Clinicoradiologic Criteria for the Diagnosis of Stroke-like Episodes in MELAS.

Background and Objectives: 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. Methods: 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. Results: 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, p < 0.01) and had a lower body mass index (18 ± 2.6 vs 29 ± 4, p < 0.01), more commonly reported hearing loss (91% vs 5%, p < 0.01), and more commonly presented with headache and/or seizures (41% vs 0%, p < 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%, p < 0.01), previous cortical lesions with typical SLE distribution (46% vs 9%, p = 0.03), acute lesion tissue hyperemia and venous engorgement on CT angiography (CTA) (45% vs 0%, p < 0.01), and no large vessel occlusion on CTA (0% vs 100%, p < 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). Discussion: Clinicoradiologic criteria based on simple anamnesis and a CT scan at presentation can accurately diagnose SLE and lead to early administration of appropriate therapy. Classification of Evidence: 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.

Clinical score for early diagnosis and treatment of stroke-like episodes in MELAS syndrome.

BACKGROUND AND OBJECTIVES: Stroke-like episodes (SLEs) in patients with MELAS syndrome are often initially misdiagnosed as acute ischemic stroke (AIS), resulting in treatment delay. We aimed to determine clinical features that may distinguish SLEs from AISs and explore the benefit of early L-arginine treatment on patient outcomes. METHODS: We looked retrospectively for MELAS patients admitted between January 2005 and January 2022 and compared them to an AIS cohort with similar lesion topography. MELAS patients who received L-arginine within 40 days of their first SLE were defined as the early treatment group and the remaining as late or no treatment group. RESULTS: Twenty-three SLEs in 10 MELAS patients and 21 AISs were included. SLE patients had significantly different features: they were younger, more commonly reported hearing loss, lower body mass index, had more commonly a combination of headache and/or seizures at presentation, serum lactate was higher, and hemiparesis was less common. An SLE Early Clinical Score (SLEECS) was constructed by designating one point to each above features. SLEECS ≥ 4 had 80% sensitivity and 100% specificity for SLE diagnosis. Compared to late or no treatment, early treatment group patients (n = 5) had less recurrent SLEs (total 2 vs. 11), less seizures (14% vs. 25%, p = 0.048), lower degree of disability at first and last follow-up (modified ranking scale, mRS 2 ± 0.7 vs. 4.2 ± 1, p = 0.005; 2 ± 0.7 vs. 5.8 ± 0.5, p < 0.001, respectively), and a lower mortality (0% vs. 80% p = 0.048). CONCLUSIONS: The SLEECS model may aid in the early diagnosis and treatment of SLEs and lead to improved clinical outcomes.

Repeated lumbar puncture in search of oligoclonal bands - What is the yield?

BACKGROUND: Cerebrospinal fluid (CSF) oligoclonal bands (OCBs) are immunoglobulins that represent intrathecal synthesis during central nervous system infection or inflammation. As repeated lumbar puncture (LP) is usually not performed unless clinically indicated, there is very limited data on the natural history and course of OCBs status in the CSF, its relation to disease activity, duration of persistence, and the rate of either CSF conversion of OCBs or disappearance. METHODS: We retrospectively collected data from adult patients with various neurological syndromes who had repeated CSF samplings. OCBs were analyzed by agarose gel electrophoresis or by isoelectric focusing. RESULTS: During the years 2010-2020, we identified 48 patients with at least two CSF OCBs results in Rabin Medical Center. These included 11 patients with Multiple Sclerosis, ADEM and NMOSD (one patient each), 7 patients with unspecified demyelinating disease, 4 with optic neuropathy, 15 patients with unknown diagnosis. Overall, 6/48 (12.5%) patients had change in OCBs status between first and second LP's. Four (8.33%) patients changed OCBs from positive to negative, and two patients (4.2%) from negative to positive. There was no significant difference in demographic, disease category, CSF constituents or time interval to second LP between patients who changed their OCBs status to those who did not. CONCLUSION: Repeated LP for OCBs analysis in our cohort did not yield a practical benefit. The conversion rate of OCBs status was low (12.5%) and in most cases did not lead to a change in the final diagnosis or patient's clinical management.