Seizures and Epilepsy

Question 1

In what type of seizure will there not be a loss or alteration of awareness?

Answer 1

The hypersynchronous activity is limited to a very focal area

Question 2

What is the new definition of epilepsy?

Answer 2

One epileptic seizure with an enduring predisposition to further epileptic seizures, based on clinical risk factors / additional tests

Question 3

What are the cognitive, psychological, and social consequences of epilepsy?

Answer 3

Cognitive: memory loss and poor executive function
Psychological: anxiety and depression
Social: Loss of ability to work, drive to work, and stigmatization

Question 4

What are the two broad types of epilepsy? What characterized them?

Answer 4

1. Primary generalized epilepsy - bilateral synchronous activity, seizures generated reciprocally between cortex + thalamus and spread rapidly thru corpus callosum
2. Focal epilepsy - seizures begin at one area of the brain and spread to adjacent cortices

Question 5

What happens in focal epilepsy which makes it appear like primary generalized?

Answer 5

“Secondary generation” spread of seizure from focal point to contralateral hemisphere via the corpus callosum

Question 6

Why do auras typically precede seizures?

Answer 6

Because they represent focal seizures without loss of awareness, and are sensory in nature only.

The electrical activity can spread to motor areas of the brain and thus lead to other seizure manifestations

Question 7

What specific areas of the brain are affecting in auras?

Answer 7

Depending on the aura type, whatever brain part is associated with it

i.e. somatosensory tingling = poscentral gyrus, areas 5,7, and the insula (visceral - as in abdominal discomfort)

Question 8

What can lead to macropsia or micropsia?

Answer 8

This is having objects appear to increase or decrease in size, like Alice in Wonderland

Caused by basal temporal cortex seizure (optic radiations), or visual association cortices

Question 9

What can lead to psychic auras?

Answer 9

Temporal lobe seizures
i.e. fear, euphoria, distortion of familiarity, deja vu, due to involvement of amygdala

• it Jimbo!

Question 10

What are the most common types of motor seizures?

Answer 10

1. Focal seizures without loss of awareness - simple partial seizures
2. Focal seizures with loss of awareness - complex motor seizures

Question 11

What is a tonic seizure?

Answer 11

Sustained contraction of a muscle or group of muscles

Question 12

What is a clonic seizure?

Answer 12

Repetitive and rapid contraction + relaxation of muscle

Question 13

What is a myoclonic seizure?

Answer 13

A clonic seizure but it only happens once -> single contraction. Looks like a tic

Question 14

What is a versive seizure? What part of the brain is affected?

Answer 14

Forced head deviation to one side or the other

Frontal eye field (area 8) is affected

Question 15

What is an atonic seizure?

Answer 15

Loss of postural tone leading to abrupt fall

Question 16

What is the most violent type of seizure? How does it progress?

Answer 16

Generalized tonic-clonic, usually occurs with diffuse tonic contraction followed by clonic seizures

“grand mal” = bilateral, occurs in diffuse / generalized epilepsy

Question 17

What is an automatism / automotor seizure? What part of the brain is more affected?

Answer 17

Seizure characterized by loss of awareness + lip smacking / chewing behaviors, very involuntary

Temporal lobe > frontal lobe affected

Question 18

What is a hypermotor seizure? What part of brain is more affected?

Answer 18

Involuntary automatic motor behaviors, involving proximal muscles. I.e bicycling movements at night / arm flailinng

Frontal lobe > temporal lobe

Question 19

What is a gelastic seizure?

Answer 19

gelan = to laugh

Brief periods of laughter or grimaces

Question 20

What causes an aphasic seizure?

Answer 20

Focal seizure in frontal or temporal lobe in dominant hemisphere (affects Wernicke / Broca’s areas)

Question 21

What are the two primary types of non-motor seizures with unawareness? What age groups do they affect?

Answer 21

1. Complex partial seizure (CPS) - any age

2. Absence - exclusively childhood

Question 22

What are the motor features and relative lengths of CPS vs absence seizures?

Answer 22

CPS - hand / oral automatism - 1-2 minutes

Absence - eye fluttering <20 seconds

Question 23

Is postictal confusion present or absent for CPS / absence seizures? What characterizes the EEG?

Answer 23

CPS - present - left temp spikes and seizures

Absence - absent - 3 Hz spike-and-wave

Question 24

What is Todd’s paralysis and what is the etiology of most post-ictal signs?

Answer 24

Contralateral postictal paresis - due to depletion of excitatory neurotransmitter

Question 25

What are some other postictal symptoms?

Answer 25

Confusion, disorientation
Retrograde / anterograde amnesia - hard to remember back or forward
Language dysfunction
Psychosis

Question 26

What is an example of a prodromal symptom you screen for when taking a seizure history?

Answer 26

The aura, includes lightheadness, sweats, deja vu, smells and tastes

prodrome = an early symptom indicating the onset of a disease or illness.

Question 27

What is the most important thing for making history taking of seizures easy?

Answer 27

Find a witness!

Question 28

Why is situation important for seizure diagnosis?

Answer 28

Syncope / vasovagal syncope is on the differential diagnosis. Stress / prolonged standing could indicate syncope, vs sleep deprivation could point to seizures

Question 29

What is the biggest clue that you are dealing with epilepsy vs syncope?

Answer 29

Response to antiepileptic drugs

Question 30

What are some examples of epileptiform discharges that can be seen on EEG during interictal periods?

Answer 30

Spikes, polyspikes, sharp-waves, and sharp-and-slow wave complexes

Question 31

What is defined as the seizure threshold? How do drugs treat this?

Answer 31

Level of stimulation at which the brain will have a seizure, this is lower in epileptic patients.

Drugs raise the seizure threshold, but do not lower the brain activity

Question 32

What can an MRI detect for diagnosing epilepsy?

Answer 32

The lesion associated with seizures in focal epilepsy

Question 33

What are a few proprosed mechanisms of seizure generation?

Answer 33

Enhanced glutamate / excitatory transmission, with impaired inhibition -> higher basal activities to bring patients near seizure threshold in epilepsy

Lesions like scar tissues interrupting the macroenvironment