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Neuro core conditions > Epilepsy / Seizures > Flashcards

Epilepsy / Seizures Flashcards

1
Q

What is epilepsy?

How are seizures different to convulsions?

Who does it affect?

A

Epilepsy is sudden synchronous electrical discharge of cerebral neurones manifesting as seizures.

Convulsions are the motor signs of electrical discharge.

Incidence of epilepsy is highest at extremes i.e. <20yrs and >60yrs

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2
Q

What are focal and generalised seizures?

A
  1. Focal seizures:
    => restricted to a part of cortex of one cerebral hemisphere
    => characterised by either an aura, motor features or loss of awareness.
  2. Generalised seizures:
    => simultaneous involvement of both hemispheres
    => associated with loss of consciousness or awareness
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3
Q

How is epilepsy classified?

A

Seizures are divided by clinical pattern into 2 main groups:

Focal seizures:

i. Without impairment of consciousness
ii. With impairment of consciousness
iii. Evolving to a bilateral convulsive seizure

Generalised seizures:

i. Tonic-clonic seizures (grand mal)
ii. Absence seizures with 3Hz spike-and-wave discharge (petit mal)
iii. Myoclonic seizures
iv. Tonic, clonic and atonic seizures

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4
Q

What are the causes of epilepsy?

A

Idiopathic (2/3 of seizures)
=> Primary generalised

Structural:

i) Cortical scarring e.g. head injury years before onset
ii) Space-occupying lesion
iii) Stroke
iv) Hippocampal sclerosis e.g. after febrile convulsions
v) Vascular malformations
vi) Developmental e.g. dysembryoplastic neuroepithelial tumour ; cortical dysgenesis

Others:

i) Tuberous sclerosis
ii) Sarcoidosis
iii) Systemic lupus erythematous
iv) Polyarteritis nodosa
v) Antibodies to voltage gated potassium channel

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5
Q

Generalised seizure types

i) Describe a Typical Absence Seizure (petit mal).

A

Absence seizures begin in childhood

=> Each attack = 3Hz spike-and-wave EEG activity

=> Loss of awareness <10s

=> Patients often oblivious

=> Absence seizures are manifestation of primary generalised epilepsy, not due to tumours etc => children with absence seizures go on to develop generalised convulsive seizures

*Absence seizures can be confused with temporal lobe seizures causing transient loss of awareness

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6
Q

Generalised seizure types

i) Describe Generalied Tonic-Clonic Seizure (grand mal)

A

Prodrome phase:

=> no warning before generalised tonic-clonic seizures

=> an aura prior to a bilateral tonic-clonic seizure

Tonic-clonic phase:

=> Initial tonic stiffening followed by clinic phase of synchronous jerking limbs reducing in frequency >2mins

=> Initial cry then fall ; eyes open and tongue often bitten

Post-ictal phase:

=> Flaccid unresponsiveness followed by gradual return of awareness with confusion & drowsiness last 15mins

=> Headache common

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7
Q

Generalised seizure types

i) Describe Myoclonic, Tonic and Atonic Seizures.

A

Myoclonic seizures: jerks i.e. brief contraction of limb, face or trunk
=> common in primary generalised epilepsy

Tonic seizures: stiffening of body, not followed by jerking

Atonic seizures: sudden collapse with loss of muscle tone => falls

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8
Q

Focal seizure types

i) Describe focal seizures without impaired consciousness

A

Focal motor, sensory (olfactory, visual), autonomic or psychic symptoms => these are known as aura

No post-ictal symptoms

*Previously known as simple focal seizure

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9
Q

Focal seizure types

i) Describe focal seizures with impaired consciousness

A

Consciousness is impaired either on seizure onset or following a simple partial aura

=> commonly arises from temporal lobe

=> post-ictal feature = confusion

*Previously known as complex focal seizure

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10
Q

Focal seizure types

i) Describe focal seizure evolving to a bilateral convulsive seizure

A

In 2/3 of patients with partial seizures, the focal electrical disturbances spread widely causing a generalised seizure

=> typically convulsive

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11
Q

Localising features of focal seizures:

How does a temporal lobe seizure present?

