Introduction: Patients living with dementia as well as patients with neurological deficits are at significant risk for injury from multiple sources. Injuries may include falls, neglect, and, in some cases, self-injury. These patients require significant observation and closely monitored care. 

Case Report: A 90-year-old man presented to a suburban emergency department (ED) by his family, who cared for him at home. The following case report describes a patient with dementia, hemineglect, and bruxism from a previous stroke who suffered a self-induced, partial amputation of his own thumb on the neglected side of his body.   

Conclusion: Patients with dementia and neurologic deficits present frequently in the ED. These patients are at considerable risk of self-injury. The emergency physician should maintain vigilance in both screening for injuries and being aware of these risks when planning living arrangements after disposition from the ED.