An implementation evaluation of the physical activity counseling for in-patients with major depressive disorder (PACINPAT) intervention: a randomized controlled trial

BACKGROUND

The physical activity counseling for in-patients with major depression (PACINPAT) randomized controlled trial was launched to tackle physical inactivity for in-patients with major depressive disorder. Evidence shows that despite potential treatment effects, physical inactivity is prevalent in this population. To contribute to the assessment of how this in-person and remote, theory-based, individually tailored intervention was designed, received and effected behavior, the aim of this study was to evaluate its implementation.

METHODS

This implementation evaluation was conducted within a multi-center randomized controlled trial according to the Process Evaluation Framework by the Medical Research Council including the analysis of reach, dose, fidelity and adaptation. Data were collected from the implementers and the participants randomized to the intervention group of the trial.

RESULTS

The study sample comprised 95 physically inactive in-patients (mean age: 42 years, 53% women) with diagnosed major depressive disorder. The intervention reached the intended population (N = 95 in-patients enrolled in the study). The intervention dose varied between early dropouts (counseling sessions, M = 1.67) and study completers with some participants receiving a low dose (counseling sessions, M = 10.05) and high dose (counseling sessions, M = 25.37). Differences in the attendance groups were recognizable in the first two counseling sessions (duration of counseling session about 45 min in early dropouts versus 60 min for study completers). Fidelity of the in-person counseling content was partly achieved and adapted, whereas that of the remote counseling content was well achieved. Participants (86% at follow up) reported satisfaction with the implementers of the intervention. Adaptations were made to content, delivery mode and dose.

CONCLUSION

The PACINPAT trial was implemented in the intended population, in varying doses and with adaptations made to in-person counseling content and remote counseling dose. These findings are key to understanding outcome analyses within the PACINPAT trial, further developing interventions and contributing to implementation research among in-patients with depressive disorders.

TRIAL REGISTRATION

ISRCTN, ISRCTN10469580 , registered on 3^rd September 2018.

Revascularization grading in endovascular acute ischemic stroke therapy

BACKGROUND

Recanalization and angiographic reperfusion are key elements to successful endovascular and interventional acute ischemic stroke (AIS) therapy. Intravenous recombinant tissue plasminogen activator (rt-PA), the only established revascularization therapy approved by the US Food & Drug Administration for AIS, may be less effective for large artery occlusion. Thus, there is enthusiasm for endovascular revascularization therapies, which likely provide higher recanalization rates, and trials are ongoing to determine clinical efficacy and compare various methods. It is anticipated that clinical efficacy will be well correlated with revascularization of viable tissue in a timely manner.

METHOD

Reporting, interpretation, and comparison of the various revascularization grading methods require agreement on measurement criteria, reproducibility, ease of use, and correlation with clinical outcome. These parameters were reviewed by performing a Medline literature search from 1965 to 2011. This review critically evaluates current revascularization grading systems.

RESULTS AND CONCLUSION

The most commonly used revascularization grading methods in AIS interventional therapy trials are the thrombolysis in cerebral ischemia (TICI, pronounced "tissy") and thrombolysis in myocardial ischemia (TIMI) scores. Until further technical and imaging advances can incorporate real-time reliable perfusion studies in the angio-suite to delineate regional perfusion more accurately, the TICI grading system is the best defined and most widely used scheme. Other grading systems may be used for research and correlation purposes. A new scale that combines primary site occlusion, lesion location, and perfusion should be explored in the future.

The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) Trial

BACKGROUND

Transcranial Doppler ultrasound (TCD) and magnetic resonance angiography (MRA) can identify intracranial atherosclerosis but have not been rigorously validated against the gold standard, catheter angiography. The WASID trial (Warfarin Aspirin Symptomatic Intracranial Disease) required performance of angiography to verify the presence of intracranial stenosis, allowing for prospective evaluation of TCD and MRA. The aims of Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) trial were to define abnormalities on TCD/MRA to see how well they identify 50 to 99% intracranial stenosis of large proximal arteries on catheter angiography.

STUDY DESIGN

SONIA standardized the performance and interpretation of TCD, MRA, and angiography. Study-wide cutpoints defining positive TCD/MRA were used. Hard copy TCD/MRA were centrally read, blind to the results of angiography.

