(Stroke. 1997;28:2347-2352.)
© 1997 American Heart Association, Inc.
Articles |
From the Department of Neurology, Middelheim Hospital and University of Antwerp, Belgium (P.P.D.D.), Department of Neurology, University Hospital, Ghent, Belgium (J.D.R.), Department of Clinical Research and Development, UCB Pharma, Braine-l'Alleud, Belgium (W.D.), Department of Genetic Epidemiology, University of Louvain, Belgium (R.V.), and Department of Neurology, Pellegrin Hospital, University of Bordeaux II, Bordeaux, France (J-M.O.).
Correspondence to Professor De Deyn, Department of Neurology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium. Reprint requests to B. Raoult, UCB Pharma, Chemin du Foriest, Building S3, 1420 Braine-l'Alleud, Belgium.
| Abstract |
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Methods Patients received placebo or 12 g piracetam as an initial intravenous bolus, 12 g daily for 4 weeks and 4.8 g daily for 8 weeks. The primary end point was neurologic outcome after 4 weeks as assessed by the Orgogozo scale. Functional status at 12 weeks as measured by the Barthel Index was the major secondary outcome. CT scan was performed within 24 hours of the onset of stroke but not necessarily before treatment. Analyses based on the intention to treat were performed in all randomized patients (n=927) and in an "early treatment" population specified in the protocol as treatment within 6 hours of the onset of stroke but subsequently redefined as less than 7 hours after onset (n=452).
Results In the total population, outcome was similar with both treatments (the mean Orgogozo scale after 4 weeks: piracetam 57.7, placebo 57.6; the mean Barthel Index after 12 weeks: piracetam 55.8, placebo 53.1). Mortality at 12 weeks was 23.9% (111/464) in the piracetam group and 19.2% (89/463) in the placebo group (relative risk 1.24, 95% confidence interval, 0.97 to 1.59; P=.15). Deaths were fewer in the piracetam group in those patients in the intention-to-treat population admitted with primary hemorrhagic stroke. Post hoc analyses in the early treatment subgroup showed differences favoring piracetam relative to placebo in mean Orgogozo scale scores after 4 weeks (piracetam 60.4, placebo 54.9; P=.07) and Barthel Index scores at 12 weeks (piracetam 58.6, placebo 49.4; P=.02). Additional analyses within this subgroup, confined to 360 patients with moderate and severe stroke (initial Orgogozo scale score <55), showed significant improvement on piracetam in both outcomes (P<.02).
Conclusions Piracetam did not influence outcome when given within 12 hours of the onset of acute ischemic stroke. Post hoc analyses suggest that piracetam may confer benefit when given within 7 hours of onset, particularly in patients with stroke of moderate and severe degree. A randomized, placebo-controlled, multicenter study, the Piracetam Acute Stroke Study II (PASS II) will soon begin.
Key Words: cerebral ischemia neuroprotection clinical trials piracetam
| Introduction |
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We describe a clinical trial with piracetam, a drug reported to increase compromised regional cerebral blood flow3 and depressed glucose metabolism in infarcted and adjacent tissue.4 Improved outcome relative to placebo was found in two pilot studies in acute stroke in which high-dose piracetam was given intravenously 3-5 days after the onset of stroke.3 5
The mode of action of piracetam is unique and, although not entirely clear, may be explained by neuroprotective properties6 mediated through effects on the cell membrane,7 8 which are most marked in the presence of hypoxia.6 Piracetam has been found to be present in the polar heads of phospholipid membrane models,7 and this interaction has been shown to restore membrane fluidity.8 This probably accounts for the maintenance or improvement of membrane-bound cell functions including ATP production,9 neurotransmission,10 and secondary messenger activity.11 Piracetam has been shown in placebo-controlled studies to improve learning and memory,12 vertigo,13 cortical myoclonus,14 and, as an adjunct to speech therapy, aphasia.15 16
The Piracetam Acute Stroke Study (PASS) tested the primary hypothesis that in acute ischemic supratentorial stroke, piracetam improves neurologic status at 4 weeks compared with placebo. Ability to perform activities of daily living at 12 weeks was the major secondary outcome parameter. Treatment was initiated within 12 hours of the onset of symptoms, and because therapy is more likely to be efficacious the sooner it is introduced, the protocol specified analysis in all randomized patients and in a subgroup treated within 6 hours of the onset of stroke.
| Subjects and Methods |
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Steering and safety committees supervised the trial. Members of the latter were otherwise unconnected with the project, and their functions included review of deaths and serious adverse events and, in the event of untoward findings, termination of the trial. The study was performed according to European Community Guidelines for Good Clinical Practice18 after approval of the protocol by relevant ethics committees.
