Which findings on EEG are characteristic of encephalopathy?

Updated: Oct 09, 2019
  • Author: Eli S Neiman, DO, FACN; Chief Editor: Selim R Benbadis, MD  more...
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In general, the most prominent feature of the EEG record in encephalopathies (if there is a change) is slowing of the normal background frequency. Over the course of the disease if serial EEGs are performed, disorganization of the record may develop gradually. Reactivity to photic or other type of external stimulation may be altered. If a QEEG is performed, it may show a frequency shift or decreased interhemispheric coherence of background frequencies. Some conditions are associated with an increase in seizure frequency, and in such cases, epileptic activity may be recorded. [5]

In a given context, EEG can play a clinically useful role, especially because functional MRI, positron emission tomography (PET), and single-photon emission computed tomography (SPECT) are either still in an experimental stage or require special settings that are not widely available.

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