Unilateral hippocampal infarction associated with an attempted suicide: a case report

INTRODUCTION: In our case report we describe the case of a patient who experienced a stroke in her left hippocampus that was found following an attempted suicide via glyphosate overdose. To the best of our knowledge this is the first case report to describe a hippocampal infarction associated with a drug overdose. CASE PRESENTATION: A 64-year-old Japanese woman was brought to our emergency department after ingestion of an unknown dose of glyphosate surfactant herbicide in order to attempt suicide. On admission, she was assumed to be presenting with depression or psychiatric illness, however, sudden-onset memory deficit became apparent. The patient manifested delirium, confusion, and severe anxiety. In addition, short-term memory loss was prominent, with the patient forgetting her attempted suicide. Following an array of standard tests and a brain computed tomography scan (which only showed an old infraction), we performed a magnetic resonance imaging scan and neuropsychological evaluations. The brain magnetic resonance image revealed a small high-intensity lesion in the dorsal part of the left hippocampal body, and memory tests demonstrated severe short-term recall deficits. We diagnosed her with a left hippocampal infarction and administered a course of 75mg of clopidogrel. She gradually became less confused over the course of a week, and a follow-up memory test revealed partial improvement in some domains. No abnormalities were found on a follow-up brain scan. However, despite rehabilitation, memory impairments remain. CONCLUSIONS: It is important to note that had the symptom of short-term memory been absent or less severe, she might have been misdiagnosed with depression or another psychiatric illness. Although a computed tomography scan failed to detect hippocampal lesions, a diffusion-weighted magnetic resonance imaging scan clearly revealed a lesion within the left hippocampus. Therefore, in addition to assessments focusing on psychiatric illnesses that might be the root cause of an attempted suicide, organic factors should be considered along with radiological examination and precise memory assessments for diagnosing similar cases.