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Biomedical subjects

S E Kasner

Publications and source records attributed to S E Kasner.

At least 19 recordsLinked to original sources
PubMed1999

Initial clinical experience with IV tissue plasminogen activator for acute ischemic stroke: a multicenter survey. The t-PA Stroke Survey Group.

We assessed initial clinical experience with IV tissue plasminogen activator (t-PA) treatment of acute ischemic stroke in a standardized retrospective survey of hospitals with experienced acute stroke treatment systems. The incidence of symptomatic intracerebral hemorrhage (ICH) was 6% (11 of 189 patients; 95% CI 3 to 11%), similar to that in the National Institute of Neurological Disorders and Stroke (NINDS) t-PA Stroke Study. Deviations from the NINDS protocol guidelines were identified in 30% of patients (56 of 189). The incidence of symptomatic ICH was 11% among patients with protocol deviations as compared with 4% in patients who were treated according to the NINDS protocol guidelines, suggesting that strict adherence to protocol guidelines is prudent.

Aged↗
PubMed1999

Noninvasive magnetic resonance imaging evaluation of cerebral blood flow with acetazolamide challenge in patients with cerebrovascular stenosis.

To evaluate the utility of using magnetic resonance imaging (MRI) of cerebral blood flow (CBF) in conjunction with pharmacologic flow augmentation, the authors imaged 14 patients with ischemic symptoms referable to large artery cerebrovascular stenosis of the anterior circulation. CBF was measured by using continuous arterial spin labeling (CASL) both at rest and 10 minutes after 1 g intravenous acetazolamide on a commercial 1.5 Tesla scanner. Quantitative CBF images were calculated along with augmentation images showing the effects of acetazolamide. Interpretable studies were obtained from all patients. Based on the image data as well as a region of interest analysis of CBF changes in middle cerebral artery distributions, varying patterns of augmentation were observed that suggested differing mechanisms of ischemic symptomatology. The ability to obtain this information in conjunction with a structural MRI examination extends the diagnostic potential for MRI in cerebrovascular disease and allows the value of augmentation testing in clinical management to be assessed more widely. J. Magn. Reson. Imaging 1999;10:870-875.

Acetazolamide↗
PubMed1999

Safety of air medical transportation after tissue plasminogen activator administration in acute ischemic stroke.

BACKGROUND AND PURPOSE: We sought to determine the safety of air medical transport (AMT) of patients with acute ischemic stroke (AIS) immediately after or during administration of tissue plasminogen activator (tPA). Patients with AIS treated with tPA in nonuniversity hospitals frequently need transfer to tertiary care centers that can provide specialized care. AMT is a widely available mode of transport that is crucial in providing expedient and quality health care to critically ill patients while assuring high level of care during transportation. The safety of AMT of patients with AIS after or during administration of tPA has not been examined. METHODS: We performed retrospective chart review of 24 patients with AIS who were treated with intravenous tPA and transferred by helicopter to the Hospital of the University of Pennsylvania or the University of Cincinnati Hospital. The charts were reviewed for neurological complications, systemic complications, and adherence to the National Institutes of Neurological Disorders and Stroke (NINDS) protocol for AIS management. RESULTS: No major neurological or systemic complications occurred. Four patients had hypertension warranting treatment, 3 patients experienced motion sickness, 1 patient developed a transient confusional state, and 1 patient experienced minor systemic bleeding. Four NINDS protocol violations occurred, all related to blood pressure management. CONCLUSIONS: In this small series, AMT of AIS patients after thrombolysis was not associated with any major neurological or systemic complications. Flight crew education on the NINDS AIS protocol is essential in limiting the number of protocol violations. AMT of patients with AIS provides fast and safe access to tertiary centers that can provide state of the art stroke therapy.

Acute Disease↗
PubMed1999

Helicopter transfer offers a potential benefit to patients with acute stroke.

