Neurology: Epilepsy Flashcards

1
Q

What is Epilepsy?

A
  • Common neurological condition characterised by recurrent seizures due to abnormal excessive or synchronous neuronal activity in the brain
  • Epilepsy most commonly occurs in isolation although certain conditions have an association with epilepsy
    • Cerebral palsy: 30% have epilepsy
    • Tuberous sclerosis
    • Mitochondrial disease
  • 2/3rds of those afflicted achieve control through antiepileptic medication
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2
Q

What are common causes of Epilepsy?

A
  • Childhood: Genetic, Febrile, Syndromes, Congenital brain disorders.
  • Adolescence: Genetic, metabolic, toxins, trauma
  • Adulthood: Brain lesions, Alcohol, Drugs.
  • Elderly: Vascular, Degenerative disorders.
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3
Q

What are some differentials for Seizures?

A
  • Febrile Convulsions
  • Alcohol Withdrawals
  • Psychogenic non-epileptic seizures
  • Complex faints with cerebral hypoxia
  • Hypoglycaemia
  • Migraine
  • Cerebrovascular episodes
  • Transient Global Amnesia
  • Other causes of nocturnal incontinence
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4
Q

What are some provoking factors for seizures?

A
  • Photosensitivity -flashing lights
  • Hyperventilation
  • Sleep deprivation.
  • Alcohol
  • Menstruation - catamenial.
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5
Q

How are seizures classified?

A

Classify

  • CAUSATION of discharge
    • Idiopathic – usually genetic
    • Symptomatic – usually brain lesion/metabolic
    • Cryptogenic – presumed lesion
  • LEVEL OF AWARENESS during a seizure (may affect safety during seizure)
  • OTHER features
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6
Q

What are some types of seizures?

A
  • Focal seizures
  • Generalised Seizures
  • Focal to bilateral seizure (previously termed secondary generalized seizures)
  • Unknown onset
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7
Q

What are different variations of generalised seizures?

A
  • Tonic-clonic (grand mal)
  • Tonic
  • Clonic
  • Typical absence (petit mal)
  • Myoclonic: brief, rapid muscle jerks
  • Atonic
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8
Q

What are features of Focal Seizures?

A
  • Focal seizures start in a specific area on one side of the brain and can be Simple or Complex.
  • They can be further classfied by their level of awareness
    • Focal aware (previously termed ‘simple partial’)
    • Focal impaired awareness
    • Awareness unknown
  • Focal seizures can also be classified as being motor (e.g. Jacksonian march), non-motor (e.g. déjà vu, jamais vu;) or having other features such as aura
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9
Q

What are generalised seizures?

A
  • Generalised Seizures engage or involve networks on both sides of the brain at the onset. Consciousness lost immediately.
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10
Q

What are symptoms and signs of generalised seizures?

A
  • Biting of the tongue
  • Experience of incontinence of urine
  • Blackout and collapse
  • Postictal phase of drowsiness and tiredness for around 15 minutes following the seizure.
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11
Q

What is focal to bilateral seizures/secondary generalized seizures?

A

Starts on specific area of one side of the brain before spreading to both lobes

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12
Q

What are some special forms of epilepsy in children?

A
  • Infantile spasms (West’s syndrome)
  • Lennox-Gastaut syndrome
  • Benign Rolandic Epilepsy
  • Juvenile myoclonic epilepsy (Janz syndrome)
  • Typical absence seizures (petit mal)
  • Neonatal period seizures
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13
Q

What are features of West’s syndrome?

A

Symptoms and Signs

  • Brief spasms beginning the first few months of life
    • Flexion of head, trunk, limbs leading to extension of arms (Salaam attack). Last 1-2 secs and repeat up to 50 times
    • Progressive mental handicap
    • EEG shows hypsarrhythmia
  • Usually secondary to serious neurological abnormality (e.g. birth asphyxia, encephalitis, tuberous sclerosis) or may be cryptogenic

Management: Vigabatrin/Steroids

  • Poor prognosis
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14
Q

What are the characteristics of Lennox-Gastaut syndrome?

A

May be extension of infantile spasms (50% have history) with onset typically at 1-5 years.

  • Symptoms/Signs: Atypical absences, falls and jerks, 90% moderate-severe handicap
  • EEG: slow spike
  • Management: Ketogenic diet may help
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15
Q

What is Benign Rolandic Epilepsy?

A
  • Paraesthesia usually on waking up
  • Most common in childhood and occur more in males
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16
Q

What are Juvenile Myoclonic Epilepsy?

A
  • Typical onset in teens commonly girls
    • Infrequent generalized seizure often in morning
    • Daytime absences
    • Sudden, shock like myoclonic seizure
  • Usually a good response to sodium valproate
17
Q

What are characteristics and investigations of abscence seizures?

A
  • Characteristics: Onset 4-8 yrs and has a good prognosis. 90-95% become seizure free in adolescence
  • Investigations: EEG show 3Hz symmetrical generalized waves
18
Q

How can neonatal period seizures be managed?

A
  • Neonatal period seizures types
    • Pyridoxine dependency (AR, IV B6)
    • Benign familial neonatal seizures (AD)
    • Benign neonatal convulsions (5th day)
  • Causes
    • Hypoglycaemia
    • Meningitis
    • Head trauma
  • Management: Try vitamin B6
19
Q

What are features of tonic-clonic seizures?

A

Tonic phase → Clonic phase → Post Ictal phase

  • Aura
  • Cry
  • Tongue biting
  • Incontinence
  • Unwell after with Headaches, Confusion and Muscles aches
20
Q

What are symptoms of Complex Partial Seizures?

