And small cell carcinoma of lung. Progressive decline in mental status and seizures are seen. MRI find¬ings include diffuse T2 hypcrinicnsity throughout ihe while matter w ith predilection for periventricular region and centrum scmiovale with sparing of U fibers. En¬hancement is rarely reported.Postanoxie encephalopathy is an allergic demyelina¬tion caused by exposure to a myelin antigen during anoxic injury. It occurs after a severe anoxic episode.followed by recovery in 24 lo 4ft hours and ilien precip¬itous decline within a 2-weck period. MRI findings re¬veal diffuse T2 hy periulcnsity throughout the while mai¬ler. Particularly involving moncler clothing corpus callosum. Subcortical U fibers, and internal and external capsules. Restricted diffusion is seen. Similar findings can be produced by carbon monoxide exposure but with a propensity for bi¬lateral symmetnc globus pallidus lesions.Osmotic demyelination syndrome occurs m alcoholic, malnounshcd patients who have rapid correction of hy¬ponatremia. It is also associated wilh chronic renal failure, liver failure, diabetes mcllitus, rapid dialysis, and syn¬drome of inappropriate moncler outlet antidiuretic hormone secretion. In children, this moncler jacket syndrome has been associated with ortho¬topic liver transplantation, acutc myelogenous leukemia. Hodgk in disease. Wilson disease, andcraniophaiyngiiima. TI hypointense and moncler T2 hypenntense noncnhancing signal moncler jackets abnormalities are seen on MRI in pons wilh sparing or pe¬riphery and descending corticospinal tracts. Involvement of exirapontine structures, including basal ganglia; inter¬nal. External, and extreme capsules: amygdala and cere¬bellum. Is also seen No mass effcel or enhancement is typically present. Features of some common dysmyelinat- ing disease have been descritvd in Table 11-4. NEURODEGENERATIVE disordersalzheimer disease (dementia Alzheimer type or DAT) accounts Tor 601 to 901 of the dementing disorders. Vascular dementia (151 -301) and alcohol are the sccond uikl third most common causes of dementia, respectively. Senile plaques and neurofibrillary tangles are lite diagnostic pautologic fcatuies. Abnoimal accu¬mulation of tan protein is thought to play u key tole. Five to ten pervent or cases are familial, and early onscl or familial Alzheimer disease is associated with initiations in amyloid precursor protein gene on chromosome 21. Piesetiilin-l gene on chromosomc I. And ptesenilin-2 gene on chromosome 14. Late onset or ramilial and spo¬radic rorms of Alzheimer disease is associated wilh moncler jacket sale apof-p4 allele on chromosome 19.Parietal and temporal cortical atrophy w ith dispropor¬tionate hipjxvampal volume loss is identified on cross- sectional imaging. Temporal hom dilatation of more than 3 mm is seen in more than 651 ol patients wilh Alzheimer type dementia. Width of the temporal horn is also found to be the mosl sensitive discriminator.