We investigated the effect of CDP-choline on brain protection during extra-corporeal circulation (ECC) in patients submitted to open-heart surgery. We studied forty patients, using neurological, neuropsychological, neuroradiological (CT scan), and CBF evaluations. All the patients were evaluated two weeks before (T1), two weeks (T2), one month (T3) and six months after surgery (T4). Patients were randomly divided into two groups: subjects of the first group were treated with 2000 mg/die e.v. from two weeks before surgery to ten days after surgery, and then with 1000 mg/die i.m., 15 days per month, for the following 6 months (Group A), while subjects of the second group were treated with 100 mg/die, from two weeks before surgery to six months after surgery (Group B). After surgery, neither neurological symptoms nor morphostructural lesions were observed in the two groups. However, in the Group A, 75% (15 out of 20) of the patients evidenced reduced performances on neuropsychological tests at T2, compared to T1. At T4 only 66% (10 out of 15) of the impaired patients showed a persistence of the deficit. In the Group B 70% (14 out of 20) of the patients displayed reduced performances at T2. At T4, almost all of the patients, namely 86% (12 out of 14), showed a persistence of neuropsychological deficits. CBF data showed hypoperfusion areas in 9 patients in Group A (1.7 +/- 4.15 mean areas per patient), and in 10 patients in Group B (3.33 +/- 1.3 mean areas per patient), at T2. In 2.2+ off