Week 232 - Epilepsy Flashcards Preview

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Flashcards in Week 232 - Epilepsy Deck (61)
1

Define an epileptic seizure

A transient event experienced by a subject as a result of synchronous and excessive discharge of cerebral neurones (arising due to variety of pathologic processes)

2

List some key differential diagnoses for epilepsy

Syncope (vasovagal or cardiogenic); Non-Epilectic Attacks (psychogenic); Sleep disorders (narcolepsy/cataplexy/parasomnias); Migraine; TIA; Hypoglycaemia

3

List causes of seizure that may be mistaken for epilepsy or cause LOC

Metabolic: low calcium, magnesium, glucose; deranged LFTs
Toxic: tricyclics, MAOIs, Alcohol
Infections/Inflammation: meningitis, abscess, febrile convulsion (paeds)
Vascular / Respiratory: TIA / CVA, hypoxia
Tumours

4

What 3 types of epilepsy classification are there?

1) Seizure type
2) Localisation
3) Aetiology

5

What two seizure types are there?

Generalised or Partial AKA Focal
(Generalised spreads throughout the brain and always results in altered consciousness
Partial affects part of the brain and so causes localised symptoms)

6

What two forms of partial seizure can occur?

Simple (remain fully conscious) or Complex (altered or lost consciousness)

7

When classifying epilepsy by location what is meant?

The lobe of the brain being affected (in a partial seizure epilepsy)

8

What 3 principle aetiologies can all epilepsy be categorised into?

- Idiopathic (no know reason)
- Symptomatic (clearly identifiable cause)
- Cryptogenic (characteristics suggestive of underlying cause but not yet found)

9

What features of a vasovagal syncopal episode would be suggestive of such?

3Ps: posture, provocation and prodrome
Standing; heat, venesection, micturition; nausea, clammy, tinnitus, blurring or loss of vision, deafness
Rapid orientation with prolonged fatigue as well as a few myoclonic jerks are common; usually last no more than 30s

10

What are the Red Flags for cardiogenic syncope?

Occur on exercise
FHx sudden death
PMH of IHD
No warning
Rapid recovery

11

Describe the common features of a generalised tonic-clonic seizure

Sudden onset, tonic stiffening followed by synchronous clonic mvmts
Cyanosis
Stertorous breathing (harsh snoring/gasping)
Tongue-biting (lateral) ;incontinence; injuries
Post-ictal period (altered state of conc after), prolonged recovery

12

Absence seizures are a form of what type of epilepsy, generalised or partial?

Generalised

13

In what patient group are absence seizures most common?

Children (uncommon in adults)
They usually grow out of it.

14

Describe the typical features of an absence seizure including frequency, duration, behaviours and recovery

Can happen several times in a day
Rarely last more than ~20 secs
Individual often stares blankly
Alert immediately after with no knowledge of the seizure

15

Describe the typical features of a Temporal Lobe (complex partial) seizure including prodrome, frequency, duration, behaviours and recovery

3As > PRODROME Aura (rising epigastric sensation, olfactory and gustatory, déjà vu) BEHAVIOR - Arrest (motor / speech), Automatism (lip-smacking, semi-purposeful actions)
Rarely > couple times a week; up to several mins
Post-ictal period of confusion

16

List some features of a likely Non-Epileptic Seizure

Awareness retain; gradual onset; prolonged; Frequent; no response it AEDs; Preceded by autonomic arousal; Asynchronous movements; Eyes closed and resist opening; Back arching; Carpet burns; Biting tip of tongue

17

What is Status Epilepticus?

A medical emergency
When a seizure lasts >5 mins (some say >30 mins but intervention should have occurred well before then as they can lead to brain damage and death)

18

What clinical signs often present with epileptic seizures?

Pupil dilatation
Increased BP and Tachycardia, cyanosis
Up going plantars
Fall in pO2 and pH
Rise in creatinine kinase levels

19

What examinations would be sensible to perform with suspected epilepsy?

Neurological examinations (peripheral, cranial nerve)
Lying and standing BP
Cardio
Check for injuries and neurocutaneous lesions (e.g. From neurofibromatosis)

20

What investigations should be performed?

ECG (all blackouts)
EEG
Imaging (cranial - CT for masses/CVA; MRI

21

Give 3 reasons for imaging the brain in epilepsy

1) to find the cause
2) for treatment: response to AEDs or surgery
3) important for prognosis
(All new-onset unprovoked seizures need imaging)

22

Give 3 major causes of epilepsy in infants

Developmental malformations
Perinatal injuries
Infections

23

What is the major cause / type of epilepsy among children/adolescents?

Idiopathic Generalised Epilepsy

24

Besides idiopathic generalised epilepsy give 4 possible causes of epilepsy in young adults

head injury, alcohol, vascular malformations, hippocampal sclerosis

25

What is the major cause of epilepsy in 30-50s?

Brain tumours

26

What is the major cause of epilepsy in >50s?

Cerebrovascular disease

27

What is often seen on EEG and brain imaging with IGE?

Imaging is ALWAYS normal
EEG often abnormal, showing generalised 'Spike and Wave'

28

What type of epilepsy does Juvenile Myoclonic Epilepsy come under and what normally precipitates seizures?

Type of IGE
Waking, alcohol excess and sleep deprivation can precipitate

29

What are the first line drugs for IGE?

male = sodium valproate
female (of reproductive age) = lamotrigine or levetiracetam

30

What are the first line AEDs used for partial/focal epilepsy?

Carbemazepine, lamotrigine or levetiracetam

2nd line is one of those above not used 1st line in its place or in addition (though generally aim for mono-therapy )

31

What is the most common side effect of lamotrigine?

Rash

32

What is the most common side effect of levetiracetam?

