Clinicoradiologic Criteria for the Diagnosis of Stroke-like Episodes in MELAS
Vadim Khasminsky, Eitan Auriel, Judith Luckman, Ruth Eliahou, Edna Inbar, Keshet Pardo, Yuval E. Landau, Rani Barnea, Maor Mermelstein, Shahar Shelly, Jonathan Naftali, Shlomi Peretz
Abstract
<h3>Background and Objectives</h3> Stroke-like episodes (SLEs) in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome are often misdiagnosed as acute ischemic stroke (AIS). We aimed to determine unique clinical and neuroimaging features for SLEs and formulate diagnostic criteria. <h3>Methods</h3> We retrospectively identified patients with MELAS admitted for SLEs between January 2012 and December 2021. Clinical features and imaging findings were compared with a cohort of patients who presented with AIS and similar lesion topography. A set of criteria was formulated and then tested by a blinded rater to evaluate diagnostic performance. <h3>Results</h3> Eleven MELAS patients with 17 SLE and 21 AISs were included. Patients with SLEs were younger (median 45 [37–60] vs 77 [68–82] years, <i>p</i> < 0.01) and had a lower body mass index (18 ± 2.6 vs 29 ± 4, <i>p</i> < 0.01), more commonly reported hearing loss (91% vs 5%, <i>p</i> < 0.01), and more commonly presented with headache and/or seizures (41% vs 0%, <i>p</i> < 0.01). The earliest neuroimaging test performed at presentation was uniformly a noncontrast CT. Two main patterns of lesion topography with a stereotypical spatiotemporal evolution were identified—an anterior pattern (7/21, 41%) starting at the temporal operculum and spreading to the peripheral frontal cortex and a posterior pattern (10/21, 59%) starting at the cuneus/precuneus and spreading to the lateral occipital and parietal cortex. Other distinguishing features for SLEs vs AIS were cerebellar atrophy (91% vs 19%, <i>p</i> < 0.01), previous cortical lesions with typical SLE distribution (46% vs 9%, <i>p</i> = 0.03), acute lesion tissue hyperemia and venous engorgement on CT angiography (CTA) (45% vs 0%, <i>p</i> < 0.01), and no large vessel occlusion on CTA (0% vs 100%, <i>p</i> < 0.01). Based on these clinicoradiologic features, a set of diagnostic criteria were constructed for possible SLE (sensitivity 100%, specificity 81%, AUC 0.905) and probable SLE (sensitivity 88%, specificity 95%, AUC 0.917). <h3>Discussion</h3> Clinicoradiologic criteria based on simple anamnesis and a CT scan at presentation can accurately diagnose SLE and lead to early administration of appropriate therapy. <h3>Classification of Evidence</h3> This study provides Class III evidence that an algorithm using clinical and imaging features can differentiate stroke-like episodes due to MELAS from acute ischemic strokes.