Patients
Patients aged 40 to 85 years admitted with a clinical diagnosis
of acute ischemic supratentorial stroke
were randomized and treated if they were arousable and if symptoms
occurring within the preceding 12 hours were disabling as defined by an
Orgogozo scale score of >5 and <70. Onset 2 hours after going to bed
was arbitrarily assumed in those who awoke with stroke-related symptoms
(n=83). The diagnosis was confirmed by CT; a scan performed within 24
hours of onset and, if necessary, repeated within 8 days had to show
evidence of a nonlacunar supratentorial infarct
(>1 cm2) consistent with the clinical deficit. CT
criteria for exclusion were evidence of cerebral hemorrhage and
a mass effect with a midline shift (
0.5 cm) on the early scan. Other
exclusion criteria were stupor or coma defined as a score of <5 on the
Glasgow Coma Scale,19 previous stroke with clinical
sequelae, and confounding neurologic or systemic illness. Patients or
relatives provided written informed consent.
Treatment
Patients were randomly assigned to treatment with piracetam
or placebo from a computer-generated randomization schedule stratified
by study center. Immediately after randomization, eligible patients
received an intravenous bolus of 12 g of piracetam
(Nootropil®) or matching placebo administered over 20 minutes
followed by treatment for 12 weeks (12 g daily or placebo for 4 weeks
and 4.8 g daily or placebo for 8 weeks) (Table 1
). UCB Pharma supplied and packaged all
piracetam and matched placebo solutions and tablets.
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Nonstudy medications allowed were calcium antagonists for hypertension or heart disease, osmotic diuretics for cerebral edema, and heparin in low dosage to prevent deep venous thrombosis and in full dosage after 48 hours to prevent embolism of cardiac origin. Although concomitant aspirin was not recommended for at least 24 hours after the start of treatment, its use before or immediately after the stroke was not a reason for exclusion. Dipyridamole and ticlopidine were prohibited during the first 4 weeks. Thrombolytic agents, hemodilution, and drugs acting on the cerebral vasculature were forbidden.
Assessments
Study assessments were performed 1 and 3 days and 1, 2, 4, 8,
and 12 weeks after the start of treatment. Neurologic status evaluated
by the Middle Cerebral Artery neurologic scale17 after 4
weeks was the primary end point. Functional capacity for activities of
daily living at 12 weeks assessed by the Barthel Index20
was the major secondary outcome. Serial measurements of both indexes
allowed evaluation of the clinical course.
The Orgogozo scale,17 developed for clinical trial evaluation of middle cerebral artery strokes, has been validated21 22 and provides objective, reproducible ratings of high prognostic value even in the early hours after a stroke. The scale evaluates 10 items: vigilance, verbal communication, elevation of the arm, finger and thumb movements, arm tone, deviation of head and eyes, facial movements, elevation of the leg, dorsiflexion of the foot, and leg tone. Weighted scores for each item vary between 0 and 5 or 10 and 15 to provide a maximum score of 100.
The Barthel Index has been widely used to assess functional outcome or activities of daily living in the evaluation of stroke. Patients who can perform all specified activities unaided receive a score of 100 but may remain handicapped by neurologic impairments even though they are independent in daily activities. Patients who die cannot be rated. The Barthel Index was therefore modified so that patients scored as 100 and without neurologic abnormality (Orgogozo scale, 100) received a score of 110, and patients who died, a score of -10. Barthel Index responses were also grouped into six dependency classes to assess clinically relevant outcome23 : death; score <40, needing constant care; 40 to 55, needing institutional care; 60 to 80, assisted independence; 85 to 100, nearly complete independence but with neurologic deficit; Barthel Index 100 and Orgogozo scale 100, complete recovery. The Barthel Index was first scored after 3 days as earlier measurements are not assessable in patients with moderate to severe deficits.
Statistics
Estimation of sample size was based on clinically relevant
improvement in the Orgogozo scale, assuming that a mean difference of
3.5 points relative to placebo at 4 weeks is equivalent to a mean
improvement of 10 points in 35% of patients. Computer simulations
using Orgogozo scale measurements during the pilot phase of the trial
indicated that using a level of
=.05, 250 patients in each treatment
group surviving for 4 weeks would yield a power of 0.80 to detect these
changes. To allow for deaths and withdrawals, we planned to include
900 patients.
