Background: The lack of systematic evidence on leptomeningeal enhancement (LME) on MRI in neurological diseases, including multiple sclerosis (MS), hampers its interpretation in clinical routine and research settings.
Purpose: To perform a systematic review and meta-analysis of MRI LME in MS and other neurologi-cal diseases.
Materials and Methods: In a comprehensive literature search in Medline, Scopus, and Embase, out of 2292 publications, 459 records assessing LME in neurological diseases were eligible for qualitative synthesis. Of these, 135 were included in a random effects model meta-analysis with subgroup analyses for MS.
Results: Of eligible publications, 161 investigated LME in neoplastic neurological (n=2392), 91 in neuroinfectious (n=1890), and 75 in primary neuroinflammatory diseases (n=4038). The LME proportions for these disease classes were 0.47 [95%CI: 0.37 to 0.57], 0.59 [95%CI: 0.47 to 0.69], and 0.26 [95%CI: 0.20 to 0.35], respectively. In a subgroup analysis comprising 1605 MS cases, LME proportion was 0.30 [95%CI 0.21 to 0.42] with lower proportions in relapsing-remitting (0.19 [95%CI 0.13 to 0.27]) compared to progressive MS (0.39 [95%CI 0.30 to 0.49], p=0.002) and higher proportions in studies imaging at 7T (0.79 [95%CI 0.64 to 0.89]) compared to lower field strengths (0.21 [95%CI 0.15 to 0.29], p<0.001). LME in MS was associated with longer disease duration (mean difference 2.2 years [95%CI 0.2 to 4.2], p=0.03), higher Expanded Disability Status Scale (mean difference 0.6 points [95%CI 0.2 to 1.0], p=0.006), higher T1 (mean difference 1.6ml [95%CI 0.1 to 3.0], p=0.04) and T2 lesion load (mean difference 5.9ml [95%CI 3.2 to 8.6], p<0.001), and lower cortical volume (mean difference -21.3ml [95%CI -34.7 to -7.9], p=0.002).
Conclusions: Our study provides high-grade evidence for the substantial presence of LME in MS and a comprehensive panel of other neurological diseases. Our data could facilitate differential diagnosis of LME in clinical settings. Additionally, our meta-analysis corroborates that LME is associ-ated with key clinical and imaging features of MS.
PROSPERO No: CRD42021235026.
Leptomeningeal enhancement in multiple sclerosis and other neurological diseases: A systematic review and Meta-Analysis
