Seizures - ACEM Fellowship Notes

see [[Seizure (paediatric)]] and [[Febrile seizure]], [[Pre-eclampsia|Eclampsia]], [[Syncope]], #tables #Neuro #toxicology - [Dunn anti-confulsants for seizure prevention](x-devonthink-item://DDEB78BA-9D6F-478C-BC41-865330758739) > prolonged altered mental status following seizure should not be attributed to an uncomplicated post-ictal state # Causes ***VITAMINS*** - general cause mnemonic from med school **Vascular**: stroke, AV malformations **Infection**: menengioencephalitis, lyme, TB, brain abscess, HIV, cerebral malaria **Trauma**: brain injury (eg subdural haematoma), [post-traumatic seizure](https://www.seizure-journal.com/article/S1059-1311(16)30249-7/fulltext) **Autoimmune**: SLE, CNS vasculitis **Metabolic**: hepatic encephalopathy, uremia, hypoglycaemia, low Na, Ca, Mg, porphyria **Idiopathic and Ingestion**: epilepsy, withdrawl, lithium … see [[#Toxicological Seizures]] **Neoplasm**: primary brain tumor, breast/lung/GIT mets **Syndromes**: tuberous sclerosis, down’s, sturge weber, von hippel lindau, lennox gessult ***Rx-induced seizure*** - Sub-therepeutic AED - Lithium tox - TCA - theiphyline - Flucloxacillin - Cipro - Flumazanil - Imipramine, imapenem - Bupropion - Cocaine/amphetamines - EtOH/ benzo withdrawl **issues with status:** - hypoxia - hypotension - hyperthermia - [[rhabdomyolysis]] - DIC - trauma from seizure itself eg head injury - dental injury - tongue lac # Toxicological Seizures see also: [[Toxicology#Tox Seizures]] ![[Pasted image 20230701120548.png]] Tox Seizure **mnemonic** OTIS CAMPBELL - [[organophosphates]] - [[TCA overdose]] - Isoniazid, [[Insulin Overdose]] - sympathomimetics, [[Aspirin overdose|Salicylates]], [[Serotonin Syndrome]] - [[carbon monoxide]], [[Cyanide]], cocaine, cholrinated hydrocarbons - amphetamines, [[Anticholinergic toxicity]] - [[toxic alcohols#Methanol]], theophylline - PCP, [[beta blocker overdose|propranolol]] - benzodiazepine withdrawal, GHB - ethanol withdrawal, [[toxic alcohols#Ethylene Glycol]] - [[Lithium Toxicity|lithium]], [[Local anaesthetic systemic toxicity|lignocaine toxicity]] - [[Lead]] # electrolyte seizure thresholds - glucose: <2 or >25 - Na <115 - Ca <1.2 - Mg <0.3 - urea > 36 - Cr > 884 # special situations for seizures | situation | tx | dose/comment | | ---------------------------- | -------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------- | | [[hyponatremia\|hypo-na]] | hypertonic saline 3% | adults: 100mL over 10 min children 2-5 mL/kg up to 150mL over 20 min | | [[Hypocalcemia\|hypo-Ca]] | calcium chloride or gluconate | sequental ampules until seizures stop | | [[TCA overdose]] | [[HCO3 therapy\|sodium bicarb]] | 1-2 mEq/kg IV bolus, repeat as needed to maintain ECG QRS ≤ 100ms | | [[Aspirin overdose]] | sodium bicarb [[haemodialysis]] if severe | 1-2 mEq/kg IV bolus; target blood pH 7.4-7.5 | | isoniazid OD | pyridoxine | 5g IV adult 70mg/kg IV paeds | | [[Cocaine]] | benzos | | | [[Lithium Toxicity]] | haemodialysis | | | EtOH-withdrawal seizure | benzos | | | MDMA | benzos | be aware of hyperthermia or hyponatremia | | [[Pre-eclampsia\|Eclampsia]] | [[Magnesium]] | IV loading 4g over 15-20 min, then 1-2g/h infusion monitor for hyporeflexia can also use benzos to terminate seizure | # Seizure types ## focal - with awareness - most common type of focal seizure - consciousness preserved, but may not be responsive during seizure - aura common - usually lasts seconds - can have motor onset - with impaired consciousness - previously "complex partial seizure" - initial focus in temporal lobe - often have aura - post-ictal confusion - evolve over 30 