All analyses reported were based on the intention to treat. Missing data were assigned the value of the last available assessment. Outcome was analyzed in all patients and in an "early treatment" subgroup planned in the study protocol to include those treated within 6 hours of stroke onset. The steering committee subsequently redefined this period as "less than 7 hours" after stroke onset for several reasons. The precise times of onset of stroke and to treatment are often uncertain and represent best estimates. They were frequently recorded to the nearest 15 minutes. In the total population, the steering committee therefore agreed to include patients treated less than 13 hours after stroke onset. Similarly, the early treatment subgroup was redefined to include patients treated less than 7 hours after stroke onset; the additional patients thereby included increased the power of the analysis. This subgroup analysis therefore differed slightly from that specified in the initial protocol.
We performed additional analyses in those patients in the early treatment subgroup with moderate and severe neurologic deficits, defined by baseline Orgogozo scale scores as less than 55. Patients with moderate to severe deficits at the onset of stroke have been shown to be more responsive to drug effect in previous trials.24
Characteristics at baseline were compared using
2,
t, and Mann-Whitney tests. Mean differences in Orgogozo
scale and Barthel Index scores were compared using the
nonparametric Cochran-Mantel-Haenszel test; means and
standard deviations were used in a descriptive sense. Results were
analyzed in all patients with baseline Orgogozo scale
measurements. Orgogozo scale analyses were performed after
stratification according to baseline scores to minimize imbalance
between groups in the initial severity of stroke. Deaths were scored
with the last Orgogozo scale value carried forward. To compare the
frequency with which patients reached each functional class derived
from Barthel Index scores, we used survival analysis. Risk
rates for death were estimated and compared using the
Cochran-Mantel-Haenszel test after controlling for baseline Orgogozo
scale scores. Logistic regression was used to determine which of many
potential factors predicted mortality. Adverse events were compared
using the
2 test. Tests were two tailed and assumed a
significance level of
=.048.25 SAS software
(statistical package 6.08) was used for all computations.
Interim Analysis of Efficacy and Safety
One planned interim analysis was performed on the
results in the first 514 patients using significance levels of
=.005
for efficacy and
=.05 for safety parameters. This showed
no differences between treatment groups deemed sufficient to stop the
trial.
| Results |
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All randomized patients were treated, their data were included in intention-to-treat analyses, and they were evaluated for safety. For the primary outcome, data were missing at baseline in four piracetam-treated patients (0.9%) and after 4 weeks in 39 (8.4%) and 38 patients (8.2%) in piracetam and placebo groups. Results in patients fulfilling protocol criteria did not differ significantly from those in the intention-to-treat population and are therefore not reported.
Of the intention-to-treat population, 255 patients did not meet at
least one protocol requirement on admission or during the first 4 weeks
of treatment (Table 3
). Most protocol
violations occurred on study entry because of inappropriate CT scan
findings in 148 patients. Evidence of primary hemorrhagic stroke was
present in 31 patients (piracetam 15, placebo 16) on the first CT
scan. Lacunar stroke (22), infratentorial stroke (20), and mass with
midline shift (three) also led to exclusion. The second examination was
considered normal in 65 patients (piracetam 40, placebo 25). No scan
was performed in seven patients.
|
Outcome
Efficacy
The primary end point, the mean Orgogozo scale score after 4
weeks, was similar in piracetam (57.7±31.7) (mean±SD) and placebo
(57.6±31.5) groups (Table 4
) (Fig 1
). Functional ability for activities of
daily living did not differ significantly between treatment groups:
mean Barthel Index scores after 12 weeks were slightly higher in
patients given piracetam (piracetam, 55.8±43.8; placebo, 53.1±43.3;
P=.33). (Table 4
) (Fig 2
).
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Mortality
Death within 12 weeks occurred more often in the piracetam group
than with placebo. Mortality within 12 weeks was 23.9% (111/464) in
the piracetam group and 19.2% (89/463) on placebo. The difference was
not significant (P=.15). The relative risk was 1.24 (95%
CI, 0.97 to 1.59). Of six factors that contributed significantly to
death when potential risk and prognostic and treatment-related factors
were examined using logistic regression, the two most important were
initial severity of stroke and age. The conditional relative mortality
risk with an initial Orgogozo scale score below the median value (35 in
each treatment group) was 6.01 (95% CI, 3.25 to 11.09), and with
patients aged 72 years or more it was 3.51 (95% CI, 1.89 to 6.51). No
significant contribution toward death was found for treatment, time to
initiation of treatment, or interaction between treatment and any other
factor.
