1819
BACKGROUND : A transient leukoencephalopathy mimicking cerebrovascular accident has been described as a complication of chemotherapy , most commonly in recipients of intrathecal methotrexate for childhood leukaemia .
 Disease: leukoencephalopathy; Disease: cerebrovascular accident; Chemical: methotrexate; Disease: leukaemia
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Disease: leukoencephalopathy; Disease: cerebrovascular accident; Chemical: methotrexate; Disease: leukaemia