American Heart Association

Monthly Archives: November 2018

Diabetic Condition Worsens Functional Deficits After Stroke

Lin Kooi Ong, PhD
@DrLinOng

Ma S, Wang J, Wang Y, Dai X, Xu F, Gao X, et al. Diabetes Mellitus Impairs White Matter Repair and Long-Term Functional Deficits After Cerebral Ischemia. Stroke. 2018

This article by Wang and colleagues aimed to investigate the impact of diabetes on brain recovery after stroke using a preclinical model, comparing wild type male mice to diabetes (db/db) mice. The team observed a significant decrease in sensorimotor performance in diabetes mice after stroke. It should be noted that the team did not observe deficit in memory function using the Morris water maze. There was an exacerbated white matter damage at both structural and functional levels. Further, there was an enhanced inflammatory response at the white matter in diabetes mice after stroke, such as a shift of microglia/macrophage to pro-inflammatory phenotype and higher levels of IL-1β and IL-6 expression. The inflammatory environment inhibited oligodendrogenesis, a brain repair mechanism to generate new myelinating oligodendrocytes. These findings provide compelling preclinical evidence that diabetic condition exacerbates functional deficits after stroke.

Intravenous Thrombolysis in the Endovascular Mechanical Thrombectomy Era: Clot Location Determines Perfusion Outcomes

Ravinder-Jeet Singh, MBBS, DM

Kaesmacher J, Giarrusso M, Zibold F, Mosimann PJ, Dobrocky T, Piechowiak E, et al. Rates and Quality of Preinterventional Reperfusion in Patients with Direct Access to Endovascular Treatment. Stroke. 2018

Use of intravenous tissue plasminogen activator (IV-tPA) before endovascular thrombectomy (EVT) among patients with large vessel occlusion (LVO) has become controversial in recent years. The main concerns are its limited efficacy to lyse large clots in the proximal arteries, which responds excellently to EVT. Thus, tPA use adds to the total treatment cost with potentially no additional clinical benefits over and above those provided by EVT. Furthermore, there are theoretical concerns of thrombus migration and neurological worsening, and also thrombus fragmentation with lodgement in the distal region of the involved territory, which then becomes inaccessible to EVT. In contrast, IV-tPA could lead to early recanalization in a proportion of patients leading to timely reperfusion and better outcomes and may obviate the need for EVT and associated cost.

By |November 9th, 2018|clinical|0 Comments

World Stroke Congress Session: Advances in Stroke Imaging

World Stroke Congress
October 17-20, 2018

Ravinder-Jeet Singh, MBBS, DM

The session on advances in stroke imaging was very interesting and informative. Three speakers — Dr. Ken Butcher from Edmonton and Drs. Gregory Albers and Chitra Venkatasubramanian from Stanford — discussed some of the recent changes in the field of stroke imaging and how it is influencing the practice of stroke care.

Dr. Butcher spoke about multimodal CT based imaging paradigms in acute ischemic stroke, especially use of CTA and CTP in patient selection. It is of note that two of the “early window” EVT trials (SWIFT PRIME and EXTEND IA) and both the late window trials (DAWN and DEFUSE 3) used perfusion imaging for patient selection. He discussed various software platforms available for processing and interpreting CTP data. Options include inbuilt software provided by CT vendors and other commercially available software including RAPID (iSchemaView Inc.), MIstar (Apollo Medical Imaging Technology), and OleaSphere (Olea Medical). The key message was that clinicians should be careful in interpreting CTP images and also the outputs (core, penumbra volumes, and mismatch ratios) provided by these softwares. It is essential to look at arterial input function and venous output function curves to assess the quality of CTP data. These curves should display rapid upslopes and downslopes. Presence of any truncation of these curves should also be noted, which could lead to misestimation of core and penumbra size. In addition, the presence of motion artifacts can severely degrade image quality and, therefore, its interpretation. He also pointed out another important area in which CTP could be helpful — the stroke mimics — where a normal CTP would be reassuring in the appropriate clinical context.

Collaterals vs. Time in the Natural History of Acute Ischemic Stroke

Raffaele Ornello, MD

Vagal A, Aviv R, Sucharew H, Reddy M, Hou Q, Michel P, et al. Collateral clock is more important than time clock for tissue fate – A natural history study of acute ischemic strokes. Stroke. 2018

The endovascular treatment of ischemic stroke is beneficial up to 24 hours from symptom onset, provided that neuroimaging studies show the presence of ischemic penumbra, i.e., the hypoperfused brain region which has not progressed to infarction. Over time, the ischemic penumbra progresses to infarction, thus limiting the possibility of treating ischemic stroke; however, current literature suggests that the presence of robust collateral vessels delays that progression.

Transcranial Stimulation for Aphasia Recovery in Subacute Stroke Patients

Danielle de Sa Boasquevisque, MD

Spielmann K, van de Sandt-Koenderman WME, Heijenbrok-Kal MH, Ribbers GM. Transcranial Direct Current Stimulation Does Not Improve Language Outcome in Subacute Poststroke Aphasia. Stroke. 2018

Trancranial direct current stimulation (tDCS) is a non-invasive neuromodulation therapy with the potential to enhance recovery after ischemic stroke. This technique uses a weak electrical current that ultimately leads to a polarity specific change in excitability: increasing cortical excitability (anodal tDCS), decreasing cortical excitability (cathodal tDCS), or a combination of both effects (bihemispheric). Many studies demonstrated benefit in chronic aphasia, but research within the early phase after stroke, when the mechanisms of neuroplasticity are more active, are still scarce.

In this article, the authors aimed to investigate the effects of online anodal tDCS applied over the left inferior frontal gyrus on aphasia recovery in the subacute phase after stroke. This study was a multi-center double-blinded clinical trial that enrolled patients with aphasia after ischemic or hemorrhagic stroke between 3 weeks and 3 months poststroke. Participants were randomized to 2 parallel groups: anodal tDCS (1mA, 20 minutes) and sham tDCS. They also received online tDCS while on 2 weeks (5 sessions/week) of 45-min word-finding language therapy session.

Alteplase in Minor Stroke: A Daily Dilemma

Alejandro Fuerte, MD

Levine SR, Weingast SZ, Weedon J, Stefanov DG, Katz P, Hurley D, et al. To Treat or Not to Treat? Exploring Factors Influencing Intravenous Thrombolysis Treatment Decisions for Minor Stroke. Stroke. 2018

The activase/alteplase package insert from the Food and Drug Administration was updated in February 2015. Despite this, controversy continues over the criteria for the use of this drug in minor stroke, defined as National Institutes of Health Stroke Scale (NIHSS) score 1 to 5. In this article, Levine et al explore clinical factors influencing alteplase treatment decisions for patients with ictus minor.

This is a descriptive study. A committee of stroke experts identified the key factors in making decisions about the use of alteplase. The most prominent factors on the basis of which the study was developed were the following: all patient-dependent: National Institutes of Health Stroke Scale (NIHSS), NIHSS area of primary deficit, baseline functional status, previous ischemic stroke (IS), previous intracerebral hemorrhage (ICH), recent anticoagulation, and temporal pattern of symptoms in first hour of care. A fractional factorial design was used to provide unconfounded estimates of the effect of the 7 main factors, plus first-order interactions for the NIHSS. A joint statistical analysis was then applied.