RESULTS

SONIA enrolled 407 patients at 46 sites in the United States. For prospectively tested noninvasive test cutpoints, positive predictive values (PPVs) and negative predictive values (NPVs) were TCD, PPV 36% (95% CI: 27 to 46); NPV, 86% (95% CI: 81 to 89); MRA, PPV 59% (95% CI: 54 to 65); NPV, 91% (95% CI: 89 to 93). For cutpoints modified to maximize PPV, they were TCD, PPV 50% (95% CI: 36 to 64), NPV 85% (95% CI: 81 to 88); MRA PPV 66% (95% CI: 58 to 73), NPV 87% (95% CI: 85 to 89). For each test, a characteristic performance curve showing how the predictive values vary with a changing test cutpoint was obtained.

CONCLUSIONS

Both transcranial Doppler ultrasound and magnetic resonance angiography noninvasively identify 50 to 99% intracranial large vessel stenoses with substantial negative predictive value. The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis trial methods allow transcranial Doppler ultrasound and magnetic resonance angiography to reliably exclude the presence of intracranial stenosis. Abnormal findings on transcranial Doppler ultrasound or magnetic resonance angiography require a confirmatory test such as angiography to reliably identify stenosis.

Pretreatment ipsilateral regional cortical blood flow influences vessel recanalization in intra-arterial thrombolysis for MCA occlusion

BACKGROUND AND PURPOSE

The aim of acute stroke interventions is to achieve recanalization of the target occluded artery. We sought to determine whether pretreatment cortical cerebral blood flow (CBF) was associated with vessel recanalization in patients undergoing intra-arterial therapy.

METHODS

This is a retrospective analysis of patients who underwent a quantitative xenon CT blood flow study and were noted to have a documented M1 middle cerebral artery (MCA) or carotid terminus occlusion less than 6 hours from symptom onset between January 1997 and April 2001. Twenty-three patients who underwent intra-arterial thrombolysis were included in the analysis. Univariate and multivariate analyses were performed to determine whether pretherapy CBF was correlated to the likelihood of recanalization.

RESULTS

A total of 23 patients were studied in this analysis with a median age of 69 (range 32-81) and median National Institutes of Health Stroke Score of 19 (range, 8-22). Twelve patients (52%) underwent combined intravenous/intra-arterial therapy, and 11 patients (48%) were treated with intra-arterial thrombolytics alone. Successful vessel recanalization (Thrombolysis in Myocardial Infarction classification 2 or 3 flow) occurred in 13 patients (57%). The only variable associated with recanalization in multivariate modeling was mean ipsilateral MCA CBF (odds ratio, 1.25; 95% confidence interval, 1.01-1.54; P = .035). A receiver operating characteristic curve was generated, and a mean ipsilateral MCA CBF threshold of 18 mL/100 g/min was found to be the threshold for successful recanalization.

CONCLUSIONS

Our study suggests that patients with higher mean ipsilateral MCA CBF are more likely to recanalize. The threshold for successful revascularization may be 18 mL/100 g/min. Further study is required to determine whether pretreatment CBF is related to recanalization success.

Clinical importance of microbleeds in patients receiving IV thrombolysis

BACKGROUND

Cerebral microbleeds (MBs) detected on gradient echo (GRE) imaging may be a risk factor for hemorrhagic complications in patients with stroke treated with IV tissue plasminogen activator (tPA).

METHODS

The authors prospectively evaluated patients with acute ischemic stroke treated with IV tPA between 3 and 6 hours of symptom onset. MRI scans, including GRE imaging, were performed prior to tPA treatment, 3 to 6 hours after treatment and at day 30. The authors compared the frequency of hemorrhagic complications after thrombolysis in patients with and without MBs on their baseline GRE imaging.

RESULTS

Seventy consecutive patients (mean age, 71 +/- 29 years; 31 men, 39 women) were included. MBs were identified in 11 patients (15.7%) on baseline GRE imaging. There was no significant difference in the frequency of either symptomatic or asymptomatic hemorrhagic complications after thrombolysis between patients with and without MBs at baseline. None of the 11 patients with MBs (0%) at baseline had a symptomatic intracerebral hemorrhage compared with 7 of 59 patients who did not have baseline MBs (11.9%). In addition, no patients with baseline MBs had asymptomatic hemorrhagic transformation observed at the site of any pre-treatment MB.

CONCLUSIONS

The presence of cerebral microbleeds on gradient echo imaging does not appear to substantially increase the risk of either symptomatic or asymptomatic brain hemorrhage following IV tissue plasminogen activator administered between 3 and 6 hours after stroke onset.

