Patterns: Abnormal Variants

Question 1

faster or slower

Answer 1

frequency

Question 2

higher or lower

Answer 2

voltage

Question 3

varies from usual

Answer 3

location

Question 4

differs from usual

Answer 4

morphology

Question 5

fails to react

Answer 5

reactivity

Question 6

what can be seen on an abnormal EEG

Answer 6

• background slowing
• slow waves
• paroxysmal discharge
• specific patterns

Question 7

what can abnormal EEGs present as?

Answer 7

• focal
• lateralized
• generalized

Question 8

the dominant activity of wakefulness and rest. Alpha activity is considered the most common background activity

Answer 8

normal

Question 9

the dominant activity recorded in abnormal patients during resting asymptomatic periods

Answer 9

abnormal

Question 10

when is delta abnormal?

Answer 10

in an awake patient

Question 11

delta intermixed with other frequencies

Answer 11

polymorphic (arrhythmic)

Question 12

• lesion of cerebrum
• white matter of dysfunction
• structural lesions (tumors, CVA, Abscess, Dementias)

Answer 12

Focal (polymorphic)

Question 13

• toxic encephalopathy
• metabolic encephalopathy
• degenerative disorders
• demyelinating disorders
• infectious diseases
• cerebral ischemia

Answer 13

generalized (polymorphic)

Question 14

• IRDA
• generalized brain dysfunction
• repeating delta waves of the same frequency

Answer 14

monomorphic (rhythmic)

Question 15

• frontal predominance
• adults
• bursts of sinusoidal, bilaterally synchronous, monomorphic activity

Answer 15

FIRDA

Question 16

what attenuates FIRDA?

Answer 16

• eye closure
• HV
• drowsiness

Question 17

what are causes of FIRDA?

Answer 17

• tumors
• toxic/ metabolic encephalopathy
• increased ICP

Question 18

• occipital predominance
• children
• absence seizures

Answer 18

OIRDA

Question 19

• temporal predominance
• usually associated with temporal lobe epilepsy

Answer 19

TIRDA

Question 20

• spike or sharp waves or mixed theta-delta waves
• background always disrupted
• biphasic or triphasic spike or wave discharges occur after acute insult
• non-reactive

Answer 20

Periodic Lateralized Epileptiform Discharges (PLEDS)

Question 21

what are causes of PLEDS

Answer 21

• ischemic CVA
• herpes simplex encephalitis
• tumors
• encephalitis
• cerebral abscess

Question 22

• voltage 100-200 uV
• asynchronous
• bi/triphasic spike or sharp wave discharges
• background always disrupted
• non-reactive

Answer 22

BIPLEDS

Question 23

what are causes of BIPLEDS

Answer 23

• anoxic encephalopathy
• herpes simplex

Question 24

• 9-10 Hz
• generalized
• fronto-central maximum
• usually no slow waves
• non-reactive
• poor prognosis

Answer 24

alpha coma

Question 25

what are causes of alpha coma

Answer 25

- cerebral anoxia - brainstem lesions - drug overdose

Question 26

- small negative, large positive, negative waveform - generalized with frontal maximum - anterior- posterior phase lag of 60-120 ms - abnormal background

Answer 26

triphasic waves

Question 27

causes of triphasic waves

Answer 27

- metabolic disturbances - primarily hepatic encephalopathy

Question 28

- periods of moderate-high amplitude activity usually lasting a few seconds - bursts consist of spikes, sharps, and other frequencies - generalized - deepest level of coma before brain death - non responsive

Answer 28

burst suppression

Question 29

causes of burst suppression

Answer 29

- anoxic encephalopathy - acute intoxication - hypoxia - head injury - may be reversible if due to drug overdose, hypothermia, or anesthesia

Question 30

waveforms that repeat with approximately the same interval each time

Answer 30

periodic patterns

Question 31

Give examples of periodic patterns

Answer 31

- PLEDS - BIPLEDS - CJD - Herpes Simplex Encephalitis - ECI

Question 32

- biphasic and triphasic periodic sharp waves - excessive slow activity - disorganized background - prion diseased - rapidly progressive dementia

Answer 32

Jakob-Creuzfeldt Disease (CJD)

Question 33

balance disturbance

Answer 33

ataxia

Question 34

- usually affects temporal lobes - viral infection - lies dormant in the trigeminal nerve

Answer 34

Herpes Simplex Encephalitis

Question 35

list symptoms of HSE

Answer 35

- drowsy or confusion - nuchal rigidity - fever - HA - seizures

Question 36

list examples of CJD

Answer 36

- rapidly progressive dementia - speech impairment - myoclonus - ataxia - seizures

Question 37

>2uV

Answer 37

ECI