Post-stroke Onset Research Articles

Improved Language in a Chronic Nonfluent Aphasia Patient After Treatment With CPAP and TMS

To present pretreatment and post-treatment language data for a nonfluent aphasia patient who received 2 treatment modalities: (1) continuous positive airway pressure (CPAP) for his sleep apnea, starting 1-year poststroke; and (2) repetitive transcranial magnetic brain stimulation (TMS), starting 2 years poststroke. Language data were acquired beyond the spontaneous recovery period of 3 to 6 months poststroke onset. CPAP restores adequate oxygen flow throughout all stages of sleep, and may improve cognition. A series of slow, 1 Hz repetitive TMS treatments to suppress a posterior portion of right pars triangularis has been shown to improve phrase length and naming in chronic nonfluent aphasia. The Boston Diagnostic Aphasia Examination and Boston Naming Test were administered pre-CPAP, and after 2 to 5 months of CPAP. These same tests were administered pre-TMS, and at 3 and 6 months post-TMS, and again 2.4 years later. Post-CPAP testing showed increased Phrase Length, Auditory Comprehension, and naming Animals and Tools/Implements (Boston Diagnostic Aphasia Examination). Testing at 3 and 6 months post-TMS showed significant increase in Phrase Length, Auditory Comprehension, and Boston Naming Test compared with pre-TMS. These gains were retained at 2.4 years post-TMS. CPAP use continued throughout. Physiologic treatment interventions may promote language recovery in chronic aphasia.

Mismatch-Based Delayed Thrombolysis

Clinical benefit from thrombolysis is reduced as stroke onset to treatment time increases. The use of "mismatch" imaging to identify patients for delayed treatment has face validity and has been used in case series and clinical trials. We undertook a meta-analysis of relevant trials to examine whether present evidence supports delayed thrombolysis among patients selected according to mismatch criteria. We collated outcome data for patients who were enrolled after 3 hours of stroke onset in thrombolysis trials and had mismatch on pretreatment imaging. We selected the trials on the basis of a systematic search of the Web of Knowledge. We compared favorable outcome, reperfusion and/or recanalization, mortality, and symptomatic intracerebral hemorrhage between the thrombolyzed and nonthrombolyzed groups of patients and the probability of a favorable outcome among patients with successful reperfusion and clinical findings for 3 to 6 versus 6 to 9 hours from poststroke onset. Results are expressed as adjusted odds ratios (a-ORs) with 95% CIs. Heterogeneity was explored by test statistics for clinical heterogeneity, I(2) (inconsistency), and L'Abbé plot. We identified articles describing the DIAS, DIAS II, DEDAS, DEFUSE, and EPITHET trials, giving a total of 502 mismatch patients thrombolyzed beyond 3 hours. The combined a-ORs for favorable outcomes were greater for patients who had successful reperfusion (a-OR=5.2; 95% CI, 3 to 9; I(2)=0%). Favorable clinical outcome was not significantly improved by thrombolysis (a-OR=1.3; 95% CI, 0.8 to 2.0; I(2)=20.9%). Odds for reperfusion/recanalization were increased among patients who received thrombolytic therapy (a-OR=3.0; 95% CI, 1.6 to 5.8; I(2)=25.7%). The combined data showed a significant increase in mortality after thrombolysis (a-OR=2.4; 95% CI, 1.2 to 4.9; I(2)=0%), but this was not confirmed when we excluded data from desmoteplase doses that were abandoned in clinical development (a-OR=1.6; 95% CI, 0.7 to 3.7; I(2)=0%). Symptomatic intracerebral hemorrhage was significantly increased after thrombolysis (a-OR=6.5; 95% CI, 1.2 to 35.4; I(2)=0%) but not significant after exclusion of abandoned doses of desmoteplase (a-OR=5.4; 95% CI, 0.9 to 31.8; I(2)=0%). Delayed thrombolysis amongst patients selected according to mismatch imaging is associated with increased reperfusion/recanalization. Recanalization/reperfusion is associated with improved outcomes. However, delayed thrombolysis in mismatch patients was not confirmed to improve clinical outcome, although a useful clinical benefit remains possible. Thrombolysis carries a significant risk of symptomatic intracerebral hemorrhage and possibly increased mortality. Criteria to diagnose mismatch are still evolving. Validation of the mismatch selection paradigm is required with a phase III trial. Pending these results, delayed treatment, even according to mismatch selection, cannot be recommended as part of routine care.

