[A Case of Wernicke's Encephalopathy Presenting with Acute Deterioration of Consciousness Caused by Peripheral Parenteral Nutrition].

We report the case of a 67-year-old woman with Wernicke's encephalopathy(WE), who had been suffering from repeated vomiting and poor oral intake due to both reflux esophagitis and atrophic gastritis. She presented with altered of consciousness, horizontal nystagmus, and gait disturbance, and acute deterioration of consciousness was observed after starting peripheral parenteral nutrition (PPN). Brain MRI showed bilateral high intensity lesions in the medial thalamus and the dorsal midbrain on FLAIR and T2-weighted images. Although brain MRI characteristics are useful for diagnosing WE, it is possible that there are no abnormal MRI findings in its early stages. In addition, only 10-20% of WE cases present with the classical clinical triad of confusion, ophthalmoplegia, and ataxia. Therefore, confirming the diagnosis can be challenging. In general, rapid improvement of symptoms is observed with prompt vitamin B1 supplementation. However, delays in treatment can result in irreversible amnesia and ataxia. Furthermore, in the state of vitamin B1 deficiency, even PPN, not just total parenteral nutrition, can worsen symptoms, and this deterioration is attributed to the glucose load.