[Show abstract][Hide abstract] ABSTRACT: The 2010 American Academy of Neurology guideline for the diagnosis of acute ischemic stroke recommends MRI with diffusion weighted imaging (DWI) over noncontrast head CT. No studies have evaluated the influence of imaging choice on patient outcome. We sought to evaluate the variables that influenced one-year outcomes of stroke and TIA patients, including the type of imaging utilized.
Patients were identified from a prospectively collected stroke and TIA database at a single primary stroke center during a one-year period. Data were abstracted from patient electronic medical records. The primary outcome measure was death, myocardial infarction, or recurrent stroke within the following year. Secondary outcome measures included predictors of getting an MRI study.
727 consecutive patients with a discharge diagnosis of stroke or TIA were identified (616 and 111 respectively); 536 had CT and MRI, 161 had CT alone, 29 had MRI alone, and one had no neuroimaging. On multiple logistic regression analysis, there were no differences in primary or secondary outcome measures among different imaging strategies. Predictors of the primary outcome measure included age and NIHSS, while performance of a CT angiogram (CTA) predicted a decreased odds of death, stroke, or MI. The strongest predictor of having an MRI was admission to a stroke unit.
These results suggest that long-term (one-year) patient outcomes may not be influenced by imaging strategy. Performance of a CTA was protective in this cohort. A randomized trial of different imaging modalities should be considered.
[Show abstract][Hide abstract] ABSTRACT: Cigarette smoking is the most common preventable cause of morbidity and mortality in developed countries. Smokers with brain damage involving the insula are 136 times more likely to stop smoking immediately after the injury than smokers with brain injuries elsewhere.
A 58-year-old woman with a history of hypertension, coronary artery disease, and 40 pack-year history (1 pack per day for 40 years) of smoking presented with sudden confusion and word-finding difficulty. Initial neurological examination showed disorientation to time, difficulty following commands, and perseveration. No focal motor, sensory, or visual deficit was present. Noncontrast head CT showed a new insular ischemic stroke. Five months after discharge from the hospital, the patient reported that she had not resumed smoking cigarettes, had not used any smoking cessation aids, and had not intended to stop smoking. Her daughter reported that "it was as if she forgot that she used to smoke."
Unintentional abrupt smoking cessation serves as a unique lesion localizer. Insular hypocretin transmission plays a permissive role in the motivational properties of nicotine in animals. Whether the mechanism of smoking cessation relates to hypocretin secretion has yet to be proven in humans.
Journal of neuroimaging: official journal of the American Society of Neuroimaging 04/2011; 21(2):e169-70. · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: MR imaging of the brain has significant potential in the early detection of neurodegenerative disorders such as AD. The purpose of this work was to determine if perfusion MR imaging can be used to separate AD from normal cognition in individual subjects. We investigated the diagnostic utility of perfusion MR imaging for early detection of AD compared with structural imaging.
Data were analyzed from 32 participants in the institutional review board-approved CHS-CS: 19 cognitively healthy individuals and 13 with clinically adjudicated AD. All subjects underwent structural T1-weighted SGPR and CASL MR imaging. Four readers with varying experience separately rated each CASL and SPGR scan finding as normal or abnormal on the basis of standardized qualitative diagnostic criteria for observed perfusion abnormalities on CASL or volume loss on SPGR and rated the confidence in their evaluation.
Inter-rater reliability was superior in CASL (kappa = 0.7 in experienced readers) compared with SPGR (kappa = 0.17). CASL MR imaging had the highest sensitivity (85%) and accuracy (70%). Frontal lobe CASL findings increased sensitivity to 88% and accuracy to 79%. Fifty-seven percent of false-positive readings with CASL were in controls with cognitive decline or instability within 5 years. Three of the 4 readers revealed a statistically significant relationship between confidence and correct classification when using CASL.
Readers were able to separate individuals with mild AD from those with normal cognition with high sensitivity by using CASL but not volumetric MR imaging. This initial experience suggests that CASL MR imaging may be a useful technique for detecting AD.
American Journal of Neuroradiology 05/2010; 31(5):847-55. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES.
Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg).
The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%).
Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.
American Journal of Neuroradiology 05/2009; 30(7):1371-9. · 3.17 Impact Factor