Section Editor
®
WriteClick Editor’s Choice
Robert C. Griggs, MD
Editors’ Note: Commenting on “Prehospital stroke scales in urban environments: A systematic review,” Rudd et al. cite methodologic concerns. Author Brandler explains the rationale. Totah asks how patients in “Peripheral pulse measurement after ischemic stroke: A feasibility study” measured the pulse rhythm. Authors Kallmu¨nzer and Ko¨hrmann respond. Jacques delves into the pathophysiology of multiple sclerosis and makes suggestions for classification that are in agreement with the article by Lublin et al. —Chafic Karam, MD, and Robert C. Griggs, MD
PREHOSPITAL STROKE SCALES IN URBAN ENVIRONMENTS: A SYSTEMATIC REVIEW
Matthew P. Rudd, Christopher I. Price, Newcastle upon Tyne; Gary A. Ford, Oxford, UK: Brandler et al.1 systematically reviewed stroke recognition instruments, but did not emphasize the dependence of specificity of the boundaries around the population defining the denominator. A specificity figure representing all patients in need of emergency medical services would lead to inconsistency between studies. It is also misleading because paramedics would not use stroke recognition instruments in most clinical scenarios. Positive and negative predictive values are less influenced by clinical settings and are better reflections of instrument characteristics. It is important that clinicians appreciate methodologic influences when selecting clinical instruments and use of specificity inflates the value of the Los Angeles Prehospital Stroke Screen (LAPSS). The review did not adequately reflect that stroke recognition instruments were developed for 2 purposes: to identify most stroke patients (e.g., Face Arm Speech Test2) and to identify a subpopulation likely to be suitable for thrombolysis and other acute stroke interventions (e.g., LAPSS3). The addition of thrombolysis eligibility favors specificity and false-negative cases will be harder to register compared with an instrument that seeks to identify all stroke patients. These methodologic concerns weaken the conclusion that LAPSS is preferable for prehospital stroke identification. Author Response: Ethan S. Brandler, Stony Brook, NY: Rudd et al. make an important point concerning the sensitivity and specificity of stroke screening tools 962
Neurology 84
with regard to the denominator chosen. It was difficult to choose a denominator in this case. If all cases eligible for thrombolysis were selected, would patients with contraindications for thrombolysis, whether by time- or patient-specific characteristics, be included? Defining a denominator by a decision made after selecting the numerator also leads to selection bias. If a denominator is chosen of all patients with stroke who were transported by ambulance, as we indicated,1 the study is simply the actual ability of emergency medical services to pick up stroke. This is fraught with the same issues as emergency physicians picking up more subtle strokes. Patients not identified as having stroke may languish in the emergency department until recognized as such. Therefore, defining the denominator as we have ensures optimal sensitivity. Improved sensitivity does come with decreased specificity. However, with the low rate of thrombolysis seen in the United States for acute stroke, we should look to expand the population of patients identified. As we indicated, LAPSS performed well as it had both the highest sensitivity and specificity. Defining denominators for similar studies is difficult. While our methodology is broad and all inclusive, it gave the best measure of how different stroke scales perform at picking up stroke, not just cases suitable for thrombolysis. © 2015 American Academy of Neurology 1.
2.
3.
Brandler ES, Sharma M, Sinert RH, et al. Prehospital stroke scales in urban environments: a systematic review. Neurology 2014;82:2241–2249. Harbison J. Diagnostic accuracy of stroke referrals from primary care, emergency room physicians, and ambulance staff using the face arm speech test. Stroke 2002;34:71–76. Kidwell CS, Starkman S, Eckstein M, Weems K, Saver JL. Identifying stroke in the field: prospective validation of the Los Angeles Prehospital Stroke Screen (LAPSS). Stroke 2000;31:71–76.
PERIPHERAL PULSE MEASUREMENT AFTER ISCHEMIC STROKE: A FEASIBILITY STUDY
Abraham Totah, Clearwater, FL: I read the article by Kallmünzer et al.1 with interest. However, I did not follow how measuring the pulse helps detect atrial
March 3, 2015
ª 2015 American Academy of Neurology. Unauthorized reproduction of this article is prohibited.
fibrillation (AF). It may be helpful to include the details of the education provided to the professionals or patients who did self-measurement. Was the pulse rhythm irregularity measured by palpation of the radial artery?
3.