Psychiatric problems

33

What are the more common / serious side effects of sodium valproate?

Weight gain
Tremor
Teratogenicity

34

Which AEDs are enzyme inducers and what does this mean?

Carbemazepine, Phenytoin, Topiramate
Which means that these drugs can reduce the efficacy of Warfarin and the OCP

35

After what period of seizure freedom should you consider withdrawing AEDs?

2yrs

(N.B. Seizure risk DOUBLES upon withdrawal especially if: dual therapy used, symptomatic epilepsy, seizures after pharmacological introduction, frequent seizures, Hx of GTCSs or myoclonic jerks, abnormal EEG)

36

What is Wernicke-Korsakoff syndrome

A combination of Wernicke's encephalopathy and Korsakoff Syndrome, usually secondary to alcohol abuse. 20% mortality rate, 75% brain damage
Manifestation of Vit B1 (thiamine) deficiency
Sx inc: vision changes, ataxia and impaired memory

37

What is the general approach to managing someone in Status Epilepticus?

ABC - secure airway
Obtain IV access - glucose, or thiamine (if alcohol suspected)
Oxygen
Bloods: U&Es, Ca, Mg, ABGs, ECG, +/- AED levels

38

What meds should be used in the Tx of Status Epilepticus?

Early- IV lorazepam (or diazepam, buccal midazolam)
Established - IV phenytoin (or valproate, leve., phenobarbitone)
Refractory - ITU, GA - propofol, thiopental, midazolam

39

What is catamenial epilepsy?

That which coincides with hormonal changes of menstruation

40

What considerations should be taken into account in pregancy with AEDs?

Danger of seizure greater risk to mother and baby than AED usually
Counselling!
Sodium Valproate - Teratogenicity!!!
Phenytoin - cleft lip and palate, limb or organ malformation
Valproate; Carbemazepine - neural tube defects
Folate should ALWAYS be taken through pregnancy

41

What are the rules and legal requirements with regard to driving with epilepsy?

No legal requirement though the GMC state that Drs should strongly advise patients to report to DVLA then if not report it themselves informing pt you're going to.
1yr seizure free can reapply
If only ever occur during sleep ok to drive or seizures not affecting consciousness or ability to control a vehicle

42

What score on the GCS is suggestive of Coma?

= or less than 8

43

Want are the 4 over-arching causes of coma?

1) significant structural injury to cerebral hemisphere(s)
2) significant structural injury to brainstem
3) diffuse physiological brain dysfunction
4) metabolic/endocrine dysfunction

44

List 2 important mimics of coma and state how they differ

1) Locked-in syndrome: de-efferented motor tracts, only blinking and vertical eye movements intact, awareness and arousal retained
2) psychogenic coma - exclude all others!!!

45

What is the main overarching cause of unilateral hemisphere damage? Give some causes of that outcome

Raised ICP
Expanding mass lesion, haemorrhage
large middle cerebral artery infarct can also cause

46

List causes of bilateral hemisphere brain damage?

SAH
Encephalitis
Acute Hydrocephalus
Diffuse cerebral oedema
Diffuse brain injury
Hypoxic-ischaemic encephalopathy

47

Give 5 causes for brainstem dysfunction

Bilateral thalamic lesion
Tumour
Haemorrhage
Ischaemia/Infarction
Compression (coning)

48

What should roving eye movements in a comatose patient indicate?

A intact brainstem (therefore better prognosis)

49

Give 5 causes of physiological brain dysfunction

Hypothermia
Sudden HTN
Prolonged status epilepticus (cerebral hypoxia)
Toxins (drugs, alcohol, poisoning)
Psychogenic

50

Give 3 metabolic causes of coma

Too much or too little Na or Glucose
Too much calcium
(Renal or hepatic failure can also cause coma)

51

Describe the initial management for coma?

Improve oxygenation (intubate if necessary)
Correct hypo- or extreme hypertension
Warm up if cold and cool if hot
Glucose / thiamine / naloxone / flumazenil if indicated
Identify underlying cause, gain as much Hx as possible
(Flumazenil reverses benzodiazepine OD)

52

What factors will make a neurological assessment less reliable?

Metabolic derangement
Hypothermia
Endocrine derangement
Sedative drugs in system

53

What should a neurological assessment involve?

Motor reflexes (?symmetrical. brisk, up going plantar suggests contralateral damage)
Brainstem reflexes (pupil reactivity and eye movements)
Papilloedema/retinal haemorrhage; unilateral UMN signs; meningism (could suggest SAH); pupil responses (opiate, MDMA, ecstasy OD)

54

What is a single 'blown' pupil a sign of?

Increased ICP "impending doom"!!

55

Give 4 signs of brainstem integrity

Roving eye movements
Corneal reflex
Oculocephalic response (turn head briskly side-to-side, eyes stay on you)
Oculovestibular (slow phase of nystagmus to ear irrigated)

56

What bloods should be done for a patient in a coma?

FBC, U&Es, glucose, LFTs, ABG, cultures, kidney function, thyroid, drug screen

57

Besides bloods what other investigations should you consider for a coma patient?

ECG
EEG
CT/MRI
MRA/CTA
LP (unless raised ICP)!

58

What criteria qualify a persistent vegetative state?

Recovery of arousal but not awareness
-no evidence of awareness -no language or comprehension
-roving eye movements -brainstem reflexes intact
-maintenance of respiration and circulation
(Generally due to diffuse cortical or subcortical damage)

59

Describe the main features of 'Locked-in syndrome'

Patient has awareness
Little or no motor output below CNIII
Voluntary eye movement in vertical plane and eye opening
(Recovery rare)

60

What is Locked-in syndrome usually caused by?

Pontine infarction

61

Define epilepsy

A continuing tendency to have epileptic seizures. Most common serious neurological disorder.