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
