Approach to seizures Flashcards
What are the different kinds of generalised seizures (arising within and rapidly engaging bilaterally distributed networks) (according to ILAE 2017)?
Motor 1) Tonic- Clonic 2) Clonic 3) Tonic 4 Atonic 5) Myoclonic 6) Myoclonic- atonic 7) Myoclonic- tonic- clinic 8) Epileptic spasms
Absence
- typical
- absence with special features: myoclonic absence, eyelid myoclonia
- atypical
What are focal seizures (originating within networks limited to one hemisphere) characterised by?
Characterised according to one or more features
- Aura
- Motor
- Autonomic
- Awareness/ responsiveness: altered (dyscognitive) or retained
DESCRIBING WHERE SEIZURES BEGIN
Focal Seizure
- Seizure begins in a ______________
- Only Focal Seizures will exhibit _____________
Generalised Seizure: At onset, seizure involves _____________
Secondary Generalised Seizure; A partial seizure at onset that goes on to involve both hemispheres
Unknown: if onset of a seizure is not known 🡪 we can reclassify it if the beginning of a person’s seizures becomes clear later on
single hemisphere;
Todd’s Paresis and Preceding Aura;
bilateral hemispheres;
DESCRIBING AWARENESS
________________ (previously Simple Partial): If awareness remains intact, even if the pt is unable to talk or respond during a seizure
_________________ (previously Complex Partial): If awareness is impaired / affected at any time during a seizure, even if a person has a vague idea of what happened
Awareness unknown (previously Simple Partial): Sometimes it’s not possible to know if a person is aware or not eg: If a person lives alone or has seizures only at night
______________ (previously Simple Partial): These are ALL presumed to affect a person’s awareness or consciousness in some way
Focal aware;
Focal impaired awareness;
Generalized seizures
Describing Motor and Other Symptoms in Focal Seizures
_______________: i.e. presence of movement occurs during the event e.g. twitching, jerking, stiffening, automatism (eg: licking lips, rubbing hands, walking, or running)
_______________:
This type of seizure has other symptoms that occur first, such as changes in sensation, emotions, thinking, or experiences.
Auras:
- S&S pt may feel in the beginning of a seizure, is NOT in the new classification
- Yet people may continue to use this term
- It’s important to know that in most cases, these early symptoms may be the start of a seizure.
- Eg: Déjà vu; Jamais vu; Smells; Taste; Sound; Visual; Fear / Panic; Numbness
Focal motor seizure;
Focal non-motor seizure;
What is a seizure?
A sudden change in behaviour due to electrical hyper-synchronization of neuronal networks in cortex +/- motor activity, loss of consciousness
What is an epilepsy?
Recurrent tendency to spontaneous, intermittent electrical activity in the brain, precipitating as seizures
Is this epilepsy: Provoked seizure?
No
Is this epilepsy: 1st ep of unprovoked seizure w/ normal EEG & Imaging 🡪 30% recurrence risk?
No
Is this epilepsy: 1st ep of unprovoked seizure w/ abnormality in EITHER EEG & Imaging 🡪 50% recurrence risk?
Yes
Is this epilepsy: 1st ep of unprovoked seizure w/ abnormality in BOTH EEG & Imaging 🡪 80% recurrence risk?
Yes
Is this epilepsy: 2nd / more ep of unprovoked seizure?
Yes
What are the structural causes of seizures ?
Ischaemic Stroke, intracranial haemorrhage,
What are the non structural causes of seizures ?
Non-Structural
- Neurology: Hypoxic ischaemic encephalopathy (HIE) from Respi Failure; CCF
- Infection: Meningitis, Encephalitis, Brain abscess, Sepsis
- Metabolic: Hepatic / Uraemic Encephalopathy; Na, Ca, Mg, Alcohol (Wernicke’s Encephalopathy)
- Endocrine: Hypo/ Hyperglycaemia, Thyroid Strom, Myxedema Coma
- Iatrogenic – Drugs and toxins
- Congenital: Neurocutaneous stigmata (neurofibromatosis, sturge weber syndrome)
What are the investigations to perform for first seizures?
Look for provoking factors
- Blood glucose (both hyper and hypo)
- Serum Electrolytes: mainly Na (usually Hypo), Mg, Ca, Urea
- Inflammatory markers (FBC, CRP) / Cultures (Urine, blood and CSF)
- Drug / Toxicology screen (eg: Alcohol, illicit drugs)
If found to be unprovoked (negative for above)
- Neuroimaging for scar tissue / SOL / ICH – CT / MRI
- EEG
Seizure advice: What to do in acute seizure (to tell family / friends)?
