Muscle CT scan findings in McLeod syndrome and chorea-acanthocytosis

Computed tomography (CT) scans of lower leg muscles reveal a selective patt ern of fat infiltration in the posterior compartment with spared gracilis, semitendinosus, and the lateral head of the gastrocnemius in both McLeod sy ndrome and chorea-acanthocytosis, which are disorders characterized by the presence of circulating acanthocytes. The selectivity of affected muscles i ndicates that late onset and slowly progressive muscular atrophy in both di seases could be a consequence of primary myopathy. Asymmetrical muscle invo lvement may be seen during the process of degeneration only in McLeod syndr ome, however, and may be helpful in distinguishing this disease from chorea -acanthocytosis. (C) 2000 John Wiley & Sons, Inc.