Fig. 2

Brain 18 F-FDG PET axial slices before and after combined treatment with hr-NGF and tDCS. (a) In the first patient, before the combined treatment, a moderate global reduction in 18 F-FDG uptake was observed in all cortical regions, while radiotracer uptake was slightly decreased in all subcortical areas. (b) After the combined treatment, an increase in radiotracer uptake was detected in the right and left frontal cortices (right: +11%; left: +12%), right and left parietal cortices (right: +26%; left: +25%), right and left occipital cortices (right: +26%; left: +27%). (c) Brain 18 F-FDG PET axial slices of the second patient, before the combined treatment with hr-NGF and tDCS, showed a severe global reduction in 18 F-FDG uptake in all cortical and subcortical regions, more pronounced in the latter. (d) After the combined treatment, an increase in radiotracer uptake was detected in the caudate nucleus, bilaterally (right: +51%; left: +51%) and cerebellum (+ 20%). (e) In the third patient, brain 18 F-FDG PET axial slices before the combined treatment showed a mild global reduction in 18 F-FDG uptake in all cortical regions and a more severe reduction in all subcortical regions. (f) After the combined treatment, an increase in radiotracer uptake was detected in the bilateral frontal cortex (right: +29%; left: +34%), bilateral parietal cortex (right: +15%; left: +19%), right and left occipital cortices (right: + 20%; left: +19%) and cerebellum (+ 14%)