[34] Epilepsy Flashcards
What is epilepsy?
A group of neurological disorders characterised by epileptic seizures
What are epileptic seizures?
Episodes that vary from brief, nearly undetectable periods, to long periods of vigorous shaking
What is a seizure?
A paroxysmal abnormality of motor, sensory, autonomic, and/or cognitive function due to transient brain dysfunction
What does the term ‘seizure’ include?
- Epileptic
- Syncopal (anoxic)
- Brainstem
- Emotional
- Functional
- Undetermined
What are the types of brainstem seizures?
- Hydrocephalic
- Coning
What are functional seizures also known as?
Psychogenic pseudo-seizures
What makes a seizure epileptic?
The nature of the underlying electrical activity in the brain, especially the cerebral cortex
What is the problem with the thing that makes seizures epileptic being the nature of the underlying electrical activity in the brain?
They can be difficult to distinguish from a non-epileptic seizure clinically
What are epileptic seizures due to?
Excessive and hypersynchronous electrical activity, typically in neural networks in all or part of the cerebral cortex
When can an epilepsy generally be recognised?
After two or more unprovoked epileptic seizures
What is the incidence of epilepsy in childhood?
0.05%
How does the incidence of epilepsy in children compare to other age groups?
It affects infants and children more than any other age group
What are seizures, in terms of pathophysiology?
A paroxysmal manifestation of the electrical properties or the cerebral cortex
When does a seizure result?
When there is a sudden imbalance between the excitatory and inhibitor forces within the network of cortical neurones in favour of sudden-onset net excitation
What % of epilepsies are genetic?
70-80%
What is meant by ‘genetic’ epilepsies?
Idiopathic syndromes with complex inheritance
What are the other causes of epilepsy?
- Cerebral dysgenesis/malformation
- Cerebral vascular occlusion
- Cerebral damage
- Cerebral tumour
- Neurodegenerative disorders
- Neurocutaneous syndromes
Give two examples of causes of cerebral damage that can lead to epilepsy
- Congential infection
- Hypoxic-ischaemic encephalopathy
Give an example of a neurocutaneous syndrome that can cause epilepsy
Tuberous sclerosis
What is the main risk factor for epilepsy?
Family history
What can epilepsies be broadly classified as?
- Generalised
- Focal
When do focal seizures occur?
When the seizures arise from one or part of the hemisphere
What does the manifestation of focal seizures depend on?
The part of the brain where the discharge originates and moves too
What happen to the level of consciousness during focal seizures? `
May be retained or lost
How can a focal seizure progress?
May evolve to a generalised secondary tonic-clonic seizure
What region of the brain do frontal seizures affect?
The motor or pre-motor cortex
How might frontal seizures present?
- Clonic movements, which may travel proximally (Jacksonian march)
- Tonic seizure with both upper limbs raised high for several seconds
How might temporal seizures present?
- Aura
- Smell or taste abnormalities
- Distortion of sound and shape
- Automatisms, e.g. lip smacking, plucking at one’s clothing
- Deja-vu
How might occipital seizures present?
- Stereotyped visual hallucinations
How might parietal seizures present?
- Contralateral dysesthesias
- Distorted body image
What is dysesthesias?
Altered sensation
What are generalised epileptic seizures?
Where discharges arise from both hemispheres
What are the types of generalised epileptic seizures?
- Absence
- Myoclonic
- Tonic-clonic
- Atonic
How do absence seizures present?
Transient loss of consciousness, with abrupt onset and termination unaccompanied by motor phenomena apart from some flickering of eyelids and minor alteration in muscle tone
What can absence seizures often be precipitated by?
Hyperventilation
How do myoclonic seizures present?
Brief, often repetitive jerking movements of the limbs, neck, or trunk
How do tonic seizures present?
Generalised increase in tone
How does the tonic phase of tonic-clonic seizures present?
- May fall to ground
- Do not breath, become cyanosed
What might happen when the patient falls to the ground in tonic-clonic seizures?
May injure themselves
What happens in the clonic phase of tonic-clonic seizures?
