model including: (1) executive/cognition, (2) positive symptoms, (3) negative symptoms, (4) mood/affect, and (5) oral/motor. These factors showed acceptable internal consistency (0.62 to 0.88), low to moderate interfactor correlations (0.19 to 0.61), and discriminated well between GOS defined groups. Factor validity was demonstrated by significant correlations with specific neuropsychological domains. Significant change was measured from 3 to 6 months after injury for the total score (sum of all 29 item ratings) and all factor scores except mood/affect and positive symptoms. The total score and all factor scores correlated significantly with concurrent GOS and DRS scores. CONCLUSIONS: The NRS-R is well suited as a secondary outcome measure for clinical trials as its completion rate exceeds that of neuropsychological assessment and it provides important neurobehavioural information complementary to that provided by global outcome and neuropsychological measures.

Validity and sensitivity to change of the extended Glasgow Outcome Scale in mild to moderate traumatic brain injury.

Using a structured outcome interview, this study addressed the validity and sensitivity to change of the Glasgow Outcome Scale (GOS) and the Extended GOS (GOSE) in a prospective study of patients who sustained mild (n = 30) to moderate (n = 13) traumatic brain injury (TBI) or general trauma (n = 44). The patients were recruited from the emergency center or inpatient units of Ben Taub General Hospital and invited to participate in follow-up examinations at 3 and 6 months. Using a series of functional outcome measures, assessment of affective status, and neuropsychological tests as criteria, the validity of the GOSE generally exceeded the GOS. Analysis of the outcome data for the patients who completed both the 3-month and 6-month assessments disclosed that the GOSE was more sensitive to change than the GOS. Comparison of the 3-month outcome data disclosed that the GOSE and GOS scores did not differ for the TBI and general trauma groups. These findings lend further support for utilization of the GOSE in clinical trials when it is based on a structured interview.

Using early neuropsychologic testing to predict long-term productivity outcome from traumatic brain injury.

OBJECTIVE: To evaluate whether early neuropsychologic testing is useful in predicting long-term productivity outcome after traumatic brain injury (TBI). DESIGN: Validation cohort prediction study. SETTING: Four inpatient brain injury rehabilitation programs participating in the Traumatic Brain Injury Model Systems project. PARTICIPANTS: A total of 293 adults with nonpenetrating TBI. MAIN OUTCOME MEASURES: Fifteen neuropsychologic tests were administered to patients who emerged from posttraumatic amnesia before rehabilitation discharge. Test scores were classified in the normal range or impaired range, using objective criteria. Outcome was defined as productive if the patient was competitively employed or enrolled full time in regular education. RESULTS: Productivity at follow-up was predicted by completion of at least 1 neuropsychologic test before discharge, by an injury-test interval of less than 2 months, and by normal range scores on 10 of the 15 neuropsychologic tests. Normal range scores on these tests increased the probability of a productive outcome by 40% to 130%. CONCLUSIONS: Neuropsychologic testing can help predict long-term productivity even when performed before discharge from inpatient rehabilitation and at variable injury-test intervals. Early testing should be interpreted in relation to injury-test interval. Because tests of multiple neuropsychologic domains predicted outcome, comprehensive evaluations might be more useful in predicting outcome.

Factor analysis of an outcome interview for use in clinical trials of traumatically brain-injured patients: a preliminary study.

OBJECTIVE: To study the factor structure, internal consistency, concurrent validity, and sensitivity to detect change in patient report of problems of a structured interview in relationship with accepted outcome measures. DESIGN: Outcome status of patients with severe traumatic brain injury participating in a randomized, phase III, multicenter clinical trial was assessed at 6 mo postinjury using the Glasgow Outcome Scale, the Disability Rating Scale, and the Severe Traumatic Brain Injury Outcome Interview. RESULTS: Exploratory factor analysis of the Severe Traumatic Brain Injury Outcome Interview produced a meaningful five-factor model: (1) activities of daily living; (2) cognitive; (3) affective; (4) behavioral; and (5) instrumental activities of daily living. The internal consistency of the factors ranged from moderate (0.61 instrumental activities of daily living) to high (0.94 activities of daily living); the interfactor correlations were moderate. The summed factor scores were significantly correlated with measures of global outcome: the Glasgow Outcome Scale (r = 0.66; P < 0.0001) and the Disability Rating Scale (r = 0.61; P < 0.0001). Patient report of cognitive problems correlated moderately with the neuropsychological tests. The summed factor scores were sensitive to change over time. CONCLUSIONS: Overall, the interview assessed the major important features of outcome pertinent to traumatic brain injury and demonstrated greater sensitivity to subtle changes over time than the unidimensional approaches, such as the Glasgow Outcome Scale and Disability Rating Scale.

