Neuroimaging findings in a case of fluoxetine overdose.

Brain MRI and ¹⁸F-FDG PET/CT scans were performed in a patient who had survived a suicide attempt by fluoxetine overdose. The patient presented with the following clinical signs and symptoms, and neuroimaging findings: severe signs of serotonin toxicity, including comatose state, akinetic rigid syndrome and dysautonomia; bilateral globus pallidus changes consistent with extensive pallidal necrosis and subsequent reversible diffuse ischemic changes in white matter, with posterior predominance, involving the splenium of the corpus callosum on brain MRI; and marked hypometabolism in the frontal, parietal and temporal cortical regions as well as in both caudate nuclei on ¹⁸F-FDG PET/CT performed 37 days later. These findings suggest that acute severe serotonin toxicity can induce structural and long-standing functional changes in multiple cortical and subcortical brain regions that are associated with cognitive and extrapyramidal syndromes.