Assessment scales for the evaluation of stroke patients

A Study to Estimate the Red Cell Width Distribution and the Mean Platelet Volume in Predicting the 30-Day Mortality in Acute Ischemic Stroke Patients

Background Acute ischemic stroke, a clinical disorder caused by nontraumatic cerebrovascular disease, has an acute onset, frequently causes neurological deficit, and may persist for >24 hours or can be fatal in <24 hours. This study aimed to assess the red cell width distribution (RDW) and the mean platelet volume (MPV) in predicting 30-day mortality in acute ischemic stroke patients. In general, patients with acute ischemic stroke have a rather high mortality rate in the first 30 days due to various complications, but post the 30-day mark, the prognosis is comparatively better. Material and methods The present study was conducted on patients with a confirmed diagnosis of acute ischemic stroke based on history, physical examination, CT scan, and/or diffusion-weighted MRI scan performed during the first 24 hours. It was a prospective and cross-sectional study done at Saveetha Medical College over a period of two years. The data was collected by using the intra-hospital network and was analyzed using the IBM SPSS Statistics for Windows, Version 20 (Released 2011; IBM Corp., Armonk, New York, United States). Results In the present study, among 100 patients, the mean age was 57.4 ± 13.36 years. About 55% of our subjects were males in our study. The RDW on the 1stday was 14.17 ± 0.708, and it reduced drastically on the 30thday to1st 13.55 ± 1.11, and it was statically significant (p = 0.000). The MPV on day 1 was 11.11 ± 0.969 and, on day 30, was 10.82 ± 0.90; the MPV was reduced considerably on day 30, which was statistically significant (p = 0.000). RDW on the 1st day was significantly correlated with the MPV and the volume of stroke. The correlation was significant at the 0.01 level (two-tailed). On the 30th day of acute ischemic stroke patients, the red blood cell (RBC) width was significantly correlated with the MPV. The correlation was significant at the 0.01 level (two-tailed). At the end of 30 days, 10% mortality was observed in the present study. Day 30 saw a significant decrease in the MPV and RDW, particularly in the moderate to severe and severe categories. The National Institutes of Health Stroke Scale (NIHSS) score and the volume of stroke were significantly associated with the 30-day outcome.  Conclusion The RDW and the MPV are well correlated in predicting the 30-day mortality in acute ischemic stroke patients. This could potentially be used as a significant marker for predicting mortality in stroke patients in the future, but to increase the generalization, further studies need to be carried out at other demographically distinct medical centers.

The Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment for patients following acquired brain injury: Translation and reliability study

Objective

To develop the Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment and to investigate its internal consistency, intra- and inter-rater reliability.

Design

Prospective cohort study.

Setting

Rehabilitation department.

Subjects

A total of 34 patients with acquired brain injury.

Main measure

The translation and cultural adaptation process was completed, and the testing procedures of the Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment were standardized. Internal consistency was evaluated using Cronbach's alpha index; assessment of intra- and inter-rater reliability was carried out using weighted kappa coefficient.

Results

The internal consistency of the tactile sensations and the proprioception items of the Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment were generally acceptable to excellent with a range of Cronbach's alpha between 0.73 and 0.97. The intra-rater reliability of the tactile sensations and the proprioception items of the Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment were generally good to excellent with a range of weighted kappa coefficients between 0.47 and 1.00. Likewise, the inter-rater reliabilities of these items were predominantly good to excellent with a range of weighted kappa coefficients between 0.42 and 0.92.

Conclusion

The Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment is a reliable screening tool to evaluate primary somatosensory impairments in patients with acquired brain injury. Further research is necessary to consolidate these results and establish the validity and responsiveness of the Italian version of the Erasmus MC modifications to the Nottingham Sensory Assessment.

Assessment Methods of Post-stroke Gait: A Scoping Review of Technology-Driven Approaches to Gait Characterization and Analysis

Background: Gait dysfunction or impairment is considered one of the most common and devastating physiological consequences of stroke, and achieving optimal gait is a key goal for stroke victims with gait disability along with their clinical teams. Many researchers have explored post stroke gait, including assessment tools and techniques, key gait parameters and significance on functional recovery, as well as data mining, modeling and analyses methods.

Research Question: This study aimed to review and summarize research efforts applicable to quantification and analyses of post-stroke gait with focus on recent technology-driven gait characterization and analysis approaches, including the integration of smart low cost wearables and Artificial Intelligence (AI), as well as feasibility and potential value in clinical settings.

Methods: A comprehensive literature search was conducted within Google Scholar, PubMed, and ScienceDirect using a set of keywords, including lower extremity, walking, post-stroke, and kinematics. Original articles that met the selection criteria were included.

