PERIODIC DISCHARGES

Question 1

WHAT TYPE OF EPILEPSY?

Answer 1

Frequent asymptomatic left temporal spike-and-slow waves in localization-related epilepsy (LRE).

Question 2

_________________are characteristically seen in acute (or subacute), pathological processes associated with a unilateral hemispheric structural lesion

Answer 2

Periodic lateralized epileptiform discharges (PLEDs)

Question 3

PLEDs may appear as a physiological condition exacerbated by chronic conditions such as following seizures or rarely___________

Answer 3

migraine

Question 4

WHAT IS THE LESION?

Answer 4

Left temporal PLEDs in a patient with left temporal lobe

epilepsy immediately following serial complex partial seizure

Question 5

WHAT IS THE LESION?

Answer 5

Left temporal PLEDs plus in a patient with an acute occipital ischemic infarction. Note the rhythmic ictal discharge abutting the discharge

Question 6

____________are most often associated with encephalopathy and typically occur as an epiphenomena of a severe bilateral disturbance of cerebral dysfunction.

Answer 6

Generalized periodic epileptiform discharges (GPEDs)

Question 7

WHAT IS THE LESION?

Answer 7

Generalized periodic epileptiform discharges. This ictal pattern followed a prolonged seizure. Note the high amplitude of the discharges

Question 8

The hallmark of ___________is the presence of pseudoperiodic slow complexes or PLEDs in the setting of symptoms that suggest a central nervous system infectious disease

Answer 8

herpes simplex encephalitis (HSE)

Question 9

WHAT LESION?

Answer 9

Right temporal PLEDs in a patient with herpes encephalitis and nonconvulsive SE recorded in the ICU

Question 10

Periodic discharges are the hallmark of ______________and occur in the majority of patients. The pattern is a pseudoperiodic generalized sharp wave that occurs with a diffuse slow background

Answer 10

Creutzfeldt-Jakob disease (CJD)

Question 11

WHAT DISEASE?

Answer 11

CJD in a patient with encephalopathy and myoclonic jerks

Question 12

High voltage (>300 μV) slow waves or sharp-and-slow wave complexes lasting 0.5 to 2.0 sec repeat every 4 to 10 sec in a very regular pattern, and may be provoked by hyperventilation or sleep early in the course of the disease. WHAT DISEASE?

Answer 12

Subacute sclerosing panencephalitis (SSPE

Question 13

WHAT CONDITION IS IT ASSOCIATED?

Answer 13

SSPE (early) in a patient presenting with encephalopathy and periodic episodes of atonia

Question 14

focal rhythmic ictal fast activity associated with periodic complexes (seen above), short intervals of recurrence, and abnormal background between discharges are clues that the periodic complexes are more likely to represent an___________

Answer 14

ictal phenomenon

Question 15

The waveforms have three phases with a prominent high-voltage, surface-positive deflection sandwiched between a lower amplitude initial surface negative deflection and an aftergoing slower surface- negative potential

Answer 15

TRIPHASIC WAVES

Question 16

WHAT EEG PATTERN

Answer 16

Triphasic waves noted on the EEG of another patient with

encephalopathy due to renal failure, who is on hemodialysis. The EKG however,

demonstrates ventricular fibrillation. The patient had a cardiac arrest and

died during long-term EEG monitoring.

Question 17

__________pattern consists of stereotyped bursts, usually consisting of mixed frequencies with or without intermixed epileptiform discharges. The bursts usually recur between 2 and 10 sec and are separated by intervals of suppression That demonstrate no electrocerebral activity at normal

sensitivities.

Answer 17

The burst-suppression

Question 18

__________suggests a severe bilateral cerebral dysfunction, and while nonspecific in etiology, when associated with hypoxia, This pattern suggests a poor prognosis

Answer 18

Burst suppression

Question 19

WHAT EEG PATTERN?

Answer 19

Burst-suppression following out-of-hospital cardiac arrest.