- Jerking of limbs
- Breathing is irregular and cyanosis persists
- Saliva may accumulate in mouth
- Biting of tongue
- Incontinence of urine
How long do tonic-clonic seizures last?
From a few seconds to minutes, followed by unconsciousness or deep sleep for up to several hours
How do atonic seizures present?
Transient loss of muscle tone, causing sudden fall to floor or drop of head
What are atonic seizures often preceded by?
Myoclonic jerk
What is a seizure pattern?
A pattern of epileptic seizures that has different clinical features and different ages of onset
Give 7 seizure patterns seen in children
- Infantile spasms (West syndrome)
- Lennox-Gastaut syndrome
- Childhood absence epilepsy
- Benign rolandic epilepsy
- Panaviotopolous syndrome
- Juvenile absence epilepsy
- Juvenile myoclonic epilepsy
What is the age of onset of West syndrome?
3-12 months
Describe the seizures in West syndrome
Violent flexor spasms of the head, trunk,and limbs, followed by extension of the arms
Lasts 1-2 seconds, often in multiple bursts of 20-30, often on walking or many times a day
What is the age of onset of Lennox-Gastaut syndrome?
1-3 years
Describe the seizures in Lennox-Gastaut syndrome?
There are multiple seizure types, but mostly atonic, atypical (subtle absences), and tonic seizures in sleep
What other disorders are associated with Lennox-Gastaut syndrome?
Neurodevelopmental arrest or regression and behaviour disorder
What is the age of onset of childhood absence epilepsy?
4-12 years
Describe the seizures in childhood absence epilepsy
Momentary unresponsive state with motor arrest, may twitch their eyelids or hand/mouth minimally.
Only lasts a few seconds (<30s)
Does the child recall the episodes in childhood absence epilepsy?
No, except realises they’ve missed something
Does childhood absence epilepsy impact the child developmentally?
No, they are developmentally normal, but can interfere with schooling
What is the age of onset of benign rolandic epilepsy?
4-10 years
Describe the seizures in benign rolandic epilepsy
Tonic-clonic seizures in sleep, or simple focal seizures with awareness of abnormal feelings in tongue, and distoration of face
What is the age of onset of panaviotopoulous syndrome?
1-5 years
Describe the seizures in panaviotopoulous syndrome
Autonomic features with vomiting and unresponsive staring in sleep, with head-eye deviation, progressing sometimes to convulsive seizure
What is the age of onset of juvenile absence epilepsy?
10-20 years
Describe the seizures in juvenile absence epilepsy?
Absences and generalised tonic-clonic seizures, often with photosensitivity
Is learning impaired in juvenile absence epilepsy?
No
What is the age of onset of juvenile myoclonic epilepsy?
10-20 years
Describe the seizures in juvenile myoclonic epilepsy
Myoclonic, generalised tonic-clonic, and absences may occur, mostly shortly after walking
Is learning impaired in juvenile myoclonic epilepsy?
No
What is the diagnosis of epilepsy based on?
Primarily on a detailed history from the child and eyewitnesses, sustained by video if available
What should particular attention be paid to when taking a history for epilepsy?
- Any specific triggers
- If the child has any impairment
What investigations may help in epilepsy?
- EEG
- Neuroimaging
- Blood and urine biochemistry
- Neuropsychological assessment
- ECG
What is the purpose of EEG in epilepsy?
Should be performed only to support a diagnosis of epilepsy where the clinical history suggest a seizure is likely to be epileptic in origin
What should the EEG in epilepsy involve?
- Photic stimulation
- Hyperventilation
What should be done when a standard EEG has not contributed to diagnosis or classification?
A sleep EEG should be performed
How is a sleep EEG best performed in children and young people?
Sleep deprivation or the use of melatonin
What does the EEG show in infantile spasms?
Hypsarrhythmia
What does the EEG show in Lennox-Gastaut syndrome?
Slow generalised spike and wave (1-3Hz)
What does EEG show in childhood absence epilepsy?
Fast generalised spike and wave (3-4Hz) discharges, bilaterally synchronous during and sometimes between absences
What does the EEG show in benign rolandic epilepsy?
Focal sharp waves from rolandic area
What does the EEG show in Panaviotopoulous syndrome?
