P. Pradat-Diehl

Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke

Objectives: The lack of agreement regarding assessment methods is responsible for the variability in the reported rate of occurrence of spatial neglect after stroke. The aim of this study was to assess the sensitivity of different tests of neglect after right hemisphere stroke. Methods: Two hundred and six subacute right hemisphere stroke patients were given a test battery including a preliminary assessment of anosognosia and of visual extinction, a clinical assessment of gaze orientation and of personal neglect, and paper and pencil tests of spatial neglect in the peripersonal space. Patients were compared with a previously reported control group. A subgroup of patients (n=69) received a behavioural assessment of neglect in daily life situations. Results: The most sensitive paper and pencil measure was the starting point in the cancellation task. The whole battery was more sensitive than any single test alone. About 85% of patients presented some degree of neglect on at least one measure. An important finding was that behavioural assessment of neglect in daily life was more sensitive than any other single measure of neglect. Behavioural neglect was considered as moderate to severe in 36% of cases. A factorial analysis revealed that paper and pencil tests were related to two underlying factors. Dissociations were found between extrapersonal neglect, personal neglect, anosognosia, and extinction. Anatomical analyses showed that neglect was more common and severe when the posterior association cortex was damaged. Conclusions: The automatic rightward orientation bias is the most sensitive clinical measure of neglect. Behavioural assessment is more sensitive than any single paper and pencil test. The results also support the assumption that neglect is a heterogeneous disorder.

Right spatial neglect after left hemisphere stroke: qualitative and quantitative study

Objectives: Comparatively little research has been conducted on right neglect after left brain damage. The authors sought to assess contralateral neglect in subacute left hemisphere stroke patients using a comprehensive test battery validated in a large control group after right hemisphere stroke. Methods: Seventy-eight left hemisphere stroke patients were assessed. The test battery included a preliminary assessment of anosognosia and visual extinction, a clinical assessment of gaze orientation and personal neglect, and paper-and-pencil tests of spatial neglect in the peripersonal space. Only nonverbal tests were used. Results: Drawing and cancellation tasks revealed neglect in 10 to 13% of patients. The combined battery was more sensitive than any single test alone. A total of 43.5% of patients showed some degree of neglect on at least one measure. Anatomic analyses showed that neglect was more common and severe when the posterior association cortex was damaged. Conclusions: The frequency of occurrence of right neglect was, as expected, much lower than that reported in a study using the same assessment battery in right brain damage stroke patients. Nevertheless, neglect was found in a substantial proportion of patients at a subacute stage, suggesting that it should be considered in the rehabilitation planning of left brain damage stroke patients.

Impaired efficacy of spinal presynaptic mechanisms in spastic stroke patients

Pathophysiological mechanisms underlying spasticity have been the subject of many studies. These studies performed in various kinds of spastic patients have revealed abnormalities in many spinal pathways controlling motoneurone discharge. Unfortunately, the pathophysiological mechanisms responsible for the development of spasticity remains nevertheless largely unknown since most of the previous studies failed to reveal a link between the characteristics of spasticity (severity, time course) and that of the dysfunction of a given perturbed spinal pathway. In the present series of experiments, we focused on the study of presynaptic mechanisms acting at the synapse fibre Ia-motoneurone since monosynaptic reflexes are enhanced in spasticity. Two presynaptic mechanisms have been described in both animals and humans: presynaptic Ia inhibition and post-activation depression. By increasing the number of subjects in comparison with previous studies (87 patients and 42 healthy controls) we have been able to show that these two mechanisms are unequally impaired in stroke patients depending on (i) the duration of the disease (acute, defined as less than 3 months after the causal lesion, or chronic, defined as more than 9 months after the causal lesion), (ii) the side considered (affected or unaffected) and (iii) the severity of spasticity. In this respect, only post-activation depression amount was found to be highly correlated with the severity of spasticity. Although not a definitive proof, this correlation between severity of spasticity and changes in a given spinal pathway lead us to conclude that the impairment of post-activation depression is likely one of the mechanisms underlying spasticity. On the contrary, changes in presynaptic Ia inhibition appear to be a simple epiphenomenon, i.e. a basic correlate of the brain lesions. It is argued that plastic changes develop from the disuse due to motor command impairment in both pathways.