seconds - min ## Generalised - tonic clonic - most common - loss of consciousness often with ictal cry - tonic phase - clonic phase of rhythmic jerking - face and limbs - generally 30 seconds - 2 min - a/w cyanosis and incontinence - tongue biting - usually lateral aspect - post ictal confusion 30-60 min - often mild HA following seizure - focal weakness 24 hours (Todd's paresis) - non-motor (aka absence seizures) - abrupt onset and offset - no aura or post-ictal confusion - occasional flickering of eyelids - preicpitation of event by hyperventilation - non-motor status epilepticus - consider in DDx for coma or unresponsiveness - ## status epilepticus > definition: > - ≥ 2 seizures without full recovery between > - 5 min of continuous convulsive seizures (if seizing on arrival likely > 20 min) ; or 10 min of focal seizure with impaired awareness - more common in children than adults - intellectual disability **causes** - anticonvulsant withdrawl - other drug withdrawl - EtOH - benzos - baclofen - CVA - ICH - PRES - metabolic - [[hypoglycaemia|hypoglycemia]] BGL < 2.2 - [[hyponatremia]] < 115 - [[Hypocalcemia]] <1.2 - trauma - drug toxicity - [[TCA overdose]] QRS >100 - clozapine - theophylline - encephalitis and meningitis - tumour ### management of status epilepticus - **terminate seizures** - midaz 5-10mg IV, IM or diazepam 10-20mg IV over 2-5 min + second agent: - valproate 20mg/kg, keppra 20-60mg/kg up to 4.5g, or phenytoin 15-20mg/kg - prevent recurrence - keppra, etc - O2 and assisted ventilation - coma position - venous access - thermoprotection - treat underlying pathology -- hypoglycaemia can be a prolonged bizarre seizure - eg HCO3 if tox seizure - correct electrolytes - +/- abx as indicated - Nsx, CTB, etc as indicated # anticonvulsant treatment for immediate control ## Benzos - IV if possible - diazepam can be given rectally - midaz can be given IM, IN, or buccal | drug | route | dose | | ---------- | -------- | ----------------------------- | | diazepam | IV | 0.1-0.3mg/kg diluted to 20 mL | | diazepam | pr | 0.3-0.5 mg/kg | | midazolam | IV or IM | 0.1 - 0.3 mg/kg | | clonazepam | IV | 0.008 - 0.016 mg/kg | ## second line agents **keppra (levetiracetam)** - compatible with 5% dextrose, saline, and hartmann's - few adverse effects or drug interactions - lower risk in pregnancy - 10-40mg/kg in children max 3g - 20-60mg/kg in adults max 4.5g **IV sodium valproate** - 10-40 mg/kg max dose 3g - contra-indicated in - pregnancy - teratogen - seizures 2/2 drug toxicity - children <2 - pts with known urea cycle disorders **Phenytoin** - 15-20 mg/kg IV up to 1-1.5g no greater than 2 mg/kg/min - incompatable with dextrose and most other drugs - issues: - contra-indicated in pts with na-channel toxicity seizures (eg TCA or lignocaine) - poorly effective for EtOH withdrawl seizures and partial seizures - causes local pain (contains alcohol and propylene glycol) - causes cardiovascular toxicity (hypotension and bradycardia) - benefits: - less CNS sedation than benzos → easiure neuro assessment **Barbituates** - phenobarbitone - loading dose 10-20 mg/kg as infusion up to 1g - onset 10-20 min - issues: - sedation - hypotension - resp depression - thiopentone - 3-5mg/kg bolus; infusion 100-200mg/h - rapid onset, brief action - issues: - marked resp depression requiring airway support | agent | dose | contraindications | | ---------------- | ------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------ | | levetiracetam | 60 mg/kg up to 450 mg IV over 5 min | - DRESS syndrome / hypersensitivity - japanese (relative) ; ↑ risk [[rhabdomyolysis]] - learning disabilities (??) | | sodium