Epilepsy/Seizure/Syncope Flashcards

1
Q

Define Epilepsy

A

Condition in which there is a tendency to have seizures. Seizures occur when neurones in brain are synchronously active when they shouldn’t be. Usually self resolve in <3 mins and can occur during sleep.

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2
Q

What are the main excitatory and inhibitory neurotransmitters in the brain?

A

Excitatory - Glutamate which binds to NMDA receptors, which open ion channels to let calcium in.

Inhibitory - GABA which binds to GABA receptors that cause signal inhibition by opening channels that let chloride ions in.

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3
Q

Risk factors for Epilepsy

A

Cerebrovascular disease
Head trauma
Cerebral infection
Premature birth
Congenital brain malformations
Genetic predisposition/Family history

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4
Q

Pathophysiology of Epilepsy

A

Neurones in brain become impaired, sending out excitatory signals, either due to excess excitation (fast/long acting glutmate/NMDA) or reduced inhibition (GABA).

When jerking starts in a specific muscle group and spreads to other muscles as more neurones affected over time, this is called a Jacksonian March

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5
Q

Define focal seizure

A

Focal - limited to one hemisphere, or smaller area (e.g. lobe).

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6
Q

Focal seizures. How they happen, types and a complication

A

Usually start in temporal lobes, affecting hearing, speech, memory and emotions.

Simple - Patient remains conscious, no post ictal symptoms and remembers what happened

Complex - Impaired consciousness/awareness. May not remember, presents with post ictal symptoms

Can go on to become secondary generalised seizures

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7
Q

How does a focal seizure affecting temporal lobe present

A

Temporal - Aura (Deja vu, auditory hallucinations) + anxiety, mood change, seeing flashing lights

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8
Q

How does frontal lobe seizure present

A

Frontal - Motor features (peddling of leg) Jacksonian march and Todd’s palsy.

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9
Q

How does parietal lobe seizure present

A

Parietal - Paraesthesia

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10
Q

Presentation of occipital lobe seizure

A

Occipital - Visual disturbance (spots, lines, flashes)

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11
Q

Management of focal seizures

A

1st- Carbamazepine (sodium channel blocker)

2nd- lamotrigine

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12
Q

Stages of a seizure

A
  • Prodromal phase (hours- days preceding) - Confusion, irritability, mood disturbance
  • Early ictal/ Aura (minutes before) - Deja vu, lip smacking, rapid blinking, strange smells etc (imply temporal lobe epilepsy)
  • Seizure (depends on type)
  • Post ictal (confusion, drowsiness, irritability)
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13
Q

Symptoms of a post ictal period

A
  • Headache
  • Confusion
  • Todd’s paralysis - if motor cortex affected, may have temporary paralysis and muscle weakness
  • Dysphasia
  • Amnesia
  • Sore tongue (If tongue biting in seizure)
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14
Q

Define Generalised seizure

A

Where both hemispheres of the brain are affected. Bilateral and involve a loss of consciousness

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15
Q

Types of generalised seizure

A

Tonic - Stiff/fall backwards
Atonic - Relaxed muscles/fall forwards (<3 mins)
Clonic - Violent convulsions
Tonic-Clonic - Stiff and fall before convulsions start
Myoclonic - Short muscle twitches (face, limbs, trunk)
Absence - Impaired awareness (staring blankly into space)

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16
Q

What condition is associated with Atonic seizures

A

Lennox-Gastaut syndrome

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17
Q

Describe tonic-clonic seizure

A

AKA Grand mal
- No aura
- Loss of consciousness, tonic (stiff) phase then clonic (muscle jerking)
- Associated tongue biting, incontinence, open eyes
- Prolonged post-ictal period

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18
Q

Describe Absence seizures

A

AKA Petit mal
- Childhood, 90% recover into adulthood
- Patient stares blankly into space, before carrying on as normal
- Displays 3Hz spike on EEG

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19
Q

Diagnostic criteria for epilepsy

A
  • 2 or more unprovoked seizures in 24 hours
  • 1 unprovoked seizure with probability of further seizures felt to be same as those with 2+ in a day.
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20
Q

Other investigations in Epilepsy

A

EEG - 3Hz wave spike in absence seizures
CT head/MRI - Examine hippocampus, check bleeds, tumours
FBC - Determine if there is a metabolic cause

21
Q

Complications of Epilepsy

A

Todd’s paralysis - Paralysis affecting arms or legs, usually limited to one side of body and self resolves after a few days. Usually follows frontal lobe seizure

