Dipyridamol opbouw in secundaire preventie van beroerte

INTERVENTION: Two study arms, 4 weeks medication. Both arms: Two weeks acetylsalicylic acid 160 mg once daily and week 3 and 4 80 mgs once daily. Further: 1. Week 1 and 2, 200 mgs dipyridamole retard once daily. Week 3 and 4 dipyridamole retard 200 mgs twice daily; 2. Week 1, 75 mgs dipyridamole once daily. Week 2, 75 mgs dipyrdidamole twice daily. Week 3, 200 mgs retard once daily and week 4 200 mgs retard twice daily. CONDITION: ; Stroke, Stroke, Headache, TIA, Dipyridamole ; ; PRIMARY OUTCOME: Headache frequency. INCLUSION CRITERIA: 1. Age > 18 years; 2. Ischemic CVA or TIA; 3. Patients starting treatment with acetylsalicylic acid combined with dipyridamole accoriding to Dutch standards; 4. Able to fill out a diary.