Functional magnetic resonance imaging for brain pathologies

AUGUSTOVSKI, F; PICHON-RIVIERE A,; ALCARAZ A; BARDACH, ARIEL; FERRANTE, D; GARCIA MARTÍ, SEBASTIAN; GLUJOVSKY, D; LOPEZ, A; REGUEIRO, A

Documentos de Evaluación de Tecnologías Sanitarias

IECS

Año: 2005 p. 1 - 30

1668-2793

The aim of this review is to assess the evidence of the clinical usefulness of functional magnetic resonance imaging (fMRI) of brain pathologies.A bibliographic search was carried out on the main databases (MEDLINE, Cochrane, DARE, LILACS, NHS NICE, EMBASE), on the Internet´s general search engines, in health technology assessment agencies and coverage policies of other health systems.Only some isolated reports and few patients (less than 30) were found for the following applications:- To detect functional areas in patients prior to surgery of tumors and vascular malformations. - In case of an already known focal lesion, to correlate the extent of the dysfunction with the affected area. - To assess brain reordering tending to complement the function involved in patients with specific deficits: attention deficit disorder, maniac depressive disorder, phobic syndromes, disorders of the language, etc. - To detect brain infarction during onset and to monitor functional recovery post-event. - To objectively prove changes in the neuronal activity in response to functional surgery of Parkinson´s disease. - To monitor response to drug therapy in Alzheimer´s disease. In all the previous indications, the existing evidence is not considered sufficient to support its use as common practice.A greater number of articles were found for the following two applications:A. fMRI as a neurosurgical planning tool for refractory epilepsy surgery: fMRI is presented as a presurgical assessment test for patients with temporal lobe epilepsy refractory to medical treatment as adjuvant or substitute of the classical gold standard tests (Wada´s test and cortical electrical stimulation). Most studies (cross sectional) included few patients (between 7 and 32) and did not report test operating features, suggesting high sensitivity and moderate specificity. There is no evidence of good quality supporting the use of fMRI as a presurgical test.B. fMRI for the diagnosis of Alzheimer´s disease (AD): All the tests, cross sectional most of them, included few patients (less than 30) and showed evidence of which brain areas are suffering activation deficit by fMRI, in those patients with early, intermediate or advanced AD, in patients with mild cognitive impairment and patients with high risk of AD. In patients with clinically diagnosed AD, fMRI allows to assess which the brain areas mostly affected by the disease are. In the group of patients with mild cognitive impairment or early AD, the real prognostic value of the images observed by fMRI is still to be determined in long-term prospective studies. Currently, it is not possible to determine the efficacy of fMRI in AD.