Epilepsy and Seizure

Question 1

Most common site of pathology that causes seizure

Answer 1

The temporal lobe, in particular the hippocampus, is the most common site of pathology in adults and adolescents with seizures that include alteration of awareness, accounting for as many as two thirds of cases.

Question 2

Hippocampal sclerosis

Answer 2

histopathologically defined pattern of cell loss along with astrogliosis in the hippocampal formation.

List-learning measures tend to be the most sensitive to hippocampal pathology.

Question 3

Three main features for classifying seizures:

Answer 3

focal - have onset originating in networks limited within one cerebral hemisphere and may be discretely localized within the hemisphere, more widely distributed within the hemisphere, or originate in subcortical structures.

generalized

undetermined

Question 4

What is a seizure?

Answer 4

a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain

Question 5

A diagnosis of epilepsy is made when:

Answer 5

there have been at least two unprovoked seizures, at least 24 hours apart

or after a single unprovoked seizure when the risk for another is known to be high (>60%) based on other medical factors (e.g., positive imaging findings), or an epilepsy syndrome has been diagnosed (e.g., childhood absence epilepsy).

Question 6

New onset epilepsy in a previously healthy adult is uncommon, and often associated with…

Answer 6

primary CNS neoplasm, neurovascular event, trauma,
infection, or autoimmune disorders (may be associated with primarily temporal lobe pathology)

Question 7

Neonatal seizures are frequently associated with…

Answer 7

hypoxic ischemic encephalopathy, 35–45%

Question 8

What often contributes to childhood epilepsy?

Answer 8

malformations of cortical development (MCD) and low-grade brain tumors

Question 9

Types of malformations of cortical development

Answer 9

• abnormal neuronal and glial proliferation or apoptosis (programmed cell death)
• abnormal neuronal migration
• abnormal cortical organization

Question 10

Causes of increased mortality in epilepsy in the absence of other mortality risk factors include:

Answer 10

• SUDEP (sudden unexplained death in epilepsy)
• unintentional injury (e.g., falls, drowning)
• suicide
• complications associated with status epilepticus.

Question 11

Seizure variables associated with severity of cognitive impairment include

Answer 11

• Seizure frequency
• type epilepsy risk factor (e.g., tumor, central nervous system [CNS] infection, trauma)
• younger age of seizure onset - number of antiepileptic drugs (AEDs).

Question 12

Temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS)

Answer 12

• associated with a history of febrile seizures as an infant or toddler
• difficult to treat; as many as 1/3rd of patients with TLE develop medically intractable seizures.

Question 13

Behavior associated with temporal lobe epilepsy (TLE)

Answer 13

Auras - GI symptoms (“butterflies” in the stomach) or psychic phenomena (e.g., déjà vu)

alteration of awareness and gradual alteration of awareness, but not necessarily with loss of consciousness

repetitive movements of the hands, tongue, mouth, or lips. Repetitive movements of the hand are typically ipsilateral to the side of seizure onset

Speech patterns during or immediately following a seizure in TLE are significant for lateralization
- absence of speech is not necessarily lateralizing, but the ability to continue speaking clearly is associated with non–language dominant temporal lobe onset
- aphasic or dysnomic speech typically following dominant TLE seizures.

Postictal confusion and/or fatigue is common, and the duration can vary from a few
minutes to a few hours

Secondary generalization to a tonic-clonic seizure occurs up to 50% of the time in TLE.

Question 14

Resection surgery to address TLE increases risk of

Answer 14

decreased efficiency in learning and memory
word-finding deficits (if language dominant)
visual field defects

Question 15

Childhood absence epilepsy

Answer 15

primary generalized epilepsy in that it involves widespread neural networks at seizure onset

most common epilepsy syndromes in childhood (15%)

self-limiting epilepsy syndrome - seizures typically do not
persist past adolescence

seizures can persist into adolescence and adulthood and, in approximately 15% of cases, can develop into juvenile myoclonic epilepsy.

Age of onset is typically between 3 and 8 years, with the peak occurring around 6 years.

high incidence of comorbid learning and/or attention disturbance.

involve frontal and subcortical networks involved in regulating attention.

CAE is associated with attention problems that adversely affect encoding and storage of new information, with relatively greater impact on visuospatial and nonverbal memory.