Results and Significance: This scoping review aimed to shed light on tools and technologies employed in post stroke gait assessment toward bridging the existing gap between the research and clinical communities. Conventional qualitative gait analysis, typically used in clinics is mainly based on observational gait and is hence subjective and largely impacted by the observer's experience. Quantitative gait analysis, however, provides measured parameters, with good accuracy and repeatability for the diagnosis and comparative assessment throughout rehabilitation. Rapidly emerging smart wearable technology and AI, including Machine Learning, Support Vector Machine, and Neural Network approaches, are increasingly commanding greater attention in gait research. Although their use in clinical settings are not yet well leveraged, these tools promise a paradigm shift in stroke gait quantification, as they provide means for acquiring, storing and analyzing multifactorial complex gait data, while capturing its non-linear dynamic variability and offering the invaluable benefits of predictive analytics.

Decoding of Ankle Joint Movements in Stroke Patients Using Surface Electromyography

Stroke is a cerebrovascular disease (CVD), which results in hemiplegia, paralysis, or death. Conventionally, a stroke patient requires prolonged sessions with physical therapists for the recovery of motor function. Various home-based rehabilitative devices are also available for upper limbs and require minimal or no assistance from a physiotherapist. However, there is no clinically proven device available for functional recovery of a lower limb. In this study, we explored the potential use of surface electromyography (sEMG) as a controlling mechanism for the development of a home-based lower limb rehabilitative device for stroke patients. In this experiment, three channels of sEMG were used to record data from 11 stroke patients while performing ankle joint movements. The movements were then decoded from the sEMG data and their correlation with the level of motor impairment was investigated. The impairment level was quantified using the Fugl-Meyer Assessment (FMA) scale. During the analysis, Hudgins time-domain features were extracted and classified using linear discriminant analysis (LDA) and artificial neural network (ANN). On average, 63.86% ± 4.3% and 67.1% ± 7.9% of the movements were accurately classified in an offline analysis by LDA and ANN, respectively. We found that in both classifiers, some motions outperformed others (p < 0.001 for LDA and p = 0.014 for ANN). The Spearman correlation (ρ) was calculated between the FMA scores and classification accuracies. The results indicate that there is a moderately positive correlation (ρ = 0.75 for LDA and ρ = 0.55 for ANN) between the two of them. The findings of this study suggest that a home-based EMG system can be developed to provide customized therapy for the improvement of functional lower limb motion in stroke patients.

National Institutes of Health Stroke Scale: An Alternative Primary Outcome Measure for Trials of Acute Treatment for Ischemic Stroke

Supplemental Digital Content is available in the text.

The modified Rankin Scale (mRS) at 3 months is the most commonly used primary outcome measure in stroke treatment trials, but it lacks specificity and requires long-term follow-up interviews, which consume time and resources. An alternative may be the National Institutes of Health Stroke Scale (NIHSS), early after stroke. Our aim was to evaluate whether the NIHSS assessed within 1 week after treatment could serve as a primary outcome measure for trials of acute treatment for ischemic stroke.

An EEG index of sensorimotor interhemispheric coupling after unilateral stroke: clinical and neurophysiological study

Brain connectivity has been employed to investigate on post-stroke recovery mechanisms and assess the effect of specific rehabilitation interventions. Changes in interhemispheric coupling after stroke have been related to the extent of damage in the corticospinal tract (CST) and thus, to motor impairment. In this study, we aimed at defining an index of interhemispheric connectivity derived from electroencephalography (EEG), correlated with CST integrity and clinical impairment. Thirty sub-acute stroke patients underwent clinical and neurophysiological evaluation: CST integrity was assessed by Transcranial Magnetic Stimulation and high-density EEG was recorded at rest. Connectivity was assessed by means of Partial Directed Coherence and the normalized Inter-Hemispheric Strength (nIHS) was calculated for each patient and frequency band on the whole network and in three sub-networks relative to the frontal, central (sensorimotor) and occipital areas. Interhemipheric coupling as expressed by nIHS on the whole network was significantly higher in patients with preserved CST integrity in beta and gamma bands. The same index estimated for the three sub-networks showed significant differences only in the sensorimotor area in lower beta, with higher values in patients with preserved CST integrity. The sensorimotor lower beta nIHS showed a significant positive correlation with clinical impairment. We propose an EEG-based connectivity index which is a measure of the interhemispheric cross-talking and correlates with functional motor impairment in subacute stroke patients. Such index could be employed to evaluate the effects of training aimed at re-establishing interhemispheric balance and eventually drive the design of future connectivity-driven rehabilitation interventions.

Effects of neuroserpin on clinical outcomes and inflammatory markers in Chinese patients with acute ischemic stroke

OBJECTIVE

Neuroserpin (NSP) is known for its neuroprotective effects. The aim of this study was to investigate the relationship between NSP level and clinical outcomes and inflammatory markers in Chinese patients with acute ischemic stroke.