Evaluation of Motor Recovery in Adult Patients with Hemiplegic stroke

Background: Assessment of treatment efficacy through outcomes evaluation is an established practice in stroke rehabilitation. The evaluation of motor recovery is a cornerstone of the assessment of patients with stroke; and an integral component of stroke rehabilitation. Objective: The purpose of this study was to evaluate the recovery of motor functions in patients with stroke, using the STREAM measure. Method: A pre-test/post-test research design was utilized. The performance of 19 stroke patients (11 males and 8 females) with acute stroke was assessed with the STREAM measure before and after 8 weeks of physiotherapy intervention. The mean age of the subjects was 60.21+10.81 while the mean days post-stroke onset was 11.79+6.38. Results: Wilcoxon Signed Ranks Test indicated a statistically significant increase (p Keywords : Stroke, Outcome measure, motor recovery, stroke rehabilitation. NQJHM Vol. 16 (1) 2005: pp. 10-13

Poststroke Cerebral Peduncular Atrophy Correlates with a Measure of Corticospinal Tract Injury in the Cerebral Hemisphere

Methods have not been well developed and tested to predict the extent of remote degeneration in the central nervous system that follows cerebral infarction. We hypothesized that the extent of infarction overlap with the cerebral hemispheric course of the corticospinal tract (CST) on structural MR imaging predicts the extent of ipsilateral cerebral peduncular atrophy in patients with chronic stroke. Hemiparetic patients (n = 34) with supratentorial unilateral infarctions who were at least 1 year poststroke onset and enrolled in research protocols of Constraint-Induced Movement therapy underwent volumetric T1 MR imaging of the brain. The following measures were calculated for each patient: 1) the maximal proportion of the CST in the cerebral hemisphere on axial section that was overlapped by infarction, 2) total infarction volume, and 3) the ratio of the cross-sectional area of the ipsilateral cerebral peduncle to the area of the contralateral cerebral peduncle (peduncular asymmetry ratio). Correlation analyses evaluated the predictive value of CST injury or infarction volume for the peduncular asymmetry ratio. CST injury correlated significantly with the peduncular asymmetry ratio (r = -0.65; P < .001), whereas infarction volume did not (r = -0.31; P = .09). The extent of postinfarction CST injury in the cerebral hemisphere predicts the extent of ipsilateral cerebral peduncular atrophy. More generally, the findings suggest that the extent of remote wallerian degeneration of a fiber tract is strongly related to its extent of injury directly at the site of infarction.

Lack of kringle 2 domain and high fibrin specificity differentiate the novel plasminogen activator desmoteplase from rt‐PA

Thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) is effective in treating acute ischemic stroke (AIS) within the first 3 hours after symptom onset. Desmoteplase, or rDSPAα1 (recombinant Desmodus Salivary Plasminogen Activator α1), is a novel plasminogen activator (PA) shown to treat AIS up to 9 hours post-stroke onset with a positive risk:benefit ratio not shown in previous trials with rt-PA when treating patients beyond 3 hours. The observed clinical benefit of rDSPAα1 may relate to its unique structural features. rDSPAα1 is a glycosylated serine protease structurally similar to rt-PA (with finger, epidermal growth factor-like, kringle 1, and serine protease domains), but it lacks the plasmin-sensitive cleavage site and the lysine-binding kringle 2 domain found in rt-PA. The lack of the kringle 2 domain may explain the fact that rDSPAα1 has the highest fibrin selectivity among PAs, with a 100,000-fold increase in catalytic activity compared to a 550-fold increase for rt-PA and an absence of neurotoxicity in animal models of ischemic and hemorrhagic stroke. The unique structural features of rDSPAα1 suggest an advantageous risk:benefit ratio and may explain the observed favorable clinical results including the potential for use in later time windows. Research was supported by Forest Research Institute, a division of Forest Laboratories, Inc., and PAION Deutschland GmbH.

Activities, participation and satisfaction one-year post stroke

Purpose. To evaluate the chronic consequences of stroke in terms of activity limitations, restricted participation and dissatisfaction from life, and the relationship between these variables, in stroke survivors living in the community one-year post onset.Method. A total of 56 stroke patients (mean age: 57.7) who completed an in-patient rehabilitation programme, were evaluated one-year post onset in their homes, using the following instruments: Functional Independence Measure (FIM), Instrumental Activities of Daily Living Questionnaire (IADLq), Activity Card Sort (ACS), a work questionnaire, Life-Satisfaction Questionnaire (Li-Sat 9) and the Geriatric Depression Scale (GDS).Results. One year post stroke onset the mean FIM motor score was 75.88 (max score: 91), yet more than 50% of the sample still required assistance (usually mild to moderate) in dressing, bathing and use of stairs. The majority of the sample required full assistance in some IADL domains, notably meal preparation (77%), housekeeping (70%) and laundry (82%). Only one subject returned to paid employment and the mean activity level (ACS), representing the percentage of leisure and IADL activities retained from before stroke, was 42.8%. Satisfaction ratings were generally low but varied between domains. Only 39% were satisfied from ‘life as a whole’. The lowest satisfaction rates were noted for ‘vocational situation’ (14%), ‘leisure situation’ (34%) and ‘ability in self-care’ (43%), whereas the satisfaction rate from family life was high (84%). Significant correlations were found between overall life satisfaction scores and the overall FIM motor, IADLq, and ACS scores (Pearson r values: 0.32, 0.48 and 0.57, respectively). Activity level was found to be a significant predictor of satisfaction (p = 0.007) beyond that accounted for by demographic variables and depression.Conclusions. Stroke survivors dwelling in the community demonstrate long-standing dissatisfaction one-year post onset, correlating with activity limitation and restricted participation. The findings present a compelling need for rehabilitation services with a focus on participation in IADL and leisure activities, in order to improve the satisfaction of this population.