valproate | 40 mg/kg up to 3000 mg IV 5-10 min | - pancreatic dysfunction - porphyria - urea cycle disorders - mitochondrial disorders - hepatic impairment | | phenytoin | 20 mg/kg IV 25mg/min in elderly / co-morbid no more than 50mg/min otherwise - monitor BP and ECG | - sinus bradycardia - sinoatrial block - second and third-deg AV block - **pregnancy** - porphyria | # Assessment + management of isolated seizures assess if seizure vs [[Syncope]] - Labs - very low diagnostic yield from "routine labs" if mentation normal and no prodromal illness - low HCO3 may help determine if true seizure or not - PCO3 often decreased following generalised seizure - WCC elevation common - ABG - pH ↓ ~0.2 - lactate increase ~4 mmol/L - redue BP by 40 mmHg - reduce pO2 by 55mmHg during seizure - imaging - CT generally has a low yield if no other neuro sx or focality of seizure - indicated if: new focal deficits, persitent altered mental state, recent trauma, history of ICH, history of cancer, immunosuppression, partial onset seizure - [recent UK systematic review](http://emj.bmj.com/cgi/content/short/41/9/571?rss=1) suggests that need to scan 10 - 19 first seizures to find something that changes management (eg haemorrhage, infarction and tumours). Unclear if functional seizure phenotypes were excluded. [pdf](bookends://sonnysoftware.com/ref/DL/206356) - MRI more sensitive than CT - EEG - early EEG in children <24 hours helpful in adolescents with first seizure - LP if indicated ## When is CT indicated in first seizure workup? - new *focal* deficits - *persistent altered mental state* — don’t attribute prolonged sx to “post ictal” - recent *trauma* - history of *ICH* - history of *cancer* - immunosuppression especially AIDS - partial onset seizure MRI more sensitive than CT most children with unprovoked or immediate post traumatic seizures do not require neuroimaging, but indicated if: - cerebral tumor - cancer - sickle cell - stroke - coagulopathy - focal aspect of seizure ![[Syncope#Seizure vs syncope table]] ## management of isolated seizures See also [[#First seizure workup]] below > In general drug treatment is _not_ routinely commenced after a first unprovoked seizure - no anticonvulsant therapy required if no precipitant and no risk factor for recurrence are present - *Treat if*: - a second seizure within 24 hours, unless this is not unusual for pt - a single seizure when a precipitant is found, but not easily treated ***When is no anticonvulsant treatment necessary?*** - first seizure - **due to a condition that has been reversed** and no longer likely to occur (eg hypo-Na) - no identifiable neurological condition - normal Ix - normal neuro exam / mental status Tx generally indicated if seizure due to identifiable neurologic condition ## disposition - referral to specialist first seizure clinic - EEG - +/- MRI (vs CTB in ED) - patient advise: - avoid driving (see ausroad below), swimming, operating dangerous machinery, climbing ladders until r/v by neurologist - d/c home in accompaniment of a carer - children (see [[Seizure (paediatric)]] ) # Complications of status epilepticus - Brain damage -- cerebral oedema, widespread neuronal necrosis, cognitive dysfunction - aspiration / resp failure / hypoxia - neurogenic APO - [[rhabdomyolysis]] - [[DIC]] - trauma from seizure -- head injury, posterior shoulder dislocation - [[Heat-related illness|hyperthermia]] - Todd's paralysis - heart failure/arrhythmia # First seizure workup > most important is to establish if it is [[Syncope#Seizure vs syncope table|seizure vs syncope]] (This is basically the same as [[#management of isolated