BACKGROUND AND PURPOSE: Rapid transport of patients to specialized centers is widely used in the management of myocardial infarction, trauma, and more recently, acute stroke. We evaluated the role of helicopter transportation as it relates to the availability of acute stroke therapies and patients' perceptions of care. METHODS: We reviewed records of all patients transferred to a university hospital within 24 hours of stroke onset from January 1996 to December 1997. Data were collected on demographics, neurological deficit, treatment, and outcome. In addition, a questionnaire was sent to all patients with items about perceived reasons for helicopter transfer, expected and actual treatment, outcome, and overall impression. RESULTS: Helicopter transfer was used for 73 stroke patients. Before transfer, 8 patients (11%) received tissue plasminogen activator (tPA). On arrival, no patient received tPA, 38 patients (52%) were enrolled in acute stroke studies, and 35 patients (48%) received no specific medication. All but 2 patients were managed in a specialized stroke unit. Of the 35 patients who received no specific therapy, 24 (69%) were ineligible for treatment or study enrollment owing to 1 or more exclusion criteria, but rarely (3%) because of time. Of the 45 respondents to the survey, most (84%) were transferred at the suggestion of the physician at the originating hospital because of a possible treatment that was unavailable there. Most patients (93%) believed that there was a benefit from emergent helicopter transfer to a stroke center, although 40% of respondents received no specific therapy. CONCLUSION: Interhospital transfer by air may benefit a substantial number of acute stroke patients by offering potential therapies and intensive management not available elsewhere.

Air Ambulances↗
PubMed1999

Early clinical and radiological predictors of fatal brain swelling in ischemic stroke.

BACKGROUND AND PURPOSE: Early identification of acute stroke patients at risk of fatal brain swelling is necessary to facilitate implementation of aggressive therapies. Initial clinical, laboratory, and CT characteristics that may be used as selection criteria were analyzed to determine predictors of herniation and neurological death. METHODS: Data from the placebo arm of the Lubeluzole-International-9 trial were reviewed to identify patients with fatal brain edema. Early clinical, laboratory, and radiographic parameters were evaluated in a case-control design. Initial CT scans were analyzed for early ischemic abnormalities by 2 blinded investigators. RESULTS: Twenty-three patients died from brain swelling, with minimum baseline National Institutes of Health Stroke Scale (NIHSS) scores of 20 (n=12; mean, 23.2+/-1.8) with left and 15 (n=11; mean, 17.6+/-2.2) with right hemispheric infarctions (P=0. 0001). A sample of 112 subjects with comparably severe strokes, but who did not die from brain swelling, was selected from the remaining population according to the same NIHSS scores. Among clinical and laboratory characteristics, nausea/vomiting within 24 hours after onset (odds ratio [OR], 5.1; 95% CI, 1.7 to 15.3; P=0.003) and 12-hour systolic blood pressure >/=180 mm Hg (OR, 4.2; 95% CI, 1.4 to 12.9; P=0.01) were independently associated with fatal brain swelling. Among radiographic factors, only hypodensity of >50% of the middle cerebral artery territory on initial CT scan was an independent predictor (OR, 6.1; 95% CI, 2.3 to 16.6; P=0.0004). CONCLUSIONS: Patients with baseline NIHSS score >/=20 with left or >/=15 with right hemispheric infarctions within 6 hours of symptom onset who also have nausea/vomiting or >50% middle cerebral artery territory hypodensity are at high risk for developing fatal brain swelling.

Acute Disease↗
PubMed1999

Reliability and validity of estimating the NIH stroke scale score from medical records.

BACKGROUND AND PURPOSE: The aim of our study was to determine whether the National Institutes of Health Stroke Scale (NIHSS) can be estimated retrospectively from medical records. The NIHSS is a quantitative measure of stroke-related neurological deficit with established reliability and validity for use in prospective clinical research. Recently, retrospective observational studies have estimated NIHSS scores from medical records for quantitative outcome analysis. The reliability and validity of estimation based on chart review has not been determined. METHODS: Thirty-nine patients were selected because their NIHSS scores were formally measured at admission and discharge. Handwritten notes from medical records were abstracted and NIHSS scores were estimated by 6 raters who were blinded to the actual scores. Estimated scores were compared among raters and with the actual measured scores. RESULTS: Interrater reliability was excellent, with an intraclass correlation coefficient of 0.82. Scores were well calibrated among the 6 raters. Estimated NIHSS scores closely approximated the actual scores, with a probability of 0.86 of correctly ranking a set of patients according to 5-point interval categories (as determined by the area under the receiver-operator characteristic curve). Patients with excellent outcomes (NIHSS score of </=5) could be identified with sensitivity of 0.72 and specificity of 0.89. There were no significant differences between these parameters at admission and discharge. CONCLUSIONS: For the purposes of retrospective studies of acute stroke outcome, the NIHSS can be abstracted from medical records with a high degree of reliability and validity.