Changes in cognitive function after neuronal cell transplantation for basal ganglia stroke

Reported is the change in cognitive function after neuronal cell transplantation as a treatment for basal ganglia stroke. Nine subjects (two controls, seven transplants), all over 2 years post stroke, completed a comprehensive neuropsychological test battery prior to and 6 months after treatment. Four transplanted subjects who had strokes in the nondominant hemisphere showed marked improvement on the Rey Complex Figure, a test of visuospatial/constructional ability and nonverbal memory.

Clomethiazole Acute Stroke Study in ischemic stroke (CLASS-I): final results

BACKGROUND AND PURPOSE

A previous trial (the Clomethiazole Acute Stroke Study) generated the hypothesis that clomethiazole is effective in patients with a major ischemic stroke (total anterior circulation syndrome), and this was tested in the present study.

METHODS

A total of 1198 patients with major ischemic stroke and a combination of limb weakness, higher cortical dysfunction, and visual field deficits were randomly assigned to clomethiazole (68 mg/kg IV over 24 hours) or placebo. The study drug was initiated within 12 hours of symptom onset. Functional outcome and neurological recovery were assessed at days 7, 30, and 90, with the proportion of patients with a Barthel Index > or =60 at last follow-up as the primary outcome measure.

RESULTS

The patients were randomly assigned equally, and the two treatment groups were well matched for baseline characteristics, including stroke severity (mean National Institutes of Health Stroke Scale score 16.9+/-5.2). Ninety-six percent were classified as total anterior circulation syndrome. The proportion of patients reaching a Barthel Index score of > or =60 was 42% in the clomethiazole-treated group and 46% in the placebo-treated group (odds ratio, 0.81; 95% CI, 0.62 to 1.05; P=0.11). There was no evidence of efficacy on any secondary outcome variables (modified Rankin Score, National Institutes of Health Stroke Scale, Scandinavian Stroke Scale, and 30-day CT infarct volumes) compared with placebo. Subgroup analysis showed a similar lack of treatment effect in patients treated early (<6 hours) and in those treated later (6 to 12 hours). Somnolence was an expected pharmacological effect of clomethiazole, and this occurred during treatment as an adverse event in half of the patients randomly assigned to study drug.

CONCLUSIONS

The target population was selected, and sufficient drug was given to produce the expected pharmacological effect in the brain. Clomethiazole does not improve outcome in patients with major ischemic stroke.

Serial [18F] fluorodeoxyglucose positron emission tomography after human neuronal implantation for stroke

OBJECTIVE

There is no known effective treatment for chronic stroke. In this report, we used positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) to map the metabolic brain response to neuronal cell implantation in the first human neuroimplantation trial for stroke.

METHODS

Twelve patients (nine men, three women; mean age +/- standard deviation, 60.8+/-8.3 yr) with chronic basal ganglia infarction and persistent motor deficit underwent FDG PET within 1 week before and 6 and 12 months after stereotactic implantation of human neuronal cells. Serial neurological evaluations during a 52-week postoperative period included the National Institutes of Health stroke scale and the European stroke scale.

RESULTS

Alterations in glucose metabolic activity in the stroke and surrounding tissue at 6 and 12 months after implantation correlated positively with motor performance measures.

CONCLUSION

FDG PET performed as part of an initial open-label human trial of implanted LBS-Neurons (Layton BioScience, Sunnyvale, CA) for chronic stroke demonstrates a relationship between relative regional metabolic changes and clinical performance measures. These preliminary findings suggest improved local cellular function or engraftment of implanted cells in some patients.

For how long is brain tissue salvageable? Thrombolysis-based evidence

Recombinant t-PA (tissue plasminogen activator, alteplase) was licensed for use in the United States for treatment of acute ischemic stroke on the basis of the National Institute of Neurological Disorders and Stroke (NINDS) study. In this trial, t-PA was started within 3 hours of onset of stroke symptoms. Two other trials of t-PA (the European Cooperative Acute Stroke Study [ECASS] I and ECASS II) failed to detect a significant effect in stroke patients. Both of these trials allowed treatment to begin up to 6 hours after the onset of symptoms. However, the results of a meta-analysis of all well-controlled trials of thrombolytics suggest that thrombolysis is an effective strategy when started up to 6 hours after the onset of symptoms. More than 50% of the trials included in this meta-analysis were, in fact, of t-PA. Allowing time for infusion of the thrombolytic and time for lysis of the thrombus, the findings of the meta-analysis suggest that salvageable tissue may remain for at least 8 hours after the onset of symptoms. Prourokinase was tested for efficacy in acute stroke in the PROlyse in Acute Cerebral Thromboembolism (PROACT) I trial. This trial had an insufficient number of patients to detect a meaningful effect. Consequently, the much larger PROACT II trial was conducted. In both of these studies, infusion began within 6 hours of the onset of symptoms. PROACT II demonstrated a significant improvement in outcome, and it can be concluded that, in some patients at least, salvageable tissue remained for at least 8 hours after the onset of symptoms. Consequently, treatment with a neuroprotectant during this 8-hour window might have been effective.