Development of a Position-Specific Index of Muscle Strength to be Used in Stroke Evaluation

Moriello C, Mayo NE. Development of a position-specific index of muscle strength to be used in stroke evaluation. Objective To develop a position-specific index of muscle strength for individuals with stroke. Design Cross-sectional design. Setting A major teaching hospital in a Canadian urban city. Participants Sixty-three patients with poststroke onset between 3 and 12 months. Interventions Not applicable. Main Outcome Measure The muscle strength of the lower-extremity muscles was tested bilaterally in multiple positions using hand-held dynamometry. Results A principal components analysis resulted in grouping the muscles of the affected and unaffected sides of the gravity related and gravity eliminated positions into 5 indices. The 5 indices were moderately to highly correlated ( r 2 range, .59−.81) with each other and so were combined into 1 global index. The gravity related muscle strength on the affected side was, on average, 85% of the unaffected side (range, 37%–157%); the gravity eliminated muscle strength of the affected side was, on average, 92% of the unaffected side (range, 53%–121%). Conclusions This study resolves the methodologic issue of how to summarize multiple data points that relate to one construct, namely, strength of different muscle groups assessed in several positions.

FMRI of Delayed Albumin Treatment during Stroke Recovery in Rats: Implication for Fast Neuronal Habituation in Recovering Brains

Accumulating experimental and clinical data suggest that albumin may be neuroprotective for stroke. Here, we use functional magnetic resonance imaging (fMRI) to evaluate the therapeutic efficacy of albumin and its effects on the recovery of stimuli-induced cerebral hemodynamics. For this purpose, fMRI activity in the ipsilesional somatosensory (SS) cortex was assessed using a well established rat model of transient 90 min focal ischemia and electrical forelimb stimulation. Rats were treated with either saline or albumin via intracerebroventricular injections at 12 h post-stroke onset. Despite this delayed treatment time, when compared to the saline-treated rats (n=7), there were significant enhancements of the fMRI activation in the albumin-treated rats (n=6) for both blood oxygenation level dependence (BOLD) and functional cerebral blood volume (fCBV) responses. Interestingly, the temporal characteristics of the ipsilesional SS BOLD responses in the albumin-treated rats appeared considerably altered compared to those of contralesional responses while such temporal alterations were not pronounced for the fCBV responses. These characteristic fMRI temporal profiles of the albumin-treated brains may be due to altered neuronal responses rather than altered integrity of neurovascular coupling, which implies an unusually fast habituation of neuronal responses in the lesional SS cortex. The correlation between various MRI-derived structural parameters and the fMRI response magnitude was also characteristic for albumin and control groups. Taken together, these data suggest that restoration of fMRI response magnitudes, temporal profiles, and correlations with structure may reveal the extent and specific traits of albumin treatment associated stroke recovery.

Recovery from stroke: differences between subtypes

The objective of this study was to compare the differences in patterns of recovery and incidence of medical complications in hemorrhagic and ischemic stroke patients admitted for rehabilitation, using a retrospective case series design. It was set in three tertiary care facilities in London, Ontario, Canada. Eight-hundred-and-nineteen consecutive patients, admitted from 1997 to 2001 for rehabilitation following cerebrovascular event, were reviewed. The main outcome measures were: age, length of hospital stay, time to admission, medical complications, ambulation status and functional independence measure scores on both admission and discharge. The results showed that 110 patients had strokes that were hemorrhagic, while 709 were ischemic. The hemorrhagic stroke patients were younger (66 vs. 70 years, P=0.001) and were admitted later post stroke onset (30 vs. 18 days, P<0.0001). They had a higher incidence of pneumonia (6.4 vs. 2.7%, P=0.04), pulmonary emboli (3.6 vs. 0.07%, P=0.006) and wheelchair ambulation on admission (53 vs. 41%, P=0.026). There was no significant difference in incidence of seizures or wheelchair ambulation on discharge, length of rehabilitation stay or Functional Independence Measure scores on both admission and discharge. In conclusion, hemorrhagic stroke patients took longer than ischemic stroke patients to enter into rehabilitation, and were more inclined to experience ambulatory impairments and develop medical complications.

