Physiology Epilepsy

Question 1

What is a seizure?

Answer 1

A convulsion or transient abnormal event resulting from a paroxysmal discharge of cerebral neurons

Question 2

What is epilepsy?

Answer 2

The continuing tendency to have a seizure

Question 3

List the criteria needed to diagnose a seizure.

Answer 3

1 - at least two unprovoked seizures occurring more than 24 hours apart
2 - one unprovoked seizure and a probability of further seizures similar to the general recurrence risk after two unprovoked seizures (approx. 75% or more)
3 - at least two seizures in a setting of reflex epilepsy

Question 4

List the criteria to think about when looking at seizure types.

Answer 4

Focal/Generalized/Unknown Onset (area affected)
Level of consciousness
Motor or not

Question 5

Clonic

Answer 5

Shaking/jerking movements

Question 6

Tonic

Answer 6

Being stiff

Question 7

*Automatisms

Answer 7

Automatic behaviours

Question 8

*Emotions

Answer 8

Emotions or appearance of emotions

Question 9

• Tonic

Answer 9

Extension or flexion postures

Question 10

*Autonomic

Answer 10

Flushing/sweating/piloerection

Question 11

*Myoclonous

Answer 11

Jerking arrhythmically

Question 12

*Clonus

Answer 12

Jerking rhythmically

Question 13

*Cognitive

Answer 13

Language or thinking problems, deja vu

Question 14

*Eyelid myoclonia

Answer 14

Lid jerks

Question 15

*Atonic

Answer 15

Limp

Question 16

*Sensations

Answer 16

Numb/tingling, sounds, smell, tastes, visions, vertigo

Question 17

*Behaviour arrest

Answer 17

Pausing, freezing, activity arrest

Question 18

*Hyperkinetic

Answer 18

Thrasing/pedaling

Question 19

*Spasm

Answer 19

Trunk flexion

Question 20

Why is the level of consciousness a key role in seizures?

Answer 20

Importance for driving, safety during seizures, employability, interference with schooling and learning

Question 21

Name some evidence helpful in classifying seizures.

Answer 21

Videos brought in by family
EEG patterns
Lesions detected by neuroimaging
Lab results e.g. detection of anti-neuronal antibodies
Gene mutations
Diagnosis of an epilepsy syndrome diagnosis

Question 22

Describe the EEG of a generalized seizure.

Answer 22

Sudden onset

All leads/cords have same start and pattern

Question 23

Describe the EEG of a partial/focal seizure.

Answer 23

Only some of the leads show disruption

Starts in one place and spreads to become more general

Question 24

List some differential diagnoses of seizures.

Answer 24

Syncope
Migraine
TIA 
Hypoglycaemia 
Panic attacks
Breath holding attacks
Psychogenic non-epileptic seizures

Question 25

Describe some characteristics of non-epileptic seizures.

Answer 25

``` Gradual onset Eye closure Asymmetrical thrashing movements Side to side head movements Pelvic thrusting Lack of stereotypic pattern Talking or screaming Long duration Sudden return to consciousness Waxing and waning ```

Question 26

What causes seizures?

Answer 26

Genetic predisposition Developmental e.g. neuronal migration abnormalities Trauma and surgery Pyrexia (fever) Intracranial mass lesions: tumour Vascular: cerebral infarction, arteriovenous malformation Drugs and drug withdrawal Encephalitis and inflammatory conditions Metabolic abnormalities e.g. hypocalcaemia Neural degenerative disorders Provoked seizures: photosensitivity and sleep deprivation

Question 27

What investigations do you need to perform for seizures?

Answer 27

Blood tests: FBC, urea and electrolytes, calcium, glucose, CRP, toxin screen Xray chest (mass in chest metastasized to head) ECG EEG Neuroimaging: CT or MRI Lumbar puncture if CNS infection a possibility

Question 28

When do you start treatment for seizures?

Answer 28

2 or more seizures Single seizure if risk factors (structural lesion, EEG abnormality, partial seizure, family history of seizures) Immediate treatment increases time to a second seizure and reduces the time to 2 year remission

Question 29

When do you stop treatment?

Answer 29

Consider after 2 years | Do gradually

Question 30

What is status epilepticus?

Answer 30

If seizures recur without recovery or a single seizure continues >5min, treat as status elipticus

Question 31

List examples of epilepsy surgery.

Answer 31

``` Focal resections Hemispherectomy Large multilobar resections Corpus callostomy Vagal nerve stimulation ```

Question 32

Name the drugs for Step 1 (5-20min) of status epilepticus.

Answer 32

Lorazepam: 0.1mg/kg up to 4mg IV bolus or Diazepam: 0.15 - 0.2mg/kg up to 10mg at 2mg/min (the above two drugs need to be repeated once every 5-10min if necessary) or Midazolam 10mg IV, intramuscular, intranasal or buccal = best option if no immediate IV access

Question 33

Name the drugs used for status epilepticus (step 2: 20-40min)

Answer 33

Sodium valproate Phenytoin Levetiracetam

Question 34

Name the drugs involved in step 3 (40-60min) of status epilepticus.

Answer 34

Induce a drug-induced coma in ICU: Midazolam or Propofol Monitor EEG to maintain burst suppression pattern