A

Automatism - complex motor phenomena with impaired awareness varying from:
=> oral (lip smacking, chewing, swallowing)
=> manual movements (fumbling, fiddling, grabbing)

Dysphagia

Deja vu or jamais vu

Emotional disturbance i.e. sudden terror, panic, anger, or elation or derealisation (out-of-body experience)

Hallucination of smell, taste or sound

Delusional behaviour

Bizarre associations e.g. canned music at tesco’s always makes me cry and pass out

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12
Q

Localising features of focal seizures:

How does a frontal lobe seizure present?

A

Motor features i.e. posturing or peddling movements of the leg

Jacksonian march - spreading focal motor seizure with retained awareness, starting with the face / thumb

Motor arrest

Subtle behavioural disturbances

Dysphagia

Speech arrest

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13
Q

Localising features of focal seizures:

How does a parietal lobe seizure present?

A

Sensory disturbances i.e. tingling, numbness, pain

Motor symptoms => spread to pre-central gyrus

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14
Q

Localising features of focal seizures:

How does a occipital lobe seizure present?

A

Visual phenomena i.e. spots, lines, flashes

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15
Q

Elements of a seizure:

=> Preceding prodrome lasting hours to days with change in mood / behaviour

=> Aura implies focal seizure from temporal lobe

=> Strange feeling in the gut/deja vu or strange smell or flashing lights

=> Post-ictally: headaches, confusion, myalgia or temporary weakness after focal seizure in the temporal lobe

A

INFO CARD

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16
Q

What are primary generalised epilepsies?

A

Primary generalised epilepsies:
=> present in childhood & young adult life

=> 20% of all patients with epilepsies

=> Brain is structurally normal

=> Abnormalities in ion channels influencing neuronal firing, neurotransmitter release and synaptic connection

Types of primary generalised epilepsies:

=> Childhood absence epilepsy

=> Juvenile myoclonic epilepsy

=> Monogenic disorders

17
Q

Describe juvenile myoclonic epilepsy.

Include:

  1. Clinical features
  2. Triggers
  3. Who does it affect
A

10% of all epilepsy patients

Starts in teenage years

Clinical features:
=> Myoclonic jerks
=> Generalised tonic-clonic seizures
=> Absence in 1/3

Triggers: sleep deprivation, alcohol, strobe lighting

Abnormal EEG

Good response to treatment

Requires life-long treatment

18
Q

How do you diagnose epilepsy?

A

Clinical diagnosis
=> Hx from patient and witness

Good discriminators between types of blackouts:
=> Prolonged recovery period (seizures)
=> Bitten tongue (seizures)
=> Pallor (syncope) ; cyanosis (seizure)

Poor discriminators:
=> Urinary incontinence - may occur in seizures and syncope
=> Presence of injury

*All patients with a seizure must be referred for specialist assessment in <2wks

19
Q

Diagnosis of seizure: taking Hx after an episode of loss of consciousness

Witness account is important:

  1. What happened?
    => Before: aura vs pre-syncopal prodrome

=> During: convulsion, automatism vs brief syncopal blackout and pallor

=> After: post-ictal confusion and headache vs rapid recovery in syncope

  1. Circumstances
    => Seizure triggers i.e. sleep deprivation, alcohol binge, drugs

=> Syncope triggers i.e. pain, heat, prolonged standing

A
  1. Epilepsy risk factors i.e. childhood febrile convulsions, head injury, meningitis, encephalitis, family Hx of epilepsy
  2. Previous unrecognised seizures
    => myoclonic jerks
    => absences
    => auras (focal seizures)
  3. Alcohol excess?
  4. Medication lowering seizures threshold
  5. Driving license?
20
Q

Seizures can be provoked but that would not classify as an epilepsy. ~10% of provoked seizures can reoccur because the provocation is irreversible.

What are the causes of irreversible seizures?

A

Trauma

Stroke / haemorrhage

Increased intracranial pressure

Alcohol or Benzodiazepines withdrawal

Metabolic disturbance (hypoxia, low calcium, disturbed sodium, uraemia, liver disease)

Infection i.e. meningitis, encephalitis

Drugs i.e. tricyclics, cocaine

21
Q

Which investigations are needed in diagnosing epilepsy?