Author Response: Bernd Kallmünzer, Martin Köhrmann, Erlangen, Germany: We thank Dr. Totah for his comments and interest. Screening for AF by peripheral pulse palpation is recommended by international guidelines for patients 65 years or older to prevent ischemic stroke.2 Among stroke survivors, the risk for paroxysmal AF is an expected 5–20 times higher than among cohorts of primary prevention and silent episodes are easily missed by single ECG diagnostics.3 Before this study, it was unclear if the peripheral pulse palpation technique was feasible and accurate among stroke survivors with cognitive and sensomotoric handicaps. In our study, patients were offered a training program that provided basic information on paroxysmal AF and cardioembolic stroke. Participants were tutored on performing reliable pulse measurements at the radial artery. They were instructed to distinguish between absolute arrhythmic pulse sensation (indicative for paroxysmal AF) and regular peripheral pulse (indicative for a normal heart rhythm). As Dr. Totah mentioned, the participants measured irregularities of the peripheral pulse at the radial artery and were then free to choose the side of measurement, depending on preexisting handicaps. This method could serve as a simple, noninvasive strategy to guide ECG diagnostics for secondary stroke prevention.
DEFINING THE CLINICAL COURSE OF MULTIPLE SCLEROSIS: THE 2013 REVISIONS
© 2015 American Academy of Neurology 1.
2.
Kallmünzer B, Bobinger T, Kahl N, et al. Peripheral pulse measurement after ischemic stroke: a feasibility study. Neurology 2014;83:598–603. Camm AJ, Lip GY, De Caterina R, et al. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC guidelines for the management of atrial fibrillation: developed with the special contribution of the European Heart Rhythm Association. Eur Heart J 2012;33:2719–2747.
Rabinstein AA. Prolonged cardiac monitoring for detection of paroxysmal atrial fibrillation after cerebral ischemia. Stroke 2014;45:1208–1214.
Francois H. Jacques, Gatineau, Canada: I read with interest the article by Lublin et al.1 When defining disease subtypes—like neuromyelitis optica—it is clear that pathophysiology should take precedence over clinical and subjective descriptions. The subtypes proposed by Lublin et al. are arbitrary and often diagnosed retrospectively. There is pathophysiologic evidence suggesting that multiple sclerosis (MS) is a progressive disease from the onset and that inflammatory pathologic processes persist well into the progressive phases of the disease. The absence or decrease in remission is a sign of exhaustion of CNS compensatory mechanisms rather than a change in disease process. The negative interferon and glatiramer trials in progressive MS are more likely the result of combining modest drug efficacy with insensitive clinical endpoints (i.e., Expanded Disability Status Scale) vs a different disease mechanism. Newer trials such as INFORM and ASCEND should soon confirm this. MS subtypes should be replaced by MS stages (radiologically isolated syndrome through secondary progressive MS) or more simply MS with or without disease activity or with or without progression. Author Response: Fred D. Lublin, New York: We thank Dr. Jacques for his interesting comments and hypotheses and await data to answer these questions. Our publication is in agreement with his suggestion to categorize MS by the presence of activity or progression. © 2015 American Academy of Neurology 1.
Lublin FD, Reingold SC, Cohen JS, et al. Defining the clinical course of multiple sclerosis: the 2013 revisions. Neurology 2014;83:278–286.
CORRECTION Physical activity attenuates age-related biomarker alterations in preclinical AD In the article “Physical activity attenuates age-related biomarker alterations in preclinical AD” by O.C. Okonkwo et al. (Neurology® 2014;83:1753–1760), there is an error in table 1. Under “Vascular indices,” the third row should read “Ever smoked, %,” rather than “Smoker, %” as originally published. The authors regret the error.
Author disclosures are available upon request ([email protected]). Neurology 84
March 3, 2015
963
ª 2015 American Academy of Neurology. Unauthorized reproduction of this article is prohibited.
Peripheral pulse measurement after ischemic stroke: A feasibility study Abraham Totah, Bernd Kallmünzer and Martin Köhrmann Neurology 2015;84;962-963 DOI 10.1212/01.wnl.0000462308.68863.ff This information is current as of March 2, 2015 Updated Information & Services
including high resolution figures, can be found at: http://www.neurology.org/content/84/9/962.2.full.html
References
This article cites 3 articles, 3 of which you can access for free at: http://www.neurology.org/content/84/9/962.2.full.html##ref-list-1
Permissions & Licensing
Information about reproducing this article in parts (figures,tables) or in its entirety can be found online at: http://www.neurology.org/misc/about.xhtml#permissions
Reprints
Information about ordering reprints can be found online: http://www.neurology.org/misc/addir.xhtml#reprintsus
Neurology ® is the official journal of the American Academy of Neurology. Published continuously since 1951, it is now a weekly with 48 issues per year. Copyright © 2015 American Academy of Neurology. All rights reserved. Print ISSN: 0028-3878. Online ISSN: 1526-632X.
