Leukodystrophy | |
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T2 weighted axial scan at the level of the caudate heads demonstrates marked loss of posterior white matter, with reduced volume and increased signal intensity. The anterior white matter is spared. Features are consistent with X-linked adrenoleukodystrophy. | |
Classification and external resources | |
Specialty | endocrinology |
ICD-10 | E75.2 |
ICD-9-CM | 330.0 |
DiseasesDB | 32504 |
Leukodystrophy is one of a group of disorders characterized by degeneration of the white matter in the brain. The word leukodystrophy comes from the Greek roots leuko, "white", dys, "lack of", and troph, "growth". The leukodystrophies are caused by imperfect growth or development of the myelin sheath, the fatty covering that acts as an insulator around nerve fibers.
When damage occurs to white matter, immune responses can lead to inflammation in the CNS, along with loss of myelin. The degeneration of white matter can be seen in a MRI and used to diagnose leukodystrophy. Leukodystrophy is characterized by specific symptoms including decreased motor function, muscle rigidity, and eventually degeneration of sight and hearing. While the disease is fatal, the age of onset is a key factor as infants are given a lifespan of 2–8 years (sometimes longer), while adults typically live more than a decade after onset. There is a great lack of treatment, although cord blood and hematopoietic stem cell transplantation (bone marrow transplant) seem to help in certain types while further research is being done.
The combined incidence of the leukodystrophies is estimated at 1:7,600. The majority of types involve the inheritance of a recessive, dominant, or X-linked trait, while others, although involving a defective gene, are the result of spontaneous mutation rather than genetic inheritance.
Specific types of leukodystrophies include the following with their respective ICD-10 codes when available:
Some specific symptoms vary from one type of leukodystrophy to the next but the vast majority of symptoms are shared as the causes for the disease generally have the same effects. Symptoms are dependent on the age of onset, which is predominantly in infancy and early childhood, although the exact time of onset may be difficult to determine. Hyperirritability and hypersensitivity to the environment are common, as well as some tell-tale physical signs including muscle rigidity and a backwards-bent head. Botox therapy is often used to treat patients with spasticity. Juvenile and adult onsets display similar symptoms including a decrease or loss in hearing and vision. While children do experience optic and auditory degeneration, the course of the disease is usually too rapid, causing death relatively quickly, whereas adults may live with these conditions for many years. In children, spastic activity often precedes progressive ataxia and rapid cognitive deterioration which has been described as mental retardation.Epilepsy is commonplace for patients of all ages. More progressed patients show weakness in deglutition, leading to spastic coughing fits due to inhaled saliva. Classic symptomatic progression of juvenile x-linked adrenoleukodystrophy is shown in the 1992 film, Lorenzo's Oil.