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Dive into the research topics where Wendy A. Cohen is active.

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Featured researches published by Wendy A. Cohen.


Neurology | 2001

Withdrawal of support in intracerebral hemorrhage may lead to self-fulfilling prophecies

Kyra J. Becker; Alexander B. Baxter; Wendy A. Cohen; H. M. Bybee; David L. Tirschwell; D. W. Newell; H. R. Winn; W. T. Longstreth

Background: Withdrawal of support in patients with severe brain injury invariably leads to death. Preconceived notions about futility of care in patients with intracerebral hemorrhage (ICH) may prompt withdrawal of support, and modeling outcome in patient populations in whom withdrawal of support occurs may lead to self-fulfilling prophecies. Methods: Subjects included consecutive patients with supratentorial ICH. Radiographic characteristics of the hemorrhage, clinical variables, and neurologic outcome were assessed. Attitudes about futility of care were examined among members of the departments of neurology and neurologic surgery through a written survey and case presentations. Results: There were 87 patients with supratentorial ICH; overall mortality was 34.5% (30/87). Mortality was 66.7% (18/27) in patients with Glasgow Coma Score ≤8 and ICH volume >60 cm3. Medical support was withdrawn in 76.7% (23/30) of patients who died. Inclusion of a variable to account for the withdrawal of support in a model predicting outcome negated the predictive value of all other variables. Patients undergoing surgical decompression were unlikely to have support withdrawn, and surgery was less likely to be performed in older patients (p < 0.01) and patients with left hemispheric hemorrhage (p = 0.04). Survey results suggested that practitioners tend to be overly pessimistic in prognosticating outcome based upon data available at the time of presentation. Conclusions: The most important prognostic variable in determining outcome after ICH is the level of medical support provided. Withdrawal of support in patients felt likely to have a “poor outcome” biases predictive models and leads to self-fulfilling prophecies. Our data show that individual patients in traditionally “poor outcome” categories can have a reasonable neurologic outcome when treated aggressively.


Stroke | 1999

Extravasation of Radiographic Contrast Is an Independent Predictor of Death in Primary Intracerebral Hemorrhage

Kyra J. Becker; Alexander B. Baxter; Heather M. Bybee; David L. Tirschwell; Tamer Abouelsaad; Wendy A. Cohen

BACKGROUND AND PURPOSE Hematomas that enlarge following presentation with primary intracerebral hemorrhage (ICH) are associated with increased mortality, but the mechanisms of hematoma enlargement are poorly understood. We interpreted the presence of contrast extravasation into the hematoma after CT angiography (CTA) as evidence of ongoing hemorrhage and sought to identify the clinical significance of contrast extravasation as well as factors associated with the risk of extravasation. METHODS We reviewed the clinical records and radiographic studies of all patients with intracranial hemorrhage undergoing CTA from 1994 to 1997. Only patients with primary ICH were included in this study. Univariate and multivariate logistic regression analyses were performed to determine the associations between clinical and radiological variables and the risk of hospital death or contrast extravasation. RESULTS Data were available for 113 patients. Contrast extravasation was seen in 46% of patients at the time of CTA, and the presence of contrast extravasation was associated with increased fatality: 63.5% versus 16.4% in patients without extravasation (P=0.011). There was a trend toward a shorter time (median+/-SD) from symptom onset to CTA in patients with extravasation (4.6+/-19 hours) than in patients with no evidence of extravasation (6.6+/-28 hours; P=0.065). Multivariate analysis revealed that hematoma size (P=0.022), Glasgow Coma Scale (GCS) score (P=0.016), extravasation of contrast (P=0.006), infratentorial ICH (P=0.014), and lack of surgery (P<0.001) were independently associated with hospital death. Variables independently associated with contrast extravasation were hematoma size (P=0.024), MABP >120 mm Hg (P=0.012), and GCS score of </=8 (P<0.005). CONCLUSIONS Contrast extravasation into the hematoma after ICH is associated with increased fatality. The risk of contrast extravasation is increased with extreme hypertension, depressed consciousness, and large hemorrhages. If contrast extravasation represents ongoing hemorrhage, the findings in this study may have implications for therapy of ICH, particularly with regard to blood pressure management.


Annals of Emergency Medicine | 1994

Cranial Computed Tomography Scans in Children After Minimal Head Injury With Loss of Consciousness

Robert L. Davis; Neil Mullen; Martin Makela; James A. Taylor; Wendy A. Cohen; Frederick P. Rivara

