Neuroimaging in acute stroke

This article reviews the various imaging modalities available for the evaluation of patients presenting with a potential stroke syndrome, specifically acute ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage. It reviews the various computed tomography (CT) modalities, including noncontrast brain CT (NCCT), CT angiography, and CT perfusion. It discusses multimodal magnetic resonance imaging in the evaluation of patients with acute stroke, including diffusion-weighted imaging, T2-weighted sequences/fluid-attenuated inversion recovery, magnetic resonance angiography, perfusion-weighted imaging, and gradient-recalled echo. At the end of this article, a brief review on how to read an NCCT geared toward the emergency physician is included.     

Heat stroke: a comprehensive review

Heat stroke (HS) is a serious and potentially life-threatening condition defined as a core body temperature >40.6 degrees C. Two forms of HS are recognized, classic heat stroke, usually occurring in very young or elderly persons, and exertional heat stroke, more common in physically active individuals. An elevated body temperature and neurologic dysfunction are necessary but not sufficient to diagnose HS. Associated clinical manifestations such as extreme fatigue; hot dry skin or heavy perspiration; nausea; vomiting; diarrhea; disorientation to person, place, or time; dizziness; uncoordinated movements; and reddened face are frequently observed. Potential complications related to severe HS are acute renal failure, disseminated intravascular coagulation, rhabdomyolysis, acute respiratory distress syndrome, acid-base disorders, and electrolyte disturbances. Long-term neurologic sequelae (varying degrees of irreversible brain injury) occur in approximately 20% of patients. The prognosis is optimal when HS is diagnosed early and management with cooling measures and fluid resuscitation and electrolyte replacement begins promptly. The prognosis is poorest when treatment is delayed >2 hours.     

Being a stroke patient: a review of the literature

The purpose of this paper is to review the research literature on the patient's experience of stroke. Four qualitative studies on how patients experience stroke were identified. The findings of these studies show that the stroke patient often has clear goals for himself in relation to functional abilities, against which he measures all success and forward progress in his rehabilitation. Even though the stroke patient accepts a lower level of functional ability, he is not willing to accept the rehabilitation professionals' prediction of his ultimate functional level if it is lower than his own goal. Furthermore, stroke patients see recovery as a return to the existence they had lived before the stroke, which is different from the health care providers' view. To the health care provider, recovery is measured in terms of isolated and discrete return of movement, whereas in the eyes of the patients, recovery is a return to previously valued activities. Further, studies on psychosocial function after stroke were reviewed. Recent studies show that the psychological impact of the stroke experience is immense and that stroke patients experience stress on a variety of levels. Also, depression exists in a large portion of the stroke population. The impact of stroke also influences the patient's social existence, as studies have shown that stroke patients do manifest diminished social function. However, the reviewed studies are not without limitations. Further studies, with a qualitative design, are needed to throw light on the patient's experience of being ill with stroke, and the process of his recovery.     

Acupuncture in stroke recovery: a literature review

Acupuncture is commonly used in painful conditions but has a long history of use in traditional Chinese medicine for many other illnesses, including neurological conditions. There is an upsurge of interest in the treatment of hemiplegia by acupuncture and this review investigates the most recent research literature and concludes that there are good grounds for further investigation within rigorous scientific guidelines.     

Genetics of stroke: a review of recent advances

Stroke is a multifactorial disease responsible for nearly 10% of deaths each year in industrialized countries. While some monogenic forms of stroke have been described, the vast majority result from the common polygenic form of the disease. Progress in molecular genetics has allowed the identification, through genome-wide linkage analysis, of various candidate genes, including the genes encoding PDE4D and ALOX5AP. Since then, genetic research has been extensively performed from single candidate genes to whole-genome scan studies, in parallel with the development of high-throughput technologies in molecular diagnostics. Additionally, the safety and efficacy of tissue plasminogen activator, the only approved therapy for the acute phase of stroke, is modulated by genetic background associated with the occurrence of hemorrhagic transformations and with the revascularization of the cerebral arteries. In the near future, understanding the contribution of stroke genetic factors will lead to improvements in prevention and treatments for neurovascular diseases.     