Transplantation of cultured human neuronal cells for patients with stroke

Transplantation of cultured neuronal cells is safe in animal models and improves motor and cognitive deficits in rats with stroke. The authors studied the safety and feasibility of human neuronal cellular transplantation in patients with basal ganglia stroke and fixed motor deficits, including 12 patients (aged 44 to 75 years) with an infarct 6 months to 6 years previously (stable for at least 2 months). Serial evaluations (12 to 18 months) showed no adverse cell-related serologic or imaging-defined effects. The total European Stroke Scale score improved in six patients (3 to 10 points), with a mean improvement 2.9 points in all patients (p = 0. 046). Six of 11 PET scans at 6 months showed improved fluorodeoxyglucose uptake at the implant site. Neuronal transplantation is feasible in patients with motor infarction.

Remote effects of acute ischemic stroke: A xenon CT cerebral blood flow study

OBJECTIVE

The purpose of this study was to verify transhemispheric diaschisis in the early hours after an ischemic event.

METHODS

XeCT cerebral blood flow (CBF) studies within 8 h of stroke were studied in 23 patients. Mean CBF was evaluated in the ischemic area, contralateral hemisphere and ipsilateral cerebellum.

RESULTS

A severe CBF reduction was found in the ischemic area (mean 9 +/- 3 ml/100 g/min). The mean CBF in the unaffected hemisphere (33 +/- 10 ml/100 g/min) was 35% less compared to the normal mean value. CBF was decreased in the cerebellum ipsilateral to the stroke (mean 31 +/- 12 ml/100 g/min) suggesting a blood flow depression of the whole brain.

CONCLUSIONS

During the initial hours of cerebral ischemia, the asymptomatic hemisphere demonstrated CBF depression that was part of the global flow reduction.

Intra-arterial prourokinase for acute ischemic stroke. The PROACT II study: a randomized controlled trial. Prolyse in Acute Cerebral Thromboembolism

CONTEXT

Intravenous tissue-type plasminogen activator can be beneficial to some patients when given within 3 hours of stroke onset, but many patients present later after stroke onset and alternative treatments are needed.

OBJECTIVE

To determine the clinical efficacy and safety of intra-arterial (IA) recombinant prourokinase (r-proUK) in patients with acute stroke of less than 6 hours' duration caused by middle cerebral artery (MCA) occlusion.

DESIGN

PROACT II (Prolyse in Acute Cerebral Thromboembolism II), a randomized, controlled, multicenter, open-label clinical trial with blinded follow-up conducted between February 1996 and August 1998.

SETTING

Fifty-four centers in the United States and Canada.

PATIENTS

A total of 180 patients with acute ischemic stroke of less than 6 hours' duration caused by angiographically proven occlusion of the MCA and without hemorrhage or major early infarction signs on computed tomographic scan.

INTERVENTION

Patients were randomized to receive 9 mg of IA r-proUK plus heparin (n = 121) or heparin only (n = 59).

MAIN OUTCOME MEASURES

The primary outcome, analyzed by intention-to-treat, was based on the proportion of patients with slight or no neurological disability at 90 days as defined by a modified Rankin score of 2 or less. Secondary outcomes included MCA recanalization, the frequency of intracranial hemorrhage with neurological deterioration, and mortality.

RESULTS

For the primary analysis, 40% of r-proUK patients and 25% of control patients had a modified Rankin score of 2 or less (P = .04). Mortality was 25% for the r-proUK group and 27% for the control group. The recanalization rate was 66% for the r-proUK group and 18% for the control group (P<.001). Intracranial hemorrhage with neurological deterioration within 24 hours occurred in 10% of r-proUK patients and 2% of control patients (P = .06).

