What defines a structural cause of altered mental status?

A structural cause of altered mental status refers to a physical alteration or abnormality within the brain that directly affects its function. A space-occupying lesion, such as a tumor, abscess, or hematoma, represents such an abnormality. This type of lesion can compress brain tissue, disrupt normal neurological pathways, and lead to changes in consciousness or cognition.

In contrast, severe hypoxia relates to insufficient oxygen supply, which can alter mental status but does not involve a direct physical change in brain structure. Toxic substances influence brain function through chemical means rather than structural changes. Insufficient blood flow can affect brain perfusion, leading to altered mental status, but this too is not classified as a structural cause since it doesn't involve a discrete physical entity located within the brain tissue.

Understanding the distinction between structural and non-structural causes of altered mental status is crucial in emergency medicine to guide appropriate diagnosis and treatment. Identifying structural lesions helps medical personnel prioritize interventions that may require surgical or advanced imaging considerations.