Neurology: Epilepsy Flashcards
Define what is meant by epilepsy [1]
Epilepsy is an umbrella term for a condition where there is a tendency to have seizures.
- Seizures are transient episodes of abnormal electrical activity in the brain. There are many different types of seizure.
When taking a history for a patient with epilepsy, which questions should you specifically ask? [2]
Description of seizure - before, during and after
- Before: Feeling unwell? Activities that were doing before seizure? Playing?
- During: head movements / jerking / stiffness / injury
- After: how long did it take to return to normal self?
What are risk factors for developing epilepsy? [5]
- Age < 1
- Birth Hx (pre-term more likely)
- Development delay
- FHx epilepsy, consanguinity
- Medication
Describe the pathophysiology of epilepsy [5+]
Neuronal Excitability:
- The balance between excitatory and inhibitory neuronal activity in the brain is critical for normal function
- This equilibrium can be disrupted by various mechanisms leading to increased neuronal excitability and propensity for seizure generation
Neural Network Reorganisation:
- Following an initial insult such as head trauma, stroke or infection, there may be reorganisation within neural networks. This process of epileptogenesis, involves alterations to synaptic connectivity leading to formation of hyperexcitable neuronal circuits
- Reactive gliosis following injury or inflammation contributes significantly to epileptogenesis. Astrocytes and microglia undergo morphological and functional changes - increased extracellular potassium levels, enhanced glutamate release and reduced GABA
Inflammation:
- Following an insult, there is activation of the innate immune system leading to release of pro-inflammatory cytokines, chemokines and other inflammatory mediators
- These substances can modulate neuronal excitability, promote gliosis and induce blood-brain barrier disruption
Environmental Triggers:
- Finally, environmental factors such as sleep deprivation, stress or specific drug use can lower the seizure threshold in an individual already predisposed to seizures.
Describe the different overall types of seizures [3]
Focal Onset Seizures
Generalised Onset Seizures
Unknown Onset Seizures
Describe the different types of:
Focal Onset Seizures [3]
Focal Onset Seizures
Focal Aware Seizures (previously Simple Partial Seizures):
- The individual remains conscious and can recall events during the seizure. Symptoms depend on the brain region affected.
Focal Impaired Awareness Seizures (previously Complex Partial Seizures):
- Involves alteration in consciousness. They may start as focal aware seizures and then progress.
Focal to Bilateral Tonic-Clonic Seizures:
- Begin in one hemisphere and spread to involve both, resulting in a tonic-clonic seizure.
Describe the different types of:
Generalised Onset Seizures [6]
These arise at some point within, and rapidly engage, bilaterally distributed networks.
Tonic-Clonic Seizures:
- Characterised by stiffening (tonic phase) followed by rhythmic muscle jerking (clonic phase).
Absence Seizures:
- Brief lapses in consciousness, often with staring. They can be sub-classified into typical and atypical absence seizures.
Tonic Seizures:
- Cause stiffening.
Atonic Seizures:
- Lead to loss of muscle control, often resulting in falls (‘drop attacks’).
Clonic Seizures:
- Involves repetitive jerking movements.
Myoclonic Seizures:
- Quick, sudden jerks of a muscle or group of muscles.
Describe what is meant by an unknown onset seizure [1]
When the onset of a seizure is not observed or known, it falls under this category
They can later be reclassified to either focal or generalised when more information becomes available.
Describe how epilepsy can be classified based on epilepsy syndromes [4]
An epilepsy syndrome is determined by a group of features observed together, such as the type of seizure, age of onset, EEG findings, and often prognosis. E.g:
Childhood Absence Epilepsy (CAE):
- Characterised by typical absence seizures, with onset usually between 4-10 years.
Juvenile Myoclonic Epilepsy (JME):
- Marked by myoclonic jerks, typically shortly after waking.
Dravet Syndrome:
- Severe epilepsy beginning in infancy, initially presenting as prolonged seizures with fever.
Lennox-Gastaut Syndrome:
- Characterised by multiple seizure types, cognitive dysfunction, and a specific EEG pattern.
