Neurology: Epilepsy

Question 1

What is Epilepsy?

Answer 1

• 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

Question 2

What are common causes of Epilepsy?

Answer 2

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

Question 3

What are some differentials for Seizures?

Answer 3

• 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

Question 4

What are some provoking factors for seizures?

Answer 4

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

Question 5

How are seizures classified?

Answer 5

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

Question 6

What are some types of seizures?

Answer 6

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

Question 7

What are different variations of generalised seizures?

Answer 7

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

Question 8

What are features of Focal Seizures?

Answer 8

• 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

Question 9

What are generalised seizures?

Answer 9

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

Question 10

What are symptoms and signs of generalised seizures?

Answer 10

• 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.

Question 11

What is focal to bilateral seizures/secondary generalized seizures?

Answer 11

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

Question 12

What are some special forms of epilepsy in children?

Answer 12

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

Question 13

What are features of West’s syndrome?

Answer 13

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

Question 14

What are the characteristics of Lennox-Gastaut syndrome?

Answer 14

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

Question 15

What is Benign Rolandic Epilepsy?

Answer 15

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

Question 16

What are Juvenile Myoclonic Epilepsy?

Answer 16

• 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

Question 17

What are characteristics and investigations of abscence seizures?

Answer 17

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

Question 18

How can neonatal period seizures be managed?

Answer 18

• 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

Question 19

What are features of tonic-clonic seizures?

Answer 19

Tonic phase → Clonic phase → Post Ictal phase

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

Question 20

What are symptoms of Complex Partial Seizures?

Answer 20

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

Question 21

What are symptoms and signs of abscence seizures?

Answer 21

• 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

Question 22

What are investigations for seizures?

Answer 22

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

Question 23

How are seizures managed?

Answer 23

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

Question 24

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

Answer 24

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

Question 25

What are general mechanism of actions for antiepileptic drugs?

Answer 25

* **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.

Question 26

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

Answer 26

* **Driving:** **​**Patients cannot drive for 6 months following 1^st 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.

Question 27

What are typical drugs for Generalised tonic-clonic seizures?

Answer 27

* **1st line:** Sodium valproate * **2nd line:** Lamotrigine, carbamazepine

Question 28

What are typical drugs for abscence seizures?

Answer 28

**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

Question 29

What are typical drugs for myoclonic seizures?

Answer 29

**1st line:** Sodium valproate **2nd line:** Clonazepam, Lamotrigine * Should not prescribe carbamazepine as may exacerbate myoclonic seizures

Question 30

What are typical drugs for focal seizures?

Answer 30

**1st line:** Carbamazepine or Lamotrigine **2nd line:** Levetiracetam, Oxcarbazepine or Sodium valproate

Question 31

How are seizures acutely managed?

Answer 31

* 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

Question 32

What is Status Epilepticus?

Answer 32

**Status epilepticus when seizures occur \>5mins continuously or 2+ seizures without full recovery in 30 minutes.** Recurrent attacks occur without regaining consciousness.

Question 33

What are the steps in the management of Status Epilepticus?

Answer 33

1. **A to E** 2. **Medical Management**

Question 34

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

Answer 34

* **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

Question 35

What are the steps for medically managing Status Epilepticus?

Answer 35

* **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

Question 36

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

Answer 36

**ABG – Typical pattern** * Acidotic * Lactate high * Glucose okay * Oxygen low but not quite dangerous

Question 37

What are bloods taken following Status Epilepticus?

Answer 37

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