- ABCs
- Safe Environment
- No spoon in mouth!
- Accompany person to time the duration of seizure, take note of semiology if possible
- Call ambulance if >5min
Seizure advice: what provoking factors to avoid in acute seizure (to tell family / friends)?
- Fever, Infection 🡪 get your vaccinations!
- Flickering Lights
- Alcohol Intox, Withdrawal
- Stress
- Lack of sleep
- Drugs
Seizure advice: for patients who want to get pregnant?
Which drugs are C/I – always consult the neurologist and change medication before attempting
Seizure reoccurrence is highest within 1st 2 years of Dx 🡪 hence try to avoid pregnancy during this time
If epilepsy has been Dx
- Seizure needs to be under control before getting pregnant for safety
- Good control varies amongst patients and will take diff duration depending on pt’s seizure profile
Seizure advice: for patients who want to drive?
If they are Dx of epilepsy, they cannot drive
If it is a provoked seizure w/ normal scans and EEG 🡪 cannot drive for 1 year
Sports / National Service (i.e. excuse firearms, night duties)
Seizure advice: what are the other safety concerns?
- Can swim if accompanied
- Don’t lock the toilet door
- Avoid heights
What is the definition of epilepsy?
A disorder of the brain characterised by an enduring predisposition to generate epileptic seizures
How can epilepsy be diagnosed?
- At least 2 unprovoked seizures occurring > 24 hours apart
- One unprovoked seizure and a probability of further seizures similar to the general recurrance risk (≥60%) after 2 unprovoked seizures, occurring over the next 10 years e.g. 1 unprovoked seizure but with companying EEG / CT / MRI findings
- Diagnosis of an epilepsy syndrome
What are the medications used for focal epilepsy?
Carbamazepine (1st line), Phenytoin, Phenobarbitone, Valproic Acid, Levetiracetam
What do you need to counsel patients on for Carbamazepine?
- Perform HLAB1502 genotyping & counsel for SJS / TEN
- Safe for pregnancy: drug of choice 😊
What are the medications to be used for generalised epilepsy?
Valproic acid (VPA), Lamotrigine (LTG), Levetiracetam (LEV)
- Lamotrigine 🡪 safe in pregnancy 😊, less teratogenicity compared to LEV
- Levetiracetam 🡪 safe in pregnancy 😊
What are the side effects of Sodium Valproate?
- Alopecia
- Fat = Liver dysfunction
- Severe hepatic toxicity
- Thrombocytopenia
- Weight gain
- Teratogenic: neural tube defects (e.g. spina bifida)
- Endocrine (PCOS)
- Nausea, vomiting
What are the side effects of Phenytoin?
- arrhythmias & HypoTN
- Idiosyncratic rash
- Rarely pseudolymphoma
- Peripheral neuropathy
- Stevens- Johnson Syndrome
- Dupuytren’s contracture
- Hepatotoxicity
- Osteomalacia
- Hypocalcemia
- Gingival hypertrophy
What are the side effects of Carbamazepine?
- Idiosyncratic reactions
- Rarely Stevens Johnson syndrome
- Aplastic anemia
- Hepatotoxicity
How effective is AED therapy?
70% of patients can be effective controlled on one medication
- 1st drug – 50% response rate
- Change to 2nd drug – 20-30% response
10% respond to dual drug therapy
20% have no effective drug therapy
What is the definition of status epilepticus?
EITHER: seizure lasting longer than 5 min w/o self-aborting
OR: 2 or more seizures without complete recovery in between
Status Epilepticus
- Has time dependent impact in morbidity and mortality
- Because of rhabdo and lots of other downstream effects
- Also causes ___________ (because excessive brain activation 🡪 waste build up in brain 🡪 osmotic effect 🡪 oedema)
- IMPORTANT TO TAKE AN ALCOHOL HISTORY FROM FAMILY / FRIENDS (or ask for alcohol at scene of incident, any alcohol breath) 🡪 ________________
brain edema;
Dextrose + IV Thiamine
What is the management of Status Epilepticus?
