Aneurismas intracranianos incidentais não rotos de circulação cerebral anterior : impacto da microcirurgia nas funções cognitivas e comportamentais

Abstract

BACKGROUND : Recent technological advances in neuroimaging modalities, associated with increased prevalence of cerebrovascular diseases in general, have resulted in more frequent incidental detection of unruptured intracranial aneurysms. When opting for therapeutic intervention, it is a consensus that most lesions can be treated with acceptably low morbidity and mortality rates, regardless of the method performed. Recently, some studies have suggested that changes in cognitive status could be a form of complication attributable to microsurgical treatment. However, to the present date, no study had behavioral analysis or evaluation of cognitive functions with a term greater than 12 months postoperatively. This pioneering study contributes to the pursuit of new knowledge on these topics.AIMS : To evaluate the impact of microsurgical treatment on cognitive and behavioral functions in patients with incidental unruptured intracranial aneurysms of anterior cerebral circulation.METHOD : A within-subjects clinical trial was performed including 40 patients submitted to microsurgical clipping for unruptured intracranial aneurysms of the anterior cerebral circulation through left or right pterional approach. Subjects were evaluated in three stages: preoperative period, three months and three years after surgery. The cognitive and behavioral tests applied were: Mini Mental State Examination, Wechsler Adult Intelligence Scale III, Wechsler Memory Scale III, Boston Naming Testing, Stroop Test, Verbal Fluency Test and FrSBe (Frontal Systems Behavior Scale). Traditional epidemiological and outcome parameters were also analyzed. Paired Student´s t test and analysis of variance (ANOVA), followed by post-hoc test of Bonferroni were used for statistical purposes. Results were considered significant when P ≤ 0.05.RESULTS : Among the 40 patients of the study, feminine gender predominated (87.5%) and the mean age was 54.1 years. The topographic distribution of treated aneurysms was: internal carotid artery (45%), middle cerebral artery (45%), and anterior communicating artery (10%). Five patients had multiple aneurysms. Aneurysm´s sizes ranged between 3 and 15 mm (mean: 5.67 mm). The aneurysms were xviii completely excluded by clipping in 95% of cases. Neurologic complications occurred on 7.5% of the cases and there were no deaths. The cognitive and behavioral tests showed no worsening in the performance of patients after microsurgical intervention in the short or long term. Clinical and demographic characteristics (gender, age, education and risk factors for cerebrovascular disease) were not predictive variables for cognitive or behavioral changes. Surgical approach, surgeons` learning curve, topography, multiplicity and size of aneurysms did not interfere with the results of the tests as well.CONCLUSION : Microsurgical clipping in patients with unruptured intracranial aneurysms did not alter the behavioral and cognitive functions in the short or long term. The intervention had a very high efficacy, associated to a low morbidity and mortality rates and a very good functional outcome.