=====Epilepsy===== *It is important to establish the cause of **transient loss of consciousness** for which epileptic seizures are of the most common causes. *distinguishing functional, non-epileptic seizures from syncope or true epilepsy is a challenge in the ED ====Classification==== Classification of Epilepsy generally defined by the International League against Epilepsy 2010 (ILAE): ===I. Focal Seizures=== {{ :wiki:neurology:seizureclassifcation.png?600|}} 1. focal seizures (no LOC)\\ 2. focal dyscognitive seizures *with impairment of consciousness at onset *simple partial onset followed by impairment of consciousness 3. partial seizures evolving to generalised tonic-clonic (GTC) convulsions ===II. Generalised Seizures=== *convulsive or non-convulsive with bilateral discharges involving subcortical structures -absence -myoclonic -clonic -tonic -atonic -tonic clonic ===III. Unclassified=== *when adequate description not available ====Management==== *NICE guidance - 1st seizures should be referred and seen within 2/52 *anti-epileptic medication is not required for 1st seizure unless investigations suggest high risk of recurrence *history, exam and investigations *determine whether the seizure is epileptic vs non-epileptic *aimed at excluding infective and metabolic causes, alcohol and recreational drug use as well as potential for trauma *include ECG for cardiac causes *MRI is preferred scan but CT scan if intracranial event is suspected - eg trauma, anti-coag Rx, immunodeficency, Hx of malignancy, focal seizure, new CNS signs, fever *attention to stabilising patient - secure airway, IV access,etc ==Pitfalls== *failing to recognise seizure activity - non-convulsive seizure is rare presentation of altered mental state *failing to treat early enough and aggressively enough, with neurological dysfunction thought to result after 20mins of continuous seizures *failing to consider underlying aetiology - looking for sepsis, metabolic derangement etc ====Status Epilepticus==== *Seizure which fails to self-terminate - //**can be either convulsive or non-convulsive**// *Convulsive Status - tonic clonic seizures persisting or recurring for >5mins \\ *Management priorities *stabilise airway *IV access *aggressive pharmaceutical approach to halting seizure \\ *Consensus is that benzodiazepines are drug of 1st choice with Lorazepam the most effective and has longer seizure t_1/2 than diazepam. 2nd drug choice is phenytoin but there is no data or consensus on which drug is 3rd in line: *2 doses of IV Benzodiazepines are the drug of 1st choice. Buccal Midazolam in children or rectal diazepam if not available or difficult *Lorazepam 4mg or *Midazolam 10mg Other anti-epileptic agents following benzodiazepines: *Phenytoin 20mg/kg @50mg/min = 1st choice *phenobarbital 10-15mg/kg *propofol 1-2mg/kg bolus the 2-10mg/kg/hr *//Na+ valproate 30-40mg/kg (<3g) @10mg/kg/min// *//levetiracetam 40-60mg/kg (<4.5g) @6mg/kg/min// *Although no recognised agreement on priority of drugs to use after benzodiazepines, any of the 3 drugs (levetiracetam, phenytoin, valproate) can be considered as potential first-choice, second-line drugs for benzodiazepine-refractory status epilepticus ===Paediatric (APLS guideline)=== *First-line treatment is 2 doses of a benzodiazepine given 10 min apart *continued fitting 10 min after the second dose of benzodiazepine, administer second-line anticonvulsant. APLS recommends phenytoin as the first-choice second-line anticonvulsant; if the child is allergic to phenytoin, has previously not responded to it, or has experienced a serious adverse event (SAE), phenobarbital is recommended. *Failure to stop CSE necessitates rapid sequence induction (RSI), intubation, and admission to the PICU, with consequent potential for iatrogenic consequences including pneumonia, hospital-acquired infections, and prolonged admission. ^Pharmacological agents^| ^ ^ //Benzopdiazepines (BZD's)// | ^ |• GABA-A rec modulators\\ • so-called "BZ1" rec responsible for sedative, amnesic and some anti-convulsive effects\\ • BZ2 recs mediate anxiolytic and muscle relaxant effects\\ • hepatic metabolism with renal excretion\\ • peripheral vasodilator action | ^Lorazepam |• high potency, short acting\\ • anticonvulsant and useful adjunct in psychosis\\ • unique degradation pathway allowing use in renal dysfunction | ^Midazolam |• high potency, short acting | ^Diazepam |• medium potency, long acting\\ • active metabolites which prolong clinical effect\\ | ^Clonazepam |• high potency, long acting\\ • additional serotonin agonist property | ^ ^ //Other Anti-Epileptic drugs// ^ ^Phenytoin |• 'membrane stabiliser' via Na+ blockade\\ • contraindicated with heart blocks\\ • t_1/2 = 22/24 | ^Phenobarbital |• binds to GABA_A but with lower specificity than benzo's\\ • t_1/2 = 50-140/24 | ^Propofol |• binds to GABA_A causing global CNS depression\\ • t_1/2 = 40mins the 24+/24 after infusion | ==References include:== [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334097/| Presentation and Mx in acute setting - RCP - 2018]]\\ https://emedicine.medscape.com/article/1609294-overview\\ https://www.nice.org.uk/guidance/cg137\\ [[https://www.sign.ac.uk/assets/sign143_2018.pdf| Dx and Mx of epilepsy in Adults - SIGN 2018]]\\ https://www.aci.health.nsw.gov.au/networks/eci/clinical/clinical-resources/clinical-tools/neurology/seizures\\ https://emergencymedicinecases.com/status-epilepticus/\\ [[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684331/\ Benzodiazepine pharmacology and CNS]]\\ [[https://derangedphysiology.com/main/required-reading/pharmacology-and-toxicology/Chapter%201.4.1/pharmacology-phenytoin| Intensive Care review Phenytoin]]\\ https://derangedphysiology.com/main/required-reading/neurology-and-neurosurgery/Chapter%20311/management-status-epilepticus-icu\\ [[https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30611-5/fulltext#seccestitle150|Lancet 2020. Efficacy of levetiracetam, phenytoin, valproate in status]]\\