CONCLUSION

Despite an increased frequency of early symptomatic intracranial hemorrhage, treatment with IA r-proUK within 6 hours of the onset of acute ischemic stroke caused by MCA occlusion significantly improved clinical outcome at 90 days.

Screening for atrial fibrillation in the community: A multicenter validation trial

BACKGROUND

Atrial fibrillation (AF) is an important public health problem. This arrhythmia is common and associated with a high risk of stroke. Further, appropriate interventions in AF can reduce the risk of stroke by approximately 68%. Population studies show that a large group of patients have intermittent or chronic AF that remains unrecognized. If a simple screening test for this arrhythmia could be developed and validated, application of the technique across populations might identify AF patients for early treatment, potentially reducing the incidence of stroke. In this study, we sought to determine whether individuals taken from the general community could be taught to find and classify the pulse of another as very irregular, implying AF, or regular, implying normal sinus rhythm (NSR). The aim was to establish that pulse examination for potential AF could be performed by individuals with sufficient sensitivity and specificity to be effectively used as a screening procedure for this medically important arrhythmia.

METHODS

We enrolled 178 subjects selected from the general community from four centers. Subjects received standardized education on the medical importance of AF and its signature, a very irregular pulse. A technique for palpating and characterizing the rhythm of the radial pulse was also taught. Without further coaching, subjects were then asked to find their pulse and then to find and classify the pulse of two models randomly presented who may or may not have had AF.

RESULTS

Of the 178 subjects tested, 92% were able to find their own pulse; 17 (9.6%) were unable to find the pulse of one or both patient models and were, therefore, excluded from the study. Of the remaining 161 subjects, 76% (122 of 161) correctly identified the pulse in an AF model, and 86% (139 of 161) correctly identified the pulse in an NSR model. Results did not statistically differ as a function of age, educational status, or location.

DISCUSSION

This multicenter trial established that given minimal standardized instructions, subjects from the general community can reliably and consistently find both their pulse as well as the pulse of another and to differentiate a regular pulse from a very irregular pulse. If similar educational programs were widely applied across large populations, periodic screening for AF might lead to earlier diagnosis and appropriate treatment for patients who have this major risk factor for stroke. These screening programs should be focused on the population over the age of 55 where the risk of stroke in AF increases with each decade.

Depictions of the kidney through the ages

Recent publications [American Journal of Nephrology (1985-1995)] have contributed much to our understanding of the history of nephrology. Whether the earliest medical knowledge of the kidney was kindled in Egypt, by the Hindus in India, in ancient China, or by Assyro-Babylonians we cannot determine with certainty. What is known is that the invention of the printing press (circa 1450 AD), with the subsequent availability of translations of earlier writings plus new text editions, contributed in prodigious measure to the development of the critical and questioning character of medicine. The availability of different book illustration techniques also contributed to the development of medical knowledge. We have examined major descriptions of the kidney in 16th-, 17th- and 18th-century original works, all held by the Becker Medical Library, Washington University. The accuracy of illustrations of the observed kidney was highly variable, but each description has its place in book and 'kidney' history.

Lung cancer in chromate-exposed aerospace workers

A retrospective cohort study evaluated the risk of lung cancer in aerospace workers with minimum of 6 months' employment in jobs with chromium [VI] exposure (n = 2429). Standardized incidence ratios (SIR) estimated the risk of lung cancer by duration of employment in chromate-exposure jobs and cumulative exposure based on industrial hygiene and work-history data. The overall SIR for lung cancer was 0.8 (observed [Obs] = 15). Lung cancer risk was inversely related to estimates of cumulative chromate exposure and duration of employment as a painter. Although based on few cases, an elevated lung cancer risk was found in subjects who had worked for 5 or more years as a chrome plater or surface processor tank tender (Obs = 2, SIR = 1.9) and sander/masker or polisher (Obs = 3, SIR = 2.7). A clear association was not observed between chromate exposure and the risk of lung cancer in this population of workers.

Acute stroke intervention with intraarterial urokinase infusion

PURPOSE

A preliminary evaluation of the efficacy and safety of treating patients with acute stroke with intraarterial urokinase infusions was performed.

PATIENTS AND METHODS

Twelve patients with acute stroke were treated within 8 hours of symptom onset (average, 5 hours). Thrombolysis was performed within the middle cerebral (n = 10), internal carotid (n = 1), and basilar (n = 1) arteries. Urokinase (160,000-500,000 IU) was infused through microcatheters placed into or adjacent to the thrombi.