METHODS

A total of 133 patients with acute cerebral infarction (ischemia group) and 44 controls were recruited. The modified Rankin Scale (mRS) was used to determine the functional outcome three months after onset. We investigated the relationship between serum NSP levels [on admission and a decrease in NSP levels (10 days after admission versus on admission)] and serum levels of several inflammatory markers.

RESULTS

We confirmed that NSP levels on admission in the ischemia group were significantly higher than those in the control group. NSP levels in patients with good outcomes were significantly higher than those in patients with poor outcomes. NSP levels on admission were associated with having a good outcome in these patients. We found that a larger decrease in NSP levels (on admission vs. 10 days after admission) was correlated with lower serum levels of IL-6, IL-1β, and ICAM-1 10 days after admission.

CONCLUSIONS

A larger decrease in NSP levels related to lower levels of inflammatory marker, while higher NSP levels were associated with lower inflammatory markers and better functional outcomes. Decreasing the infarct size may play a role in this process. These results provide more evidence of the neuroprotective effect of NSP in cerebral ischemic patients. Decrease in the Serum NSP level and NSP level at admission may be considered as potential predictive factors for outcome of acute ischemic stroke.

Complications in the first week after stroke: a 10-year comparison

Background

Complications after stroke have been associated with poor outcome. Modern stroke treatment might reduce the occurrence of complications. The aim of this study was to investigate whether the frequency and type of complications during the first week after stroke has changed in patients treated in a stroke unit in 2013 compared to 2003.

Methods

In total 489 patients in 2003 and 185 patients in 2013 with acute stroke were included and followed prospectively for 1 week, examining the frequency of 12 predefined complications adjusted for severity of stroke. Informed consent was given by all patients or their next of kin.

Results

Mean (SD) age was 77.2 (10.2) and 76.9 (8.5) in 2003 and 2013 respectively, P = 0.455. Severity of stroke, measured by the Scandinavian Stroke Scale, was 39.5 (16.8) versus 37.0 (16.4), P = 0.011. After adjustment for stroke severity the results showed an odds ratio of 0.64 for experiencing one or more complications in the 2013 cohort versus the 2003 cohort, P = 0.035. The subgroup analysis showed that the reduction was only significant in the group with moderate stroke, with 74 % experiencing one or more complications in 2003 compared to 45 % in 2013, P < 0.001. Progressing stroke and myocardial infarction occurred significantly less frequent in 2013 than in 2003; the frequency of other complications remained unchanged.

Conclusions

The risk of experiencing one or more complications has decreased from 2003 to 2013. The reduction was most pronounced in patents with moderate stroke with a significant reduction in progressing stroke and myocardial infarction.

Increased Endothelial Progenitor Cell Levels are Associated with Good Outcome in Intracerebral Hemorrhage

Circulating endothelial progenitor cells (EPCs) play a role in the regeneration of damaged brain tissue. However, the relationship between circulating EPC levels and functional recovery in intracerebral hemorrhage (ICH) has not yet been tested. Therefore, our aim was to study the influence of circulating EPCs on the outcome of ICH. Forty-six patients with primary ICH (males, 71.7%; age, 72.7 ± 10.8 years) were prospectively included in the study within 12 hours of symptom onset. The main outcome variable was good functional outcome at 12 months (modified Rankin scale ≤2), considering residual volume at 6 months as a secondary variable. Circulating EPC (CD34⁺/CD133⁺/KDR⁺) levels were measured by flow cytometry from blood samples obtained at admission, 72 hours and day 7. Our results indicate that patients with good outcome show higher EPC numbers at 72 hours and day 7 (all p < 0.001). However, only EPC levels at day 7 were independently associated with good functional outcome at 12 months (OR, 1.15; CI95%, 1.01–1.35) after adjustment by age, baseline stroke severity and ICH volume. Moreover, EPC levels at day 7 were negatively correlated to residual volume (r = −0.525; p = 0.005). In conclusion, these findings suggest that EPCs may play a role in the functional recovery of ICH patients.

Functional versus Nonfunctional Rehabilitation in Chronic Ischemic Stroke: Evidences from a Randomized Functional MRI Study

Motor rehabilitation of stroke survivors may include functional and/or nonfunctional strategy. The present study aimed to compare the effect of these two rehabilitation strategies by means of clinical scales and functional Magnetic Resonance Imaging (fMRI). Twelve hemiparetic chronic stroke patients were selected. Patients were randomly assigned a nonfunctional (NFS) or functional (FS) rehabilitation scheme. Clinical scales (Fugl-Meyer, ARA test, and modified Barthel) and fMRI were applied at four moments: before rehabilitation (P1) and immediately after (P2), 1 month after (P3), and three months after (P4) the end of rehabilitation. The NFS group improved significantly and exclusively their Fugl-Meyer scores at P2, P3, and P4, when compared to P1. On the other hand, the FS group increased significantly in Fugl-Meyer at P2, when compared to P1, and also in their ARA and Barthel scores. fMRI inspection at the individual level revealed that both rehabilitation schemes most often led to decreased activation sparseness, decreased activity of contralesional M1, increased asymmetry of M1 activity to the ipsilesional side, decreased perilesional activity, and decreased SMA activity. Increased M1 asymmetry with rehabilitation was also confirmed by Lateralization Indexes. Our clinical analysis revealed subtle differences between FS and NFS.

