Leukocyte count and aggregation during the evolution of cerebral ischemic injury.

We evaluated leukocyte aggregation by means of the leukergy test and count in 26 patients with atherothrombotic stroke and in 10 patients with transient ischemic attacks. The evaluation was performed within 24 h from the onset of symptoms and then repeated on day 2, 4, 6 and 8. Data were compared with those of 10 healthy controls. Stroke patients were followed until day 30 when a clinical examination and brain computed tomography were performed to evaluate the extent and outcome of cerebral damage. Both leukocyte aggregation and count were significantly increased in stroke patients with respect to controls. While leukocyte count was not able to differentiate the severity of neurological impairment in stroke patients, leukocyte aggregation was significantly higher in major than in minor stroke patients on days 2 and 4 (p < 0.05). Moreover, while values of leukocyte count recorded at entry remained substantially stable in the following determinations in all groups, leukocyte aggregation showed a significant increase (p < 0.05) on day 4 with respect to all the other determinations in major stroke patients. These findings show that the extent and temporal profile of changes in leukocyte count and aggregation are different in patients with cerebrovascular disease and suggest an involvement of altered leukocyte rheology in the development of cerebral ischemic injury.