Combined X-ray angiography and diffusion–perfusion MRI for studying stroke evolution after rt-PA treatment in rats

Clinical studies on rt-PA (recombinant tissue-type plasminogen activator) treatment of stroke showed a favorable outcome. However, there are reports of harmful effects of t-PA via the potentiation of excitotoxic injury. We used combined X-ray angiography and MRI imaging to study the balance between the beneficial effect of reperfusion and secondary detrimental effects of rt-PA. Therefore, rats ( n=15) were assigned to three groups according to recanalization or lack thereof of the middle cerebral artery (MCA) and rt-PA or saline treatment in an embolic stroke model. Diffusion and perfusion MRI showed that animals had significantly improved perfusion values and final infarct size when recanalization was successful. However, final infarct volumes at 6 h post stroke onset were greater in the rt-PA group compared to controls at comparable perfusion values when the MCA did not recanalize after treatment (67.4±5.4 versus 47.7±17.9% of ipsilateral hemisphere, P=0.042). Our results demonstrate that the combination of angiography and MR-imaging is useful to further evaluate rt-PA treatment of thromboembolic stroke.

Test-retest reliability of isokinetic muscle strength of the lower extremities in patients with stroke

Hsu A-L, Tang P-F, Jan M-H. Test-retest reliability of isokinetic muscle strength of the lower extremities in patients with stroke. Arch Phys Med Rehabil 2002;83:1130-7. Objective: To i the test-retest reliability of isokinetic strength measurements of 3 muscle groups of the lower extremities in stroke patients. Design: Isokineth tests of bilateral hip flexors, knee extensors, and ankle plantarflexors at 2 angular velocities, performed during 2 sessions scheduled 1 week apart for each subject. Setting: Outpatilitation clinic of a local hospital in Taiwan. Participants: Nts with mild spastic hemiparesis secondary to stroke and with poststroke onset time of at least 6 months. All subjects could communicate and voluntarily move the affected lower extremity. Interventions: Not applicable. Main Outcome Measure: The maximal peak torque, total work, and average power of the 3 muscle groups on the affected side examined during each test were quantified by using the normalization and the deficit methods. The normalization method divides the measured strength value by the patient's body weight, whereas the deficit method divides the difference between the strengths of the unaffected and affected extremities by the strength of the unaffected extremity. Results: The normalized strength measures for muscles on the affected side showed good to excellent test-retest reliability (intraclass correlation coefficient [ICC] range,.62–.94; P<.05), whereas the deficit strength measures did not always show good reliability (ICC range,.13–.91). The knee extensors and ankle plantarflexors, but not the hip flexors, on the affected side showed better test-retest reliability of isokinetic strength generated at faster velocity (ICC range,.73–.94) than that generated at slower velocity (ICC range,.62–.88). The normalized peak torque (ICC range,.76–.94) and total work (ICC range,.83–.91) were more reliable than the normalized average power (ICC range,.62–.90) for all 3 muscle groups on the affected side. Conclusions: Quantitative assessment of muscle strength of the affected lower extremity in patients with mild spastic hemiparesis secondary to stroke is feasible using isokinetic testing. However, the test-retest reliability of isokinetic strength measures is affected by the quantifying method, testing velocity, and strength measures. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

The size of subcortical ischemic infarction in patients with and without diabetes mellitus

Diabetes mellitus is associated with a higher frequency and poorer outcome of ischemic stroke. Determinants of the poorer prognosis of stroke in patients with diabetes are not well defined. We investigated whether size of cerebral infarction differs in patients with and without diabetes mellitus. We compared ischemic lesions in 41 consecutive stroke patients with subcortical infarction -22 with and 19 without diabetes mellitus. The location and size of the ischemic infarct were derived from magnetic resonance images obtained on day 3 or 4 post stroke onset. Cross-sectional infarct area was determined by direct measurement from film. The age of patients was similar in both groups. Patients with diabetes had higher prevalence of arterial hypertension, and previous stroke, and higher admission triglyceride and glucose levels compared to patients without diabetes. We found no significant difference in the size of ischemic lesions in patients with and without diabetes mellitus (1.87 vs. 1.72 cm2, respectively). We conclude that among patients with subcortical ischemic stroke the size of infarction is not different between patients with and without diabetes mellitus.