Depression and posttraumatic stress disorder at three months after mild to moderate traumatic brain injury.

To investigate the frequency and risk factors of major depressive disorder (MDD) after mild to moderate traumatic brain injury (TBI), 69 TBI and 52 general trauma (GT) patients were prospectively recruited and studied at 3-months postinjury. There was a nonsignificant difference in the proportion of MDD patients in the TBI and GT groups. Therefore, a composite MDD group (TBI and GT patients) was compared to patients who were nondepressed. Female gender was related to MDD, but no other risk factors were identified. MDD was associated with disability (Glasgow Outcome Scale, Community Integration Questionnaire) and cognitive impairment. MDD was comorbid with posttraumatic stress disorder. Implications for postacute management of mild to moderate TBI are discussed.

Postconcussional disorder following mild to moderate traumatic brain injury: anxiety, depression, and social support as risk factors and comorbidities.

Previous studies of postconcussional disorder (PCD) have utilized a dimensional approach (i.e., number and/or severity ratings of symptoms) to study postconcussional symptoms. This study used a syndromal approach (modified form of the DSM-IV criteria) for investigating risk factors for developing PCD, 3-months postinjury. The head trauma requirement was waived in order to determine specificity of symptoms to traumatic brain injury. Preliminary results from this ongoing study indicated significant risk factors including female gender, poor social support, and elevated self-reported depressive symptoms at 1-month postinjury. Comorbidities included concurrent diagnosis of major depressive disorder and/or posttraumatic stress disorder. Hispanics were significantly less likely to develop PCD than other racial/ethnic groups. PCD resulted more frequently from motor vehicle accidents and assaults. Screening tests for PCD risk factors/comorbidities performed shortly after injury (i.e., during routine follow-up clinic appointments) coupled with appropriate referrals for psychoeducational interventions and support groups may avoid prolonged loss of productivity and poor perceived quality of life in these patients.

Edouard Claparède and the auditory verbal learning test.

This paper describes the role of the Swiss psychologist Edouard Claparède (1873-1940) in developing the Test de mémoire des mots (Test of Memory for Words), a test consisting of one free-recall trial of a 15-word list that is the antecedent of the auditory verbal learning tests (AVLT) of Rey and others. The fact that Claparède's test has survived in modified form for 80 years makes it one of the oldest mental tests in continuous use. In addition to developing the AVLT, Claparède's pioneering contributions to neuropsychology include forensic assessment of cognitive deficits and research on implicit learning in amnesia.

Wechsler Adult Intelligence Scale-Revised Block Design broken configuration errors in nonpenetrating traumatic brain injury.

Final broken configuration errors on the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981) Block Design subtest were examined in 50 moderate and severe nonpenetrating traumatically brain injured adults. Patients were divided into left (n = 15) and right hemisphere (n = 19) groups based on a history of unilateral craniotomy for treatment of an intracranial lesion and were compared to a group with diffuse or negative brain CT scan findings and no history of neurosurgery (n = 16). The percentage of final broken configuration errors was related to injury severity, Benton Visual Form Discrimination Test (VFD; Benton, Hamsher, Varney, & Spreen, 1983) total score and the number of VFD rotation and peripheral errors. The percentage of final broken configuration errors was higher in the patients with right craniotomies than in the left or no craniotomy groups, which did not differ. Broken configuration errors did not occur more frequently on designs without an embedded grid pattern. Right craniotomy patients did not show a greater percentage of broken configuration errors on nongrid designs as compared to grid designs.

Characteristics of impaired awareness after traumatic brain injury.

Impaired awareness of the effects of brain injury is a commonly observed and poorly understood finding in traumatic brain injury survivors. Nonetheless, impaired awareness has been identified as a major factor in determining outcome for traumatic brain injury survivors. Review of previous studies of impaired awareness in this patient population revealed a number of preliminary findings regarding the nature of this phenomenon. The present paper presents the results of 2 new studies with a total of 111 traumatic brain injury patients conducted to bring further clarity to this area. Findings confirmed and extended many results of previous investigations. Specific findings included patient overestimation of functioning as compared to family member ratings, patient report of greater physical than nonphysical impairment, greater patient-family agreement on specific ratings of patient functioning than on general ratings, greater agreement of family and clinician ratings of patient functioning with each other than with patient self-ratings, and partial disagreement of different methods of measuring impaired awareness.

Inheritance of behavioural differences between two interfertile, sympatric species, Drosophila silvestris and D. heteroneura.