Physiological monitoring in acute stroke: a literature review

AIM: This paper is a report of a review of the literature that considers how physiological parameters may affect outcome after stroke and the implications of this evidence for monitoring. BACKGROUND: Throughout the world, the incidence of first-ever stroke is approximately 200 per 100,000 people per year [Sudlow et al. (1997). Stroke 28, 491]. Stroke is the third most common cause of mortality [Sarti et al. (2000). Stroke 31, 1588] and causes 5.54 million deaths worldwide [Murray & Lopez (1997). Lancet 349, 268]. Physiological monitoring is considered a fundamental component of acute stroke care. Currently, the strength of evidence to support its use and identify its components is unclear. Nurse-led physiological assessment and subsequent interventions in acute stroke may have the potential to improve survival and reduce disability. DATA SOURCES: Online bibliographic databases from 1966 to 2007, including MEDLINE, EMBASE, CINAHL, AMED, Cochrane and ZETOC, were searched systematically. We identified 475 published papers relating to blood pressure, oxygen saturation and positioning, blood glucose and body temperature. REVIEW METHODS: Titles and abstracts were reviewed independently by two reviewers and 61 relevant studies were read in full. The quality of included studies was assessed and proformas were used to record detailed data. A narrative synthesis described how the evidence from the papers could inform our understanding of physiological parameters and their association with outcome. RESULTS: Current evidence suggests that patient outcome is worse when physiological parameters deviate from 'normal' in the acute phase of stroke. CONCLUSIONS: The evidence supports the need for monitoring and recording of blood pressure, oxygen saturation (including consideration of positioning), blood glucose and body temperature in the acute phase of stroke. This review has reinforced the importance of monitoring physiological parameters in the acute phase of stroke and adds support to the recommendation that monitoring should play a key role within nursing care.     

Self-efficacy and self-management after stroke: a systematic review

Purpose.?Specific increases of reaction times (RTs) were found in normal subjects, when endogenous spatial cues and targets were separated by the vertical visual meridian (VM) or by the vertical auditory (AM) meridian, when targets were either visual or auditory. The aim of this study was to assess if this effect could be attributed to longer RTs needed to shift activation between the hemispheres, or rather to different spatial maps underlying visual and auditory attention.

Method.?We tested the VM effect in deaf subjects. If the shifting of activation from one hemisphere to the other causes the increase in RTs, then no differences between normal and sensory disabled people should take place, as the incoming perceptual information in the residual modality uses the same neural pathways while crossing the vertical meridian. Conversely, if the vertical meridian effects are related to the spatial representation systems underlying endogenous orienting mechanisms, then the lack of the auditory perceptual system in deaf people may have determined different organization processes in the brain circuits, strongly affecting the orienting mechanisms of spatial attention.

Results.?Compared with a control group of hearing subjects, we found no evidence of the VM effect in deaf subjects.

Conclusions.?This finding, jointly with those of a previous experiment which showed no AM effect on blind subjects (Olivetti Belardinelli & Santangelo 2005) supports the idea of different spatial maps underlying visual and auditory attention, and suggests that their co-existence may induce interference effects in space processing, giving rise to the anisotropic representation of visual and auditory spaces, observed in normal subjects.     

运动想象疗法在脑卒中康复中的应用现状

综述运动想象(MI)的概念、机制以及在脑卒中康复的应用现状。目前MI的研究虽多,但各研究的治疗方案并无统一标准,仍需大样本、多中心的随机对照临床研究,以验证并形成一套规范化的治疗方案。现有研究将运动想象在社区护理中进行应用和强化的较少。     

Positive experiences of caregiving in stroke: a systematic review

Objective: To identify positive experiences of caregivers, who are unpaid carers not statutory, looking after stroke survivors by systematically reviewing published quantitative and qualitative studies. Data sources: Databases were searched from 1999 to 2009 through Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), British Nursing Index (BNI), Allied and Complimentary Medicine Database (AHMED), PsychINFO, EMBASE and Social Care Online. Reference tracking of selected papers was carried out and references of recent reviews related to stroke caregiving were also scrutinised. Review methods: The relevance of studies was ascertained by the two authors from abstracts and inclusion and exclusion criteria were then applied. Where there were differences of opinion, full copies were read and consensus achieved by discussion. Results: Three hundred and twenty-three studies were found and nine selected. Exploratory and cross-sectional studies prevailed. A range of positive experiences confirmed the findings of previous studies in both stroke and other long-term illness; care recipients progress was the most common source, other aspects included strengthened relationships, feeling appreciated, increased self-esteem. Positive experiences were associated with coping strategies. Changes in positive experiences over time were noted and differences too, for example, between new and experienced caregivers. Conceptual and methodological issues remain. Conclusions: Caregivers were able to identify positive experiences of caregiving providing a more balanced view of their role. Helping caregivers to identify their own positive experiences will encourage them to manage their situation. Longitudinal research is needed to track changes and positive influences on caregiving.