Rehabilitation of verbal working memory after left hemisphere stroke

Primary objective: To assess a rehabilitation programme of working memory Research design: Single case multiple-baseline-across-behaviour design in a patient with chronic stroke suffering from a specific impairment of working memory. Methods: Rehabilitation included training of storage and processing components of verbal working memory. Outcome was assessed with specific working memory tests, non-specific tasks requiring working memory, non-target tasks not requiring working memory and questionnaires addressing daily-life functioning. This assessment was performed twice before the experimental therapy and once after. Results: Cognitive measures were stable before therapy. A statistically significant improvement was found for target measures and for daily-life skills. In contrast, no change was found on non-target tasks. Conclusion: Improvement was not apparently related to spontaneous recovery, since performance was stable before therapy. This study suggests that specific cognitive training may improve working memory in patients with brain injury.

Predictive factors for 1-year outcome of a cohort of patients with severe traumatic brain injury (TBI): Results from the PariS-TBI study

Abstract Objectives: To assess outcome and predicting factors 1 year after a severe traumatic brain injury (TBI). Methods: Multi-centre prospective inception cohort study of patients aged 15 or older with a severe TBI in the Parisian area, France. Data were collected prospectively starting the day of injury. One-year evaluation included the relatives-rating of the Dysexecutive Questionnaire (DEX-R), the Glasgow Outcome Scale–Extended (GOSE) and employment. Univariate and multivariate tests were computed. Results: Among 257 survivors, 134 were included (mean age 36 years, 84% men). Good recovery concerned 19%, moderate disability 43% and severe disability 38%. Among patients employed pre-injury, 42% were working, 28% with no job change. DEX-R score was significantly associated with length of education only. Among initial severity measures, only the IMPACT prognostic score was significantly related to GOSE in univariate analyses, while measures relating to early evolution were more significant predictors. In multivariate analyses, independent predictors of GOSE were length of stay in intensive care (LOS), age and education. Independent predictors of employment were LOS and age. Conclusions: Age, education and injury severity are independent predictors of global disability and return to work 1 year after a severe TBI.

Calculation and number processing : assessment battery; role of demographic factors

This paper describes the structure and contents of EC301, a standardized testing battery for the evaluation of brain-damaged adults in the area of calculation and number processing. The battery was administered to 180 normal subjects stratified by education (3 levels), age (3) and gender. EC301 is composed of a large variety of tasks dealing with basic arithmetic skills, and their linguistic, spatial, and mnesic dimensions. The three main notational systems for numbers--Arabic digits, written verbal, and spoken verbal number forms--are explored. Analysis of error rates indicated the effect of some demographic factors (principally, education; incidentally, gender) on normal performance in some tasks.

Assessment of unilateral spatial neglect in children using the Teddy Bear Cancellation Test.

The purpose of the study was to provide normative data for the Teddy Bear Cancellation Test (TBCT) and to evaluate prospectively the frequency of unilateral spatial neglect (USN) in children with acquired brain injury (ABI). In the control group (n=419; 218 males, 201 females; mean age 5y 1mo [SD 1y 4mo]; range 3 to 8y) omissions were rare and decreased with age. A left displacement of the first three teddy bears cancelled was observed with increasing age. This preferential left‐to‐right cancelling strategy was interpreted as learned under the influence of reading habits. The same test was used prospectively in 41 children with ABI (24 males, 17 females; mean age 5y 5mo [SD 2y]; range 3 to 8y) admitted to a paediatric rehabilitation department specializing in acquired brain lesions. In patients and controls, children under 6 years of age omitted more items than older children. The localization of omissions was skewed significantly to the left in children with right‐sided lesions compared with children with left‐sided lesions. USN was observed in seven patients with ABI. Left USN was found in three of the 10 patients with right‐sided ABI. Right USN was present in two of the patients with 15 left‐sided ABI and two of the 16 patients with non‐lateralized ABI. Left USN is frequent in children after right‐sided brain injury. The relatively high incidence of right spatial neglect in children is discussed in relation to the development of hemispheric specialization.

