EEG QUESTIONS WITH SOLUTIONS 2024

EEG QUESTIONS WITH SOLUTIONS 2024 Electroencephalogram (EEG) a recording of the rhythmic electrical activity that can be made from the cerebral cortex via electrodes placed on the skull How does opening eyes changes the EEG output? lower amplitude, higher frequency Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:03 / 0:15 Full screen Alpha rhythm 8-13 Hz, awake relaxed adult with eyes closed Beta rhythm 13-30 Hz, awake adult with open eyes Theta rhythm 4-7Hx, drowsiness Delta rhythm .5-4Hz, sleep paradoxical sleep REM sleep, the EEG looks almost like the EEG of an awake person what gives the EEG its shape? The waves are derived from alternating excitatory and inhibitory synaptic potentials that occur in cortical neurons as a result of thalamocortical and other inputs. when awake, are the alternating excitatory and inhibitory potentials that give the EEG its shape in phase or out of phase? What about in sleep? Awake- the inputs are irregular or out of phase Sleep- in phase, get a larger amplitude EEG What is the EEG pattern of a patient in a coma? EEG is dominated by delta activity what is the EEG patter of a brain dead patient? sustained flat EEG reading what is the EEG pattern of a patient with petit mal seizures? EEG displays spikes and wave activity what is the EEG activity of a patient with grand mal seizures? EEG shows widely distributed seizure activity what is the EEG activity of a patient with partial seizures? EEG reveals spikes in the affected areas how can an EEG be used to test the integrity of a sensory pathway? apply the electrodes and stimulate areas of the body and see if the sensation makes it to the brain and the brain recognizes it somatosensory evoked potentials (SEP) cortical potentials generated by the response of sensory neurons to the stimulation of peripheral nerves -can actually follow the nerve through the body In the US, as a flat EEG required to certify brain death? No, however it is considered to have confirmatory value diagnostic criteria for clinical diagnosis of brain death 1. prerequisites- clinical and neuroimaging evidence, no intoxication, poisoning, electrolyte or endocrine disturbance, core temp >32 2. coma or unresponsiveness 3. Absence of brainstem reflexes 4. Apnea How can a petit mal seizure and a grand mal seizure be distinguished? grand mal siezures have 2 phases: tonic and clonic Petit mal sieurs have regular activity, usually the brain activity is asynchronous gran mal siezure a generalized tonic-clonic seizure -the person will emit a short cry and fall to the floor -their muscles will stiffen (tonic phase) then their extremities will jerk and twitch (clonic phase) -bladder control may be lost -conciousness is regained slowly -patients have no recollection of the seizure petit mal seizure -more mild than the grand mal seizure -causes unconsciousness without causing convulsions -the seizure begins abruptly and without warning -consists of a period of unconsciousness with a blank stare, and ends abruptly -no confusion after the seizure and the person can resume full activity afterwards -there is no recollection of the seizure temporal lobe seizure -originates in the temporal lobe of the brain -involves sensory changes (ex: smelling an unusual odor) -the most common cause of medial temporal sclerosis or hippocampal sclerosis -aging, stroke, vascular risk factors