The recording was obtained at 2 μV/mm with single electrode distances

Question 20

_______________are bilateral periodic epileptiform discharges. They signify a diffuse encephalopathy and may occur with seizures, although frequently GPEDs occur as the expression of a diffuse structural injury pattern involving gray matter without seizures.

They are unreactive to somatosensory stimulation, and are associated with an absent or diffusely slow posterior dominant rhythm.

Answer 20

Generalized periodic epileptiform discharges (GPEDs)

Question 21

WHAT PATTERN?

Answer 21

GPEDs in a 75-year-old man after cardiac arrest. He was comatose but had no clinical signs that were otherwise evident. Note the periodicity

Question 22

_____________are less commonly associated with seizures than are periodic lateralized epileptiform discharges (PLEDs).

The discharges are bihemispheric and independent with different morphologies and periods of repetition and are less associated with seizures than are PLEDs or PLEDs pluS

Answer 22

Bilateral independent periodic epileptiform discharges (BiPLEDs)

Question 23

WHAT PATTERN?

Answer 23

BiPLEDs in a 37-year-old HIV-positive man admitted following a prolonged generalized tonic-clonic seizure and meningoencephalitis.

Note the right frontal and left occipital bilateral independent hemispheric discharges.

Question 24

__________may be composed of spikes, polyspikes, or sharp waves that are bilateral and synchronous at a rate of 0.5 to 1.0 Hz on a “flat” or low-amplitude recording and be associated with frequent myoclonic jerks (status myoclonus).

Answer 24

Generalized periodic epileptiform discharges (GPEDs)

Question 25

WHAT PATTERN?

Answer 25

GPED suppression in anoxic encephalopathy with facial

myoclonus reflected in the lower second chin electromyographic (EMG) channel.

(Courtesy of Greg Fisher, MD.)

Question 26

____________is represented by diffuse alpha frequencies that are part of an unreactive pattern without anterior-posterior gradient on EEG seen in patients in coma. It is most frequently seen in hypoxic encephalopathy, although it has been reported with brainstem lesions, and portends a poor prognosis

Answer 26

Alpha coma

Question 27

WHAT PATTERN?

Answer 27

Alpha coma in a post–cardiopulmonary resusitation comatose

patient following cardiac arrest. Stimulation was ineffective in creating a

change in background.

Question 28

______________is a pattern seen in comatose patients. Features on the EEG include prominent spindle-like activity similar to the spindles seen in stage 2 sleep, although they reflect abnormal spindle formation because they are unreactive, diffuse, and the patient is comatose.

Answer 28

Spindle coma

Question 29

WHAT PATTERN?

Answer 29

The EEG of a 67-year-old patient following cardiac arrest.

Note the diffuse anterior predominant spindle-like activity

Question 30

WHAT PATTERN?

Answer 30

A 52-year-old following cardiac arrest 10 days previously.

The patient met the clinical criteria for a diagnosis of brain death

Question 31

_________is defined as no cerebral activity greater Than 2 μV

Answer 31

Electrocerebral inactivity

Question 32

WHAT PATTERN?

Answer 32

Epilepsia partialis continua in a 41-year-old patient with subjective tingling and “twitching” noted at the corner of the left side of the mouth.

Note the rhythmic delta frequencies on the EEG that phase reverse at the F8 derivation.

Question 33

WHAT POSSIBLE PATTERN?

Answer 33

EEG in a patient with postanoxic generalized nonconvulsive SE that followed convulsive SE.

Electrographic seizures seen

Question 34

_____________and the syndrome of continuous spikes and waves during slow sleep (CSWS) are syndromes of acquired language (LKS) or cognitive dysfunction (CSWS) associated with seizures in about three-fourths of patients

Answer 34

Landau-Kleffner syndrome (LKS)

Question 35

The IEDs during slow-wave sleep appear diffuse, symmetrical, or asymmetrical bisynchronous, and increase so that 85% of the recording or more comprises______________

Answer 35

electrical status epilepticus of slow sleep (ESES).