STUDY OBJECTIVE To assess the need for cranial computed tomography (CT) in the emergency department evaluation of children with Glasgow Coma Scale (GCS) score of 15 after mild head injury with loss of consciousness. DESIGN Retrospective case series of children aged 2 to 17 years with documented loss of consciousness after head injury from January 1, 1988, to July 31, 1992. All had a GCS score of 15 on initial ED evaluation and were further categorized according to physical examination findings, neurologic status, and whether the head injury was isolated or nonisolated. Recursive partitioning was used to identify variables predictive of the presence and absence of intracranial hemorrhage. SETTING ED in two settings: a regional tertiary care trauma center and a community childrens hospital. RESULTS Of the 185 patients who met study criteria, 17 had evidence of depressed or basilar skull fractures on physical examination or had a ventriculoperitoneal shunt in place before head injury. In the remaining 168 patients, recursive partitioning identified two variables (neurologic status and head injury type) associated with intracranial hemorrhage. Overall, 12 of 168 patients (7%) had intracranial bleeding. However, none of the 49 neurologically normal children with isolated head injury had intracranial hemorrhage (95% confidence interval, 0.0 to 6.0). CONCLUSION The prevalence of intracranial hemorrhage in children with mild closed-head injury appears to vary with the presence of neurologic abnormalities and other noncranial injuries. After isolated head injury with loss of consciousness, children older than 2 years who are neurologically normal and without signs of depressed or basilar skull fracture may be discharged home from the ED without a cranial CT scan after careful physical examination alone.


Neurosurgery | 1998

Risks and Benefits of Diagnostic Angiography after Aneurysm Surgery: A Retrospective Analysis of 597 Studies

Peter D. Le Roux; J. Paul Elliott; Joseph M. Eskridge; Wendy A. Cohen; H. Richard Winn

INTRODUCTION Cerebral angiography performed after aneurysm surgery can identify causes of morbidity and mortality that may be corrected. The risks and benefits of angiography that is performed after aneurysm surgery, however, have not been clearly defined. We therefore reviewed our experience with postoperative angiography to determine its dangers and benefits. METHODS During 10 years, 543 consecutive patients received treatment for cerebral aneurysms. A retrospective analysis of 597 diagnostic angiograms obtained after aneurysm surgery for 494 of these patients was performed. RESULTS Catheter-induced vessel spasm and dissection, occurring most frequently in the internal carotid artery, were observed in seven (1.2%) and six (1%) studies, respectively. No angiography-associated strokes were identified. No association between age, smoking, hypertension, blood pressure, atherosclerosis, or severe vasospasm and angiographic complications was observed. Aneurysm remnants were identified in 36 (5.7%) of the 637 aneurysms that were surgically treated. Atherosclerosis (P < 0.01) or multiple clip applications (P < 0.01) were significantly associated with aneurysm remnants. Angiographic vessel occlusion was observed in 28 (5.7%) patients and resulted in stroke in 14 of these patients. Vessel occlusion was significantly associated with increasing aneurysm size (P < 0.001), atherosclerosis (P < 0.001), temporary clips (P < 0.001), multiple clips (P=0.03), multiple clip applications (P=0.001), and a new postoperative neurological deficit (P=0.002). Severe vasospasm and newly identified aneurysms were observed in 51 and 16 patients, respectively. CONCLUSION Angiography after aneurysm surgery is safe and can be routinely performed. Angiography after aneurysm surgery should be particularly considered for patients with large aneurysms or cerebrovascular atherosclerosis and for those who develop new postoperative neurological deficits.


Neurosurgery | 2006

DYNAMIC PERFUSION COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF CEREBRAL VASOSPASM

Gill E. Sviri; Gavin W. Britz; David H. Lewis; David W. Newell; M. Zaaroor; Wendy A. Cohen

OBJECTIVE:The aim of the study was to correlate absolute cerebral blood flow (CBF) and mean transient time (MTT) measured by dynamic perfusion computed tomographic (PCT) scanning with the clinical course, vasospasm severity, and perfusion abnormality in patients with cerebral vasospasm after aneurysmal subarachnoid hemorrhage. METHODS:Forty-six patients with vasospasm after aneurysmal subarachnoid hemorrhage had 63 PCT images obtained during the course of vasospasm. All patients had transcranial Doppler measurements, 28 had an angiography study, and 38 had 99mTc single-photon emission computed tomographic imaging performed in conjunction with the PCT scan. RESULTS:The average minimal regional CBF (rCBF) and maximal regional MTT in patients with delayed ischemic deficit were significantly different in comparison with patients without delayed ischemic deficit (22.6 ± 11.2 cm3/100 g/min versus 45.2 ± 21.3 cm3/100 g/min, P < 0.001; 7.3 ± 2.5 s versus 3.3 ± 1.7 s, P < 0.05). The average minimal rCBF and maximal regional MTT in middle cerebral vascular territories in which severe middle cerebral artery vasospasm was measured by transcranial Doppler were significantly different in comparison with middle cerebral vascular territories in which no vasospasm was measured by transcranial Doppler (29.3 ± 1.7 cm3/100 g/min versus 54.1 ± 25.4 cm3/100 g/min, P < 0.01; 4.5 ± 2.4 s versus 2.8 ± 1.1 P < 0.001). The average minimal rCBF and maximal rMTT in vascular territories with estimated severe hypoperfusion on single-photon emission computed tomographic imaging were significantly different in comparison with values in vascular territories with unimpaired perfusion as estimated by single-photon emission computed tomographic imaging (18.9 ± 6.9 cm3/100 g/min versus 54.2 ± 23.4 cm3/100 g/min, P < 0.001, 0.001; 8.1 ± 1.9 s versus 2.5 ± 0.39 s, P < 0.001). CONCLUSION:The present study suggests that, in general, quantitative measurements of rCBF and regional MTT by PCT show high concordance rates with the clinical course, vasospasm severity, and hemodynamic impairments in patients with cerebral vasospasm aneurysmal subarachnoid hemorrhage.