The initial score for the Orgogozo scale was <35 in 214 piracetam-treated patients compared with 195 in the placebo group, a difference of 19. Mortality in these patients was similar in each group (piracetam, 36% 77/214; placebo, 33% 64/195). Age distribution was similar in each group.
Safety
Adverse events, regardless of cause and including those considered
serious, occurred with similar frequency in each group and caused
withdrawal from the study in 10 piracetam-treated patients and six who
had received placebo. Symptomatic hemorrhagic
transformation of the infarct, which occurred in 17 piracetam-treated
and 16 placebo-treated patients, was fatal in four patients given
piracetam and in three given placebo. After 12 weeks, three of 15
patients admitted with primary hemorrhagic stroke and receiving
piracetam had died compared with six of 16 receiving placebo. In these
patients, stroke was more severe at baseline in the piracetam group
(mean Orgogozo scale score: piracetam, 28.7±25.0; placebo,
38.4±37.5).
Post Hoc Subgroup Analyses
Early Treatment Subgroup
The early treatment population consisted of 452 patients (224
piracetam, 228 placebo) whose baseline characteristics were similar in
each group and differed in no significant respect from the total
population. Mortality within 12 weeks was similar in both treatment
groups: piracetam, 19.6% (44/180); placebo, 19.7% (45/183). We found
differences in neurologic outcome favoring piracetam in this subgroup.
The mean Orgogozo scale score after 4 weeks was 5.5 points greater in
the piracetam (60.4±32.0) than in the placebo group (54.9±32.4), a
difference approaching significance (P=.07).
The mean Barthel Index score at 12 weeks was significantly higher in the active group (58.6±42.8) compared with placebo (49.4±43.2) (P=.02). When the numbers of patients reaching each Barthel dependency class were compared, more patients recovered completely in the piracetam group (18.8%) than on placebo (13.6%), and in contrast, a level of function requiring constant care was more frequent on placebo (25.0%) than on piracetam (19.6%). These differences were not significant.
Fig 3
shows the evolution of mean scores
for the Orgogozo scale and Barthel Index in both treatment groups. For
both measures, consistent differences favored piracetam. For
the Orgogozo scale, these differences appeared within 24 hours. For the
Barthel Index, the difference increased with time and was greatest (9.2
points, P=.02) at 12 weeks.
|
Because patients with mild stroke have a high rate of spontaneous
recovery, a ceiling effect occurs in responses measured by neurological
scales. Thus, when outcomes in the early treatment subgroup were
related to the initial severity of stroke, differences favoring
piracetam were confined to patients with moderate and marked neurologic
impairment defined by an Orgogozo scale score <55 and were minimal in
the presence of milder deficits (baseline Orgogozo scale,
55). (Fig 4
). Exploratory analyses were
performed in 360 such patients, approximately 80% of the early
treatment subgroup.
|
The baseline characteristics of both these treatment subgroups were similar. We found significant improvement in patients on active treatment. The mean Orgogozo scale score at 4 weeks was more than 7 points greater in the piracetam group (54.9±31.9) than on placebo (47.6±30.4) (P<.02). At 12 weeks, the mean Barthel Index score in piracetam-treated patients (52.1±42.6) exceeded that on placebo (41.1±41.3) by 11 points (P<.02). For the number of patients reaching each Barthel dependency class, complete recovery occurred in 15.8% of piracetam-treated patients compared with 8.2% in the placebo group. Conversely, the need for constant care was more frequent in patients treated with placebo (29.7%) than piracetam (24.1%). These differences were not significant. There was no difference in mortality: piracetam, 23.0% (41/137); placebo, 23.1% (42/140).
| Discussion |
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Contrary to our prior hypothesis, the power of the study proved insufficient. Retrospective calculation indicated that the power to show the required difference of 3.5 points between groups in the Orgogozo scale at 4 weeks was 44%. The probability of a false-negative result in the study sample was thus 56%.
Piracetam is known to possess an unusually benign safety profile.
Adverse events have been occasional and mild, and there has not been
evidence of organ toxicity (A. Delaere, unpublished data, 1997).
Tolerance was good in this trial as in other studies in acute
stroke3 5 and cortical myoclonus,14 which
employed daily dosage with
12 g of piracetam. Importantly,
hemorrhagic transformation of the infarct occurred with similar
frequency in each treatment group. In addition, of those included with
primary hemorrhagic stroke, fewer piracetam-treated patients died. This
suggests that piracetam could be administered acutely, before hospital
admission and CT scanning, to patients presenting clinically with
stroke.
