Epilepsy (Final Exam)

Question 1

this is a group of disorders characterized by excessive excitability of neutrons within the CNS. usually a chronic condition. alterations in inhibitors mechanisms or enhancement of local excitatory circuits

Answer 1

epilepsy

Question 2

this is a general term applied to all types of epileptic events

Answer 2

seizure

Question 3

this is an abnormal motor phenomena (i.e. jerking movements)

Answer 3

convulsions

Question 4

true or false: all convulsions can be seizures

Answer 4

true

Question 5

true or false: all seizures can be convulsions

Answer 5

false

Question 6

this is a class of seizures; can be further described as having an intact or impaired awareness, motor or non motor onset, or evolve from focal to bilateral tonic clonic

Answer 6

focal onset

Question 7

this is a class of seizures;
motor
- tonic-clonic
- other motor (atonic, myoclonic)

nonmotor (absence)

Answer 7

generalized onset

Question 8

this is a class of seizures; motor, nonmotor or unclassified

Answer 8

unknown onset

Question 9

what is the basic pathophysiology of seizures

Answer 9

recurrent seizures initiated by synchronous high frequency discharges from a group of hyper-excitable cortisol neurone (focus). autonomous in nature. spreads to neighbouring and distal neurons which is known as recruitment

Question 10

what are some inhibitory mechanisms, that if interrupted, can cause seizures

Answer 10

• GABA
• Adenosine
• reorganization of neural networks (favouring excitatory circuits - usually a Brian injury does this)
  *domoic acid and penicillin can cause seizures

Question 11

how does recruitment occur?

Answer 11

high frequency of discharges leads to:
- increase in extracellular K+
- accumulation of Ca++ in presynaptic terminals
- depolarization-induced activation of NMDA
- changes in tissue osmolarity & cell swelling
- enhanced neurotransmitter release at excitatory synapses (post tetanic potentiation)
- desensitization of GABA receptors
- recruitment of nearby neurone (through cortisol connections)
- recruitment of distal areas (corpus collosum)

Question 12

what are some triggers of seizures

Answer 12

• fever
• stress, fear, anger and worry
• poor nutrition (alcohol)
• allergies
• flickering lights
• lack of sleep

Question 13

what are the two main classes of seizures

Answer 13

focal and generalized

Question 14

this is one of the two main classes of seizures; activity begins focally in cerebral cortex (focal brain disease/tramua). spreads minimally to cortical areas. signs/symptoms depend on area affected

Answer 14

focal

Question 15

this is one of the two main classes of seizures; focal seizure activity is conducted widely throughout both hemispheres. leads to loss of consciousness

Answer 15

generalized

Question 16

this type of seizures arise from discrete or broadly distributed neuronal networks within a cerebral hemisphere
- can have intact or impaired awareness
- the onset can be motor or nonmotor
- can evolve into a generalized seizure
- may need surgically implanted electrode (medial temporal lobe or inferior frontal lobe)

Answer 16

focal onset seizures

Question 17

this type of focal seizures has discrete symptoms that depend on the area of the brain affected
- no LOC
- twitching, numbness, visual hallucinations, salivations, incontinenece, feelings of unreality
- lasts 20-60 secs
- Jacksonian march (tingling/twitching begins in a small region then “marches” to a larger area of the body)
- Todd’s paresis (weakness or paralysis of part or all of the body as soon as the ictal discharge (seizure) has ended)
- could last hours to days (epilepsia partialis continua)

Answer 17

focal seizure - with intact awareness

Question 18

what are some signs/symptoms of frontal seizures with intact awareness

Answer 18

primary motor cortex
- involuntary movements of the contralateral hand

temporal or frontal cortex
- unusual, intense odors
- strange sounds
- epigastric sensation to the head
- fear, a sense of impending change, detachment, depersonalization
- illusions of microplasia/macroplasia (objects seem bigger/smaller than their actual size)

Question 19

this type of focal seizure, person is unable to maintain contact with the environment during the ictal event
- unable to respond during the ictal episode
- impaired recollection of the event
- the ictal phase often begins with a motionless stare
- automatism and confusion following the ictal phase (chewing, lip smacking, swallowing, picking movements of the hands

Answer 19

focal seizure with impaired awareness
* think of Dale!!

Question 20

true or false: focal seizure can spread to a generalized seizure

Answer 20

true: can spread to both hemispheres

• usually tonic-clonic type (involve both tonic (stiffening) and clonic (twitching/jerking) phases of muscle activity
• commonly frontal lobe involved

Question 21

this type of seizures arises at some point in the brain but immediately and rapidly spreads to both cerebral hemispheres

Answer 21

generalized seizures

Question 22

what are the four categories of generalized seizures

Answer 22

1. typical and atypical absence
2. tonic-clonic
3. atonic
4. myoclonic

Question 23

this type of generalized seizure has
- sudden, brief lapses of consciousness without loss of postural control (10 to 30 sec)
- no post seizure confusion
- blinking of the eyelids, chewing movements, clonic movements of the hands
- genetic predisposition onset ages 4-10
- main type of seizures in children
- can occur hundreds of times a day
- child unaware or able to convey its existence
- often missed, first clue is daydreaming and decline in school performance
- attention deficit disorder

Answer 23

generalized seizure - typical absence seizure

Question 24

this type of generalized seizure differs from typical absence seizures by:
LOC
- less abrupt in onset andcessaiton
- longer duration

Seizure
- more obvious motor signs
- usually associated with multifocal structural brain abnormalities, mental retardation
- less responsive to anticonvulsants

Answer 24

generalized seizures - atypical absence seizures

Question 25

how do absence seizures occur

Answer 25

• synchronous thalamic discharges
• caused by activations of low-threshold calcium channels (T channels)
• activated by hyper polarization of the cell membrane mediated by GABA-beta receptor activation

Question 26

this type of generalized seizure
- main seizure in 10% of people with epilepsy
- commonly result from metabolic derangement
- seizure begins abruptly without warning
- vague premonitory symptoms occurs hours before seizures
- tonic and clonic phase

Answer 26

generalied tonic-clonic seizures

Question 27

this phase of generalized tonic-clonic seizures is the initial phase that lasts for 10-20 secs
- tonic contraction of muscles throughout the body
- mucles of expiration and the larynx (ictal cry, pooling of secretions in the oropharynx, cyanosis)
- jaw muscles
- enhanced sympathetic tone (HR, BP, pupil dilation)
- evolves into the clonic phase of muscle relaxation
- ictal episode lasts about 1 min

Answer 27

tonic phase

Question 28

this phase of generalized tonic-clonic seizures can last for many hours
- unresponsiveness, muscular flaccidity, and excessive salivation
- stridorous breathing
- airway obstruction
- bladder and bowel incontinence
- headache, fatigue and muscle pain
- confusion can be very long

Answer 28

postical phase

Question 29

A seizure that lasts longer than 30 minutes, or having more than 1 seizure within a 5 minutes period, without returning to a normal level of consciousness between episodes
- must go to energy department as oxygen is limited to the brain

Answer 29

status epilepticus (SE)

Question 30

this is a severe form of epilepsy that usually develops during preschool years. it is characterized by developmental delay and a mixed of partial and generalized seizures

Answer 30

Lennox-Gastaut syndrome