NONHEREDITARY chorea is usually thought to be caused by rheumatic fever.1-4 In patients without rheumatic disease, chorea is often attributed to psychiatric problems, or it is given no specific etiology.5-8 The terms "pure" or nonrheumatic chorea have been used for such cases.6,7 There are, however, many less common and frequently overlooked causes of chorea which should be considered when there is no evidence of rheumatic fever. In some of these conditions, the movement disorder appears as part of a well-defined process, but in other instances, the abnormal movements are the presenting or major complaint and the diagnosis may be difficult.
Among the illnesses in which chorea has been observed are Addison's disease,9 ataxia-telangiectasia,10 beriberi,11 brain tumors,12-14 burns in children,15 carbon monoxide intoxication,16 cerbral lipidoses,11 cerebral vascular disease,17,18 diptheria,19 encephalitis (St. Louis, inclusion body and epidemic),11,18 Henoch-Schönlein purpura,20 hyoscine intoxication,21 hypocalcemia,22 hypoglycemia,21 hypomagnesemia,23 hypoparathyroidism,22 incontinentia pigmenti,24 isoniazid (INH) poisoning,11
GREENHOUSE AH. On Chorea, Lupus Erythematosus, and Cerebral Arteritis. Arch Intern Med. 1966;117(3):389-393. doi:10.1001/archinte.1966.03870090073012