Current and future bioanalytical approaches for stroke assessment

Efforts are underway to develop novel platforms for stroke diagnosis to meet the criteria for effective treatment within the narrow time window mandated by the FDA-approved therapeutic (<3 h). Blood-based biomarkers could be used for rapid stroke diagnosis and coupled with new analytical tools, could serve as an attractive platform for managing stroke-related diseases. In this review, we will discuss the physiological processes associated with stroke and current diagnostic tools as well as their associated shortcomings. We will then review information on blood-based biomarkers and various detection technologies. In particular, point of care testing that permits small blood volumes required for the analysis and rapid turn-around time measurements of multiple markers will be presented.

Cardiac arrest survivors treated with or without mild therapeutic hypothermia: performance status and quality of life assessment

BACKGROUND

Hypoxic-ischaemic encephalopathy is the main determinant of clinical outcome after cardiac arrest. The study was designed to determine long-term neurological and psychological status in cardiac arrest survivors, as well as to compare neuropsychological outcomes between patients treated with mild therapeutic hypothermia (MTH) and patients who did not undergo hypothermia treatment.

METHODS

The article describes a single-center, retrospective, observational study on 28 post-cardiac arrest adult patients treated in the cardiac intensive care unit who qualified for MTH vs. 37 control group patients, hospitalized at the same center following cardiac arrest in the preceding years and fulfilling criteria for induced hypothermia, but who were not treated due to unavailability of the method at that time. Disability Rating Scale (DRS), Barthel Index and RAND-36 were used to assess performance status and quality of life in both study groups after hospital discharge.

RESULTS

There were no statistically significant differences in physical functioning found between groups either at the end of hospital treatment or at long-term follow-up (DRS: p = 0.11; Barthel Index: p = 0.83). In long-term follow-up, MTH patients showed higher vitality (p = 0.02) and reported fewer complaints on role limitations due to emotional problems (p = 0.04) compared to the control group. No significant differences were shown between study groups in terms of physical capacity and independent functioning.

CONCLUSION

To conclude, in long-term follow-up, MTH patients showed higher vitality and reported fewer complaints on role limitations due to emotional problems compared to the control group. This suggest that MTH helps to preserve global brain function in cardiac arrest survivors. However, the results can be biased by a small sample size and variable observation periods.

Interhemispheric cerebral blood flow balance during recovery of motor hand function after ischemic stroke--a longitudinal MRI study using arterial spin labeling perfusion

BACKGROUND

Unilateral ischemic stroke disrupts the well balanced interactions within bilateral cortical networks. Restitution of interhemispheric balance is thought to contribute to post-stroke recovery. Longitudinal measurements of cerebral blood flow (CBF) changes might act as surrogate marker for this process.

OBJECTIVE

To quantify longitudinal CBF changes using arterial spin labeling MRI (ASL) and interhemispheric balance within the cortical sensorimotor network and to assess their relationship with motor hand function recovery.

METHODS

Longitudinal CBF data were acquired in 23 patients at 3 and 9 months after cortical sensorimotor stroke and in 20 healthy controls using pulsed ASL. Recovery of grip force and manual dexterity was assessed with tasks requiring power and precision grips. Voxel-based analysis was performed to identify areas of significant CBF change. Region-of-interest analyses were used to quantify the interhemispheric balance across nodes of the cortical sensorimotor network.

RESULTS

Dexterity was more affected, and recovered at a slower pace than grip force. In patients with successful recovery of dexterous hand function, CBF decreased over time in the contralesional supplementary motor area, paralimbic anterior cingulate cortex and superior precuneus, and interhemispheric balance returned to healthy control levels. In contrast, patients with poor recovery presented with sustained hypoperfusion in the sensorimotor cortices encompassing the ischemic tissue, and CBF remained lateralized to the contralesional hemisphere.

CONCLUSIONS

Sustained perfusion imbalance within the cortical sensorimotor network, as measured with task-unrelated ASL, is associated with poor recovery of dexterous hand function after stroke. CBF at rest might be used to monitor recovery and gain prognostic information.

