Trends in Utilization of Magnetic Resonance Imaging for Stroke Patients With Cardiac Rhythm Devices.

Background and Purpose: Magnetic resonance imaging (MRI) is safe for most patients with cardiovascular implantable electronic devices (CIEDs). However, patients presenting with acute ischemic stroke or transient ischemic attack (AIS/TIA) who have CIEDs may undergo MRI less frequently than patients without devices. We assessed contemporary use of MRI for patients with AIS/TIA and the effect of a recent coverage revision by the Center for Medicare and Medicaid Services (CMS) on MRI utilization. Methods: Using Optum® claims data from January 2012 to June 2019, we performed an interrupted time series analysis of MRI utilization during AIS/TIA hospitalizations with the April 2018 CMS coverage revision serving as the intervention. For patients treated after the coverage revision, we used multivariable logistic regression to determine the association between lack of CIED and MRI utilization for AIS/TIA. Results: We identified 417,899 patient hospitalizations for AIS/TIA, of which 30,425 (7%) had a CIED present (CIED vs non-CIED patients: age 77.6 ± 9.8 vs 72.7 ± 12.3 years; 45.5% vs 54.3% female). From 2012 to 2019, annual MRI utilization increased from 3% to 20% for CIED patients and 58% to 66% for non-CIED patients. The CMS coverage revision was associated with a 4.2% absolute additional increase in MRI utilization for CIED patients. Non-CIED patients treated after the CMS coverage revision were substantially more likely than CIED patients to undergo MRI (adjusted OR 6.7, 95% CI: 6.3-7.1, P<.001). Conclusions: MRI utilization has increased for stroke patients with CIEDs but remains far lower than in similar patients without devices.

Cryptogenic new-onset refractory status epilepticus (NORSE) following blood transfusion in a patient with severe anemia.

New-onset refractory status epilepticus (NORSE) is a rare neurological emergency in which a patient without prior seizure disorder develops seemingly unprovoked status epilepticus refractory to treatment. We report the case of a middle-aged woman who developed NORSE after receiving multiple blood transfusions for subacute blood loss anemia secondary to menorrhagia. Although the mechanism is unclear, we propose that sudden changes in blood viscosity and vasogenic tone resulted in cortical edema and irritation. Although seizures have been documented in patients who undergo blood transfusion and develop posterior reversible encephalopathy syndrome (PRES), there was no radiographic evidence of PRES in this case. This is the first reported case of cryptogenic NORSE following blood transfusion.

Hypoperfusion Intensity Ratio Predicts Malignant Edema and Functional Outcome in Large-Vessel Occlusive Stroke with Poor Revascularization.

BACKGROUND AND OBJECTIVE: Malignant cerebral edema (MCE) is a well-known complication in patients with acute ischemic stroke with core infarcts ≥ 80 mL caused by large-vessel occlusions. MCE can also develop in patients with smaller infarcts with moderate -to-large volume of tissue at risk who do not achieve successful revascularization with endovascular thrombectomy (ET). Features that predict the development of MCE in this population are not well-described. We aim to identify predictors of MCE and 90-day functional outcome in stroke patients with an anterior circulation large vessel occlusion (LVO) and a < 80 mL ischemic core who do not achieve complete reperfusion. METHODS: We reviewed our institutional stroke registry and included patients who achieved unsuccessful revascularization, mTICI 0-2a, after ET and whose baseline imaging was notable for a core infarct < 80 mL, a Tmax > 6 s volume ≥ 80 mL, and a mismatch ratio ≥ 1.8. MCE was defined as ≥ 5 mm of midline shift on follow-up imaging, obtained 6-48 h after the pre-ET perfusion scan. RESULTS: Thirty-six patients met inclusion criteria. Unadjusted analysis demonstrated that younger age, higher systolic blood pressure, larger core volume, and higher hypoperfusion intensity ratio (HIR) were associated with MCE (all p < 0.02). In multivariate logistic regression analysis, age, HIR, and core infarct volume were independent predictors of MCE. The optimal HIR threshold to predict MCE was ≥ 0.54 (OR 14.7, 95% CI 2.4-78.0, p = 0.003). HIR was also associated with 3-month mRS (HIR ≥ 0.54 for mRS of 3-6: OR 10.8, 95% CI 1.9-44.0, p = 0.02). CONCLUSIONS: Younger age, larger core infarct volume, and higher HIR are predictive of MCE in patients with anterior circulation LVO, moderate-to-large tissue at risk, and suboptimal revascularization. HIR is correlated with three-month functional outcomes.

