Toxic Leukoencephalopathy

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Toxic Leukoencephalopathy

• Christopher M. Filley, M.D.
• B.K. Kleinschmidt-DeMasters, M.D.
• Douglas K. Novins, M.D.
• Spero M. Manson, Ph.D.
• Departments of Neurology,
• Psychiatry, and Pathology
• University of Colorado School of Medicine

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Background

• Leukoencephalopathy is a structural alteration of
  brain white matter
• Toxic causes include drugs of abuse, cranial
  irradiation, therapeutic drugs, and
  environmental toxins
• Affected individuals may develop white matter
  dementia

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Cranial Irradiation

• Radiation for brain tumors can reduce the tumor
  size but also can produce unwanted
  leukoencephalopathy
• The left MRI scan shows a malignant brain tumor
  before radiation after radiation (right), the
  tumor is smaller but the white matter is damaged

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Other Toxins that Can Damage Brain White Matter

• Alcohol (ethanol)
• Cocaine
• Intravenous heroin
• Hallucinogenic drugs (psilocybin)
• Probably Ecstacy
• Even anticancer drugs doctors use for treatment
  of the tumor may have the unwanted (but currently
  unpreventable) side effect of leukoencephalopathy

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Pathogenesis

• In toxic leukoencephalopathy, white matter damage
  can result from injury to any important part of
  the white matter including myelin,
  oligodendrocytes, axons, astrocytes, or blood
  vessels

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Toluene Abuse

• Toluene is an organic solvent commonly used in
  many household products, including spray paint,
  and in industry
• Heavy glue/paint/ or gasoline sniffing, a form
  of inhalant drug abuse often used by American
  Indian and urban youth, results in
  leukoencephalopathy

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Future Aim

• Study brain damage due to toluene abuse in
  American Indian and urban youth, in whom the
  prevalence of this problem is high, by performing
  detailed neurological, neuropsychological,
  psychiatric evaluations, in conjunction with
  advanced brain imaging (MRI) techniques, to
  clarify the impact of this toxin on brain
  function
• This population has NEVER been adequately
  studied, nor has the impact of the problem been
  fully appreciated

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The American Indian and Alaska Native Program
Mission

• To promote the health and well-being of American
  Indians and Alaska Natives, of all ages, by
  pursuing research, training, continuing
  education, technical assistance, and information
  dissemination within a biopsychosocial framework
  that recognizes the unique cultural contexts of
  this special population.