Supplementary Material for: Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia Can Present as Frontotemporal Dementia Syndrome

Background/Aims: We review the characteristics of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia(ALSP) and determine prevalence of behavioral variant of frontotemporal dementia (bvFTD) features in ALSP. Methods: Clinical and pathological information was abstracted from histopathologically confirmed ALSP cases identified by a systematic literature search. A new case of ALSP presenting as bvFTD was also described. Results: We retrieved 51 ALSP cases. Mean age of onset was 42.2 years. Mean disease duration was 6.2 years, with 24 cases lasting 4 years or fewer. Fourteen cases had 3 or more of the 6 key bvFTD features. White matter hyperintensities on T₂-weighted MRI, motor symptoms, seizures and amnesia were common. Conclusion: ALSP can underlie FTD syndrome, as well as rapidly progressive dementia.