The natural history of untreated brain AVM. Analysis of a series of 57 patients

Clinical Material: 57 patients with untreated supratentorial cerebral AVMs were observed, the AVM having been assessed as unsuitable for any kind of therapeutical treatment: the patients either refused surgery or it was assessed that the operation would carry a high risk of postoperative functional deficit. Method: The average time of observation was 64 months (range from 2-228 months); the average age was 34 years (range from 6-63 years). AVMs were classified according to Martin-Spetzler scale (MSs); the patientsʹ conditions were assessed according to the Karnofsky-index. According to the initial clinical presentation, the patients were divided into the following groups: a) patients with hemorrhages, b) with seizures, c) with neurological deficits. Results: Two patients died in the course of observation. The patients with hemorrhages (38 cases) suffered from 52 episodes of recurrent hemorrhages, in the total cumulative observation period of 2440 months, which corresponds to the statistical probability that 4 out of 100 patients of this group will be afflicted by new hemorrhages in the course of one-year observation. Surprisingly, the frequency of recurrent hemorrhages is not influenced by AVM volume from the statistical point of view (p> 0.05). On the other hand, the AVMs in functional zones are statistically highly inclined to recurrent hemorrhages (p < 0.01), whereas they are more frequent in AVMs with deep vein drainage, compared to the superficial one. Grading according to MArtin-Spetzler scale did not prove useful for the prediction of recurrent hemorrhages. Regarding patients with seizures as initial symptoms (20 cases), 80% of them responded well to the medication therapy (statistically highly significant). Kaplan Mayer curve exhibited the decline in Karnofsky index after 18 months of observation: the MSs 4 group proved the most homogeneous. Conclusion: The natural course of illness of this patients series suggests a relatively benign natural course, which may ask for patience in the therapeutical treatment selection and timing.