European Journal of Radiology | 2003

Evidence-based approach to using CT in spinal trauma

Frederick A. Mann; Wendy A. Cohen; Ken F. Linnau; Danial K. Hallam; C. Craig Blackmore

Computed tomography has revolutionized the diagnosis and treatment planning of the acutely injured spine. In the cervical spine, its appropriate use can improve outcome and save money. Although there are no clinical prediction rules validated outside of the cervical spine, these proven capabilities have been extrapolated to the thoracolumbar spine.


Journal of Acquired Immune Deficiency Syndromes | 1992

Central nervous system manifestations in human immunodeficiency virus infection without AIDS.

Ann C. Collier; Christina M. Marra; Robert W. Coombs; Claypoole K; Wendy A. Cohen; Longstreth Wt; Townes Bd; Ken Maravilla; Cathy W. Critchlow; Victory Murphy

To characterize neurological and neuropsychological findings associated with human immunodeficiency virus type-I (HIV) infection, 77 seropositive homosexual or bisexual males with no or minor symptoms of HIV were compared prospectively to 44 HIV seronegative men by observers blinded to serological status of the subjects. Neurological symptoms and examination findings were not significantly different between seropositives and seronegatives except for cranial nerve findings, predominately mild hearing impairment. Mean performance scores for a 15-test neuropsychological battery were within an unimpaired range for both groups, although for five tests, mean scores were significantly poorer in seropositives. After adjustment for vocabulary score, and demographic and psychosocial variables, the mean score of seropositives was significantly worse only for the Benton Visual Retention Test. Magnetic resonance (MR) images of brain were abnormal in 14 (27%) of 52 seropositives and one of 10 seronegatives (value was not significant). HIV was isolated from cerebrospinal fluid (CSF) in 31 (61%) of 51 seropositives. The only clinical or laboratory difference between CSF culture positives and negatives was a higher CSF immunoglobulin synthesis rate in the former subjects (medians of 10.3 versus 0.1 mg/day; p = 0.03). An additional 13 seropositive subjects had immunologic evidence of central nervous system HIV infection, defined by a serum-to-CSF HIV antibody ratio of <5.5. Intracranial abnormalities on MR imaging were associated with CSF immunologic responses to HIV. Nervous system involvement occurred in the vast majority of men with early HIV infection, but clinically significant impairment was uncommon.


Journal of The American College of Radiology | 2015

Toward Quantifying the Prevalence, Severity, and Cost Associated With Patient Motion During Clinical MR Examinations

Jalal B. Andre; Brian W. Bresnahan; Mahmud Mossa-Basha; Michael N. Hoff; C. Patrick Smith; Yoshimi Anzai; Wendy A. Cohen

PURPOSE To assess the prevalence, severity, and cost estimates associated with motion artifacts identified on clinical MR examinations, with a focus on the neuroaxis. METHODS A retrospective review of 1 randomly selected full calendar week of MR examinations (April 2014) was conducted for the detection of significant motion artifacts in examinations performed at a single institution on 3 different MR scanners. A base-case cost estimate was computed from recently available institutional data, and correlated with sequence time and severity of motion artifacts. RESULTS A total of 192 completed clinical examinations were reviewed. Significant motion artifacts were identified on sequences in 7.5% of outpatient and 29.4% of inpatient and/or emergency department MR examinations. The prevalence of repeat sequences was 19.8% of total MRI examinations. The base-case cost estimate yielded a potential cost to the hospital of


Journal of The American College of Radiology | 2011

Variation in Pediatric Head CT Imaging Protocols in Washington State

Kalpana M. Kanal; Monica S. Vavilala; Colin Raelson; Abhishek Mohan; Wendy A. Cohen; Jeffrey G. Jarvik; Frederick P. Rivara; Brent K. Stewart

592 per hour in lost revenue due to motion artifacts. Potential institutional average costs borne (revenue forgone) of approximately


American Journal of Roentgenology | 2009

Radiation Dose and Excess Risk of Cancer in Children Undergoing Neuroangiography

Colin Raelson; Kalpana M. Kanal; Monica S. Vavilala; Frederick P. Rivara; Louis J. Kim; Brent K. Stewart; Wendy A. Cohen

115,000 per scanner per year may affect hospitals, owing to motion artifacts (univariate sensitivity analysis suggested a lower bound of

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David H. Lewis

University of Washington

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H. Richard Winn

Icahn School of Medicine at Mount Sinai

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Ken F. Linnau

University of Washington

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