<prompt> In metabolic encephalopathy, EEG will most likely show:Alpha activityBeta activityGamma activityDelta activity  <response>: Ans. d. Delta activity Ref: Ganong 24e p273; Guyton 11741-743; Samson Wrights 13e p315-318In metabolic encephalopathy, EEG will most likely show delta activity.In metabolic encephalopathy, Delta waves are seen predominantly due to a decrease in the consciousness.EEG Patterns In Sleep Beta b WaveAlpha aWaveTheta WaveDelta WaveSeen in Parietal and frontalQ region Patients awake, at rest with eyes openQ Recorded from parieto occipital regionQ. Related to decreased level of attention Seen in awake patient at rest with eyes closedQ and mind wandering Seen in hippocampusQ in childrenQ and drowsiness Found over parietal and temporal areas. Seen in deep NREM sleepQ and infantQFrequency14 Hz Q8-13 Hz4-7 Hz3-5 Hz minimumQAmplitudeLow amplitudeHigh amplitudeHigh amplitudeQLarge amplitude MaximumQCharacteristic Feature: Low-voltage, high frequency desynchronized electrical activity Can be produced by any form of sensory stimulation or mental concentration, such as solving arithmetic problems alpha rhythm gets replaced by beta, therefore beta rhythm known as alpha blockFrequency of alpha rhythm is decreased by: Old age Low blood glucose Low body temperature Low levels of adrenal glucocorticoids High arterial PaCO2 SleepRecorded in: Newborn infants Stage 1 of NREM sleep Emotional stress in adults particularly disappointment and frustration Many brain disorders Accentuated in children when they are crying High-voltage, low frequency synchronized electrical activity. Evoked by overbreathing Seen in pathological states in which thalamocortical transmission is blocked,such as coma. Beta rhythm is also known as arousal or alerting response, because it is correlated with the aroused, alert state Presence of intracranial tumor act as a source of delta wave activity. In metabolic encephalopathy, Delta waves are seen predominantly due to a decrease in the consciousness. 