Initial severity of stroke and age are the strongest predictors of mortality after stroke.26 We confirmed this using logistic regression and could show no correlation between treatment-related factors and death. The higher mortality in piracetam-treated patients was not statistically significant and is mostly explained because the initial stroke was severe in more of these patients. Piracetam is therefore most unlikely to influence mortality in acute stroke.
Post hoc analyses in the early treatment subgroup showed a trend toward improvement in favor of pira-cetam. Since most patients with mild neurologic impairment after a stroke recover spontaneously, it is difficult to detect small differences due to treatment because of a ceiling effect on responses measured by neurologic scales.24 We therefore performed additional analyses in patients with stroke of moderate and severe degree, which showed significant differences in favor of piracetam.
Piracetam and placebo did not differ significantly in effects on neurologic or functional status in patients treated within 12 hours of the onset of acute ischemic stroke. Post hoc analyses suggest that when given within 7 hours of onset, piracetam may be beneficial, particularly in patients with stroke of moderate and severe degree. A randomized, placebo-controlled, multicenter study, the Piracetam Acute Stroke Study II (PASS II), will soon begin.
| Acknowledgments |
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| Appendix 1 |
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Austria: E. Diabl (Linz); Belgium: E. Baeck (Antwerp), S. Blecic (Brussels), A. Capon (Brussels), H. Carton (Louvain), A. Catano (Montigny-le-Tilleul), M. Cornette (Seraing), P.P. De Deyn (Middelheim, Antwerp), I. Dehaene (Bruges), B. De Potter (Ghent), J.L. De Reuck (Ghent), H. De Vooght (St. Truiden), J. Janssens (Louvain), F. Piessens (Duffel), M. Vandewoude (St. Elisabeth, Antwerp); France: B. Dupuy (Cherbourg), H. Duclos (Pontoise), D. Joyeux (Valence), D. Milandre (Marseille), M. Salzman (Roanne), A. Setiey (Gleize), J.F. Savet (Macon), J.M. Warter (Strasbourg); Germany: W. Christe (Berlin), L. Harms (Berlin), G.H. Kessler (Greifswald), P. Marx (Berlin); Greece: I. Milonas (Thessaloniki); Hungary: A. Fazekas (Budapest), Z. Haflner (Budapest), P. Harczos (Budapest), J. Szanto (Zalaegerszeg Pòzna), L. Szegedy (Budapest), L. Vécsei (Szeged); Netherlands: J.A. Haas (Almelo), J.M. Minderhoud (Groningen), J. Swen (Delft), P. Raedts (Helmond), E. Sanders (Breda); Portugal: J. Ferro (Lisbon); Spain: J. Alvarez-Sabín (Barcelona), C. Hernández-Lahoz (Oviedo), C. Martinez-Parra (Sevilla), D. Mateo González (Madrid), M. Noya (Santiago de Compostella), M. Rebollo (Santander), J. Vilchez Padilla (Valencia); United Kingdom: D. Barer, M. Lye (Liverpool), M. Datta Chaudhury (Stockport), M. Finlay (Rochdale), J. George (Carlisle), M.A. Samad (Fulwood), A.K. Sharma (Liverpool), R.C. Tallis (Manchester), R.H. Taylor (Haslar).
Committees
Steering: P.P. De Deyn (Antwerp, Belgium), J.L. De
Reuck (Ghent, Belgium), P. Marx (Berlin, Germany), J.M. Minderhoud
(Groningen, The Netherlands), Z. Nagy (Budapest, Hungary), R.C.
Tallis (Manchester, United Kingdom), UCB Pharma Participant: W. Deberdt
(Braine-l'Alleud, Belgium); Safety: A. Dresse (Liege,
Belgium), J-M. Orgogozo (Bordeaux, France), R. Vlietinck (Louvain,
Belgium); Monitoring & Data Management: BRI International
(Mechelen, Belgium); Statistics: M-P Derde, Data
Investigation Company Europe (DICE) (Brussels, Belgium).
Received April 11, 1997; accepted September 25, 1997.
