|PURPOSE OF THE STUDY A retrospective analysis of the effect of anticoagulation and anti-aggregation treatments on the post-injury clinical status, frequency of necessary surgical interventions including re-operations, course of intracranial haemorrhage dynamics and treatment outcome in patients with acute traumatic intracranial haematoma. MATERIAL AND METHODS The group consisted of 328 patients with acute post-traumatic intracranial haemorrhage treated at the author's institution from 2008 to 2012. Fifteen patients with anticoagulation therapy (warfarin; 8 females, 7 males; median age, 72.0 years) and 46 patients with anti-aggregation treatment (21 females, 25 males; median age, 75.5 years ; 37 with acetylsalicylic acid, 5 with thienopyridines, 2 with new antithrombotics and 2 taking dual anti-aggregation therapy), all older than 55 years, were included in statistical analysis. The post-injury clinical condition (Glasgow Coma Scale), incidence of haemorrhagic contusions, intracranial haematoma progression, particularly when surgery was indicated, incidence of re-operations and treatment outcome (Glasgow Outcome Scale - GOS) were the study parameters. The control group included 77 patients with post-traumatic intracranial haematoma with normal coagulation who were older than 55 years (27 females, 50 males; median age, 67 years). Patients younger than 55 years and those with normal coagulation were not included in the statistical analysis. The treatment of all patients with anti-aggregation or anticoagulation therapy was consulted with the haematology specialist. RESULTS The median age and initial status evaluated by the Glasgow Coma Scale were similar in the groups of anti-aggregated and anticoagulated patients and the control group. The number of good treatment outcomes, as evaluated by the GOS, was significantly higher in the anti-aggregated patients than in those on warfarin. A comparison of anti-aggregated, anticoagulated and normal coagulation patients did not show any statistically significant differences in the incidence of patients operated on, in the incidence of haemorrhagic contusions requiring surgery as a marker of the severity of brain parenchyma injury, intracranial haemorrhage progression with time, particularly when requiring surgery, and the rate of re-operations. However, when comparing the group of anti-aggregated patients with the control group, the higher incidence of haemorrhagic contusions and the lower number of patients requiring surgery were found to be close to the level of statistical significance. DISCUSSION The positive effect of anti-aggregation and anticoagulation treatment on the morbidity and mortality from cardiovascular diseases should be regarded in relation to a higher risk of haemorrhagic complications. If a bleeding complication occurs, the possibility of neutralising this treatment should be considered, but this is particularly difficult in new agents. The relationship between anti-aggregation or anticoagulation treatment and the treatment results in the patients with head injury is particularly important from the neurosurgical point of view, because the relevant literature data are ambiguous. CONCLUSIONS The results did not confirm any statistically significant adverse effects of anticoagulation or anti-aggregation treatment on the severity of post-injury status and risk of intracranial bleeding progression. The incidence of poor outcomes is higher in anticoagulated patients than in anti-aggregated patients. Although not reaching the level of statistical significance, the results also indicate higher risk of significant haemorrhagic brain contusions in anti-aggregated patients.