Question 16

Behaviors of childhood absence epilepsy

Answer 16

alteration in awareness is apparent - described as “staring.”

possible minor motor automatisms, such as eyelid fluttering or lip movements,

Question 17

Landau-Kleffner syndrome

Answer 17

progressive encephalopathy (sometimes referred to as acquired epileptic encephalopathy) that particularly affects language.

onset between the ages of three and seven years

Characterized by language and cognitive deficits:
- progressive aphasia begins with development of receptive language impairment and verbal auditory agnosia, followed by gradual development of expressive language deficits.
- progressive cognitive impairments: including regression of overall intellectual ability and deficits in attention

Typically, the course does not typically include spontaneous recovery of language

Question 18

Lennox-Gastaut syndrome

Answer 18

referred to as “encephalopathic generalized epilepsy syndrome” due to the progressive and severe cognitive impairments/regression that are typically observed.

may present with multiple different seizure types

Risk factor: history of infantile spasms, MCD, neurocutaneous disorders (e.g., tuberous sclerosis [TS] complex), CNS infection (meningitis, encephalitis), and hypoxic-ischemic injury.

Question 19

Rasmussen syndrome

Answer 19

characterized by a progressive unilateral encephalopathy and medically refractory seizures (drug resistant)

the most commonly reported presentation is in children between 3 and 14 years.

premorbid cognitive and behavior development is normal.

Once seizures begin, a progressive course generally results in loss of cognitive skills related to the side of seizure onset (e.g., language decline in dominant hemisphere; visuospatial decline in nondominant hemisphere). Ultimately, there is nearly complete loss of function in the affected hemisphere, including hemiparesis.

Question 20

Electrophysiological findings in Landau-Kleffner syndrome implicate…

Answer 20

the language-dominant perisylvian region but can be bilateral and also include frontal lobe pathology.

Question 21

Treatment of Rassmusen syndrome

Answer 21

aggressive surgical intervention (modified functional hemispherectomy) is often considered the best course.

Question 22

Factors associated with normal IQ

Answer 22

less severe epilepsy & more focal seizure onset

Question 23

risk factors for low IQ

Answer 23

age of seizure onset, with earlier onset associated with lower overall IQ

independent of other factors thought to be related to cognitive decline, such as seizure frequency or location of seizure onset.

localization of seizure onset may not have the expected influence on IQ; for example, verbal–nonverbal intellectual skill discrepancies have not been found to be a lateralizing sign in focal epilepsy syndromes.

Question 24

Risk factors for IQ decline

Answer 24

seizure severity and treatment with multiple medications (which may also be a result of seizure severity)

Question 25

encephalopathic epilepsies

Answer 25

Landau-Kleffner syndrome, Lennox-Gastaut syndrome, and Rasmussen syndrome.

Question 26

?? tend to be more highly associated with attention problems than other kinds of seizures

Answer 26

absence seizures

Question 27

Attention difference in ADHD vs. secondary to seizures

Answer 27

More difficulties with sustained attention are observed in children with epilepsy,

compared with more complex and divided attention problems in children with ADHD who do not have epilepsy.

Question 28

Attention problems with AEDs

Answer 28

Attention problems are not accounted for by medication effects alone.

Problems with attention often precede development of seizures, suggesting that there may be antecedent neurobiological insult or developmental

Question 29

??? deficits are among the commonly cited side effects of anticonvulsant medications.

Answer 29

processing speed

because AEDs reduce hyperexcitability and neuronal transmission by increasing inhibitory action (e.g., GABA-ergic inhibition) or reducing availability and function of excitatory neurotransmitters (e.g., glutamate).

Question 30

crowding effect

Answer 30

early-onset epileptic lesions that provoke reorganization of language from the left to the right hemisphere or engage bilateral support of language, visuospatial deficits can be observed.

When there is an early injury to the primary language system, those resources are shifted to “back-up” systems in homologous areas in the contralateral hemisphere, but at a cost to functions that would have been mediated by those areas in the absence of injury.

This is supported by a large body of literature that identifies relatively weak visuospatial function in epilepsy patients with early left-hemisphere injury and who are right- hemisphere dominant for language.

Question 31

Febrile seizure

Answer 31

seizure brought on by a fever

4–5% of children will have at least one febrile seizure.

do not constitute epilepsy and are not usually treated with AEDs.

but they are a risk factor for later development of unprovoked seizures, particularly within one year and seizures arising from the temporal lobe.

Question 32

The highest rate of new onset seizures occurs those…?

Answer 32

5 years or younger

Question 33

The second highest rate of new onset seizures occurs in those…?

Answer 33

over 70 years old

Question 34

Although seizures can occur at any age, new onset epilepsy in adolescents and adults is less common and more frequently associated with..

Answer 34

new onset neurological risk factor (e.g., brain tumor).

Question 35

Is there a lateralizing mood effect in temporal lobe epilepsy (TLE)?

Answer 35

No. studies show higher level of anxiety and depression in persons with epilepsy regardless of laterality of seizure onset

Question 36

Supplementary motor area focal seizures often include:

Answer 36

Fencing posture with extension of contralateral upper extremity

Tonic posturing

speech arrest and unusual sounds

Question 37

What % of the population will experience at least one seizure in their lifetime?

Answer 37

5%