seizures]] above; this section is just quick points w/r/t local department’s “first seizure” pathway) - PRIMARY (unprovoked): Idiopathic recurrent seizures; secondary causes excluded - SECONDARY (provoked): due systemic/metabolic CNS insults. - Trauma, bleeds, tumours, infection - Metabolic, toxic including withdrawal syndromes (alcohol, benzodiazepine) - Glucose, electrolyte abnormalities Diagnostic yield of all investigations for first seizure is generally low in patient who is totally normal post recovery. Investigations are aimed at finding secondary causes of seizure (which happens occasionally and misses tend to end up in M&M meetings). ***Investigations for 1st seizure:*** Vary by department, but generally include: - Glucose, FBC, electrolyte, ECG - Other tests as indicated by history, examination, medications, drug use - CTB (non-contrast); is done in ED for all first seizures in *adult* patienrs - Lumbar Puncture possibly indicated if: - febrile - immunocompromised; (AIDS patients should have LP looking for [[Meningitis#Cryptococcal meningitis|cryptococcus meningitis]] - Sudden headache where Subarachnoid is suspected and CT negative (controversial) - Persisting confusion / [[Encephalopathy]] Starting anti-epileptic drugs from the ED - No indication for AEDs in ED in uncomplicated unprovoked first seizure ***Disposition for 1st seizure*** - admit SSU for - \>1-hour post seizure, GCS >12 and improving conscious state prior to admit - post ictal observation - awaiting CTB/bloods or - psychosocial factors or - pseudo seizure awaiting recovery - Medical management of - alcohol intoxication/withdrawal - single seizure in context of SSRI OD - Discharge home with follow up: - first seizure clinic - Opd EEG ***Inpatient Admission:*** prolonged post ictal state, incomplete recovery, status epilepticus, secondary causes. ## Discharge Advice avoid the following until reviewed in First Seizure clinic - no driving for 6 months after a first seizure (see Ausroads or VicRoads in next section) - No Swimming - No Operating dangerous machinery - No Working at heights or climbing ladders - Provide family with seizure management advice (Better health channel) # Seizure and driving restrictions (Austroads) see: [Austroads legislation related to reporting](https://austroads.gov.au/publications/assessing-fitness-to-drive/ap-g56/legislation-relating-to-reporting) - only a specialist in epilepsy may permit driving for a commercial vehicle driver - a GP can liaise w/ driver licensing authority regarding whether criteria are met for driving a private vehicle > Healthcare reporting varies state-by-state (see above Austroads tables), however may need to report to licensing authority / roads if patient high index of concern or refusing to cease driving or high risk occupation ; may need to get social work involved. **restrictions** | restriction | time limit off driving | | ---------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------- | | single or benign siezure in child <11 | no restrictions | | single seizure on withdrawal of medication on medical advise | - 4 weeks if due to an avoidable provoking factor - 3 months if no provoking factor | | first single seizure (2 seizures/24 hours considered a single seizure), recent dx, partial epilepsy syndromes | 6 months | | any seizure while driving, temporal lobectomy, sleep epilepsy | 1 year | --- # Psychogenic non-epileptic seizures (PNES) / pseudoseizures See: [Functional neurological disorder: A rule-in diagnosis. - EMA 2024](bookends://sonnysoftware.com/ref/DL/247736), ['It is just a big question mark': a qualitative interview study of patient