Evaluation of CSF1R‐related adult onset leukoencephalopathy with axonal spheroids and pigmented glia diagnostic criteria.

Background and purpose: Diagnostic criteria for adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) due to colony‐stimulating factor 1 receptor (CSF1R) mutation have recently been proposed. Our objective was to assess their accuracy in an independent multicenter cohort. Methods: We evaluated the sensitivity and specificity of the diagnostic criteria for ALSP (including the "probable" and "possible" definitions) in a national cohort of 22 patients with CSF1R mutation, and 59 patients with an alternative diagnosis of adult onset inherited leukoencephalopathy. Results: Overall, the sensitivity of the diagnostic criteria for ALSP was 82%, including nine of 22 patients diagnosed as probable and nine of 22 diagnosed as possible. Twenty of the 59 CSF1R mutation‐negative leukoencephalopathies fulfilled the diagnostic criteria, leading to a specificity of 66%. Conclusions: Diagnostic criteria for ALSP have an overall limited sensitivity along with a modest specificity. We suggest that in patients suspected of genetic leukoencephalopathy, a comprehensive magnetic resonance imaging pattern‐based approach is warranted, together with white matter gene panel or whole exome sequencing. [ABSTRACT FROM AUTHOR]