Anterograde Amnesia after Acute Glufosinate Ammonium Intoxication

Abstract

Glufosinate ammonium (GA) intoxication causes several neurologic complications. We report a rare but typical case of GA intoxication associated with anterograde amnesia and bilateral hippocampal involvement. A 53-year-old woman with GA intoxication presented to the emergency department. Initial general and neurologic examinations were unremarkable but, from the day after admission, she exhibited anterograde amnesia. On brain magnetic resonance imaging, the signal intensity in the hippocampus was symmetrically and bilaterally increased. She was discharged with no medical problems, but the anterograde amnesia remained. Eleven days after the onset of amnesia, she returned to the neurology outpatient department with persisting anterograde amnesia but improving symptoms.

Prolonged cognitive dysfunction in patient with splenial lesion of the corpus callosum caused by glufosinate ammonium poisoning

“…This excitotoxicity mechanism is associated with glufosinate-induced convulsions, and it is also associated with memory impairment by hippocampal injury. [ 3 4 ] Furthermore, GLA irreversibly inhibits the synthesis of glutamine from ammonia by inhibiting glutamine synthetase, causing intracellular accumulation of ammonia. Hyperammonemia can cause oxidative stress on neurons, leading to cell death and tissue necrosis.…”

“…Hyperammonemia can cause oxidative stress on neurons, leading to cell death and tissue necrosis. [ 3 5 ] Surfactants such as polyoxyethylene alkyl ether sulfate can increase the permeability of the blood–brain barrier, thereby enhancing GLA's neurotoxicity. [ 6 ] A recent study reported decreased glucose metabolism in the lower frontal and temporal lobes on F-18 fluorodeoxyglucose positron emission tomography scan of patients with GLA poisoning.…”

“…Most previous studies of GLA poisoning have reported late-onset memory impairment due to GLA-induced hippocampal lesions. [ 1 2 3 5 8 ] Furthermore, several reports of GLA-induced SCC lesions presented that there were no neurological complications other than reversible memory impairment. [ 6 9 ] However, our patient developed not only memory impairment, but also prolonged overall cognitive dysfunction.…”

Neurotological Findings in a Patient with Glufosinate Ammonium Intoxication

“…Various neurological symptoms including loss of consciousness, convulsion, and memory impairment due to acute GLA intoxication have been reported [1][2][3][4][5][6][7]. However, no study has reported brainstem and cerebellar dysfunction associated with GLA.…”

“…Our patient with ingestion of GLA presented with cerebellar ataxia and ocular motor findings suggestive of cerebellum involvement such as upward gaze tendency, spontaneous downbeat, gaze-evoked nystagmus, perverted head impulse test, and impaired smooth pursuit. Most neurological manifestations related to GLA intoxication were found to be mental change, seizure, and memory dysfunction[1,[3][4][5]. We could find one report on neurotological finding related to GLA.…”