Table 1.

Glucose metabolism imaging approach to assess therapeutic effectiveness.

Disorder	Physiopathological approach	Radioligand	Population	Therapeutical class	Main findings	References
HD	Glucose metabolism	18F-FDG	11 riluzole-treated HD patients versus 12 untreated HD patients	Riluzole (benzothiazole)	Placebo-treated patients showed significantly greater proportional volume loss of grey matter and decrease in metabolic FDG uptake than patients treated with riluzole in all cortical areas (p < 0.05).	Squitieri et al. [6]
AD	Glucose metabolism	18F-FDG	6 months treatment pramipexole 20 mild-to-moderate AD, 15 completed all visits	Pramipexole (D2-family dopamine receptor agonist)	Broad regions where glucose uptake decreased suggesting a relative decrease in metabolism (consistent with regions of reduced metabolism in individuals with AD). Nonapparent effect of r-pramipexole on brain regional glucose uptake.	Benett et al. [7]
	Glucose metabolism	18F-FDG	12 months treatment rosiglitazone versus placebo in 80 mild-to-moderate AD patients	Rosiglitazone (PPAR agonist)	Rosiglitazone is associated with an early increase in whole brain glucose metabolism but not with any biological or clinical evidence for slowing progression over a 1 year follow up in the symptomatic stages of AD.	Tzimopoulou et al. [8]
PD	Glucose metabolism	18F-FDG	12 patients with advanced PD were assessed before and after 6 months of add-on apomorphine	Apomorphine	Significant metabolic changes were observed, with overall increases in the right fusiform gyrus and hippocampus, alongside a decrease in the left middle frontal gyrus. Consistent correlations between significant changes in clinical scores and metabolism were established.	Auffret et al. [9]
SCZ	Glucose metabolism	18F-FDG	18 neuroleptic-naïve first-episode schizophrenic patients	Olanzapine	Glucose metabolism in responders was significantly increased after treatment in the left precentral gyrus, left postcentral gyrus, and left paracentral lobule and significantly decreased in the left hypothalamus.	Yoshimuta et al. [10]
	Glucose metabolism	18F-FDG	30 never-previously medicated psychotic adolescents (ages 13–20)	Olanzapine or haloperidol	Individuals treated with olanzapine showed increased relative metabolic rates in the frontal lobe more than the occipital lobe while patients treated with haloperidol failed to show increase in frontal metabolic rates and did not show an anteroposterior gradient in medication response.	Buchsbaum et al. [11]
	Glucose metabolism	18F-FDG	17 schizophrenic patients previously treated with antipsychotics	Olanzapine	No significant regional metabolic changes were related to previous treatment with classical neuroleptics.	Molina et al. [12]

AD, Alzheimer disease; FDG, fluorodeoxyglucose; HD, Huntington disease; PD, Parkinson disease; PPAR, peroxisome proliferator-activated receptor; SCZ, schizophrenia.