[Clinical symptoms of the supratentorial arteriovenous malformations and factors influencing their occurrence].

BACKGROUND AND PURPOSE

The aim of this study was to assess frequency of main symptoms of the supratentorial arteriovenous malformations (AVM) and attempt to find factors influencing their occurrence.

MATERIAL AND METHODS

88 consecutive patients operated on for AVM located supratentorially in the years 1983-2000 were included in a retrospective analysis. Statistical analyses including chi-square test and exact Fisher test were performed for comparisons among groups.

RESULTS

The most common cause of diagnostics was intracranial hemorrhage--62.5%. Epilepsy, headaches and non-hemorrhagic focal deficits were described in 38.6%, 9.1% and 4.5%, respectively. Deterioration (focal deficits and/or disturbances of consciousness) after hemorrhage occurred in 30%. The risk of hemorrhage from AVM was 2.2% per year. Hemorrhage was more frequent in the cases of small size (<3 cm) of AVM (p=0.001), deep location (p<0.05) and when single (p=0.001) and exclusively deep (p<0.05) venous drainage were present. However, superficial location of AVM and nidus size >3 cm significantly influenced epilepsy occurrence (p<0.05 and p=0.001, respectively). Sex and coexisting aneurysm did not influence occurrence of epilepsy or hemorrhage.

CONCLUSIONS

Supratentorial AVMs manifest most common as intracranial hemorrhage and epilepsy. Factors increasing the risk of hemorrhage are: small size, deep location of AVM, single and exclusively deep venous drainage. Factors increasing the risk of epilepsy are: superficial location and size >3 cm.