A case of glyphosate encephalopathy presented with retrograde amnesia and an increase of blood flow in the medial temporal lobes on the arterial spin labeling images.

Background: Suicide attempts with glyphosatebased herbicides are not rare in rural areas in Japan. There are some reports on glyphosate encephalopathy, however, the detailed features of the clinical course are still unclear. Case: A female case in her early 70s was hospitalized after ingesting a glyphosate-based herbicide. On the fifth day after admission, she developed confusion and cognitive impairment including retrograde amnesia, even though her general condition was improved. An increase of blood flow in the bilateral medial temporal lobes was observed on the arterial spin labeling (ASL) of magnetic resonance image (MRI). The electroencephalogram (EEG) showed paroxysmal activities centered on the right temporal electrodes, suggesting pathological lesions with abnormal neuronal activity or glial activity in the medial temporal lobes. After sodium valproate and olanzapine were administered, her psychiatric symptoms and cognitive impairment were improved and the findings on the MRI and the EEG were rectified, although retrograde amnesia remained. Conclusions: Patients who ingested glyphosate would need careful management considering the subsequent glyphosate encephalopathy with pathological lesions in the medial temporal lobes. The findings of ASL study and EEG were salient and may be useful for the early detection and management of encephalopathy.departmental bulletin pape