Implications for Rehabilitation

• There is some evidence that caregivers are able to identify what they value providing a more positive and balanced view of caregiving experiences other than just negative aspects.

• Positive aspects of coping are associated with positive experiences. Offering training to caregivers of a cognitive and behavioural nature, which includes a focus on positive experiences, may be beneficial and needs further consideration.

• The diversity of caregivers’ experiences – both positive and negative – should be taken into account by clinicians when supporting them.

     

Detection of eating difficulties after stroke: a systematic review

BACKGROUND: It is highly important in nursing care for persons with stroke to screen for, assess and manage eating difficulties. The impact on eating after stroke can be of different types, comprising dysphagia as well as eating difficulties in a larger perspective. Eating difficulties can cause complications such as malnutrition, dehydration, aspiration, suffocation, pneumonia and death. There is a lack of systematic reviews about methods to be used by nurses in their screening for eating difficulties. AIM: This review aims at systematically capturing and evaluating current peer-reviewed published literature about non-instrumental (besides pulse oximetry) and non-invasive screening methods for bedside detection of eating difficulties among persons with stroke. METHODS: A search was performed in Medline and 234 articles were obtained. After a selection process 17 articles remained, covering seven screening methods and including about 2,000 patients. CONCLUSION: Best nursing practice for detecting eating difficulties includes as the first step the Standardized Bedside Swallowing Assessment (SSA) to detect dysphagia (strong evidence). As the second step an observation should be made of eating including ingestion, deglutition and energy (moderate evidence). Applying pulse oximetry simultaneously to SSA can possibly add to the accuracy of aspiration detection, especially silent aspiration (limited evidence). The methods should be used as a complement to interviews.     

Neuroimaging experimental studies on brain plasticity in recovery from stroke

Topographical cortical organization of sensorimotor area has been shown to be highly plastic, altering his configuration in response to training in different tasks in healthy controls and neurological patients. The term 'brain plasticity' encompasses all possible mechanisms of neuronal reorganization: recruitment of pathways that are functionally homologous to, but anatomically distinct from, the damaged ones (eg, non-pyramidal corticospinal pathways), synaptogenesis, dendritic arborisation and reinforcement of existing but functionally silent synaptic connections (particularly at the periphery of core lesion). The study of neuroplasticity has clearly shown the ability of the developing brain--and of the adult and ageing brain--to be shaped by environmental inputs both under normal conditions (ie, learning) and after a lesion. Neuronal aggregates adjacent, or distant to a lesion in the sensorimotor area can progressively adopt the function of the injured area. Imaging studies indicate that recovery of motor function after a lesion (i.e. stroke) is associated with a progressive change of activation patterns in specific brain structures. Transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) can detect reshaping of sensorimotor areas; they have a high temporal resolution but have several limitations. TMS can only provide bidimensional scalp maps and MEG depicts three-dimensional spatial characteristics of virtual neural generators obtained by use of a mathematical model of the head and brain. However, the use of objective methods that assess brain reactivity to a physical stimulus (i.e., TMS) or to a sensory input (ie, electrical stimulation to hand and fingers) can integrate information from self-paced motor tasks, because the resolution of abnormal activation over time could be secondary to recovery. Functional MRI (fMRI) and positron emission tomography (PET), on their own, have insufficient time resolution to follow the hierarchical activation of relays within a neural network; however, because of their excellent spatial resolution, they can integrate the findings of TMS and MEG. An integrated approach constitutes, at present, the best way to assess the brain plasticity both under normal conditions and after a lesion.     

Rehabilitation of gait after stroke: a review towards a top-down approach

Background

Approximately 60% of stroke survivors experience hand dysfunction limiting execution of daily activities. Several methods have been proposed to objectively quantify fingers' joints range of motion (ROM), while few studies exist about multi-finger coordination during hand movements. The present work analysed this aspect, by providing a complete characterization of spatial and temporal aspects of hand movement, through the mathematical modelling of multi-joint finger motion in healthy subjects and stroke patients.

