Valproate-Induced Hyperammonemic Encephalopathy: Imaging Findings on Diffusion-Weighted MRI

Short Reports subject with AD was a 53-year-old right-handed man with a 4-year history of progressive memory decline and an MMSE score of 17. Neuropsychological evaluations showed verbal and visual memory impairments as well as mild frontal executive dysfunctions but no evidence of visuospatial dysfunction, dressing apraxia, Gerstmann syndrome, simultanagnosia (as assessed by the same Navon figures) or other elements of Balint syndrome. The patient could also trace the outlines of figures with a pen (fig. 1D). FDG-PET findings (fig. 1F) and an SPM analysis (fig. 2B) showed hypometabolism mainly in temporal area. All 4 subjects performed comparably in holding the laser point still for 10 s. By contrast, when tracing the outlines of figures, our patient showed severe visuomotor ataxia (fig. 1G) compared to controls (fig. 1H–J).

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