Magnetic Resonance Imaging and Clinical Patterns of Patients with ‘Spectacular Shrinking Deficit’ after Acute Middle Cerebral Artery Stroke

Abstract

Background: Rapid resolution of neurological deficits after severe middle cerebral artery (MCA) stroke has been coined spectacular shrinking deficit (SSD). We studied clinical and MRI patterns in patients with SSD. Methods: Patients with acute MCA stroke <6 h were examined by stroke MRI (perfusion- and diffusion-weighted imaging (PWI, DWI), MR angiography (MRA)) at admission, day 1 and day 7. SSD was defined as a ≧8-point-reduction of neurological deficit in the National Institute of Health Stroke Scale (NIHSS) to a score of ≤4 within 24 h. PWI and DWI lesion volumes were measured on ADC (ADC < 80%) and time to peak maps (TTP > +4 s). Recanalization was assessed by MRA after 24 h. Final infarct volumes were defined on T2 weighted images at day seven. Outcome was assessed after 90 days using modified Rankin Scale (mRS) and Barthel Index (BI). Results: SSD was present in 14 of 104 patients. Initial DWI and PWI lesion volumes were smaller in SSD patients – ADC < 80%: 8.9 (4.3–20.5) vs. 30 (0–266.7) ml; TTP > +4 s: 91.6 (29.7–205.8) vs. 131.5 (0–311.5) ml. Early recanalization was associated with SSD resulted in smaller final infarct volumes (11.9 (2.4–25.9) vs. 47.7 (1.2–288.5)). All SSD patients were independent at day 90 (mRS 0 (0–2); BI 100). Conclusion: The clinical syndrome of SSD is reflected by a typical MRI pattern with small initial DWI and PWI lesion volumes, timely recanalization and small final infarct volumes.