Stacy Chu

Measurement of blood perfusion in spinal metastases with dynamic contrast-enhanced magnetic resonance imaging: evaluation of tumor response to radiation therapy.

Study Design. This was a retrospective study focusing on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to assess treatment response in patients with spinal metastases. Objective. To demonstrate DCE-MRI changes before and after radiation treatment and correlating with other imaging and clinical findings. Summary of Background Data. Currently, conventional imaging is limited in evaluating early treatment success or failure, which impacts patient care. Methods. Consecutive patients with known spinal metastases underwent DCE-MRI before and after radiotherapy. Perfusion data on 19 lesions were analyzed. Radiotherapy was classified as success (n = 17) or failure (n = 2) on the basis of evidence of tumor contraction (n = 4), negative positron emission tomography (n = 2), or stability for more than 11 months (n = 11). Perfusion parameters blood plasma volume (Vp), time-dependent leakage (Ktrans), area under the curve, and peak enhancement were derived from the signal intensity-time curves and changes in parameter values from pre- to post-treatment were calculated. Curve morphologies were also qualitatively assessed in 13 pre- and 13 post-treatment scans. Results. Vp was the strongest predictor of treatment response (false-positive rate = 9.38 × 10−9 and false-negative rate = 0.055). All successfully treated lesions showed decreases in Vp, and the 2 treatment failures showed drastic increases in Vp. Changes in area under the curve and peak enhancement demonstrated similar relationships to the observed treatment response, whereas changes in Ktrans showed no significant relationship. Signal intensity curve morphologies also demonstrated specificity for active disease (11 of 13) and treated disease (8 of 13). Conclusion. Changes in perfusion, particularly Vp, reflect tumor responses to radiotherapy in spinal bone metastases. These changes were able to predict positive outcomes earlier than 6 months after treatment in 16 of 17 tumors. The ability of DCE-MRI to detect early treatment response has the potential to improve patient care and outcome.

Temporal relationship between infective endocarditis and stroke.

Objective: Stroke frequently complicates infective endocarditis (IE). However, the temporal relationship between these diseases is uncertain. Methods: We performed a retrospective study of adult patients hospitalized for IE between July 1, 2007, and June 30, 2011, at nonfederal acute care hospitals in California. Previously validated diagnosis codes were used to identify the primary composite outcome of ischemic or hemorrhagic stroke during discrete 1-month periods from 6 months before to 6 months after the diagnosis of IE. The odds of stroke in these periods were compared with the odds of stroke in the corresponding 1-month period 2 years earlier, which was considered the baseline risk of stroke. Results: Among 17,926 patients with IE, 2,275 strokes occurred within the 12-month period surrounding the diagnosis of IE. The risk of stroke was highest in the month after diagnosis of IE (1,640 vs 17 strokes in the corresponding month 2 years prior). This equaled an absolute risk increase of 9.1% (95% confidence interval 8.6%–9.5%) and an odds ratio of 96.5 (95% confidence interval 60.1–166.0). Stroke risk was significantly increased beginning 4 months before the diagnosis of IE and lasting 5 months afterward. Similar temporal patterns were seen when ischemic and hemorrhagic strokes were considered separately. Conclusions: The association between IE and stroke persists for longer than previously reported. Most diagnoses of stroke and IE are made close together in time, but a period of heightened stroke risk becomes apparent several months before the diagnosis of IE and lasts for several months afterward.

Cerebral Microhemorrhages and Meningeal Siderosis in Infective Endocarditis

Objective: Patients with infective endocarditis (IE) frequently experience cerebral insults, and neurological involvement in IE has been reported to herald a worse prognosis. In this manuscript, we describe a distinctive pattern of findings on susceptibility-weighted imaging (SWI) sequences in subjects with IE. Methods: Patients with IE who underwent SWI MRI at an academic hospital from 2009 to 2014 were retrospectively analyzed. The pattern of findings was compared to SWI findings in groups of subjects with cerebral amyloid angiopathy (CAA) or severe hypertension. Results: Sixty-six subjects with IE were included; 64 (94%) had microhemorrhages and the average number per patient was 21.5. In 11 (17%) patients, microhemorrhages were the only neuroimaging abnormality. The majority of microhemorrhages were between 1 and 3 mm. In a direct comparison of gradient-echo T2* (GRE-T2*) and SWI, many microhemorrhages in this size range were not detected by GRE-T2*. Microhemorrhages in IE involved every part of the brain with a significant predilection for the cerebellum. This pattern was distinct from that seen in hypertension or CAA. Small subarachnoid hemorrhage or meningeal siderosis were also frequently detected in IE, but were not associated with mycotic aneurysms. Interpretation: SWI is a sensitive diagnostic technique for detecting infectious cerebral angiopathy in subjects with IE, producing a pattern of microhemorrhages that were distinct from other common microangiopathies.

