Reversible severe functional decline in an older patient with Alzheimer's dementia: A case report

BACKGROUND: Enteral feeding via percutaneous endoscopic gastrostomy (PEG) is generally discouraged in advanced dementia, because it has not been shown to improve survival, aspiration risk, or functional outcomes. However, these recommendations assume accurate disease staging. Reversible conditions such as metabolic encephalopathy and severe malnutrition may mimic terminal-stage dementia, leading to premature limitation of potentially beneficial nutritional support. This case highlights the importance of individualized reassessment before concluding that enteral feeding is futile. CASE PRESENTATION: An 85-year-old woman with an 8-year history of Alzheimer dementia developed profound functional decline over 3-4 months, including mutism, inability to ambulate, incontinence, and minimal oral intake. At a routine visit with her primary care clinician (PCC), she was presumed to have progressed to advanced dementia, and no further evaluation was pursued, because current guidelines discourage artificially administered nutrition and hydration in advanced dementia. After transitioning to home-based primary care, her new PCC investigated the unusually rapid decline. Laboratory testing revealed severe hypernatremia (sodium, 158 mmol/L), acute kidney injury, and severe malnutrition (body mass index [BMI], 16.1). She was diagnosed with metabolic encephalopathy superimposed on moderate-stage Alzheimer dementia. Nutritional assessment confirmed severe malnutrition by Global Leadership Initiative on Malnutrition (GLIM) criteria. Following transdisciplinary evaluation and shared decision-making with the patient's daughter, her designated health care proxy, PEG placement was performed. Nutritional rehabilitation normalized laboratory values, restored BMI to 21-22, and resulted in marked cognitive and functional improvement. CONCLUSIONS: Severe malnutrition and metabolic derangements may produce a reversible syndrome that mimics advanced dementia. Careful evaluation of reversible contributors to rapid decline is essential before forgoing nutritional support, thus allowing for individualized, goal-concordant decisions and avoiding inappropriate therapeutic nihilism.