Ischemic stroke functional outcomes are independently associated with C-reactive protein concentrations and cognitive outcomes with triiodothyronine concentrations: a pilot study

Elevated concentrations of C-reactive protein (CRP) and decreased concentrations of triiodothyronine (T3) were shown to predict poor outcomes in patients with stroke. However, the prognostic value of CRP and T3 has not been studied simultaneously in relation to stroke functional and cognitive outcomes despite of close interaction between inflammatory markers and thyroid function. We evaluated the association of thyroid hormone and CRP concentrations with immediate outcomes after ischemic stroke. Eighty-eight ischemic stroke patients on admission to the stroke unit were evaluated for clinical stroke severity (Scandinavian stroke scale or SSS) and concentrations of thyroid-stimulating hormone, free thyroxin, free T3, and CRP. Functional outcome (modified Rankin scale) and cognitive outcome (Mini mental state examination) were evaluated at discharge. Greater ln CRP concentrations (r = -0.35, p = 0.001), but not thyroid hormone concentrations, correlated with score on the SSS. In univariate analyses lower free T3 concentrations and higher CRP concentrations were associated with poor functional and poor cognitive outcomes. After adjustment for clinical stroke severity, higher CRP concentrations (β = 0.18, p = 0.04) remained associated with worse functional outcome and lower free T3 concentrations with worse cognitive outcome (β = 0.23, p = 0.03). In sum, clinical stroke severity is associated with elevated CRP concentration. Higher CRP concentration is independently associated with worse functional outcomes and lower free T3 concentration with worse cognitive outcomes at discharge. T3 and CRP can be important biomarkers in patients with acute ischemic stroke.

Platelet derived growth factor-CC isoform is associated with hemorrhagic transformation in ischemic stroke patients treated with tissue plasminogen activator

OBJECTIVE

Platelet derived growth factor-CC (PDGF-CC) isoform is activated by tissue plasminogen activator (tPA) regulating blood brain barrier permeability after ischemia. We aimed to study the association of PDGF isoforms serum levels with hemorrhagic transformation (HT) and edema after thrombolytic treatment in ischemic stroke.

METHODS

We studied 129 patients with ischemic stroke treated with tPA within the first 4.5 h (h) from stroke onset. CT was performed on admission and at 24-36 h. On the 2nd CT, HT was classified according to ECASS II criteria, and severe brain edema was diagnosed if extensive swelling causing any shifting of the structures of the midline was detected. PDGF-AA, PDGF-AB, PDGF-BB and PDGF-CC serum levels were analyzed by ELISA on admission (before tPA bolus), at 24 and 72 h.

RESULTS

Patients who developed HT showed only higher levels of PDGF-CC isoform on admission and at 24 h (all p < 0.0001). In the multivariate analysis, PDGF-CC levels on admission (OR, 1.02; CI 95%, 1.00-1.04) and at 24 h (OR, 1.05; CI 95%, 1.02-1.08) were independently associated with HT after adjustment by confounding factors. On the other hand, patients with severe edema showed also higher levels of PDGF-CC on admission and at 24 h (p < 0.0001), but this statistical association was lost in the logistic regression analysis. PDGF-CC levels ≥ 175 ng/mL at 24 h predict the development of PH with a sensitivity of 90% and specificity of 88% (area under the curve 0.936; p < 0.0001).

CONCLUSION

Increased PDGF-CC levels after tPA treatment is associated with HT.

Lesions to primary sensory and posterior parietal cortices impair recovery from hand paresis after stroke

Background

Neuroanatomical determinants of motor skill recovery after stroke are still poorly understood. Although lesion load onto the corticospinal tract is known to affect recovery, less is known about the effect of lesions to cortical sensorimotor areas. Here, we test the hypothesis that lesions of somatosensory cortices interfere with the capacity to recover motor skills after stroke.

Methods

Standardized tests of motor skill and somatosensory functions were acquired longitudinally over nine months in 29 patients with stroke to the pre- and postcentral gyrus, including adjacent areas of the frontal, parietal and insular cortices. We derived the recovery trajectories of each patient for five motor subtest using least-squares curve fitting and objective model selection procedures for linear and exponential models. Patients were classified into subgroups based on their motor recovery models. Lesions were mapped onto diffusion weighted imaging scans and normalized into stereotaxic space using cost-function masking. To identify critical neuranatomical regions, voxel-wise subtractions were calculated between subgroup lesion maps. A probabilistic cytoarchitectonic atlas was used to quantify of lesion extent and location.

Results

Twenty-three patients with moderate to severe initial deficits showed exponential recovery trajectories for motor subtests that relied on precise distal movements. Those that retained a chronic motor deficit had lesions that extended to the center of the somatosensory cortex (area 2) and the intraparietal sulcus (areas hIP1, hIP2). Impaired recovery outcome correlated with lesion extent on this areas and somatosensory performance. The rate of recovery, however, depended on the lesion load onto the primary motor cortex (areas 4a, 4p).

Conclusions

Our findings support a critical role of uni-and multimodal somatosensory cortices in motor skill recovery. Whereas lesions to these areas influence recovery outcome, lesions to the primary motor cortex affect recovery dynamics. This points to a possible dissociation of neural substrates for different aspects of post-stroke recovery.

