Epilepsy Flashcards
Prevalence in children
4 in 1000
Defintion
chronic brain disorder characterized by recurrent (≥ 2), unprovoked seizures
A single seizure is not considered an epileptic seizure. Epilepsy is often idiopathic, but various brain disorders, such as malformations, strokes, and tumors, can cause symptomatic epilepsy.
Types of generalised seizures
absence (typical or atypical), myoclonic, clonic, tonic, tonic-clonic, and atonic (astatic) types
Types of partial seizures
Motor
Sensory
Autonomic
Psychiatric
What is a seizure
transient neurological dysfunction caused by excessive activity of cortical neurons,
resulting in paroxysmal alteration of behaviour and/or EEG changes
Describe an absent seizure
usually only seen in children, unresponsive for 5-10 s with arrest of activity, staring, blinking or eye-rolling, no post-ictal confusion; 3 Hz spike and slow wave
activity on EEG
Most common cause of late onset >50 yo seizures
dementia
Describe the presentations of simple->motor, sensory, psychiatric
simple (preserved LOC)
motor: postural, phonotory, forceful turning of eyes and/or head, focal muscle rigidity/jerking ± Jacksonian march (spreading to adjacent muscle groups)
sensory: unusual sensations affecting vision, hearing, smell, taste or touch
autonomic: epigastric discomfort, pallor, sweating, flushing, piloerection, pupillary dilatation
psychiatric: symptoms rarely occur without impairment of consciousness and are more
commonly complex partial
Presentation of complex seizures
complex (altered LOC)
patient may appear to be awake but with impairment of awareness
classic complex seizure is characterized by automatisms such as chewing, swallowing, lipsmacking,
scratching, fumbling, running, disrobing and other stereotypic movements
other forms: dysphasic, dysmnesic (déjà vu), cognitive (disorientation of time sense),
affective (fear, anger), illusions, structured hallucinations (music, scenes, taste, smells),
epigastric fullness
Compare motor activity in seizure vs pseudoseizure
Seizure:
Synchronous, stereotypic, automatisms, lateral
tongue biting, eyes rolled back
Pseudoseizure/conversion:
Opisthotonos, rigidity, forced eye closure, irregular extremity movements, shaking
head, pelvic thrust, crying, geotropic eye movements, tongue biting at the tip
Clinical features
Key diagnostic factors presence of risk factors (common) staring spells or inattention (common) tonic-clonic convulsions (common) brief, arrhythmic muscular jerking movements (common) unexplained falls (common) eyes rolling back in head (common) apnoea (common) intercurrent illness (common)
Other diagnostic factors incontinence (common) tongue biting (common) post-ictal phenomena (common) precipitated by fatigue or lack of sleep (common) precipitated by light or noise (common) developmental delay (common) neurocutaneous stigmata (uncommon)
Risk factors for generalised seizures
Strong genetic predisposition or FHx perinatal asphyxia metabolic/neurodegenerative disorders head trauma structural abnormalities of the CNS
Weak autistic spectrum disorder CNS infection neurocutaneous syndromes Hx of febrile seizures
How is diagnosis of epilepsy made
Clinical
Use of EEG has limited value is diagnostic process
Four key questions to ask with possible epilepsy
- Is the seizure epilepsy
- What type of seizure
- What type of epilepsy
- What is the cause of the epilepsy
Prognosis
Generally good
>70% will have resolution resolution when idiopathic
Important components in the follow-up
- Frequency of fits
- Side effects
- Psychosocial, schooling etc
- Anticonvulsant levels if uncontrolled
When a neurological problem is suspected but cannot be found, name given to this type of epilepsy
Cryptogenic
Why is EEG not ideal to diagnose epilepsy
50% epileptics will have normal EEG and 5% of normal children will have abnormal findingd
When might an EEG be appropriate for diagnostic purposes
Absence seizure
Infantile seizures
Most common anticonvulsants started for children with generalised, for infantile, absence
Sodium valproate or carbamazepine
Steroid or vigabatrin in infantile
Ethosuxamide is alternative to valproate in absence seizures.
When to check anticonvulsant levels
When control is inadequate
Management overview
Treatment
• avoid precipitating factors
• indications for medical therapy (anticonvulsants): 2 or more unprovoked seizures, known
organic brain disease, EEG with epileptiform activity, first episode of status epilepticus,
abnormal neurologic examination or findings on neuroimaging
• psychosocial issues: stigma of seizures, education of patient and family, status of driver’s license,
pregnancy issues
• safety issues: driving, operating heavy machinery, bathing, swimming alone
• consider surgical treatment if focal and refractory
Number of children having a seizure in their lifetime
5% will have at least one seizure, this is not considered epilepsy
Causes of epilepsy
Most commonly unknown
May have genetic component
May follow head injury, stroke or infection
May be due to malformation, benign or cancerous, scar/cyst present at birth
Parental advice for precautions to take at home
xSwimming, bathing alone Showers Turn on cold first Caution hot things Avoid heights Appropriate education provided to other potential carers so know what to do Need first aid kit at home Ensure the bedroom door remains unlocked
Counselling use of valproate
Mode of action
Multiple mechanisms. Prevents repetitive neuronal discharge by blocking voltage‑ and use-dependent sodium channels. Other actions include enhancement of GABA, inhibition of glutamate and blockade of T-type calcium channels.
Cautions: hepatic, pregnant/breastfeeding, pancreatic dysfunction, women (ensure on contraception)
Common (>1%)
nausea, vomiting, increased appetite, weight gain, tremor (dose-related), thinning or loss of scalp hair (usually temporary), paraesthesia, drowsiness, dizziness, memory impairment, ataxia, elevated aminotransferase concentrations (dose-related), asymptomatic hyperammonaemia, thrombocytopenia (dose-related), menstrual irregularities, polycystic ovaries, hyperandrogenism in females
Take with food May make drowsy- avoid machiner \+Appetite: may need to watch food Tell doctor if develop rash, easy bruising/bleeding, jaundice, abdominal pain vomiting. Do not stop suddenly
FBE prior to commencing
LFTs monitoring not indicated
BMD if long term use
