Abstract
Toxic leukoencephalopathy (TLE) refers to a series of diseases with central nervous system damage caused by poisoning of various toxic substances, including medications, gases, drugs, and ethanol as the main clinical manifestation. TLE mainly causes the damage to white matter fibers and subcortical gray matter nuclei, including basal ganglia nuclei, thalamus and brainstem nuclei (substantia nigra red nucleus), as well as cerebellar dentate nucleus, which manifests as altered mental status, epilepsy, paresthesia, hemiparesis, tetraparesis, or even death. Magnetic resonance spectroscopy (MRS) has contributed to understanding the etiology and stage of TLE. Moreover, the change of brain metabolites, which can be evaluated by MRS, provides additional information for confirming diagnosis, monitoring disease progression, and informing treatment response. In order to describe the MRS characteristics of TLE caused by different etiologies, we will review the spectroscopy change of TLE which is associated with psychoactive substances, immunosuppressant, chemotherapy, and environment (PICE). Therefore, we reviewed the MRS characteristics of heroin-induced TLE, methadone-induced TLE, oxycodone-induced TLE, Wernicke encephalopathy, Marchiafava-Bignami disease, methotrexate-related TLE, metronidazole-induced TLE, carbon monoxide-related encephalopathy, and toluene TLE in this chapter.