experiences of the initial assessment of transient loss of consciousness.](bookends://sonnysoftware.com/ref/DL/299755) - usually imitate generalised tonic-clonic seizures - occur in front of audience - on ambulance arrival - on ambulance arrival at ED - when placed in ED cubicle - when advised of planned discharge - emotional triggers - often prolonged - often do not respond to anti-convulsants - associated with the presence of multiple drug ‘allergies’ - ==estimated that pseudo-seizures becomes 3% more likely with each additional allergy in excess of one== - virtually never occur during sleep Examination - no opisthotinus or cry at onset - non-symmetrical and non-synchronous limb movements common - side-to-side head movements - swimming movements - ==bizarre pelvic thrusting common== - virtually never occurs in true seizures - eyes - closed - often look away from examiner - resistance to eye opening common - body rotation > 90 degrees during episode common - rare in true seizures - cyanosis absent - may urinate in their clothes - no biting of tongue or cheeks - crying, yelling, screaming, weeping - little or no post-ictal drowsiness - positive avoidance manoeuvres - arm drop - anion gap metabolic acidosis usually absent - may be present with prolonged, good imitations - serum prolactin not elevated in post-ictal period # Related Questions ## seizure - [ ] 1Q: [Heat related illness](x-devonthink-item://EE8AC47E-BE40-4377-885E-FA9C91C8C262?page=14) -- [Answer]() - [ ] 2Q: [Collapse, cause unclear](x-devonthink-item://8AAAF35C-CCF4-4157-9551-5B05727AA0CD?page=13) -- [Answer](x-devonthink-item://FDFBA3A1-6207-4204-AB6D-7483D80C5B5C?page=13) - [ ] 3Q: [4 year old with seizure](x-devonthink-item://B257662E-D069-4044-AF7A-736487B5CA99?page=15) -- [Answer](x-devonthink-item://1658DB69-4D34-47EF-9495-B6B43E0BE3BE?page=18) - [ ] 4Q: [Paediatric seizure](x-devonthink-item://1A2C485F-D4AD-4821-AFF2-452BA753717F?page=26) -- [Answer](x-devonthink-item://FD716379-1A77-4B5B-B257-1154995ECA6E?page=15) - [ ] 5Q: [Seizure](x-devonthink-item://5DC0999B-D537-4002-86AF-FD7B54B45E2E?page=46) -- [Answer](x-devonthink-item://406AF611-5CD4-4B3B-9795-327E8F4E3626?page=21) - [x] 6Q: [Hyponatraemia](x-devonthink-item://5DC0999B-D537-4002-86AF-FD7B54B45E2E?page=60) -- [Answer](x-devonthink-item://406AF611-5CD4-4B3B-9795-327E8F4E3626?page=29) - [ ] 7Q: [Seizure](x-devonthink-item://834C484F-DDAA-4819-8DF0-84AE5E70DA1D?page=40) -- [Answer](x-devonthink-item://D46998FE-62E2-4A3A-860D-C32C94B86E42?page=19) - [ ] 8Q: [Seizure](x-devonthink-item://92A26505-5B6B-4ADD-995F-6AAA2E05C637?page=18) -- [Answer](x-devonthink-item://0808A030-AF19-4671-BE84-3E8BCBEC6124?page=19) - [ ] 9Q: [Seizure](x-devonthink-item://662C8511-01CD-4659-B57D-5A01CF74D69B?page=10) -- [Answer](x-devonthink-item://79A95C0A-634E-4B38-9131-78949F63D56F?page=8) - [ ] 10Q: [Amitriptyline Overdose](x-devonthink-item://7E9EF652-F67B-42C5-A536-2EE85BA1954F?page=45) -- [Answer](x-devonthink-item://2DE5FACA-6D8F-41A2-8EAA-8DFE1E76FA61?page=28) - [ ] 11Q: [Seizure](x-devonthink-item://A077BF03-A063-4A6D-9330-67795A4B931D?page=4) -- [Answer](x-devonthink-item://C6B02ACE-5059-45D1-81CD-F99A8A13A863?page=3) - [ ] 12Q: [Seizure and Abnormal CT Head](x-devonthink-item://078484BD-EA8D-4380-B88A-19048B494073?page=19) -- [Answer](x-devonthink-item://16D9B527-CEE4-41A5-B147-D3AE54CBF312?page=12) -- [prop](x-devonthink-item://3124817F-4CDF-46FB-993B-1501587D1E75?page=8) ## seizures - [ ] 13Q: [Unknown ingestion and seizure](x-devonthink-item://1EA9311E-0B9E-49F7-8D6E-4C4187A838C4?page=16) -- [Answer](x-devonthink-item://B1CB2E8F-5D04-49EE-8274-043871389D28?page=9)