Cerebral infarction in children is often caused by
intracranial vascular disorder,
cardiac disease,
head injury, or
infection, and is rarely induced by
blood disease. In this paper, we describe an infantile case of
cerebral infarction associated with
thrombocytosis. A female infant of eight months of age developed left
hemiparesis after a slight
head injury. Her CT and MRI demonstrated a
cerebral infarction located from the right internal capsule to the right corona radiata. Laboratory findings revealed
iron-deficiency anemia and
thrombocytosis with a platelet count 107.5 x 10(4)/mm3. Although she had no disorder that had caused
iron deficiency, serum Fe value of the patient was low with a count of 18 micrograms/dl. Her bone marrow was normal except for a slight increase in the number of megakaryocytes. One month later, her
anemia was improved by means of oral
iron replacement. However, her platelet count remained at more than 100 x 10(4)/mm3 as it had been before. Her condition of left-sided
hemiparesis gradually improved by a program of rehabilitation, and did not recur after
aspirin administration. Although the main cause of her
thrombocytosis that led to a transient
cerebrovascular accident is obscure, it is postulated that her
iron deficiency anemia induced secondary
thrombocytosis, or else the patient had essential
thrombocytosis.