Methods

Hand opening and closing movements were examined in 12 healthy volunteers and 14 hemiplegic stroke survivors by means of optoelectronic kinematic analysis. The flexion/extension angles of metacarpophalangeal (MCPJ) and proximal interphalangeal joints (IPJ) of all fingers were computed and mathematically characterized by a four-parameter hyperbolic tangent function. Accuracy of the selected model was analysed by means of coefficient of determination (R²) and root mean square error (RMSE). Test-retest reliability was quantified by intraclass correlation coefficient (ICC) and test-retest errors. Comparison between performances of healthy controls and stroke subjects were performed by analysing possible differences in parameters describing angular and temporal aspects of hand kinematics and inter-joint, inter-digit coordination.

Results

The angular profiles of hand opening and closing were accurately characterized by the selected model, both in healthy controls and in stroke subjects (R² > 0.973, RMSE < 2.0°). Test-retest reliability was found to be excellent, with ICC > 0.75 and remarking errors comparable to those obtained with other methods. Comparison with healthy controls revealed that hemiparetic hand movement was impaired not only in joints ROM but also in the temporal aspects of motion: peak velocities were significantly decreased, inter-digit coordination was reduced of more than 50% and inter-joint coordination patterns were highly disrupted. In particular, the stereotypical proximal-to-distal opening sequence (reversed during hand closing) found in healthy subjects, was altered in stroke subjects who showed abnormally high delay between IPJ and MCPJ movement or reversed moving sequences.

Conclusions

The proposed method has proven to be a promising tool for a complete objective characterization of spatial and temporal aspects of hand movement in stroke, providing further information for a more targeted planning of the rehabilitation treatment to each specific patient and for a quantitative assessment of therapy's outcome.     

Positioning of the stroke patient: a review of the literature

Stroke in a common and disabling illness, adversely affecting the quality of life of hundreds of people each year. While there are many therapeutic approaches to stroke patient rehabilitation, encouraging patients to adopt “reflex-inhibiting” patterns of posture is a widely advocated strategy for helping patients to avoid complications of hemiplegia such as spasticity and contractures. However, while the central role of nurses in thus helping patients is recognized, the influence of posture on recovery from stroke has never been evaluated. Prior to undertaking such an evaluative study, texts on stroke patient care were reviewed to clarify the received view about the recommended positioning for patients with hemiplegia. Consensus on some issues was evident (such as positioning the patient with the affected shoulder protracted, spine straight, fingers extended and avoiding external rotation of the affected hip). However, opinion was divided on others and a number of potentially important aspects were ill-covered. This paper integrates a summary of the findings of this review with the physiological rationale for the recommendations. The main areas of agreement are highlighted and issues as yet unanswered are raised for further consideration.     

Prognostic factors in functional outcome after stroke: a review

Survivors of stroke constitute the largest group of patients receiving rehabilitative therapy. Purpose of this article is to review the prognostic factors which can affect functional outcome after stroke. An accurate prognostic assessment is fundamental after cerebrovascular accident, in order to plan the rehabilitative project and define both early and long-term objectives. We found agreement of opinions about the prognostic value of some factors, whereas three are difference of opinions about other prognostic factors in predicting neurological outcome.     

Acupuncture for shoulder pain after stroke: a systematic review

Abstract Objectives: Shoulder pain, for which acupuncture has been used, is a common complication after a stroke that interferes with the function of the upper extremities. The aim of this systematic review is to summarize and evaluate the effects of acupuncture for shoulder pain after stroke. Methods: Randomized controlled trials (RCTs) involving the effects of acupuncture for shoulder pain, published between January 1990 and August 2009, were obtained from the National Libraries of Medicine, MEDLINE(?), CINAHL, AMED, Embase, Cochrane Controlled Trials Register 2009, Korean Medical Database (Korea Institute of Science Technology Information, DBPIA, KoreaMed, and Research Information Service System), and the Chinese Database (China Academic Journal). Results: Among the 453 studies that were obtained (300 written in English, 137 in Chinese, and 16 in Korean), 7 studies met the inclusion criteria for this review. All of them were RCTs published in China and reported positive effects of the treatment. The quality of the studies was assessed by the Modified Jadad Scores (MJS) and the Cochrane Back Review Group Criteria List for Methodologic Quality Assessment of RCTs (CBRG); the studies scored between 2 and 3 points on MJS, and between 4 and 7 points on CBRG. Conclusions: It is concluded from this systematic review that acupuncture combined with exercise is effective for shoulder pain after stroke. It is recommended that future trials be carefully conducted on this topic.