High blood glutamate oxaloacetate transaminase levels are associated with good functional outcome in acute ischemic stroke

The capacity of the blood enzyme glutamate oxaloacetate transaminase (GOT) to remove glutamate from the brain by means of blood glutamate degradation has been shown in experimental models to be an efficient and novel neuroprotective tool against ischemic stroke; however, the beneficial effects of this enzyme should be tested in patients with stroke to validate these results. This study aims to investigate the association of GOT levels in blood with clinical outcome in patients with acute ischemic stroke. In two clinical independent studies, we found that patients with poor outcome show higher glutamate and lower GOT levels in blood at the time of admission. Lower GOT levels and higher glutamate levels were independently associated with poorer functional outcome at 3 months and higher infarct volume. These findings show a clear association between high blood glutamate levels and worse outcome and vice versa for GOT, presumably explained by the capacity of this enzyme to metabolize blood glutamate.

Comprehensive cognitive neurological assessment in stroke

BACKGROUND

Cognitive syndromes (CS) after stroke may be important to measure and monitor for management and emerging therapies.

AIM

To incorporate known behavioral neurological and neuropsychiatric syndromes into a bedside cognitive assessment in patients with stroke.

METHODS

A validated cognitive examination (comprehensive cognitive neurological test in stroke, Coconuts) was administered during the first month of stroke presentation and analyzed according to five large-scale networks for cognition and correlated with neuropsychological tests. Validity testing of the test was performed for overall sensitivity, specificity, positive predictive value and negative predictive value to stroke in comparison with MRI diagnosis of stroke as well as discriminant validity, construct validity and inter-rater reliability.

RESULTS

Overall the sensitivity of the Coconuts scale was 91% and specificity 35%, PPV 88% and NPV 41% vs stroke lesions using MRI. Cognitive syndrome frequencies: frontal network syndrome frequency was 908/1796 (51%), left hemisphere network syndrome frequency was 646/1796 (36%), right hemisphere network included 275/1796 (15.3%), occipitotemporal network for complex visual processing 107/1796 (6%), the hippocampal limbic network for amnesias and emotional disorders 397/1796 (22%) and miscellaneous network syndromes 481/1796 (27%).

CONCLUSION

The Coconuts is a valid and practical test of a comprehensive array of known behavioral neurological and neuropsychiatric syndromes in patients with stroke.

Microembolic signals in subarachnoid hemorrhage

Microembolic signals (MES) detected by transcranial Doppler (TCD) have been reported in subarachnoid hemorrhage (SAH), although their origin and contribution to brain ischemia remain uncertain. We conducted a prospective study to evaluate the frequency of MES among patients with SAH and to determine their origin. Twenty-seven patients with SAH, comprising 15 aneurysmal and 12 non-aneurysmal patients, participated in the study. TCD evaluation was performed using a 2 MHz probe. Patients were studied three times per week during their in-patient stay to detect vasospasm, and then each middle cerebral artery (MCA) was monitored for 30 min using the Monolateral Multigate mode to detect MES. Using this method, MES were detected in 7 out of 15 patients (47%) with aneurysmal SAH and were not seen in non-aneurysmal patients (p=0.007). Vasospasm occurred in 52% (14/27) of cases. However, clinical signs and symptoms of vasospasm were identified in only 18.5% (5/27). There was no significant relationship between MES and vasospasm (p=0.224). Also, no relationship was found between MES and the location of the aneurysm (p=0.685). Thus, in this study MES were only detected in aneurysmal SAH. However, we did not find a relationship between the location of the aneurysm and MES, or the presence of vasospasm and MES. Therefore, MES in patients with SAH may also originate from vascular pathology other than the aneurysm sac or vascular spasm.

The Los Angeles Motor Scale (LAMS): a new measure to characterize stroke severity in the field

OBJECTIVE

To develop and retrospectively analyze an instrument that rapidly characterizes pretreatment stroke severity for use in prehospital acute stroke clinical trials.

METHODS

The Los Angeles Motor Scale (LAMS) was constructed by assigning point values to Los Angeles Prehospital Stroke Screen (LAPSS) items of facial weakness, arm strength, and grip to yield a total 0-5 scale. The concurrent, discriminant, and predictive validities of the LAMS were probed using data from 90 patients enrolled in acute stroke clinical trials. Predictive performance of the LAMS was compared with that of the initial full National Institutes of Health Stroke Scale (NIHSS) and the five-item shortened NIHSS (sNIHSS) in projecting long-term outcomes on standard functional end points.

