The EEG findings in a sample suggestive of moderate-severe encephalopathy would likely show which characteristic?

In a sample suggestive of moderate to severe encephalopathy, excessive slowing is a hallmark EEG finding. This slowing reflects the disruption of normal cortical function and is indicative of the underlying neuronal dysfunction associated with encephalopathy. Typically, in healthy brains, EEG patterns display a mix of different frequencies, but in the case of moderate to severe encephalopathy, there is a significant increase in slower frequency waves, such as theta or delta activity, which indicates a state of impaired brain function.

When the brain is under stress, such as in cases of metabolic disturbances, infections, or toxic exposures, one can observe this excessive slowing as an EEG manifestation. This slowing may be diffuse across the scalp EEG recording due to widespread impairment, highlighting the brain's compromised state in encephalopathy.

As for the other options, normal voltage patterns would suggest preserved function, while enhancement of fast activity and focal deficits do not align with the general observation of widespread slowing in moderate to severe encephalopathy. These findings reinforce why excessive slowing is the correct characteristic associated with this condition.