Predicting Outcome for Intracerebral Hemorrhage Patients: Current Tools and Their Limitations

Accurate outcome prognostication is critical to the management of patients with primary or spontaneous intracerebral hemorrhage (ICH). Prognostication may guide the decision to pursue aggressive acute management or to plan proper goals of care for patients who will likely suffer long-term severe disability. In particular, early predictions of poor outcome for ICH patients routinely influence discussions with surrogate decision makers to pursue do-not-resuscitate orders or comfort care, practices that may often be appropriate, but that are at risk for self-fulfilling prophecies. The authors review the literature pertaining to these concepts. Currently available baseline severity scores, with a focus on the ICH Score, are summarized and compared, with a discussion of the limitations and biases of such clinical scales derived from observational cohorts. New research on the accuracy of the subjective early clinical judgment of physicians and nurses for predicting ICH functional outcome as it compares to that of baseline severity scores, is also summarized.

Decompressive Craniectomy in Neurocritical Care

Opinion statementDecompressive craniectomy (DC) involves the removal of a portion of the skull in the setting of life threatening brain edema or potentially uncontrollable intracranial pressures. Often performed on an emergent basis, evaluation and arrangement for DC should be swift and decisive. However, the evidence base for DC in the wide range of conditions for which it is currently performed is still developing. The procedure is associated with a number of complications and ethical considerations; thus, its place in contemporary practice remains controversial. While randomized trials conducted in the last decade have provided valuable data on the indications, eligibility criteria, and outcomes for DC in the treatment of traumatic brain injury and malignant middle cerebral artery infarction, important outstanding issues continue to complicate the decision to pursue DC on an individual case basis and in the number of other clinical settings presenting with brain edema and intracranial hypertension. In this review, we present the existing evidence and remaining questions regarding DC in various neurologic conditions including traumatic brain injury, ischemic stroke, subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, encephalitis, and others. We also discuss perioperative considerations and ethical issues likely to be encountered by clinicians caring for patients and families who are considering or have undergone DC.

Readmission for Infective Endocarditis After Ischemic Stroke or Transient Ischemic Attack

Background and Purpose: Providers vary in their thresholds for obtaining blood cultures in patients with ischemic stroke or transient ischemic attack (TIA). We assessed the rate of missed diagnoses of infective endocarditis (IE) in patients discharged with stroke or TIA before blood culture results could have been available. Methods: Using administrative claims data, we performed a retrospective cohort study of all patients discharged from nonfederal California emergency departments or acute care hospitals from 2005 through 2011 with stroke (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 433.x1, 434.x1, or 436 in any position) or TIA (ICD-9-CM code 435 in the primary diagnosis position). We excluded patients with a length of stay >2 days to focus on those discharged before conclusive blood culture results could have been available. Our outcome was hospitalization within 14 days with a new diagnosis of IE (ICD-9-CM codes 391.1 or 421.x in any position). Results: Among 173 966 eligible patients, 24 were subsequently hospitalized for IE—a readmission rate of 1.4 per 10 000 (95% confidence interval [CI], 0.8-1.9 per 10 000). Multiple logistic regression identified the following potential associations with readmission: prosthetic valve: odds ratio (OR), 15.8 (95% CI, 1.9-129.0); other valvular disease: OR, 1.5 (95% CI, 0.2-10.8); urinary tract infection: OR, 3.5 (95% CI, 1.0-12.3; P = .05). Conclusions: In patients with acute cerebral ischemia discharged before blood culture results could have been available, the rate of subsequent IE was negligible. These findings argue against the liberal use of blood cultures for the routine evaluation of stroke or TIA.

Evolution of blood pressure management in acute intracerebral hemorrhage

Intracerebral hemorrhage (ICH) remains a prevalent and severe cause of death and disability worldwide. Control of the hypertensive response in acute ICH has been a mainstay of ICH management, yet the optimal approaches and the yield of recommended strategies have been difficult to establish despite a large body of literature. Over the years, theoretical and observed risks and benefits of intensive blood pressure reduction in ICH have been studied in the form of animal models, radiographic studies, and two recent large, randomized patient trials. In this article, we review the historical and developing data and discuss remaining questions surrounding blood pressure management in acute ICH.