Cerebrovascular Disorders↗
PubMed1998

Ischemic stroke.

Acute ischemic stroke is a neurological emergency that requires ultra-rapid intervention. Stroke teams and stroke protocols can be devised to expediate evaluation and treatment. In carefully selected patients, thrombolytic therapy offers a significant benefit but must be initialized within 3 hours of stroke onset. Emerging alternative strategies for reperfusion and neuroprotection must also be initiated during the hyperacute period. The role of more traditional therapies, such as antiplatelet agents and anticoagulants, have been better defined through several recent major clinical trials.

Anticoagulants↗
PubMed1998

Intravenous tissue plasminogen activator for acute ischemic stroke: feasibility, safety, and efficacy in the first year of clinical practice.

BACKGROUND AND PURPOSE: The feasibility, safety, and efficacy of intravenous tissue plasminogen activator (t-PA) for patients with acute ischemic stroke in clinical practice need to be assessed. METHODS: We initiated a prospective open-label study at a university hospital and two community hospitals in Houston, Tex, immediately after the publication of the National Institute of Neurological Disorders and Stroke (NINDS) t-PA study. A total of 30 patients, age 32 to 90 years, were treated with 0.9 mg/kg of intravenous t-PA (maximum dose, 90 mg) within 3 hours of acute ischemic stroke between December 1995 and December 1996. RESULTS: Six percent (6%) of all patients hospitalized with ischemic stroke received intravenous t-PA at the university hospital and 1.1% at the community hospitals. The rates of total, symptomatic, and fatal intracerebral hemorrhage were 10%, 7%, and 3%. Thirty-seven percent (37%) of patients recovered to fully independent function. The average time from stroke onset to emergency department arrival was 57 minutes; emergency department arrival to computed tomography scan 41 minutes; and computed tomography scan to administration of treatment 59 minutes. CONCLUSIONS: When treatment guidelines are carefully followed in an urban hospital setting, intravenous t-PA for acute ischemic stroke is feasible and shows safety and efficacy comparable to the results of the NINDS study.

Activities of Daily Living↗
PubMed1998

Hemopericardium and cardiac tamponade after thrombolysis for acute ischemic stroke.

Hemorrhage is the major complication of IV recombinant tissue plasminogen activator (rt-PA) treatment for stroke. We report three patients with mild or indistinct cardiac symptoms prior to thrombolysis in whom hemodynamically significant cardiac tamponade occurred after treatment with rt-PA. Acute ischemic stroke patients may have undetected myocardial or pericardial disease that may pose a risk for hemopericardium and life-threatening tamponade after treatment with rt-PA.

Aged↗
PubMed1997

Emergency identification and treatment of acute ischemic stroke.

In this review we describe the pathophysiology of cerebral ischemia and its implications for potential therapy. We summarize the results of recently completed trials of acute stroke intervention and explore some of the controversy surrounding thrombolysis for acute stroke. We also introduce the key concepts of neuroprotection and its therapeutic possibilities. Finally, we discuss the delays that may occur in the emergency evaluation and management of acute ischemic stroke and suggest some methods to expedite the process.

Brain Ischemia↗
PubMed1997

Magnetic resonance angiography demonstrates vascular healing of carotid and vertebral artery dissections.