RESULTS

LAMS score at entry averaged mean 2.6, median 2. Entry LAMS scores correlated closely with entry NIHSS scores (r=0.75). LAMS score correlations with three-month functional outcome measures were robust. Receiver operator curve analyses (c statistic) for performance in predicting three-month outcomes were: three-month modified Rankin-LAMS 0.75, sNIHSS 0.69, NIHSS 0.74; three-month Barthel Index-LAMS 0.77, sNIHSS 0.76, NIHSS 0.82; three-month NIHSS-LAMS 0.76, sNIHSS 0.62, NIHSS 0.70; and three-month GOS-LAMS 0.55, sNIHSS 0.67, NIHSS 0.76. Considering dichotomized three-month measures, entry LAMS scores were markedly lower in patients destined for excellent outcome, e.g., three-month modified Rankin score<or=1, mean entry LAMS score 2.2 versus 3.7, p=.0002.

CONCLUSIONS

A motor score derived from the LAPSS rapidly quantifies stroke severity in the field and predicts functional outcomes with accuracy comparable to that of the full NIHSS and the sNIHSS.

A modified National Institutes of Health Stroke Scale for use in stroke clinical trials: preliminary reliability and validity

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) is accepted widely for measuring acute stroke deficits in clinical trials, but it contains items that exhibit poor reliability or do not contribute meaningful information. To improve the scale for use in clinical research, we used formal clinimetric analyses to derive a modified version, the mNIHSS. We then sought to demonstrate the validity and reliability of the new mNIHSS.

METHODS

The mNIHSS was derived from our prior clinimetric studies of the NIHSS by deleting poorly reproducible or redundant items (level of consciousness, face weakness, ataxia, dysarthria) and collapsing the sensory item into 2 responses. Reliability of the mNIHSS was assessed with the certification data originally collected to assess the reliability of investigators in the National Institute of Neurological Disorders and Stroke (NINDS) rtPA (recombinant tissue plasminogen activator) Stroke

TRIAL

Validity of the mNIHSS was assessed with the outcome results of the NINDS rtPA Stroke Trial:

RESULTS

Reliability was improved with the mNIHSS: the number of scale items with poor kappa coefficients on either of the certification tapes decreased from 8 (20%) to 3 (14%) with the mNIHSS. With the use of factor analysis, the structure underlying the mNIHSS was found identical to the original scale. On serial use of the scale, goodness of fit coefficients were higher with the mNIHSS. With data from part I of the trial data, the proportion of patients who improved >/=4 points within 24 hours after treatment was statistically significantly increased by tPA (odds ratio, 1.3; 95% confidence limits, 1.0, 1.8; P=0.05). Likewise, the odds ratio for complete/nearly complete resolution of stroke symptoms 3 months after treatment was 1.7 (95% confidence limits, 1.2, 2.6) with the mNIHSS. Other outcomes showed the same agreement when the mNIHSS was compared with the original scale. The mNIHSS showed good responsiveness, ie, was useful in differentiating patients likely to hemorrhage or have a good outcome after stroke.

CONCLUSIONS

The mNIHSS appears to be identical clinimetrically to the original NIHSS when the same data are used for validation and reliability. Power appears to be greater with the mNIHSS with the use of 24-hour end points, suggesting the need for fewer patients in trials designed to detect treatment effects comparable to rtPA. The mNIHSS contains fewer items and might be simpler to use in clinical research trials. Prospective analysis of reliability and validity, with the use of an independently collected cohort, must be obtained before the mNIHSS is used in a research setting.

Effect of intravenous recombinant tissue plasminogen activator on ischemic stroke lesion size measured by computed tomography. NINDS; The National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study Group

Background and Purpose-When given within 3 hours of symptom onset, recombinant tissue plasminogen activator (rtPA) improves outcome 3 months after ischemic stroke. Prespecified secondary end points of the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Trial were CT lesion volumes in the 2 treatment groups (tPA and placebo) at 24 hours, 7 to 10 days, and 3 months after stroke.

METHODS

-The trial included 2 independent studies, part I and part II, with identical methods of data collection. Before part I, uniform standards were established for CT scanning. CT images were obtained at baseline, 24 hours, 7 to 10 days, and 3 months after stroke onset and were reviewed centrally by reviewers blinded to treatment group and clinical findings. Since the individual studies were not powered to test for lesion volume differences, data from both parts of the trial were combined for all analyses. The primary analysis was conducted with the use of an intention-to-treat algorithm (including patients who died or were lost to follow-up). Measured lesion volume (excluding deaths and those lost to follow-up) was used as a secondary outcome in an exploratory analysis.

RESULTS

-After tPA treatment, there was a trend toward a reduction in 3-month median lesion volume in the tPA group: 15 cm(3) (interquartile range, 2 to 87) compared with 24 cm(3) (interquartile range, 4 to 101) in the placebo group (P:=0.06, log model) with a reduction of 11% in cumulative lesion volume, computed with Smirnov's D statistic. After exclusion of deaths and those lost to follow-up, similar trends toward positive treatment effects were seen at all time points.

CONCLUSIONS

-The direction of the effect of tPA on CT lesion volume at all time points was consistent with the observed clinical effects at 3 months. CT lesion volume may not be as sensitive a measure of treatment effect as clinical evaluation, at least as used in this study. An intention-to-treat analysis for the radiographic end point in this acute ischemic stroke clinical trial is a less biased approach to account for missing radiographic data than an analysis that uses only measured radiological data.