RESULTS

Thrombolysis was angiographically successful in nine patients (75%), all of whom had long-term neurologic improvement. No or minimal neurologic deficits were present in six patients (50%). Thrombolysis failed in three patients (25%); one patient died and two developed severe permanent neurologic deficits. No hemorrhagic complications occurred.

CONCLUSION

Preliminary results suggest that intraarterial urokinase infusion may be effective and safe for treating patients with acute stroke. Potentially devastating neurologic damage was averted or lessened in nine patients (75%). No additional neurologic damage was caused by intervention in the remaining three patients (25%).

Recent developments in transcranial Doppler sonography

Transcranial Doppler mapping, dual monitoring, color imaging, emboli detection, and insonation after administration of contrast media are recent technological advances that promise to bring new capabilities to transcranial Doppler ultrasonography, and are likely to change its applications in the near future. This article presents a critical review of these developments.

CT after intracranial intraarterial thrombolysis for acute stroke

PURPOSE

To determine the incidence, appearance, and clinical significance of lesions mimicking intraparenchymal hemorrhages on CT in patients treated with intracranial intraarterial thrombolysis for acute strokes.

METHODS

Ten cases of acute stroke treated with direct intraarterial urokinase infusion were retrospectively reviewed. Clinical and radiographic findings before and after therapy were all evaluated.

RESULTS

Six (60%) of the 10 patients showed areas of increased attenuation on CT shortly after thrombolytic therapy. The lesions were associated with clinical deterioration in two cases (20%); in these two cases the lesions persisted on CT for several days. The lesions were asymptomatic in two (20%) cases; the lesions cleared on CT within 24 hours in those two patients. In two (20%) patients, immediate clinical improvement was evident despite the radiodense areas. These lesions also cleared within 24 hours. CT Hounsfield unit measurements of four of the lesions revealed very high Hounsfield units in two lesions, only one of which was a symptomatic lesion. MR in two cases revealed residue of hemorrhage.

CONCLUSION

Intraparenchymal areas of increased attenuation may be seen on the CT scans of patients after intraarterial thrombolysis. The density is often at least partially attributable to contrast extravasation. The lesions should not necessarily be interpreted as hemorrhage alone, especially in the absence of clinical deterioration. Rapid clearing may be a positive prognostic sign.

Neuroradiologic evaluation of patients with acute stroke treated with recombinant tissue plasminogen activator. The rt-PA Acute Stroke Study Group

PURPOSE

1) To describe the effectiveness and safety of thrombolytic therapy in patients with acute atherothrombotic and embolic stroke and 2) to study the variables of the occlusion site as seen on the angiograms, the CT signs of early ischemia, the hyperdense middle cerebral artery sign (HMCAS), and the size of the infarcts as seen on the 24-hour CT scan.

METHODS

Ninety-three of 139 patients with acute stroke were treated with intravenous tissue plasminogen activator (rt-PA). The initial disease and the effects of treatment were assessed with both CT and cerebral angiography.

RESULTS

Recanalization of occluded arteries occurred in 32 patients and was more frequent in distal occlusions. In general, patients displaying recanalization tended to develop small infarcts and patients with a HMCAS tended to develop large infarcts. Patients with signs of early ischemia developed large infarcts. The presence of a HMCAS was 100% fic for an occluded artery, but only 27% sensitive. Hemorrhagic transformations occurred in the distribution of the occluded arteries in 32 patients.

CONCLUSIONS

Emergency cerebral angiography, which can be carried out relatively safely, adds important information about the nature and extent of the arterial occlusions, and the recanalization efficacy of fibrinolytic therapy for patients with acute stroke. Fibrinolytic therapy can be carried out with a relatively low complication rate that still needs to be correlated with the clinical benefits of the treatment. Fibrinolytic therapy in the doses utilized in this study, is more effective with distal than with proximal carotid territory occlusions.