Tilt-Corrected Region Boundaries May Enhance the Alberta Stroke Program Early Computed Tomography Score for Less Experienced Raters.

BACKGROUND: The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is widely used to quantify early ischemic changes in the anterior circulation but has limited inter-rater reliability. AIMS: We investigated whether application of 3-dimensional boundaries outlining the ASPECTS regions improves inter-rater reliability and accuracy. METHODS: We included all patients from our DEFUSE 2 database who had a pretreatment noncontrast computed tomography scan (NCCT) of acceptable quality. Six raters (2 neuroradiologists, 2 vascular neurologists, and 2 neurology residents) scored ASPECTS of each NCCT without ("CT-native") and with the superimposed boundary template ("CT-template"). Gold-standard ASPECTS were generated by the 2 neuroradiologists through joint adjudication. Inter-rater reliability and accuracy were assessed using the intraclass correlation coefficient (ICC) for full-scale agreements and Gwet's AC1 for dichotomized (ASPECTS 0-6 vs 7-10) agreements. RESULTS: Eighty-two patients were included. Inter-rater reliability improved with higher training level for both CT-native (ICC = .15, .31, .54 for residents, neurologists, and radiologists, respectively) and CT-template (ICC = .18, .33, .56). Use of the boundary template improved correlation with the gold-standard for one resident on full-scale agreement (ICC increased from .01 to .31, P = .01) and another resident on dichotomized agreement (AC1 increased from .36 to .64, P = .01), but resulted in no difference for other raters. The template did not improve ICC between raters of the same training level. CONCLUSIONS: Inter-rater reliability of ASPECTS improves with physician training level. Standardized display of ASPECTS region boundaries on NCCT does not improve inter-rater reliability but may improve accuracy for some less experienced raters.

Gastrointestinal dysfunction in postural tachycardia syndrome.

BACKGROUND: Postural tachycardia syndrome (POTS) is a dysautonomia defined by an exaggerated increase in heart rate upon changing posture. It is associated with disturbances involving multiple organ systems, including neurologic, dermatologic, and gastrointestinal (GI) symptoms. Previous studies identified GI complaints in these patients and showed gastric emptying and electrical activity abnormalities. However, the full spectrum of GI symptoms and their impact on quality of life remains unclear. METHODS: A 30-question survey of GI symptoms was collected from 28 patients with POTS seen in the Boston Medical Center Autonomic Clinic. Answers were recorded on a Likert rating scale. Symptoms were positive if patients answered "strongly agree" or "agree" and negative if they answered "strongly disagree" or "disagree." Responses were collected and analyzed. RESULTS: The most commonly reported GI symptoms were nausea (86%), irregular bowel movements (71%), abdominal pain (70%), and constipation (70%). Additionally, 82% of patients reported having GI symptoms more than once per week, and 71% reported having seen a GI specialist, and symptoms did not improve with changes in position. Twelve patients had undergone a gastric emptying study, and six of these patients reported receiving a diagnosis of gastroparesis or delayed gastric emptying. CONCLUSIONS: GI disturbances are common, frequent, and prolonged in patients with POTS, likely impacting quality of life. Given the importance of the enteric nervous system to normal GI functioning, the same autonomic impairment leading to POTS may result in abnormal gut motility and ultimately subjective GI discomfort.

A survey-based analysis of symptoms in patients with postural orthostatic tachycardia syndrome.

Postural orthostatic tachycardia syndrome (POTS) is a type of dysautonomia seen most commonly in young women and children. It is defined as an increase in heart rate of 30 beats per minute (bpm) or more within 10 minutes of standing in adults, or by 40 bpm or more in children in the absence of orthostatic hypotension. In addition to typical autonomic symptoms, POTS patients report a wide range of subjective complaints in multiple organ systems, though the exact frequencies are unclear. To address the symptom frequency, we had 39 patients with POTS at our institution complete an intake form consisting of a list of 37 symptoms. The most frequently reported symptoms included palpitations, lightheadedness, and headache, although sleep disturbances, gastrointestinal complaints, sensitivity to temperature, and rash were also common.