Spatial and motor neglect in children

Objective: To determine if unilateral spatial neglect can be found in very young children with acquired brain lesions. Methods: A retrospective study was carried out over a 10-year period in a pediatric rehabilitation department specializing in acquired brain lesions. Twelve cases were selected involving children aged 7 months to 14 years. Neglect was assessed by behavior observation for all children and, depending on age, by drawing, copying, reading, writing, and arithmetic tasks. Seven patients underwent the experimental “Teddy Bear” cancellation task, specially adapted to children. Results: All children exhibited spatial and motor neglect in daily activities. In addition, children who were over 2 years of age made lateralized omissions in paper and pencil tasks as well as in the “Teddy Bear” cancellation task. Nine of the 12 children exhibited left spatial and motor neglect, whereas the other three, all of whom were very young (under 4 years), exhibited right spatial neglect. In three cases, cortical lesions were restricted to one lobe, either the parietal, frontal, or temporal. In eight children, lesions extended over more than one lobe, and one child sustained only subcortical lesions. Conclusion: Unilateral spatial and motor neglect occurs even in very young children. Right spatial neglect described in very young children may be related to the development of hemispheric specialization.

Predictors of Informal Care Burden 1 Year After a Severe Traumatic Brain Injury: Results From the Paris-tbi study

Objective:To investigate predictors of informal care burden 1 year after a severe traumatic brain injury (TBI). Participants:Patients (N = 66) aged 15 years or older with severe TBI (Glasgow Coma Scale score of 8 or less) and their primary informal caregivers. Setting:Multicenter inception cohort study over 22 months in Paris and the surrounding area (PariS-TBI study). Main measures:Patients’ preinjury characteristics; injury severity data; outcome measures at discharge from intensive care and 1 year after the injury; Dysexecutive Questionnaire; Medical Outcome Study Short Form-36; Zarit Burden Inventory. Results:Among the 257 survivors at discharge from acute care, 66 patient-caregiver couples were included. Primary informal caregivers were predominantly women (73%), of middle age (age, 50 years), supporting male patients (79%), of mean age of 38 years. The majority (56%) of caregivers experienced significant burden, and 44% were at risk of depression. Caregivers’ impaired health status and perceived burden significantly correlated with patients’ global disability (as assessed with the Glasgow Outcome Scale-Extended) and impairments of executive functions (as assessed with the Dysexecutive Questionnaire). A focused principal component analysis suggested that disability and executive dysfunctions were independent predictors of perceived burden, whereas demographics, injury severity, and Glasgow Outcome Scale at discharge from acute care did not significantly correlate with caregivers burden. Conclusion:Global handicap and impairments of executive functions are independent significant predictors of caregiver burden 1 year after TBI.

Assessment of executive functioning in children after TBI with a naturalistic open-ended task: A pilot study

Purpose: Traumatic brain injury (TBI) often leads to executive functions (EF) deficits, resulting in severe longstanding disabilities in daily life activities. The sensitivity and ecological validity of neuropsychological tests have been questioned. The aim of this study was to pilot a novel open-ended naturalistic task and to compare it to other standardized assessments of EF in children post-TBI. Methods: Ten children aged 8–14, with moderate-to-severe TBI, and 18 matched controls participated in the study. The clinical group was assessed using cognitive tests and parent-based questionnaires of EF. An interactive ecological cooking task was designed. Results: Analyses indicated mild-to-moderate executive deficits in the cognitive tests in approximately half of the TBI group. For the experimental cooking task, all quantitative and qualitative variables were significantly impaired for the TBI group compared to the control group and failure in the cooking task was associated with lower scores in cognitive tests of EF. The task was able to discriminate the TBI children from the control group. Conclusion: This pilot study highlights the role of naturalistic assessments, to complement standardized tests in assessing patients’ dysexecutive impairments in complex activities of daily living post-childhood TBI.