A
  • Aura – smell, taste, déjà vu
  • Absence
  • Automatism
  • Prolonged
  • Nausea
  • Headache
  • No convulsion
21
Q

What are symptoms and signs of abscence seizures?

A
  • Seizure duration short duration (few-30 secs)
  • Quick recovery
  • Occur in children
  • Multiple attacks during the day
  • Sudden onset w/o aura
  • Staring only
  • Patient may not be aware
  • Speech arrest
  • 3p/s spike and wave on EEG
22
Q

What are investigations for seizures?

A
  • Electroencephalogram (EEG)
  • MRI - neuroimaging
  • ECG
  • Bloods e.g. electrolytes, blood glucose.
23
Q

How are seizures managed?

A

Single Seizure

  • Confirm diagnosis and establish cause.
  • Advise on how to avoid future attacks
  • Discuss risk factors: up to 50% risk of recurrence.

Two or more attacks

  • Diagnosis now epilepsy and there is a higher risk of more attacks.
  • Same consideration of risk factors.
  • Most neurologist start anti-epileptics following second epileptic seizure as general rule
24
Q

When would it be considered appropriate to start antiepileptics following the first seizures?

A
  1. The patient has a neurological deficit
  2. Brain imaging shows a structural abnormality
  3. The EEG shows unequivocal epileptic activity
  4. The patient or their family or carers consider the risk of having a further seizure unacceptable
25
Q

What are general mechanism of actions for antiepileptic drugs?

A
  • Modulation of Neurotransmitters
    • Enhance GABA
    • Suppress Glutamate.
  • Effect on Cell Membrane
    • Action of Na+ / K+ channels
    • Effect on Na/Ca dependent action potentials.
    • Direct effect on neuronal firing.
26
Q

What are other factors need consideration in the management of epilepsy?

A
  • Driving: Patients cannot drive for 6 months following 1st seizure. Patients with established epilepsy, must be seizure/fit free for 12 months to drive
  • Other Medications: Antiepileptics can induce/inhibit the P450 system to vary the metabolism of other medications
  • Women Wishing To Be Pregnant: Antiepileptics can be teratogenic (e.g. sodium valproate). Women need neurologist’s advice prior to becoming pregnant regarding the most suitable antiepileptic medication. Breastfeeding can be safe (exception of barbiturates).
  • Women Taking Contraception: ​Contraceptives can vary the effect of antiepileptic medications and antiepileptic medications can also vary the effect of contraceptives.
27
Q

What are typical drugs for Generalised tonic-clonic seizures?

A
  • 1st line: Sodium valproate
  • 2nd line: Lamotrigine, carbamazepine
28
Q

What are typical drugs for abscence seizures?

A

Sodium Valproate or Ethosuximide

  • Sodium valproate particularly effective if co-existent tonic-clonic seizures in primary generalised epilepsy
  • Should not prescribe Carbamazepine as may exacerbate absence seizures
29
Q

What are typical drugs for myoclonic seizures?

A

1st line: Sodium valproate

2nd line: Clonazepam, Lamotrigine

  • Should not prescribe carbamazepine as may exacerbate myoclonic seizures
30
Q

What are typical drugs for focal seizures?

A

1st line: Carbamazepine or Lamotrigine

2nd line: Levetiracetam, Oxcarbazepine or Sodium valproate

31
Q

How are seizures acutely managed?

A
  • Rescue medication if seizures don’t terminate after 5-10 minutes
    • Benzodiazepines such as diazepam typically may be administered rectally or intranasally/under the tongue
  • If status epilepticus occurs then further benzodiazepines, infusions of antiepileptics or even use of general anaesthetics
32
Q

What is Status Epilepticus?

A

Status epilepticus when seizures occur >5mins continuously or 2+ seizures without full recovery in 30 minutes.

Recurrent attacks occur without regaining consciousness.

33
Q

What are the steps in the management of Status Epilepticus?

A
  1. A to E
  2. Medical Management
34
Q

What are the features of the A to E management of Status Epilepticus?

A
  • Airway: Crucial in the scenario. Can be difficult to assess and if compromised need arrest call and ITU/Anaesthetist
  • Breathing: Can be quite difficult. SATs are quite unreliable and early oxygen suggested
  • Circulation: Attempt to obtain an accurate HR/BP. Assessment crucial and needed quickly. ABG needed if possible
  • Disability: No GCS is possible, but glucose must be accessed. Hypoglycaemia can cause seizures.
  • Everything else: Medications, Other substances, Vomit or soiling
35
Q

What are the steps for medically managing Status Epilepticus?

A
  • IV Lorazepam – 4mg
    • If no Access
      • 10mg IM midazolam or 10mg PR diazepam
  • After 10-15 mins another bolus of IV lorazepam 4mg
  • Phenytoin infusion needed if 2 boluses of IV lorazepam do not work
    • Dose: 20mg/kg - max rate 50mg/min
  • After this, call ITU and rapid sequence induction-thiopental etc
36
Q

What are the typical pattern seen on ABG in status epilepticus?

A

ABG – Typical pattern

  • Acidotic
  • Lactate high
  • Glucose okay
  • Oxygen low but not quite dangerous
37
Q

What are bloods taken following Status Epilepticus?

A
  • FBC
  • U&E/LFT/Bone profile
  • CRP/Culture if suspecting infective cause
  • Glucose
  • Clotting screen
  • Toxicology screen
  • Viral PCR