Posted by Asim from IP 160.94.237.142 on February 01, 2006 at 11:17:51:
In Reply to: My Q280 posted by peter on January 31, 2006 at 17:57:08:
C.Adrenal Leukodystrophy (ALD)
Clinical Sx:
The disease usually presents in males age 5-10 years old with a gradual disturbance in gait and slight intellectual impairment. There is usually rapid progression with hypotension, seizures, visual complaints, and difficulty in swallowing appearing with time. Abnormal skin pigmentation or other signs and symptoms of adrenal insufficiency may become apparent before CNS symptoms. In some cases, adrenal symptoms never appear.
Etiology/Pathophysiology:
Classic ALD and the adult variant adrenomyeloneuropathy (AMN) are X-linked diseases in which there is deficiency of lignoceroyl-CoA ligase, a perioxisomal enxyme needed for the degradation of very long chain fatty acids (VLCFA).
Pathology:
White matter diseases are usually classified as demyelinating or dysmyelinating diseases. Dysmyelinating diseases such as ALD are inherited enzymatic deficiencies that cause abnormal formation or increased breakdown of myelin. Demyelinating diseases result in the loss of normally formed myelin by processes such as infection, chemotherapy, radiation, and autoimmune disorders such as multiple sclerosis.
The diagnosis of ALD is made by the assay of plasma, red cells, or cultured fibroblasts for increased amounts of VLCFA.
Imaging:The classic presentation on CT is low attenuation in the central occipital white matter that extends into the splenium of the corpus callosum.