[Toxic changes of the central nervous system].

CLINICAL ISSUES: Various toxic agents can cause changes to the white matter of the brain leading to leukoencephalopathies. These changes often lead to signal alterations of the white matter with or without a diffusion restriction signal. White matter lesions can be reversible or irreversible. There are many differential diagnoses of toxic leukoencephalopathies. PRACTICAL RECOMMENDATIONS: For the radiologist it is necessary to be familiar with the causes, the clinical and the imaging presentation of toxic leukoencephalopathies because early treatment often leads to improved prognosis.