MRI-based functional neuroimaging in ALS: an update.

With non-invasive functional imaging techniques, neuroscience has reached a new era of connecting anatomy and function. Although other techniques bear the advantage of either higher temporal or spatial resolution, functional magnetic resonance imaging (fMRI) is the most widely used non-invasive brain imaging technique. fMRI provides an acceptable balance between low patient load and high information capacity with good spatial resolution, making it ideal for clinical research in patients with physical restrictions like those with ALS. Most fMRI studies have provided evidence of a spatial shift of function in motor and extramotor areas in ALS patients. Furthermore, MRI-based functional imaging has supported the clinical findings of frontal cortical involvement not only in patients with ALS/dementia complex but also in patients with ALS and sub-clinical cognitive impairment. Functional MRI will identify the preserved but non-executable functions in ALS patients in the end stage and will set the direction for a new way of thinking on the functional capacities of these patients which will have a major impact on our way of thinking about end-of-life decisions.