®
WriteClick Editor’s Choice
Robert C. Griggs, MD
Editors’ Note: Commenting on “Prehospital stroke scales in urban environments: A systematic review,” Rudd et al. cite methodologic concerns. Author Brandler explains the rationale. Totah asks how patients in “Peripheral pulse measurement after ischemic stroke: A feasibility study” measured the pulse rhythm. Authors Kallmu¨nzer and Ko¨hrmann respond. Jacques delves into the pathophysiology of multiple sclerosis and makes suggestions for classification that are in agreement with the article by Lublin et al. —Chafic Karam, MD, and Robert C. Griggs, MD
PREHOSPITAL STROKE SCALES IN URBAN ENVIRONMENTS: A SYSTEMATIC REVIEW
Matthew P. Rudd, Christopher I. Price, Newcastle upon Tyne; Gary A. Ford, Oxford, UK: Brandler et al.1 systematically reviewed stroke recognition instruments, but did not emphasize the dependence of specificity of the boundaries around the population defining the denominator. A specificity figure representing all patients in need of emergency medical services would lead to inconsistency between studies. It is also misleading because paramedics would not use stroke recognition instruments in most clinical scenarios. Positive and negative predictive values are less influenced by clinical settings and are better reflections of instrument characteristics. It is important that clinicians appreciate methodologic influences when selecting clinical instruments and use of specificity inflates the value of the Los Angeles Prehospital Stroke Screen (LAPSS). The review did not adequately reflect that stroke recognition instruments were developed for 2 purposes: to identify most stroke patients (e.g., Face Arm Speech Test2) and to identify a subpopulation likely to be suitable for thrombolysis and other acute stroke interventions (e.g., LAPSS3). The addition of thrombolysis eligibility favors specificity and false-negative cases will be harder to register compared with an instrument that seeks to identify all stroke patients. These methodologic concerns weaken the conclusion that LAPSS is preferable for prehospital stroke identification. Author Response: Ethan S. Brandler, Stony Brook, NY: Rudd et al. make an important point concerning the sensitivity and specificity of stroke screening tools 962
Neurology 84
with regard to the denominator chosen. It was difficult to choose a denominator in this case. If all cases eligible for thrombolysis were selected, would patients with contraindications for thrombolysis, whether by time- or patient-specific characteristics, be included? Defining a denominator by a decision made after selecting the numerator also leads to selection bias. If a denominator is chosen of all patients with stroke who were transported by ambulance, as we indicated,1 the study is simply the actual ability of emergency medical services to pick up stroke. This is fraught with the same issues as emergency physicians picking up more subtle strokes. Patients not identified as having stroke may languish in the emergency department until recognized as such. Therefore, defining the denominator as we have ensures optimal sensitivity. Improved sensitivity does come with decreased specificity. However, with the low rate of thrombolysis seen in the United States for acute stroke, we should look to expand the population of patients identified. As we indicated, LAPSS performed well as it had both the highest sensitivity and specificity. Defining denominators for similar studies is difficult. While our methodology is broad and all inclusive, it gave the best measure of how different stroke scales perform at picking up stroke, not just cases suitable for thrombolysis. © 2015 American Academy of Neurology 1.
2.
3.
Brandler ES, Sharma M, Sinert RH, et al. Prehospital stroke scales in urban environments: a systematic review. Neurology 2014;82:2241–2249. Harbison J. Diagnostic accuracy of stroke referrals from primary care, emergency room physicians, and ambulance staff using the face arm speech test. Stroke 2002;34:71–76. Kidwell CS, Starkman S, Eckstein M, Weems K, Saver JL. Identifying stroke in the field: prospective validation of the Los Angeles Prehospital Stroke Screen (LAPSS). Stroke 2000;31:71–76.
PERIPHERAL PULSE MEASUREMENT AFTER ISCHEMIC STROKE: A FEASIBILITY STUDY
Abraham Totah, Clearwater, FL: I read the article by Kallmünzer et al.1 with interest. However, I did not follow how measuring the pulse helps detect atrial
March 3, 2015
ª 2015 American Academy of Neurology. Unauthorized reproduction of this article is prohibited.
fibrillation (AF). It may be helpful to include the details of the education provided to the professionals or patients who did self-measurement. Was the pulse rhythm irregularity measured by palpation of the radial artery?
3.