The Hawaiian fly species, Drosophila silvestris and D. heteroneura, are sympatric and interfertile but show strong behavioural isolation and major differences in male aggressive behaviour and the associated morphology. As a first step in elucidating the genetic control of the differences between these species, we examined the mating and aggressive behaviour of their reciprocal F1 hybrids. The latency to the first wing vibration and the latency to copulate did not differ significantly between the parental species. However, D. heteroneura females had a very low tendency to copulate with D. silvestris males, rarely mating during the observation period. The duration of copulation also differed significantly; same-species pairs of D. silvestris had copulations that lasted about 50% longer than those of same-species pairs of D. heteroneura. The hybrids were intermediate between the parental species for both the tendency to copulate with D. silvestris males and the duration of copulation, suggesting codominance or polygenic inheritance for those traits. The aggression traits that we scored were the leg posture and wing extension during early aggression, and the leg posture and head position during escalated aggression. The parental species showed clear differences for each of these traits. The F1 hybrids resembled one parent or the other, without showing intermediate values, suggesting single-gene dominance or threshold expression of many genes for those traits. None of the courtship or aggressive traits showed X-chromosomal effects, although the head shape of hybrids is influenced by genes on the X chromosome. It is difficult to reconcile the patterns of inheritance of aggressive behaviour and the lack of an X-chromosomal effect with the hypothesis that these traits are influenced by a coadapted gene complex.

Prediction of employment outcome one to three years following traumatic brain injury (TBI).

The current study investigated the relationship between age, education (EDUC), pre-injury productivity (PIP), Glasgow Coma Scale score, and a functional rating score at admittance and discharge from rehabilitation (Disability Rating Scale [DRS]) to employment status at one to three years following traumatic brain injury. EDUC, admit DRS, discharge DRS, and PIP all correlated significantly with follow-up employment status, 0.29, -0.32, -0.36, and 0.25 respectively. All possible combinations were then evaluated by Mallow's Cp statistic. The best fitting model was then used in a discriminant function analysis. The discriminant function correctly classified 84% of the employed subjects, 66% of the unemployed, and 75% across both groups. The current results compare favourably with those obtained in previous studies.

The Awareness Questionnaire: factor structure and internal consistency.

Patients with traumatic brain injuries often show impaired awareness of their impairments. This impaired awareness can decrease motivation for treatment and limit eventual functional outcome. The importance of this phenomenon has led to the development of multiple techniques and scales for measuring impaired awareness. The present paper briefly reviews the various methods of operationalizing impaired awareness and describes a new scale (the Awareness Questionnaire) designed to incorporate all these methods. Findings of previous studies supporting the validity of the Awareness Questionnaire are presented. The present investigation examined the factor structure and internal consistency of the Awareness Questionnaire with samples of 126 traumatic brain injury survivors and 75 family members/significant others. Principal components factor analysis with varimax rotation indicated three factors: cognitive, behavioural/affective, and motor/sensory. Investigation of internal consistency (Cronbach Coefficient Alpha) in both the patient and family sample yielded satisfactory results. These findings are supportive of continued use and investigation of the Awareness Questionnaire.

On the evolution of premating isolation after a founder event.

We present a new simple model for the evolution of premating reproductive isolation. Using this model we first analyze the level of genetic variability maintained by mutation in a large stable population. Then we consider the plausibility of the evolution of strong premating reproductive isolation after a founder event. We demonstrate that after a founder event a new adaptive combination of genes may rise to high frequencies in the presence of an old combination of genes. We compare the probabilities of speciation after a founder event with those in a stable population and with those when reproductive isolation is due to viability selection against hybrids. We argue that premating reproductive isolation is more efficient than postmating reproductive isolation in maintaining the integrity of sympatric species. This might have contributed to the pattern of stronger premating isolation than postmating isolation between closely related pairs of sympatric species.

Is sexual selection and species recognition a continuum? Mating behavior of the stalk-eyed fly Drosophila heteroneura.

If behavioral isolation between species can evolve as a consequence of sexual selection within a species, then traits that are both sexually selected and used as a criterion of species recognition by females should be identifiable. The broad male head of the Hawaiian picture-winged fly Drosophila heteroneura is a novel sexual dimorphism that may be sexually selected and involved in behavioral isolation from D. silvestris. We found that males with broad heads are more successful in sexual selection, both through female mate choice and through aggressive interactions. However, female D. heteroneura do not discriminate against hybrids on the basis of their head width. Thus, this novel trait is sexually selected but is not a major contributor to species recognition. Our methods should be applicable to other species in which behavioral isolation is a factor.