The need to recognize the difference between a quality register and a randomized controlled trial.

Functional Stimulation There is no reason why the large number of functional stimulation studies performed with near infrared spectroscopy should not be directly transferred to a bed-side assessment in patients suffering from neurovascular or neurodegenerative diseases. The major problem here rather is the reluctance of clinical practice to focus on functional rather than structural brain imaging. The traditional exception is electroencephalography (EEG) and the assessment of visually, somatosensory, and acoustically evoked potentials (VEP/SSEP/AEP), which have been used for decades. The slow introduction into clinical practice is by no means specific to optical methods; Functional magnetic resonance imaging (fMRI) and positron emission tomography share a similar problem. Because spatial resolution of optical topography will most probably not reach that of fMRI techniques, primary cortical areas (motor and visual) may serve as indicators of a normal or disturbed neurovascular coupling. Much like evoked potentials, this will help link evidence of structural lesions (as seen in routine imaging approaches) to the clinical examination (which by no means is objective but still the gold standard when therapeutic success is evaluated).