Anna M. Barrett

Cognitive Rehabilitation Interventions for Neglect and Related Disorders: Moving from Bench to Bedside in Stroke Patients

The spatial neglect syndrome, defined by asymmetric attention and action not attributed to primary motor or sensory dysfunction and accompanied by functional disability, is a major cause of post-stroke morbidity. In this review, we consider the challenges and obstacles facing scientific researches wishing to evaluate the mechanisms and effectiveness of rehabilitation interventions. Spatial neglect is a heterogeneous disorder, for which consensus research definitions are not currently available, and it is unclear which of the deficits associated with the syndrome causes subsequent disability. We review current opinion about methods of assessment, suggest a rational approach to selecting therapies which requires further study, and make systems-level and theoretical recommendations for building theory. We lastly review some creative questions for consideration in future research.

Unawareness of cognitive deficit (cognitive anosognosia) in probable AD and control subjects

Objective: To develop a quantitative method of assessing cognitive anosognosia in six cognitive and two noncognitive domains. Methods: Control (n = 32) and probable Alzheimer disease (pAD) (n = 14) subjects self-estimated memory, attention, generative behavior, naming, visuospatial skill, limb praxis, mood, and uncorrected vision, both before and after these abilities were assessed. Based on this estimate and their performance the authors calculated an anosognosia ratio (AR) by dividing the difference between estimated and actual performance by an estimated and actual performance sum. With perfect awareness, AR = 0. Overestimating abilities would yield a positive AR (≤1); underestimation would yield a negative AR (≥−1). Results: Relative to controls, pAD subjects demonstrated anosognosia. Pre-testing (off-line), pAD subjects overestimated their visuospatial skill; post-testing (on-line), pAD subjects overestimated their memory. Control subjects also made self-rating errors, underestimating their attention pre-testing and overestimating limb praxis and vision post-testing. Conclusions: This anosognosia assessment method may allow more detailed examination of distorted self-awareness. These results suggest that screening for anosognosia in probable Alzheimer disease (pAD) should include self-estimates of visuospatial function, and that, in pAD, it may be useful to assess anosognosia for amnesia both before and after memory testing.

Risk factors associated with injury attributable to falling among elderly population with history of stroke

Background and Purpose— Stroke survivors are at high risk for falling. Identifying physical, clinical, and social factors that predispose stroke patients to falls may reduce further disability and life-threatening complications, and improve overall quality of life. Methods— We used 5 biennial waves (1998–2006) from the Health and Retirement Study to assess risk factors associated with falling accidents and fall-related injuries among stroke survivors. We abstracted demographic data, living status, self-evaluated general health, and comorbid conditions. We analyzed the rate ratio (RR) of falling and the OR of injury within 2 follow-up years using a multivariate random effects model. Results— We identified 1174 stroke survivors (mean age±SD, 74.4±7.2 years; 53% female). The 2-year risks of falling, subsequent injury, and broken hip attributable to fall were 46%, 15%, and 2.1% among the subjects, respectively. Factors associated with an increased frequency of falling were living with spouse as compared to living alone (RR, 1.4), poor general health (RR, 1.1), time from first stroke (RR, 1.2), psychiatric problems (RR, 1.7), urinary incontinence (RR, 1.4), pain (RR, 1.4), motor impairment (RR, 1.2), and past frequency of ≥3 falls (RR, 1.3). Risk factors associated with fall-related injury were female gender (OR, 1.5), poor general health (OR, 1.2), past injury from fall (OR, 3.2), past frequency of ≥3 falls (OR, 3.1), psychiatric problems (OR, 1.4), urinary incontinence (OR, 1.4), impaired hearing (OR, 1.6), pain (OR, 1.8), motor impairment (OR, 1.3), and presence of multiple strokes (OR, 3.2). Conclusions— This study demonstrates the high prevalence of falls and fall-related injuries in stroke survivors, and identifies factors that increase the risk. Modifying these factors may prevent falls, which could lead to improved quality of life and less caregiver burden and cost in this population.