Recombinant tissue plasminogen activator in acute thrombotic and embolic stroke

An open angiography-based, dose rate escalation study on the effect of intravenous infusion of recombinant tissue plasminogen activator (rt-PA) on cerebral arterial recanalization in patients with acute focal cerebral ischemia was performed at 16 centers. Arterial occlusions consistent with acute ischemia in the carotid or vertebrobasilar territory in the absence of detectable intracerebral hemorrhage were prerequisites for treatment. After the 60-minute rt-PA infusion, arterial perfusion was assessed by repeat angiography and computed tomography scans were performed at 24 hours to assess hemorrhagic transformation. Of 139 patients with symptoms of focal ischemia, 80.6% (112) had complete occlusion of the primary vessel at a mean of 5.4 +/- 1.7 hours after symptom onset. No dose rate response of cerebral arterial recanalization was observed in 93 patients who completed the rt-PA infusion. Middle cerebral artery division (M2) and branch (M3) occlusions were more likely to undergo recanalization by 60 minutes than were internal carotid artery occlusions. Hemorrhagic infarction occurred in 20.2% and parenchymatous hematoma in 10.6% of patients over all dose rates, while neurological worsening accompanied hemorrhagic transformation (hemorrhagic infarction and parenchymatous hematoma) in 9.6% of patients. All findings were within prospective safety guidelines. No dose rate correlation with hemorrhagic infarction, parenchymatous hematoma, or both was seen. Hemorrhagic transformation occurred significantly more frequently in patients receiving treatment at least 6 hours after symptom onset. No relationship between hemorrhagic transformation and recanalization was observed. This study indicates that site of occlusion, time to recanalization, and time to treatment are important variables in acute stroke intervention with this agent.

Correlative angiographic and pathologic findings in the diagnosis of ulcerated plaques in the carotid artery

We determined the accuracy of angiography in the diagnosis of internal carotid ulcers by comparing the angiographic reports with the pathologic findings in 36 endarterectomy specimens. Eighteen of these specimens had microscopic ulcerations, and the observer with the highest accuracy rate read 12, of which ten were ulcerated. These results revealed a sensitivity of 56%, a specificity of 89%, and an overall accuracy of 61% for angiography. The ulcers were classified into types A, B, and C to assess the interobserver agreement rate among three readers. This resulted in a 4% interobserver agreement among a total of 75 ulcers. Because of the high interobserver disagreement and the poor correlation between angiographic and pathologic findings in the surgical specimens, we conclude that the diagnosis of carotid artery ulceration by angiography is not reliable.

Transcranial Doppler in brain death

Transcranial Doppler examinations (TCD) of 24 brain-dead adult patients demonstrated persistent movement of blood within the middle cerebral arteries in 21. The characteristic pattern of Doppler shift frequencies, seen in 14, was a sharply contoured, brief anterograde systolic envelope with reversed diastolic flow. Five others had variants of this pattern, and two had anterograde flow throughout the cardiac cycle, except at the end of diastole. This suggests that the internal carotid and proximal middle cerebral artery circulation remains patent, but distal resistance to flow in the brain is very high in the majority of brain-dead patients. Three other patients with absent brainstem reflexes but persistent EEG activity had normal TCD patterns. The characteristic pattern on TCD may be a useful ancillary finding in the diagnosis of brain death, and normal TCD patterns probably exclude the diagnosis.

Swallowing syncope: observations in the absence of conduction system or esophageal disease

A patient is described with the clinical syndrome of "swallowing syncope" who reproducibly demonstrated sinus bradycardia, A-H prolongation, and intranodal atrioventricular block in response to swallowing during electrophysiologic study. Baseline electrophysiologic and esophageal manometric results were normal, as was his response to other vagal maneuvers. Demand ventricular pacing alleviated his symptoms. These findings suggest that "swallowing syncope" is mediated via an esophageocardiac reflex and can occur in the absence of cardiac conduction system or esophageal disease.

Quantitation of regional cerebral glucose metabolism

Kinetic analysis of 18F-labeled 2-fluoro-2-deoxy-D-glucose (2FDG) has been carried out in 28 studies on 25 subjects. The object of the analysis was to determine the practical problems of quantitation of glucose metabolic rate (GMR) using the Sokoloff model with 2FDG. We found that arterial and venous plasma concentration of 2FDG yielded equivalent values of the integrated plasma concentration (IPC*) and that one arterial or venous plasma sample at 30 min serves to predict IPC* to within +/- 7%. These observations suggest that quantitation is indeed possible in such subjects without using complex arterial or venous sampling procedures. The average values of K1, K2, and K3 are observed to be 0.14 +/- 0.08, 0.20 +/- 0.10, and 0.030 +/- 0.012 min-1. The data are consistent with a value of lumped constant of 0.4 and a considerable spread in global values of GMR (30%) in an unselected group of subjects.