EEG Changes

Question 1

ConditionCJD (sporadic only, does not apply to variant)

Answer 1

EEG findingsEarly on there is non specific slowing, later periodic biphasic and triphasic synchronous sharp wave complexes superimposed on a slow background rhyth

Question 2

Huntington’s

Answer 2

EEG findingsLow voltage EEG, in particular no alpha (flattening)

Question 3

Delirium

Answer 3

EEG findingsDiffuse slowing, decreased alpha, increased theta and delta

Question 4

Delirium tremens

Answer 4

EEG findingsHyperactive trace, fast

Question 5

Alzheimer’s

Answer 5

EEG findingsReduced alpha and beta, increased delta and theta

Question 6

ConditionPetit mal epilepsy (absence seizure)

Answer 6

EEG findingsGeneralised, bilateral, synchronous, 3Hz (3 waves per second) spike and wave pattern

Question 7

Generalised epilepsy

Answer 7

EEG findingsSharp spikes, 25-30Hz

Question 8

Partial epilepsy

Answer 8

EEG findingsFocal spikes

Question 9

Myoclonic epilepsy

Answer 9

EEG findingsGeneralised spike and wave activity

Question 10

Encephalopathy

Answer 10

EEG findingsDiffuse slowing

Question 11

Antipsychotics (typical)

Answer 11

Effect on EEGDecreased beta with Increased alpha, and delta, haloperidol least effect

Question 12

Antipsychotics (atypical)

Answer 12

Effect on EEGVaried effect, clozapine most significant effect

Question 13

Antidepressants

Answer 13

Effect on EEGReduce beta, increase all others

Question 14

Anticonvulsants

Answer 14

No effect

Question 15

Lithium

Answer 15

Slowing

Question 16

Benzodiazepines

Answer 16

Effect on EEGIncrease beta, decrease alpha

Question 17

Barbiturates

Answer 17

Increase beta

Question 18

Drug of abuseStimulants (cocaine, nicotine)

Answer 18

Increase alpha

Question 19

Drug of abuseDepressants (alcohol, opioids)

Answer 19

Decrease alpha

Question 20

Cannabis

Answer 20

Increase alpha

Question 21

Metabolic encephalopathy

Answer 21

Generalised diffuse delta and theta waves can be considered as diffuse slowing, which is associated with encephalopathy.