Adverse effect of dopamine agonist therapy in a patient with motor-intentional neglect

Studies in animals and humans report dopamine agonists can improve neglect. Because dopamine deficit reduces intention to act, it has been suspected the dopamine agonist bromocriptine would improve deficient hemispatial intention. Thus, the effect of bromocriptine on line bisection was examined in a patient with neglect and failure of the action-intention system. The 58-year-old patient had left-sided neglect from a right cerebral infarction involving both cortical and subcortical (striatal) structures. It was determined that neglect on a line bisection task was attributable to a motor-intentional bias by testing under congruous and incongruous video monitoring. Testing sessions were held before starting bromocriptine, on 20 mg/d, and after stopping bromocriptine. The patients ipsilesional bias increased on bromocriptine, and improved when bromocriptine was stopped. Bromocriptine may worsen neglect if putamenal receptors are damaged. Dopamine agonists may activate the normal hemisphere, increasing an intentional bias. Clinicians using dopaminergic pharmacotherapy should assess patients for this possible adverse effect.

Emotional Perception Deficits in Amyotrophic Lateral Sclerosis

ObjectiveCognitive deficits associated with frontal lobe dysfunction can occur in amyotrophic lateral sclerosis (ALS), particularly in individuals with bulbar ALS who can also suffer pathologic emotional lability. Because frontal pathophysiology can alter emotional perception, we examined whether emotional perception deficits occur in ALS, and whether they are related to depressive or dementia symptoms. MethodsBulbar ALS participants (n=13) and age-matched healthy normal controls (n=12) completed standardized tests of facial emotional and prosodic recognition, the Geriatric Depression Scale, and the Mini-Mental State Examination. Participants identified the basic emotion (happy, sad, angry, afraid, surprised, disgusted) that matched 39 facial expressions and 28 taped, semantically neutral, intoned sentences. ResultsALS patients performed significantly worse than controls on facial recognition but not on prosodic recognition. Eight of 13 patients (62%) scored below the 95% confidence interval of controls in recognizing facial emotions, and 3 of these patients (23% overall) also scored lower in prosody recognition. Among the 8 patients with emotional perceptual impairment, one-half did not have depressive, or memory or cognitive symptoms on screening, whereas the remainder showed dementia symptoms alone or together with depressive symptoms. ConclusionsEmotional recognition deficits occur in bulbar ALS, particularly with emotional facial expressions, and can arise independent of depressive and dementia symptoms or comorbid with depression and dementia. These findings expand the scope of cognitive dysfunction detected in ALS, and bolsters the view of ALS as a multisystem disorder involving cognitive and also motor deficits.

Emotional experience and perception in the absence of facial feedback.

The facial feedback hypothesis suggests that facial expressions are either necessary or sufficient to produce emotional experience. Researchers have noted that the ideal test of the necessity aspect of this hypothesis would be an evaluation of emotional experience in a patient suffering from a bilateral facial paralysis; however, this condition is rare and no such report has been documented. We examined the role of facial expressions in the determination of emotion by studying a patient (F.P.) suffering from a bilateral facial paralysis. Despite her inability to convey emotions through facial expressions, F.P. reported normal emotional experience. When F.P. viewed emotionally evocative slides her reactions were not dampened relative to the normative sample. F.P. retained her ability to detect, discriminate, and image emotional expressions. These findings are not consistent with theories stating that feedback from an active face is necessary to experience emotion, or to process emotional facial expressions.