Posterior focal sharp waves and occipital discharges when eyes are shut
What is the purpose of neuroimaging in epilepsy?
Should be used to identify structural abnormalities that cause certain epilepsies
What is the neuroimaging investigation of choice in epilepsy?
MRI
What in the purpose of functional neuroimaging, e.g. PET and SPECT, in epilepsy?
Can detect areas of abnormal metabolism by using isotopes and ligands injected and taken up by metabolically active cells
When is functional neuroimaging done in epilepsy?
Used in the workup for patients for possible epilepsy surgery
When should investigations such as blood and urine biochemistry?
Should be done at discretion of specialist, to exclude other diagnoses and determine an underlying cause of epilepsy
When should neuropsychological assessment be performed in epilepsy?
When it is important to evaluate learning disabilities and cognitive dysfunction, particularly in regard to language and memory
Who is ECG recommended for in epilepsy?
All children with seizures, even when epilepsy is most likely
What is the purpose of ECG is epilepsy?
To ensure there is no convulsive syncope to arrhythmia, e.g. long-QT syndrome
What are the differentials for epilepsy?
- Syncope
- Night terrors
- Reflex anoxic seizures
- Febrile convulsions
- Fabricated or induced illness by carers
- Migraine
What things should be considered when deciding on a drug management for epilepsy?
- Not all children with epileptic seizures require anti-epileptic drug (AED) therapy
- Choose an appropriate AED for the seizure and epilepsy
- All AEDs have potential unwanted effects
What should the decision as to whether a child needs AED therapy be made based on?
- Seizure type
- Epilepsy type
- Frequency
- Social and educational consequences of the seizures set against the possibility of unwanted effects of AED
What is the desired goal of AED therapy?
Monotherapy at the minimum dosage, to prevent seizures without adverse effects
Who should the potential unwanted effects of AED therapy be discussed with?
Child and parent
When can AED therapy be discontinued?
After 2 years free of seizures, depending on the seizure syndrome
What are the first line drug options for tonic-clonic, absence, and myoclonic seizures?
- Valproate
- Carbamazepine
- Lamotrigine
What are the first line drug options for focal seizure?
- Carbamazepine
- Valproate
- Levetiracetam
- Lamotrigine
What are the second-line drug options for tonic-clonic and absence seizures?
- Clobazam
- Levetiracetam
- Topiramate
What are the second-line drug options in myoclonic seizures?
- Clobazam
- Piracitam
What are the second line drug options in focal seizures?
- Clobazam
- Topiramate
- Gabapentin
- Tigabine
What other treatment options are there for children with intractable epilepsies?
- Ketogenic diet
- Vagal nerve stimulation
- Surgery
How is vagal nerve stimulation delivered?
Using an externally programmable stimulation of a wire implanted around the afferent (left) vagal nerve
What is the purpose of surgery in epilepsy?
Cessation of seizures and AED therapy
When can surgery be performed in epilepsy?
When epilepsy has a well-localised structural cause or epileptogenic zone
How can a well-localised structural cause or epileptogenic zone be demonstrated?
Good concordance between ictal EEG, MRI, and functional imaging findings
What is the main surgical procedure used in epilepsy?
Temporal lobectomy
What is temporal lobectomy used for in epilepsy?
Mesial temporal sclerosis
What other surgical procedures may be used in epilepsy?
- Hemispherotomy
- Focal restrictions
What is a hemispherotomy?
Disconnection of the hemisphere
What biopsychosocial considerations are there when managing epilepsy?
- Some children with epilepsy and their families need psychological help to adjust to the condition
- School needs to be aware of the child’s problem, and teachers advised on the management of seizures
- Situations where having a seizure could lead to injury or death should be avoided, e.g. swimming
What biopsychosocial considerations are there specifically regarding adolescents when managing epilepsy?
Issues to discuss around driving, contraception, and pregnancy. May also be issues with concordance and the precipitation of seizures by alcohol and poor sleep routines
How do the educational and social outcomes of epilepsy compare to those of other chronic illnesses such as diabetes?
They are worse
What are the potential complications of epilepsy?
- Status epilepticus
- SUDEP