Author Response: Bernd Kallmünzer, Martin Köhrmann, Erlangen, Germany: We thank Dr. Totah for his comments and interest. Screening for AF by peripheral pulse palpation is recommended by international guidelines for patients 65 years or older to prevent ischemic stroke.2 Among stroke survivors, the risk for paroxysmal AF is an expected 5–20 times higher than among cohorts of primary prevention and silent episodes are easily missed by single ECG diagnostics.3 Before this study, it was unclear if the peripheral pulse palpation technique was feasible and accurate among stroke survivors with cognitive and sensomotoric handicaps. In our study, patients were offered a training program that provided basic information on paroxysmal AF and cardioembolic stroke. Participants were tutored on performing reliable pulse measurements at the radial artery. They were instructed to distinguish between absolute arrhythmic pulse sensation (indicative for paroxysmal AF) and regular peripheral pulse (indicative for a normal heart rhythm). As Dr. Totah mentioned, the participants measured irregularities of the peripheral pulse at the radial artery and were then free to choose the side of measurement, depending on preexisting handicaps. This method could serve as a simple, noninvasive strategy to guide ECG diagnostics for secondary stroke prevention.
DEFINING THE CLINICAL COURSE OF MULTIPLE SCLEROSIS: THE 2013 REVISIONS
© 2015 American Academy of Neurology 1.
2.
Kallmünzer B, Bobinger T, Kahl N, et al. Peripheral pulse measurement after ischemic stroke: a feasibility study. Neurology 2014;83:598–603. Camm AJ, Lip GY, De Caterina R, et al. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC guidelines for the management of atrial fibrillation: developed with the special contribution of the European Heart Rhythm Association. Eur Heart J 2012;33:2719–2747.
Rabinstein AA. Prolonged cardiac monitoring for detection of paroxysmal atrial fibrillation after cerebral ischemia. Stroke 2014;45:1208–1214.
Francois H. Jacques, Gatineau, Canada: I read with interest the article by Lublin et al.1 When defining disease subtypes—like neuromyelitis optica—it is clear that pathophysiology should take precedence over clinical and subjective descriptions. The subtypes proposed by Lublin et al. are arbitrary and often diagnosed retrospectively. There is pathophysiologic evidence suggesting that multiple sclerosis (MS) is a progressive disease from the onset and that inflammatory pathologic processes persist well into the progressive phases of the disease. The absence or decrease in remission is a sign of exhaustion of CNS compensatory mechanisms rather than a change in disease process. The negative interferon and glatiramer trials in progressive MS are more likely the result of combining modest drug efficacy with insensitive clinical endpoints (i.e., Expanded Disability Status Scale) vs a different disease mechanism. Newer trials such as INFORM and ASCEND should soon confirm this. MS subtypes should be replaced by MS stages (radiologically isolated syndrome through secondary progressive MS) or more simply MS with or without disease activity or with or without progression. Author Response: Fred D. Lublin, New York: We thank Dr. Jacques for his interesting comments and hypotheses and await data to answer these questions. Our publication is in agreement with his suggestion to categorize MS by the presence of activity or progression. © 2015 American Academy of Neurology 1.
Lublin FD, Reingold SC, Cohen JS, et al. Defining the clinical course of multiple sclerosis: the 2013 revisions. Neurology 2014;83:278–286.
CORRECTION Physical activity attenuates age-related biomarker alterations in preclinical AD In the article “Physical activity attenuates age-related biomarker alterations in preclinical AD” by O.C. Okonkwo et al. (Neurology® 2014;83:1753–1760), there is an error in table 1. Under “Vascular indices,” the third row should read “Ever smoked, %,” rather than “Smoker, %” as originally published. The authors regret the error.
Author disclosures are available upon request ([email protected]). Neurology 84
March 3, 2015
963
ª 2015 American Academy of Neurology. Unauthorized reproduction of this article is prohibited.
Peripheral pulse measurement after ischemic stroke: A feasibility study Abraham Totah, Bernd Kallmünzer and Martin Köhrmann Neurology 2015;84;962-963 DOI 10.1212/01.wnl.0000462308.68863.ff This information is current as of March 2, 2015 Updated Information & Services
including high resolution figures, can be found at: http://www.neurology.org/content/84/9/962.2.full.html
References
This article cites 3 articles, 3 of which you can access for free at: http://www.neurology.org/content/84/9/962.2.full.html##ref-list-1
Permissions & Licensing
Information about reproducing this article in parts (figures,tables) or in its entirety can be found online at: http://www.neurology.org/misc/about.xhtml#permissions
Reprints
Information about ordering reprints can be found online: http://www.neurology.org/misc/addir.xhtml#reprintsus
Neurology ® is the official journal of the American Academy of Neurology. Published continuously since 1951, it is now a weekly with 48 issues per year. Copyright © 2015 American Academy of Neurology. All rights reserved. Print ISSN: 0028-3878. Online ISSN: 1526-632X.