Attentional grasp in far extrapersonal space after thalamic infarction

Studies of animals and humans with focal brain damage suggest that attention in near and far extrapersonal space may be mediated by anatomically separate systems. Thalamic lesions have been associated with spatial neglect, but whether asymmetric attention specific to near or far space occur after thalamic damage has not been explored. It is also unclear if thalamic injury can induce contralesional defective response inhibition. We tested a woman with a left thalamic infarction who reported that, when driving, she had a tendency to veer towards people or objects on the right side of the road. Our patient and four controls performed a line bisection task with a laser pointer in near and far extrapersonal space. The experimenter marked each bisection either from the right of the presented line (right-distractor, RD) or the left (left-distractor, LD). RD and LD trials were pseudo-randomized. Our patient performed similarly to controls (mean -0.7 mm, controls -0.6 mm) on the line bisection task in near space. In far space she erred significantly rightward compared to her performance in near space (p<0.001). Controls performed similarly in near and far space. The experimenter position did not affect our patients performance on near line bisections, nor did controls demonstrate a distractor effect for the near condition. In the far condition, however, our patient showed a significant distractor effect (LD -3.3 mm, RD 35.3 mm, p<0.001). Controls also demonstrated a distractor effect in the far condition (LD -6.4 mm, RD 0.7 mm, p<0.01), though of much smaller magnitude. Our results suggest that frontal-thalamic systems regulating visual attention may be disrupted by thalamic infarction. Such damage may produce an attentional grasp specific to far extrapersonal space.

Concurrent vision dysfunctions in convergence insufficiency with traumatic brain injury.

Purpose This study assessed the prevalence of convergence insufficiency (CI) with and without simultaneous vision dysfunctions within the traumatic brain injury (TBI) sample population because although CI is commonly reported with TBI, the prevalence of concurrent visual dysfunctions with CI in TBI is unknown. Methods A retrospective analysis of 557 medical records from TBI civilian patients was conducted. Patients were all evaluated by a single optometrist. Visual acuity, oculomotor function, binocular vision function, accommodation, visual fields, ocular health, and vestibular function were assessed. Statistical comparisons between the CI and non-CI, as well as inpatient and outpatient subgroups, were conducted using &khgr;2 and Z tests. Results Approximately 9% of the TBI sample had CI without the following simultaneous diagnoses: saccade or pursuit dysfunction; third, fourth, or sixth cranial nerve palsy; visual field deficit; visual spatial inattention/neglect; vestibular dysfunction; or nystagmus. Photophobia with CI was observed in 16.3% (21 of 130), and vestibular dysfunction with CI was observed in 18.5% (24 of 130) of the CI subgroup. Convergence insufficiency and cranial nerve palsies were common and yielded prevalence rates of 23.3% (130 of 557) and 26.9% (150 of 557), respectively, within the TBI sample. Accommodative dysfunction was common within the nonpresbyopic TBI sample, with a prevalence of 24.4% (76 of 314). Visual field deficits or unilateral visual spatial inattention/neglect was observed within 29.6% (80 of 270) of the TBI inpatient subgroup and was significantly more prevalent compared with that of the outpatient subgroup (p < 0.001). Most TBI patients had visual acuities of 20/60 or better in the TBI sample (85%; 473 of 557). Conclusions Convergence insufficiency without simultaneous visual or vestibular dysfunctions was observed in about 9% of the visually symptomatic TBI civilian population studied. A thorough visual and vestibular examination is recommended for all TBI patients.

Functional Assessment of Spatial Neglect: A Review of the Catherine Bergego Scale and an Introduction of the Kessler Foundation Neglect Assessment Process

Abstract Spatial neglect is a debilitating poststroke neurocognitive disorder associated with prolonged hospitalization and poor rehabilitation outcomes. The literature suggests a high prevalence of this disorder, but clinicians have difficulty reliably identifying affected survivors. This discrepancy may result from suboptimal use of validated neglect assessment procedures. In this article, we suggest use of a validated assessment tool that is sensitive to identification of neglect and its functional consequences – the Catherine Bergego Scale (CBS). We provide detailed item-by-item instructions for observation and scoring – the Kessler Foundation Neglect Assessment Process (KF-NAP). Rehabilitation researchers may be able to use the CBS via the KF-NAP to measure ecological outcomes and specific, separable perceptual-attentional and motor-exploratory spatial behaviors.

Mental object rotation in Parkinson's disease.

Deficits in visual-spatial ability can be associated with Parkinsons disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.