Describe the type of seizure that would exist if it was localised to the temporal lobe [4]
An aura occurs in most patients:
* typically a rising epigastric sensation
* also psychic or experiential phenomena, such as dejà vu, jamais vu
* less commonly hallucinations (auditory/gustatory/olfactory)
Seizures typically last around one minute:
- automatisms (e.g. lip smacking/grabbing/plucking) are common
Temporal lobe focal seizures - HEAD
Hallucinations (auditory/gustatory/olfactory)
Epigastric rising sensation
Automatisms (lip smacking/grabbing/plucking)
Deja vu or jamais vu
Describe the type of seizure that would exist if it was localised to the frontal lobe [4]
Head/leg movements
posturing
post-ictal weakness
Jacksonian march (The seizure usually begins with a tingling or twitching sensation in a small area such as finger, toe, corner of the mouth. The sensation then spreads to a larger area of the body)
NB: Frontal lobe is motor lobe
Describe the type of seizure that would exist if it was localised to the parietal [1] or occipital lobes [1]
Parietal lobe (sensory):
- Paraesthesia
Occipital lobe (visual)
- Floaters/flashes
Describe the presentation of Generalised Tonic-Clonic Seizures [5]
There is loss of consciousness and tonic (muscle tensing) and clonic (muscle jerking) movements.
- Tonic before clonic (mostly)
- Tongue biting
- Incontinence
- Groaning
- Irregular breathing
- After the seizure there is a prolonged post-ictal period where the person is confused, drowsy and feels irritable or low.
What is the treatment for generalised tonic-clonic seizures [2]
Management of tonic-clonic seizures is with:
First line:
- sodium valproate
Second line:
- lamotrigine or carbamazepine
Focal seizures start in the [] lobes.
Describe their presentation [3]
Focal seizures start in the temporal lobes. They affect hearing, speech, memory and emotions. There are various ways that focal seizures can present:
* Hallucinations
* Memory flashbacks
* Déjà vu
* Doing strange things on autopilot
How do you treat focal seizures [2]
One way to remember the treatment is that the choice of medication is the reverse of tonic-clonic seizures:
First line:
- carbamazepine or lamotrigine
Second line:
- sodium valproate or levetiracetam
Describe the typical presentation of abscence seizures [4]
What is the management? [2]
Absence seizures:
- typically happen in children
- the patient becomes blank, stares into space and then abruptly returns to normal.
- During the episode they are unaware of their surroundings and won’t respond
- These typically only lasts 10 to 20 seconds.
- Most patients (more than 90%) stop having absence seizures as they get older.
Management is:
- First line: sodium valproate or ethosuximide
How do you differentiate daydreaming from childhood absence epilepsy? [1]
What spike wave frequency on an EEG would indicate CAE? [1]
In daydreaming can distract a person out of daydreaming, in CAE can’t stop them
Spike wave at frequency of 2.5-3Hz
Describe in detail the presentation of atonic seizures.
What is their management? [2]
Atonic seizures are also known as drop attacks.
- They are characterised by brief lapses in muscle tone.
- These don’t usually last more than 3 minutes
- They typically begin in childhood.
Management is:
First line:
- sodium valproate
Second line:
- lamotrigine
Atonic seizures - may be indicative of [] syndrome.
They may be indicative of Lennox-Gastaut syndrome.
Describe the presentation of myoclonic seizures [2]
They normally occur in children with which form of epilepsy? [1]
Myoclonic seizures present as sudden brief muscle contractions, like a sudden “jump”
- They occur in various forms of epilepsy but typically happen in children as part of juvenile myoclonic epilepsy.
What is first line mx of myoclonic seizures [1]
Management is:
First line:
- sodium valproate
Other options:
- lamotrigine, levetiracetam or topiramate
Infantile Spasms
- This is also known as [] syndrome
Infantile Spasms
- This is also known as West syndrome
Describe the triad of features seen in infantile epileptic seizures [3]
Describe how a mum might describe baby presentation [2]
1-24 months
Triad:
- Epileptic spasms
- Hypsarrhthmia on EEG
- Developmental plateauing or regression
baby used to smile and now doesn’t really, episodes where flex arms and drop head
What are treatment options for IESS? [3]
Steroids
Vigabatrin
+/- ACTH
Describe what is meant by self-limited epilepsy with centrotemporal spikes (SeLECTS)
Describe the presentation
Describe the EEG
Presentation:
- 4-10 years old
- Focal seizures are brief, typically < 2/3 mins, few from sleep, associated with somatosensory symptoms
EEG:
- High amplitude centrotemporal sharp and slow wave complexes
Describe the tx for SeLECTS [2]
Offer NO tx - most resolves by puberty
If severe - Lamotrigine or levetiracetam
Describe the investigations used for epilepsy [+]
First-Line Investigations
- EEG: can detect interictal epileptiform discharges (IEDs), which indicate a high likelihood of epilepsy. Perform an EEG after the second simple tonic-clonic seizure. Children are allowed one simple seizure before being investigated for epilepsy.