BACKGROUND AND PURPOSE: Dissection of the carotid and vertebral arteries is most accurately diagnosed with conventional angiography. MR techniques are sensitive for detecting the abnormalities associated with dissection but may lack specificity. We hypothesized that MR may be useful for serial monitoring of dissection and may therefore guide therapy. METHODS: All patients with angiographically proven carotid and/or vertebral artery dissection from July 1994 to June 1996 were followed for a median duration of 10.5 months. Of these 29 patients (44 vessels), 18 were concurrently evaluated with MR, and a target group of 9 patients (17 vessels) was prospectively followed with MR at 3-month intervals. RESULTS: In the 18 patients with both imaging studies at baseline, angiography revealed 30 dissected vessels while MR detected 27 (90%). In the target group of 9 patients, initial MR identified 15 of the 17 dissections diagnosed with angiography. Serial MR revealed complete healing in 5 vessels, improvement in 6 vessels, no change in 4 vessels, and worsening in 2 vessels. The radiographic features most likely to resolve were stenosis and mural hematoma, while occlusion and luminal irregularity tended to persist. Late ischemic events occurred in 2 patients, both with persistent MR evidence of dissection, one while subtherapeutic on warfarin therapy and the other occurring 1 week after warfarin was discontinued. CONCLUSIONS: MR is a reliable noninvasive method for following the vascular response to treatment and may guide the course of a clinical trial comparing medical therapies for carotid and vertebral artery dissection.

Adolescent↗
PubMed1997

Magnetization transfer imaging in progressive multifocal leukoencephalopathy.

We report a patient with biopsy-proven progressive multifocal leukoencephalopathy (PML) who was serially imaged with MRI and magnetization transfer imaging. The magnetization transfer ratio (MTR) was profoundly and significantly diminished when compared with normal control subjects. The pattern of MTR was distinct from that of MS and periventricular ischemic white matter disease. Magnetization transfer imaging techniques may aid in the differential diagnosis of PML.

Aged↗
PubMed1997

Neuro-ophthalmologic aspects of aneurysms.

The visual pathways and the ocular motor cranial nerves are frequently injured by expanding cerebral aneurysms. Neuro-ophthalmologic signs and symptoms may be the only indications of an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm in the carotidophthalmic, supra clinoid carotid, internal carotid bifurcation, or anterior communicating artery distributions. Diplopia and retro-orbital pain may be warning signs that precede the discovery of a posterior communicating, basilar, or cavernous sinus aneurysm.

Acute Disease↗
PubMed1996

Nitric oxide relaxes rabbit corpus cavernosum smooth muscle via a potassium-conductive pathway.

We tested the hypothesis that acetylcholine-induced relaxation in cavernosal tissue is the result of nitric oxide production that alters K+ conductance. In the organ bath, acetylcholine- and sodium nitroprusside-induced relaxation of corpus cavernosum were significantly attenuated by tetraethylammonium. Basal [K+]i in cavernosal smooth muscle cells was 102 +/- 11 mM using a K+-sensitive fluorescent dye. Acetylcholine produced a decrease in [K+]i to 74 +/- 10 (n > 4, P < 0.05). Tetraethylammonium pretreatment blunted the acetylcholine- and sodium nitroprusside-induced decrease in [K+]i by 82%, (n > 5, P < 0.001), respectively. L-NMMA blunted the acetylcholine- and sodium nitroprusside-induced fall in [K+]i by 93% and 83% (n > 4, P < 0.001), respectively. These data suggest that acetylcholine-mediated cavernosal smooth muscle cells relaxation occurs through nitric oxide release with activation of K+ conductance.

Acetylcholine↗
PubMed1996

Cavernous sinus syndrome in Hodgkin's disease.

Hodgkin's disease has not been reported to produce an isolated cavernous sinus syndrome, although this phenomenon is well-described in non-Hodgkin's lymphoma. We review the 16 cases of cavernous sinus syndrome caused by non-Hodgkin's lymphoma and report two patients with Hodgkin's disease in clinical remission who developed recurrent disease in the cavernous sinus. MRI revealed a mass lesion in the left cavernous sinus in each patient. Corticosteroids and radiation therapy were effective palliative measures. In both patients, recurrence in the cavernous sinus preceded other systemic evidence of recurrent Hodgkin's disease.

Adult↗