Other Primary Demyelinating Diseases
Acute disseminated encephalomyelitis (parainfectious or postinfectious encephalomyelitis) is a rare type of inflammation leading to demyelination of nerves in the brain and spinal cord. It usually develops after a viral infection (such as measles, chickenpox, or rubella) or vaccination. It is thought to be a misguided immune reaction triggered by the virus. Typically, the inflammation develops 5 to 10 days after the viral illness begins. It can be treated with corticosteroids given intravenously. Guillain-Barré syndrome seems to be a similar disorder of the peripheral nerves.
Adrenoleukodystrophy and adrenomyeloneuropathy are rare hereditary metabolic disorders. Adrenoleukodystrophy affects young boys, usually by the age of 7. A more slowly developing form of the disorder can begin in adults in their 20s. Adrenomyeloneuropathy affects adolescent boys. In these disorders, widespread demyelination is accompanied by adrenal gland dysfunction. Eventually, mental deterioration, spasticity, and blindness occur. No cure for either disorder is known. Dietary supplements with glycerol trioleate and glycerol trierucate (known as Lorenzo's oil) have not been shown to slow the progression of the disease. Bone marrow transplantation is an experimental treatment.
Leber's hereditary optic neuropathy causes demyelination leading to partial blindness. The disorder is more common among men. Usually, symptoms begin in the late teens or early 20s. This disorder is inherited through the mother, and the defective genes seem to be located in mitochondria, which are structures in cells that provide energy for the cell.
Tropical spastic paraparesis (HTLV-associated myelopathy (see Section 6, Chapter 89)), a disorder that causes demyelination in the spinal cord, results from infection with the human T-cell lymphotropic virus (HTLV). The disorder worsens over several years, leading to gradual spasticity and weakness of the legs as well as frequent, strong urges to urinate, urinary incontinence, and bowel dysfunction. No cure is available, but use of corticosteroids has produced improvement, and plasmapheresis has produced temporary improvement.
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