- First give _____________🡪 we give BDZ because it is fast acting
a) Put patient in ____________
b) Check BP, hypocount etc
c) Watch and wait for 3-5min - If does not stop within 3-5min, give another dose of IV diazepam or lorazepam
a) Can only give up to _________
b) Each dose only works for ___________ while you monitor vitals + decide what antiepileptic to use
c) Patiently usually stops after 1st dose! - If patient STOPS seizing
a) Do _______________
b) Take + Send ______________
c) Infuse antiepileptics:
i. 1st Line Phenytoin (can cause arrhythmia, C/I if _________________)
ii. 2nd Line Valproate (C/I in _____________)
iii. 3rd Line Keppra (Levetiracetam) (requires _______________)
d) Unless we have the patient’s recent bloods, we often give drugs first before blood results are back (esp for new admission) as we have no choice. In fact, we often give phenytoin as it has least C/I and does not depend on liver or renal function
5) Once patient I stable: ___________ based on neuro exam findings
IV Diazepam/ Lorazepam (5mg);
left lateral position
20mg;
15-20min;
ECG (to check arrhythmia – may be the ppt, influences drug choice too);
bloods (Electrolytes, FBC), Renal Function (to prevent side effects of drugs), Liver Function;
pt has hx of arrhythmia;
transaminitis of liver dysfunction;
renal dose adjustment;
CT scan
What if seizures is not aborted despite benzodiazepines and AED?
Firstly, intubate and secure airway
- Reason is b/c these 2nd line meds also have anaesthetic properties!
- Give muscle paralytics and other meds for RSI
- While securing the airway, attempt to give a different AED from Step 2
Give 2nd line AEDs INFUSION
- Propofol infusion
- Midazolam infusion
- Phenobarbitone
- Thiopentone
How should you manage seizures after seizures were aborted?
Disposition: monitor in HDU / ICU
Monitoring
- Vitals monitoring and GCS charting
- Keep on EEG monitoring if required
- Monitor for Cx of seizures and AEDs
Assess etiology: Investigate and treat underlying cause; CT scan for structural lesions
Maintenance therapy
- Indications: Usually not needed unless patient is at high risk for subsequent seizures eg: Prev Epilepsy Dx, abnormal CT brain
- In patients who has provoked SE 🡪 less likely to require maintenance Tx
- Administer maintenance AEDs
- Check AED levels & aim for therapeutic blood [AED]
[History to ask in a patient with seizures]
Ask about the ______________: to better classify the seizure.
What type of seizure is this?
• First Seizure? 🡪 important to: 1) Characterise seizure 2) Hunt for Aetiology
- In young boys, ask about _______________
- Focal/Generalised, Simple/Complex
• ____________ 🡪 important to make a formal Dx of Epilepsy, followed by management
• ____________ 🡪 in a known epileptic🡪 important to elucidate 1) Precipitant 2) adjust drugs
• ____________
Duration – if no observer
• ____________? _____________________?
• Whereas in syncope patients, they will say that before the ambulance came pt could already hear his friends talking (aka LOC was resolving)
nature of the jerky movement;
Birth History [complicated birth? Any instrumentation? Febrile Fits when young? (febrile fits a/w increased risk of seizures subsequently)]
Recurrent Seizure?;
Breakthrough Seizure?;
Status Epilepticus?
When did you start remembering things;
Did you wake up in the hospital/ambulance
What are features of seizures that are highly suspicious of underlying intracranial pathology?
- status epilepticus
- confusion, decreased GCS, focal neurological signs >30 minutes post fit
- recent head injury
- acute severe headache
- meningism
- known malignancy
- immunosuppression
- change in seizure pattern or type in known epilepsy
What are the investigations needed if there are that are features highly suspicious of underlying intracranial pathology?
Urgent neuroimaging: CT
+ LP (if infection suspected)
Imaging also useful to assess complications of seizure (Eg. Fall)
What are the triggers for seizures?
- alcohol excess or withdrawal
- recreational drug use
- sleep deprivation
- physical/mental exhaustion
- metabolic disturbance (↓Na, ↓Mg, ↓Ca, uremia, liver failure)
- infection (intracranial or systemic)
- drugs (tricyclics, cocaine, tramadol, theophylline)
- flickering lights (provoking factor)
What is the investigations to work up the triggers for seizures?
Screen electrolytes, glucose, inflammatory markers, LP, septic workup, toxicology, ECG, BP
When do we start treatment for non-SE seizure?
We DO NOT give medication if the cause of seizure is REVERSIBLE
• Hypoglycaemia
• Electrolytes
• Infection
• Drugs
• Or if seizure is FIRST UNPROVOKED (aka no clear aetiology) as the risk of another seizure is only 30%!
We GIVE medication if seizure is IRREVERSIBLE e.g. Brain scars
We GIVE medication if >1 UNPROVOKED SEIZURE
We only give Anti-Epileptic medication if there is >60% of having another seizuire
• After second unprovoked seizure the chance of third is 70%. Hence, we will always start after second unprovoked seizure + label condition as EPILEPSY
