Chronic levamisole-induced leukoencephalopathy: Uncommon presentation of two cases with adult-onset progressive symptoms

Toxic leukoencephalopathies are abnormalities in the cerebral white matter associated with the use of legal or illegal substances. Levamisole-induced leukoencephalopathy (LILE) is a rare condition that typically presents with a subacute progression and has a clear temporal relationship to compound exposure. However, we describe two cases with a chronic progression of adult-onset progressive spastic-ataxia syndrome, likely due to recurrent exposure to levamisole. Both cases exhibited typical abnormalities on brain magnetic resonance imaging (MRI) and had normal cerebrospinal fluid (CSF) analysis. In both instances, clinical stability was closely associated with drug abstinence. These cases are distinct from the literature due to their chronic presentation, and LILE should always be considered as a differential diagnosis when toxic exposure is suspected.