- Magnetic Resonance Imaging (MRI): This imaging technique provides detailed images of brain structures and can identify abnormalities that may be causing seizures, such as tumours, vascular malformations or cortical dysplasias.
NB:
- While EEG and MRI are frequently used as initial investigations, they do not confirm epilepsy definitively. A normal EEG does not exclude epilepsy, nor does an abnormal EEG confirm it. Similarly, an MRI may show structural changes in the brain but these need to be interpreted in the context of clinical findings.
When are MRIs indicated for ?epilepsy [3]
- The first seizure is in children under 2 years
- Focal seizures
- There is no response to first line anti-epileptic medications
Which investigations would you conduct for epilepsy to rule out other causes of seizures? [4]
ECG to exclude problems in the heart.
Blood electrolytes including sodium, potassium, calcium and magnesium
Blood glucose for hypoglycaemia and diabetes
Blood cultures, urine cultures and lumbar puncture where sepsis, encephalitis or meningitis is suspected
Describe what is meant by status epilepticus [2]
Status epilepticus:
- This is a medical emergency where seizures last longer than 5 minutes or when two + seizures occur close together without regaining consciousness in between
- It can lead to severe neurological deficits and even death if not promptly managed.
Describe the management of status epilepticus [+]
Management of status epileptics in the hospital (take an ABCDE approach):
* Secure the airway
* Give high-concentration oxygen
* Assess cardiac and respiratory function
* Check blood glucose levels
* Gain intravenous access (insert a cannula)
* IV lorazepam, repeated after 10 minutes if the seizure continues
* If the seizures persist the final step is an infusion of IV phenobarbital or phenytoin. At this point intubation and ventilation to secure the airway needs to be considered, along with transfer to the intensive care unit if appropriate.
What are the medical options in the community for status epilepticus [2]
Medical options in the community:
Buccal midazolam
Rectal diazepam
Individuals with epilepsy have higher rates of [mental health disorders (2)] compared to the general population.
[] is also more prevalent among children with epilepsy.
Individuals with epilepsy have higher rates of depression and anxiety disorders compared to the general population.
Attention deficit hyperactivity disorder (ADHD) is also more prevalent among children with epilepsy.
What advice do you give to patients with epilepsy in case they have a seizure? [5]
Take showers rather than baths
Don’t lock the door when showering / bathroom
Be very cautious with swimming unless seizures are well controlled and they are closely supervised
Be cautious with heights
Be cautious with traffic
Be cautious with any heavy, hot or electrical equipment
Describe the notable side effects of:
- Sodium Valproate [4]
- Carbamazepine [3]
Sodium Valproate:
* Teratogenic, so patients need careful advice about contraception
* Liver damage and hepatitis
* Hair loss
* Tremor
Carbamazepine:
* Agranulocytosis
* Aplastic anaemia
* Induces the P450 system so there are many drug interactions
What are notable side effects of:
- Phenytoin [3]
- Ethosuximide [2]
Phenytoin
* Folate and vitamin D deficiency
* Megaloblastic anaemia (folate deficiency)
* Osteomalacia (vitamin D deficiency)
Ethosuximide
* Night terrors
* Rashes
What are notable side effects of Lamotrigine [2]
- Stevens-Johnson syndrome or DRESS syndrome. These are life threatening skin rashes.
- Leukopenia
Which of the following causes hyponatraemia [2]
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following causes hyponatraemia
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause secondary angle closure glaucoma
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause secondary angle closure glaucoma
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause alopecia
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause alopecia
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause tremor and ataxia?
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause tremor and ataxia?
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which antiepileptic can cause Dupuytren’s contracture? [1]
Phenytoin
Describe the monitoring needed when prescribing phenytoin for epilepsy? [3]
Phenytoin levels do not need to be monitored routinely but trough levels, immediately before dose should be checked if:
* Adjustment of phenytoin dose
* Suspected toxicity
* Detection of non-adherence to the prescribed medication
Describe chronic common side effects of phenytoin use [+]
gingival hyperplasia
hirsutism
coarsening of facial features, drowsiness
Megaloblastic anaemia
Peripheral neuropathy
Enhanced vitamin D metabolism causing osteomalacia
Lymphadenopathy
Dyskinesia
What are acute initial [5] and later [2] associated effects of phenytoin use for epilepsy
Acute
Initially:
- dizziness, diplopia, nystagmus, slurred speech, ataxia
Later:
- confusion, seizures
Which of the following can cause - Stevens-Johnson syndrome?
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
Which of the following can cause - Stevens-Johnson syndrome?
Carbamazepine
Lamotrigine
Levetiracetam
Sodium valproate
Topiramate
