EEG patterns

Question 1

Antipsychotics

Answer 1

-slowing of beta activity with increase in alpha, theta and delta activity

Question 2

Antidepressants

Answer 2

-slowing of beta activity with increase in alpha, theta and delta activity

Question 3

Lithium

Answer 3

-slowing of alpha or paroxysmal activity

Question 4

Anticonvulsants

Answer 4

-no effect on awake EEG

Question 5

Benzos

Answer 5

• increased beta
• decreased alpha
• overdose leads to diffuse slowing

Question 6

opioids

Answer 6

• decreased alpha
• increased voltage of theta and delta
• in overdose slow waves are seen

Question 7

Barbiturates

Answer 7

• effects are opposite to that of alcohol
• increased beta activity
• spikes in withdrawal

Question 8

Alcohol

Answer 8

• increased alpha
• increased theta activity
• withdrawal increases beta
• beta are fast in DTs

Question 9

Marijuana

Answer 9

• increased alpha activity in frontal area of brain

- overall slow alpha activity

Question 10

Cocaine

Answer 10

-Same as marijuana; longer lasting

Question 11

Nicotine

Answer 11

-increased alpha activity, in withdrawal marked decrease in alpha activity

Question 12

Caffeine

Answer 12

-withdrawal causes increase in amplitude or voltage of theta activity

Question 13

Absence seizures

Answer 13

-regular 3 Hz complexes

Question 14

Alzheimers

Answer 14

-rarely normal in advanced dementia

Question 15

Angelman’s syndrome

Answer 15

-prolonged runs of 2-3hz frontal activity

Question 16

Antisocial personality disorder

Answer 16

-increased incidence of abnormal EEGs in those with aggressive behaviour

Question 17

ADHD

Answer 17

-up to 60% have EEG abnormalities (spike/spike waves)

Question 18

Borderline personality disorder

Answer 18

-positive spikes in 25%

Question 19

CJD

Answer 19

• generalised periodic 1-2Hz sharp waves seen in nearly 90% patients with sporadic CJD
• not seen in variant or familiar

Question 20

Closed head injuries

Answer 20

• focal slowing

- focal delta slowing

Question 21

Diffuse atherosclerosis

Answer 21

-slowed alpha frequency and increased generalised theta slowing

Question 22

Herpes simplex encephalitis

Answer 22

-episodic discharges are recurring every 1-3 seconds with variable focal waves over the temporal areas

Question 23

Huntingtons

Answer 23

• initial loss of alpha

- latter flattened trace

Question 24

Infantile spasms

Answer 24

• seen in tuberous sclerosis
• hypsarrhythmia (diffuse giant waves) with chaotic background of irregular, asynchronous multifocal spikes and sharp waves
• clinical seizures are associated with a marked suppression of the background- called the electrodecremental response

Question 25

Infectious disorders

Answer 25

-diffuse, often synchronous, high voltage slowing

Question 26

Metabolic and endocrine disorders

Answer 26

• diffuse generalised slowing

- triphasic waves 1.5-3.0 per second high-voltage slow-waves especially in hepatic encephalopathy

Question 27

Neurosyphilis

Answer 27

-non-specific increase in slow waves occurring diffusely over the scalp

Question 28

Panic disorder

Answer 28

• paroxysmal EEG changes consistent with partial seizure activity in one third
• focal slowing in about 25% of patients

Question 29

Seizures

Answer 29

-generalised, hemispheric or focal spike/spike wave discharge

Question 30

Stroke

Answer 30

-focal or regional delta activity

Question 31

Structural lesions

Answer 31

-focal slowing/focal spike activity