Finding the most powerful measures of the effectiveness of tissue plasminogen activator in the NINDS tPA stroke trial

BACKGROUND AND PURPOSE

We sought to identify the most powerful binary measures of the treatment effect of tissue plasminogen activator (tPA) in the National Institute of Neurological Disorders and Stroke (NINDS) rTPA Stroke Trial.

METHODS

Using the Classification and Regression Tree (CART) algorithm, we evaluated binary cut points and combination of binary cut points with the 4 clinical scales and head CT imaging measures in the NINDS tPA Stroke Trial at 4 times after treatment: 2 hours, 24 hours, 7 to 10 days, and 3 months. The first analysis focused on detecting evidence of "early activity" of tPA with the use of outcome measures derived from the 2-hour and 24-hour clinical and radiographic measures. The second analysis focused on longer-term outcome and "efficacy" and used outcome measures derived from 7- to 10-day and 3-month measures. After identifying the cut points with the ability to classify patients into the tPA and placebo groups using part I data from the trial, we then used data from part II of the trial to validate the results.

RESULTS

Of the 5 most powerful outcome measures for early activity of tPA, 4 involved the National Institutes of Health Stroke Scale (NIHSS) score at 24 hours or changes in the NIHSS score from baseline to 24 hours. The best overall single outcome measure was an NIHSS score </=2 at 24 hours, which provided an odds ratio of 5.4 (95% CI, 2.4 to 12.1) and a projected sample size of 58 per treatment group assuming an alpha of 0.05 (2-sided test) and a power of 80% using part I data. The top 2 and 3 of the top 5 outcome measures for detecting the longer-term efficacy of tPA also involved the NIHSS score. A Rankin score of 0 or 1 at 3 months was the third most powerful outcome measure. Outcome measures identified by CART from part I data were not as sensitive in detecting the effectiveness of tPA when applied to part II data.

CONCLUSIONS

Measures using the NIHSS and a Rankin score </=1 were the most sensitive discriminators of the effectiveness of tPA in the NINDS tPA Stroke Trial compared with the other clinical and radiological measures. The outcome measures identified in this exploratory analysis (eg, NIHSS score </=2 at 24 hours) would be best used as an outcome measure in future phase II trials of recanalization begun within the first 3 hours after stroke onset, with inclusion and exclusion criteria similar to those in the NINDS tPA Stroke Trial.

Underlying structure of the National Institutes of Health Stroke Scale: results of a factor analysis. NINDS tPA Stroke Trial Investigators

BACKGROUND AND PURPOSE

No stroke scale has been validated as an outcome measure using data from a clinical trial demonstrating a positive therapeutic effect. Therefore, we proposed to use data from the National Institute of Neurological Disorders and Stroke (NINDS) tPA Stroke Trial to determine whether the National Institutes of Health Stroke Scale (NIHSS) was valid in patients treated with tissue plasminogen activator (tPA) and to explore the underlying clinimetric structure of the NIHSS.

METHODS

We performed an exploratory factor analysis of NIHSS data from Part 1 (n=291) of the NINDS tPA Stroke Trial to derive a hypothesized underlying factor structure. We then performed a confirmatory factor analysis of this structure using NIHSS data from Part 2 of the same trial (n=333). We then tested whether this final factor structure could be found in tPA- and placebo-treated patients serially over time after stroke treatment. Using 3-month outcome data, we tested for an association between the NIHSS and other measures of stroke outcome.

RESULTS

The exploratory analysis suggested that there were 2 factors underlying the NIHSS, representing left and right brain function, confirming the content validity of the scale. An alternative structure composed of 4 factors could be derived, with a better goodness of fit: the first 2 factors could represent left brain cortical and motor function, respectively, and the second 2 factors could represent right brain cortical and motor function, respectively. The same factor structures were then found in tPA and placebo patient groups studied serially over time, confirming the exploratory analysis. All 3-month clinical outcomes were associated with each other at subsequent time points, confirming predictive validity.

CONCLUSIONS

This is the first study of the validity of a stroke scale in patients treated with effective stroke therapy. The NIHSS appeared to be valid in patients with acute stroke and for finding treatment-related differences. The scale was valid when used serially over time after stroke, up to 3 months, and showed good agreement with other measures of outcome.

Thrombolysis for acute stroke

Thrombolysis for acute stroke is effective if administered according to the approved protocol. Since the initial report of success in 1995, a number of subsequent reports confirmed the safety and efficacy of this treatment. There is no particular subgroup of patients at increased likelihood of benefit or hemorrhage that can be identified at baseline. Unlike many expensive therapies, thrombolysis for acute stroke saves the health care system considerable long-term costs. The search for even safer and more effective thrombolytics continues.