The EEG of a patient with a tumor in the left frontal lobe would most likely show which type of brain activity?

In the context of a tumor in the left frontal lobe, the presence of left frontal polymorphic delta activity on the EEG reflects the pathological changes associated with the tumor. Tumors can disrupt normal electrical activity in adjacent areas of the brain, and as a result, polymorphic delta waves can arise. These waves may indicate a disturbance in the local neuronal function in the frontal lobe, often related to underlying abnormalities such as edema, increased intracranial pressure, or direct irritative lesions caused by the tumor itself.

Left frontal polymorphic delta activity is particularly significant because it would be localized to the area of the brain affected by the tumor, contrasting with other types of activity that might not specifically relate to the tumor’s presence. The identifying nature of delta waves, particularly when they are polymorphic, indicates a level of encephalopathy or altered cortical function, which is consistent with the presence of a significant structural lesion.