MR spectroscopy in patients after surgical clipping and endovascular embolisation of intracranial aneurysms

BACKGROUND: In MR spectroscopy, we evaluated cerebral metabolic changes in patients 2–4 years after clipping or endovascular therapy of intracranial aneurysms. MATERIAL/METODHS: A prospective study was conducted in 36 patients after SAH, treated surgically (n=23) or by endovascular embolisation (n=13). Control group consisted of 20 healthy volunteers. The clinical evaluation was based on the Glasgow Coma Scale, Hunt and Hess grade, and Glasgow Outcome Scale. MR spectroscopy was performed with 1.5T system with PRESS sequence, at echo time of 35 ms, in frontal lobes unchanged in MR examination. Ratios of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI) and glutamine/glutamate complex (Glx) to creatine were assessed. RESULTS: Only a slight, statistically insignificant reduction of NAA/Cr and an insignificant increase of mI/Cr were noted; other metabolite ratios were close to the ones in the control group. Similar results were obtained in patients after surgical clipping and after endovascular therapy. Only in patients with aneurysms of anterior communicating artery complex (AcoA), the NAA/Cr ratio showed a significant reduction as compared to that of non-AcoA patients and of the control group. No significant changes of metabolite ratios were found in patients with internal carotid artery (ICA) and middle cerebral artery (MCA) aneurysms, with regard to aneurysm lateralisation. CONCLUSIONS: Surgical clipping and endovascular embolisation of ICA, MCA and posterior circulatory aneurysms do not induce changes in metabolite concentration in frontal lobes assessed in MR spectroscopy. In patients with AcoA aneurysms, 2–4 years after obliteration, there were found persistent metabolic changes in unchanged brain tissue of the frontal lobes, corresponding to neuronal damage (dysfunction).