Diagnosis of DWI-negative acute ischemic stroke

Absolutely no clue what this means or how it could be used to get stroke survivors to 100% recovery. More wasted research.
http://www.neurology.org/content/early/2017/06/14/WNL.0000000000004120.short?rss=1

A meta-analysis

1. Brian L. Edlow, MD,
2. Shelley Hurwitz, PhD and
3. Jonathan A. Edlow, MD

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1. Correspondence to Dr. Edlow: bedlow@mgh.harvard.edu

1. Published online before print June 14, 2017, doi: http:/​/​dx.​doi.​org/​10.​1212/​WNL.​0000000000004120 Neurology 10.1212/WNL.0000000000004120

• Abstract
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2. Data Supplement

Abstract

Objective: To determine the prevalence of diffusion-weighted imaging (DWI)–negative acute ischemic stroke (AIS) and to identify clinical characteristics of patients with DWI-negative AIS.

Methods: We systematically searched PubMed and Ovid/MEDLINE for relevant studies between 1992, the year that the DWI sequence entered clinical practice, and 2016. Studies were included based upon enrollment of consecutive patients presenting with a clinical diagnosis of AIS prior to imaging. Meta-analysis was performed to synthesize study-level data, estimate DWI-negative stroke prevalence, and estimate the odds ratios (ORs) for clinical characteristics associated with DWI-negative stroke.

Results: Twelve articles including 3,236 AIS patients were included. The meta-analytic synthesis yielded a pooled prevalence of DWI-negative AIS of 6.8%, 95% confidence interval (CI) 4.9–9.3. In the 5 studies that reported proportion data for DWI-negative and DWI-positive AIS based on the ischemic vascular territory (n = 1,023 AIS patients), DWI-negative stroke was strongly associated with posterior circulation ischemia, as determined by clinical diagnosis at hospital discharge or repeat imaging (OR 5.1, 95% CI 2.3–11.6, p <0.001).

Conclusions: A small but significant percentage of patients with AIS have a negative DWI scan. Patients with neurologic deficits consistent with posterior circulation ischemia have 5 times the odds of having a negative DWI scan compared to patients with anterior circulation ischemia. AIS remains a clinical diagnosis and urgent reperfusion therapy should be considered even when an initial DWI scan is negative.

• Received January 21, 2017.
• Accepted in final form April 20, 2017.

• © 2017 American Academy of Neurology