Status epilepticus - Single, continuous seizure lasting 5+ mins or 2 more without regaining consciousness in between. Treated with benzodiazepines (diazepam)

Injury during seizure

Social stigma

22
Q

Treatment of Epilepsy

A

Tonic-clonic, atonic, myolconic
1st - Sodium valproate first (GABA analogue)
2nd - Lamotrigine (sodium channel blocker) second

Absence
- Ethosuximide (calcium channel blocker)

23
Q

Ethosuximide Indication in Epilepsy

A

Absence seizures

24
Q

Ethosuximide side effects

A

Night terrors
Rashes

25
Q

Ethosuximide MoA

A

Blocks T type Ca2+ channels of thalamic neurones, decreasing firing

26
Q

Sodium valproate indication in epilepsy

A

1st line in generalised seizures EXCEPT in pregnancy!

27
Q

Sodium valproate MoA

A

GABA analogue - Increases GABA activity (inhibitory neurotransmitter)

28
Q

Sodium valproate side effects

A

Highly Teratogenic!!
Hair loss
Tremors

29
Q

Lamotrigine Indication in epilepsy

A

Second line generalised seizures, except in pregnancy/women of child bearing age. Then first line.

30
Q

Lamotrigine MoA

A

Na+ channel blocker and suppresses release of glutamate, reducing excitability of neurones.

31
Q

Lamotrigine Side effects

A

Blurred vision
Leukopenia
Stevens-Johnson syndrome (life threatening rash)

32
Q

Carbamazepine indication in epilepsy

A

Focal seizures

33
Q

Carbamazepine MoA

A

Sodium channel blocker, reduces excitability of neurones, preventing action potentials.

34
Q

Carbamazepine side effects

A

Agranulocytosis
Aplastic anaemia
Dizziness
Rash

35
Q

How is status epilepticus treated

A

Benzodiazepine (IV Lorazepam) then pheytoin

36
Q

What are the driving rules in epilepsy

A

Single seizure = stop driving 6 months

Drivers must be seizure free for 12 months before being given a licence. Seizure free for 5 years for HGV.

If medicine withdrawn, wait 6 months after medication stoppage before driving again

37
Q

Define Syncope

A

Temporary loss of consciousness due to disruption in blood flow. Also called vasovagal episode/fainting

38
Q

Pathophysiology of syncope

A

Vasovagal episode: Vagus nerve receives a strong stimulus (emotion, pain, temperature change), stimulating the parasympathetic nervous system, keeping smooth muscles in blood vessels constricted. As blood vessels relax, brain is hypoperfused, causing loss of consciousness.

39
Q

2 other causes of syncope

A

Carotid sinus hypersensitivity - Mild external pressure induces fainting as reflex response

Orthostatic hypotension (drop in 20+ mmHg when person goes from lying to standing quickly)

40
Q

Signs/symptoms of syncope

A
  • Fainting secondary to exercise or going quickly from sitting/lying to standing.
  • Lasts 5-30 seconds and recovery within another 30
  • Presyncopal clamminess/dizziness etc but no post ictal symptoms
  • Can have twitching but duration is much less
41
Q

Lifestyle advice to a syncope patient

A

Avoid dehydration
Avoid missing meals
Avoid standing still for long periods
Sit or lie down if prodromal dizziness/clamminess/blurry vision occurs

42
Q

Investigations in syncope patient

A

History taking
- Check features that distinguish syncope from seizure
- Triggers? /After exercise?
- Any concurrent illness/family history
- Any associated neurological or cardiac symptoms

Examination
- Head for injury
- Lying+standing blood pressure

43
Q

Explain non-epileptic seizure

A
  • Usually caused by psychosocial distress
  • 1-20 mins
  • Dramatic motor phenomena
  • Eyes closed with ictal crying and speaking
  • Usually history of psychiatric illness
44
Q

Differentiating features of non epileptic seizures vs epileptic

A
  • Seizures dont occur during sleep
  • Pelvic thrusting but no incontinence, tongue biting or ictal injury
  • Long duration, eyes/mouth closed
  • Ictal crying and speaking
  • Unusually rapid or slow recovery
45
Q

Different causes of Epilepsy, NES, and syncope

A

Epilepsy - Hypersynchronous neuronal discharge
NES - Psychosocial stress
Syncope - Insufficient brain perfusion

46
Q

Duration of seizure in epilepsy, NES, syncope

A

Epilepsy - <3 mins
NES - 1-20 mins
Syncope - seconds

47
Q

How does a focal seizure affecting temporal lobe present

A
48
Q

How does parietal lobe seizure present

A

Parietal - Paraesthesia