A

Look for provoking causes/precipitating factors

Consider EEG

Others tests:
=> MRI brain (structural lesions)
=> Drug levels - if compliant on anti-epileptic drugs
=> Lumbar puncture if infection suspected
=> Blood tests including serum calcium
=> ECG

Counselling: advise on dangers after seizure - avoid driving, swimming, heights
=> contact DVLA and avoid driving till seizure free >1yr

22
Q

What is the treatment for focal partial seizures?

A

1st line: Carbamazepine or Lamotrigine

2nd line: Levetiracetam ; oxcarbazepine ; sodium valproate

23
Q

What is the treatment for generalised tonic-clonic seizures?

A

1st line: Sodium valproate or Lamotrigine

2nd line: Carbamazepine ; Levetiracetam ; Topiramate

24
Q

What is the treatment for absence seizures?

A

1st line: Sodium valproate (SE: teratogenic)

2nd line: Lamotrigine (SE: Steven Johnson’s syndrome / toxic epidermal necrolysis)

25
Q

What is the treatment for myoclonic seizures?

A

1st line: Sodium valproate

2nd line: Levetiracetam ; Topiramate

*Carbamazepine / oxycarbazepine may worsen attack

26
Q

What is the treatment for tonic or atonic seizures?

A

Sodium valproate or Lamotrigine

27
Q

Management of epilepsy:

Treat with one drug and with one doctor in charge only.

=> Slowly build up dosage over 2/3 months until seizures controlled or maximum dose reached

A

INFO CARD

28
Q

What other interventions may help manage epilepsy?

A

Relaxation or CBT => psychological therapies used in adjunct to medical treatment

Surgery => if a single focus identified

29
Q

Most seizures only last minutes and end spontaneously.

A prolonged seizure >5minutes or repeated seizures may be terminated using which medications?

A
  1. Rectal diazepam
  2. IV Lorazepam
  3. Buccal Midazolam

O2 should be given and airways monitored for post-ictal phase

30
Q

Status epileptics occurs in patients with known epilepsy.

What is status epilepticus?

A

Medical emergency

Seizures lasting >30 mins or two or more seizures without recovery of consciousness between them.

Mortality & risk of permanent brain damage increases with length of attack

31
Q

What are the types of status epilepticus seizures?

A
  1. Tonic-clonic status - diagnosis is usually obvious
2. Non-convulsive status e.g.
=> Absence status
=> Continuous partial status with preservation of consciousness
=> More difficult to diagnose
=> Look for subtle eye or lid movement
  1. Check if patient pregnant => could be eclampsia (check urine and BP)
32
Q

What are the investigations carried out in status epilepticus?

A
  1. Start treatment first if suspecting status
  2. Then investigate:
Bloods:
=> glucose 
=> ABG
=> U&E
=> Calcium
=> FBC
=> ECG

Anti-convulsant levels ; Toxicology screen

Lumbar puncture

Blood and urine culture

EEG => can be very helpful ; CT brain

Carbon monoxide level

Pulse oximetry ; cardiac monitor

33
Q

How do you manage status epilepticus?

A
  1. Open & secure the airway
  2. Oxygen 100% + suction
  3. IV access & take blood
    => U&E, LFT, FBC, glucose, calcium
    => Toxicology screen if indicated
    => Anticonvulsant levels
  4. IV bolus to stop seizures i.e. Lorazapam 4mg
    => Give 2nd dose of Lorazapam if no response after 10-20mins
  5. Thiamine IV if alcoholism or malnourishment ; glucose IV (unless glucose normal) ; treat acidosis if severe
  6. Correct hypotension with fluids
  7. If seizure continues => phenytoin IV - monitor ECG and BP
  8. Continued seizure after 60-90mins of therapies above require expert help with paralysis and ventilation
    => continuous EEG monitoring in ICU
    => Never spend >20 mins with status patient without help from anaesthetist

Neuro core conditions (9 decks)

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