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M. Niewada, M. Skowronska, D. Ryglewicz, B. Kaminski, A. Czlonkowska, and on behalf of the Polish National Stroke Prevention Acute Ischemic Stroke Care and Outcome in Centers Participating in the Polish National Stroke Prevention and Treatment Registry Stroke, July 1, 2006; 37(7): 1837 - 1843. [Abstract] [Full Text] [PDF] |
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J. S. Elkins, T. Khatabi, L. Fung, J. Rootenberg, and S. C. Johnston Recruiting Subjects for Acute Stroke Trials: A Meta-Analysis Stroke, January 1, 2006; 37(1): 123 - 128. [Abstract] [Full Text] [PDF] |
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C. S. Weaver, J. Leonardi-Bee, F. J. Bath-Hextall, and P. M.W. Bath Sample Size Calculations in Acute Stroke Trials: A Systematic Review of Their Reporting, Characteristics, and Relationship With Outcome Stroke, May 1, 2004; 35(5): 1216 - 1224. [Abstract] [Full Text] [PDF] |
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A. Evans, F. Harraf, N. Donaldson, and L. Kalra Randomized Controlled Study of Stroke Unit Care Versus Stroke Team Care in Different Stroke Subtypes Stroke, February 1, 2002; 33(2): 449 - 455. [Abstract] [Full Text] [PDF] |
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J. Croom, N. J. Lobaugh, G. Koren, J. Rovet, and R. Haslam Piracetam Study: Poorly Designed and Misinterpreted Arch Pediatr Adolesc Med, October 1, 2001; 155(10): 1176 - 1178. [Full Text] [PDF] |
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R. L. Sacco, J. T. DeRosa, E. C. Haley Jr, B. Levin, P. Ordronneau, S. J. Phillips, T. Rundek, R. G. Snipes, J. L. P. Thompson, and for the GAIN Americas Investigators Glycine Antagonist in Neuroprotection for Patients With Acute Stroke: GAIN Americas: A Randomized Controlled Trial JAMA, April 4, 2001; 285(13): 1719 - 1728. [Abstract] [Full Text] [PDF] |
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N. J. Lobaugh, V. Karaskov, V. Rombough, J. Rovet, S. Bryson, R. Greenbaum, R. H. Haslam, and G. Koren Piracetam Therapy Does Not Enhance Cognitive Functioning in Children With Down Syndrome Arch Pediatr Adolesc Med, April 1, 2001; 155(4): 442 - 448. [Abstract] [Full Text] [PDF] |
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K. Uchino, D. Billheimer, and S. C. Cramer Entry Criteria and Baseline Characteristics Predict Outcome in Acute Stroke Trials Stroke, April 1, 2001; 32(4): 909 - 916. [Abstract] [Full Text] [PDF] |
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G. P. Samsa and D. B. Matchar Have Randomized Controlled Trials of Neuroprotective Drugs Been Underpowered? : An Illustration of Three Statistical Principles Stroke, March 1, 2001; 32(3): 669 - 674. [Abstract] [Full Text] [PDF] |
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M. Fisher and W. Schaebitz An Overview of Acute Stroke Therapy: Past, Present, and Future Arch Intern Med, November 27, 2000; 160(21): 3196 - 3206. [Full Text] [PDF] |
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J. Kessler, A. Thiel, H. Karbe, and W. D. Heiss Piracetam Improves Activated Blood Flow and Facilitates Rehabilitation of Poststroke Aphasic Patients Stroke, September 1, 2000; 31(9): 2112 - 2116. [Abstract] [Full Text] [PDF] |
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P. W. Duncan, H. S. Jorgensen, and D. T. Wade Outcome Measures in Acute Stroke Trials : A Systematic Review and Some Recommendations to Improve Practice Stroke, June 1, 2000; 31(6): 1429 - 1438. [Abstract] [Full Text] [PDF] |
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G DEVUYST and J BOGOUSSLAVSKY Recent progress in drug treatment for acute stroke J. Neurol. Neurosurg. Psychiatry, October 1, 1999; 67(4): 420 - 425. [Full Text] [PDF] |
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M. Davis and D. Barer Neuroprotection in acute ischaemic stroke. II: Clinical potential Vascular Medicine, August 1, 1999; 4(3): 149 - 163. [Abstract] [PDF] |
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G. Sulter, C. Steen, and Jacques De Keyser Use of the Barthel Index and Modified Rankin Scale in Acute Stroke Trials Stroke, August 1, 1999; 30(8): 1538 - 1541. [Abstract] [Full Text] [PDF] |
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P. C. Njemanze, A. Chidi-Ebere, and J.-M. Orgogozo Three-Dimensional Vector Component Analysis of Neurological Stroke Scales • Response Stroke, August 1, 1999; 30(8): 1731 - 1733. [Full Text] [PDF] |
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