Cerebral EEG

Question 1

Beta wave frequency range and the associated mental activity

Answer 1

13-30 Hz and associate with mental activity and is observed during active, alert wakefulness andREM sleep

Question 2

Alpha wave frequency range and the associate brain function

Answer 2

8-13 and associated with a state of relaxed wakefulness and is mainly prominent in the parietal and occipital lobes

Question 3

Theta waves and the associated mental activity

Answer 3

4-8 Hz (young adult more than older) and observed in awake, drowsy, and non-R.E.M. Sleep states

Question 4

Delta wave frequency and the associated mental function

Answer 4

.5-3.5 and prominent during non REM sleep

Question 5

Current sink definition

Answer 5

The flow of inward membrane current (movement of positive charge into the intracellular compartment

Question 6

How can current sinks be created

Answer 6

Ion channel gating that allows net inward current ot flow

Question 7

What is current source

Answer 7

The return flow of current to the extracellular space (a local transient increase in extracellular positivity

Question 8

What is the principal determinant in EEG amplitude

Answer 8

The degree of synchronization within the neuronal population being measured

Question 9

Why does an EEG measure synaptic activity rather than action potentials

Answer 9

Because synaptic potentials usually last much longer than action potentials

Question 10

Why is an EEG ambiguous of excitatory or inhibitory synaptic activity

Answer 10

Because a current(extracellular negativity) sink may be created by either a local inward current flow at the site of excitatory synapses or it can be created by
a return current flow at a site distant from excitatory synapses or outward flow at the site of inhibitory synapses

Question 11

What is a sensory evoked potential

Answer 11

A specific change in ongoing eeg activity caused by stimulation of a sensory pathway

Question 12

What does a deflection in the evoked potential represent

Answer 12

One synaptic relay in the auditory system. The earliest being cochlear and brain stem processing, the latest representing cortical processing

Question 13

What causes a seizure physiologically

Answer 13

Abnormal patterns of neuronal activity

Question 14

Partial seizures

Answer 14

Restricted to one area of the brain

Question 15

Generalized seizures

Answer 15

Involve abnormal activation of many areas of the brain

Question 16

Simple partial seizure

Answer 16

The patient retains consciousness but may experience unusual sensation or smells or tastes or feelings that aren’t actually present

Question 17

Complex partial seizure

Answer 17

The patient has a change in consciousness that may be accompanied by twitches or movements called automatisms

Question 18

What is an aura

Answer 18

The preceding of a partial seizure

Question 19

What is secondary generalization of a seizure

Answer 19

Where a seizure spreads to another area of the brain

Question 20

Generalized seizures

Answer 20

Result from abnormal neuronal activity appearing synchronously across many parts of the brain involving loss of consciousness/spasms

Question 21

EEG recording for a partial seizure

Answer 21

Abnormalities are seen in only a few EEG channels

Question 22

generalized seizure EEG reading

Answer 22

Simultaneous abnormal activity on most or all channels of the recording