If john's eeg reveals abnormal waves caused by brain malfunctions, he may be suffering from

By studying theta and delta wave frequencies in an EEG, the brain can be diagnosed. Malfunction to a region of the brain can be revealed by focal slowing of the EEG frequencies that can be attributed to tumors, stroke, and hemorrhage. General slowing reveal general brain malfunction such as neurodegenerative disorders like encephalopathy.