Fisch EEG Primer Chapter 19

Question 1

rythmical focal or multifocal EEG abnormalities often without spike and sharp waves components are features of…

Answer 1

ictal patterns in neonates; frequently occurs without clinical correlates

Question 2

These three conditions of neonates have features of both focal and generalized epileptiform activity, appear in infants and young children as the result of a variety of organic brain disorders…(3)

Answer 2

• Hypsarrythmia
• slow-spike-and-wave
• multifocal independent spikes

Question 3

How do you characterized pseduoperiodic patterns?

Answer 3

fairly regular recurrence of various paroxysmal forms of activity

Question 4

ictal patterns without spikes and sharps are seen in…

Answer 4

patients that also have focal and generalized interictal epileptiform patterns

Question 5

What is the relationship of pseudoepileptogenic (PLEDs, periodic generalized sharp waves, periodic generalized complexes, suppresion-burst, triphasic waves) patterns to seizures or epilepsy?

Answer 5

There is no proven relationship to epilepsy or seizures

Question 6

READ 19.1 Neonatal seizures

Answer 6

READ 19.1 Neonatal seizures

Question 7

READ 19.2 Infantile patterns of hypsarrythmia, slow spike and wave….

Answer 7

READ 19.2 Infantile patterns of hypsarrythmia, slow spike and wave….

Question 8

pseudoperiodic complexes are simliar to eachother in that they

Answer 8

1) consist of complexes which recur at fairly regular intervals on a background of slow waves of usually low amplitude
2) most are generalzied or widespread in distribution and synchronous with timing and produce a myoclonic seizure manifestations

Question 9

Periodic Lateralizing epileptiform discharges (PLEDs) and bilateral indenpendent periodic lateralized epileptiform dischares (BIPLEDs)…(morphology, distribution

Answer 9

di- or multiphasic sharp waves and may include a slow wave; often lateralized but can have a mirror focus

Question 10

Periodic generalized sharp waves (mono-to-multiphasic) are often associated with which disease

Answer 10

creutzfeld jakob disease, seen usually within 12 weeks of symptom onset and are present in 90% of those with fully developed disease

Question 11

What are the two ways that an electrographic seizure pattern may evolve from PLEDs?

Answer 11

• focal seizure evolves directly from PLEDs
• seizure pattern develops alongside ongoing PLEDs (usually only persist for seconds before disappearing as seizure continues)

Question 12

Why might PLEDs represent an interictal pattern rather than an ictal pattern?

Answer 12

PLEDs often coexist with simultaneous and independent electrographic seizure patterns
NOTE: PLED patterns is generally considered a highly epileptogenic interictal pattern

Question 13

What is the setting PLEDs are usually found?

Answer 13

stroke (38%), neoplasm (20%), epilepsy (17%), misc (34%)–hsv, sickle cell, metabolic, sdh, tuberculoma
NOTE: recently reported with mitochondrial encephalopathies (MERRF, MELAS) and CJD.

Question 14

What are some features special to PLEDs

Answer 14

-rarely reactive to stimuli changes in state; persist into sleep

Question 15

Myoclonic jerking that occurs in PLEDs often is seen…

Answer 15

contralateral to the electrographic seizure pattern

Question 16

What is the typical time course of PLEDs

Answer 16

in general considered to be continuous and invariant but may transiently attenuate during state changes. Patterns simplifys over weeks or months but may last for years.

Question 17

BIPLEDs are commonly seen in…

Answer 17

diffuse or bilateral multifocal cerebral diseases such as HSV encephalitis, epilepsy, sickle cell anemia, anoxic encephalopathy - their presence indicates a guarded prognosis

Question 18

What is a potential trigger for the Periodic generalized sharp waves seen in CJD

Answer 18

Startling stimuli caused by light flashes

Question 19

Which other disorders can have a similar Periodic generalized sharp waves as seen in CJD

Answer 19

• Post anoxic encephalopathy

- cerebral fat embolism

Question 20

Periodic generalized complexes are often associated with which disorder?

Answer 20

Subacute slerosing panencephalitis (SSPE)

Question 21

What are the EEG features of SSPE?

Answer 21

periodic generalized complexes of high voltage (300 - 1500microV) with sharp and delta waves, not usually enhanced by sensory stimuli, sleep may enhance or obscure, clinically appears as myoclonic jerking

Question 22

Which other disorders can have a similar Periodic generalized complexes as seen in SSPE?

Answer 22

Postanoxic encephalopathy, head injury, drug intoxication, lipidoses, HSV encephalitis, tuberous sclerosis

Question 23

What are conditions in which suppression-burst pattern would be encountered?

Answer 23

comatose patients with reversible conditions (general anesthesia, hypothermia, Reye’s syndrome) or irreversible conditions (cardiopulmonary arrest, acute stroke, wernicke’s disease and encephalopathy, and encehpalitis)

Question 24

What are the suspected underlying physiolgical changes associated with suppression burst pattern?

Answer 24

cortical neuronal inactivity followed by depolarization and hyperpoloarization; anesthesia likely modifies thalamocortical interactions through GABAergic inhibition

Question 25

What is the typical morphology and distribution of a triphasic wave?

Answer 25

3 phases: largest phase is typically positive

Question 26

what clinical conditions are associated with the triphasic wave pattern?

Answer 26

metabolic/toxic disturbances (hepatic and renal failure, elderly, stroke, CHF, postictal

Question 27

What is the significance of the lateralized triphasic wave pattern?

Answer 27

no specific association with seizures, some association with underlying structural lesions however involved hemisphere cannot be predicted from amplitude asymmetry