Seizures
1. Consider the possibility of a seizure in the differential diagnosis for a patient with an atypical presentation but without witnessed frank seizure movements (e.g., confused or altered level of consciousness, incontinence, fall/injury/accident, tics in children).
Classifications
- Generalized
- tonic-clonic / Grand Mal
- Absence / Petit Mal: <1min staring spells
- Myoclonic
- Atonic
- Simple partial – consciousness maintained & no post-ictal
- Motor: focal tonic movement; Jacksonian march (simple partial progressing to generalized seizure)
- Sensory: visual, auditory, oral, olfactory, gustatory
- Complex partial (temporal lobe) – no LOC ,but AMS/impairment +/- amnesia
- automatisms: lip smacking, repeated swallowing, picking at clothes
- hallucinations: olfactory/gustatory – temporal lobe; visual – occipital
- may have postictal confusion
- Pseudoseizures / PNES (psychogenic non-epilepticus Seizures)
- no postictal, acidosis, leukocytosis
- normal prolactine level and plantar reflex
2. Given a patient with a seizure, investigate for rapidly reversible causes (e.g., hypoglycemia, toxicology, arrhythmias) and treat promptly.
Secondary causes
- Metabolic:
- Hypoglycemia (DM), Hyponatremia (neonates/infants), hypocalcemia
- Drugs & toxins
- anticholinergics/ cholinergics/ sympathomimetics
- Antidepressants / toxic alcohols / Mushrooms (gyromitra sp)
- Alcohol W/D: BZD/thiamine Tx of choice; may need intubation + phenobarb vs propofol
- Drugs: theophylline (asthma), INH (Injures Neurons & Hepatocytes – TB), baclofen w/D; TCA OD (bicarb)
- CNS infection – encephalitis / meningitis
- CNS lesions / trauma: neurocysticercosis, hemorrhage, tumors, stroke, vasculitis, hydrocephalus
- Febrile – simple (<15min, <2/24hr, 6mo-6yo) vs complex; antiepileptics not indicated
- prevalent family; Sz w/u not req if simple febrile Sz
- LP if: Meningeal signs, <12mo w/o HiB or S. Pneumo Imm, Febrile status epilepticus
- risk factor for recurrence: <12mo, lower temp and shorter duration of fever at onset, + family hx, complex febrile Sz
- Eclampsia
- Pseudo – hysterical epilepsy
- Syncope / arrhythmia – ECG for all Sz patients
3. Given a patient with ongoing repeated seizures or persistent altered mental status between seizures, make the diagnosis of status epilepticus and treat promptly.
Status epilepticus
- Sz >5min or >=2 Sz w/o fully recovery of consciousness between seizures
- Pt may have EEG discharge even after tonic-clonic movements ended; Must monitor EEG after intubation + paralyzed
4. In a patient who continues to seize actively, manage by:
• Assessing the airway and ventilation and supporting as necessary
• Identifying specific conditions that require treatment other than standard anticonvulsant therapy (e.g., pre-eclampsia, toxidromes)
Reversible causes
- infectious – consider empiric abx and acyclovir
- Eclampia – up to 6wk postpartum – consider empiric MgSO4 4-6g IV
- Isoniazid toxicity – antidote: pyridoxine 5g IV
- consider tox causes if unresponsive to drug therapy
- Hyponatremia – 100ml (2ml/kg) 3% hypertonic saline; repeat 10min prn
- HypoCa/Mg – replace
- EtOH W/D – needs more BZD / thiamine
- Cyanide – antidote: hydroxycobalamine and cyanide antidote kite – sodium thiosulfate
- Structural brain dz if focal Sz – obtain CT
- tumor – steroids
• Using anticonvulsants in a progressive fashion to terminate the seizures as promptly as possible
Management of status epilepticus:
- airway – roll pt on side to dec aspiration, establish patent airway, suction prn & oxygen through non-rebreather facemask
- BZD: Ativan 0.1mg/kg IV & search for reversible causes
- consider eclampsia up to 6wk pp – treat empirically w/ MgSO4 4-6g IV
- Midazolam IV/IM/IN; Diazepam IV/PR; Ativan IV/IM
- Thiamine and glucose if hypoglycemic / EtOH
- Check BG, lytes, tox, HCG, liver and renal function
- Phenytoin / fosphenytoin (IM/IV) 20mg/kg IV over 10min & prepare for intubation
- Give second dose of BZD at the same time – Ativan 0.1mg/kg IV
- Phenytoin – nystagmus if therapeutic
- Valproic acid 20mg/kg IV or Keppra 40mg/kg IV good safety profile
- useful in HoTN, noncompliance to oral valproic acid, sensitive to phenytoin
- Intubation – RSI; avoid Etomidate – lowers Sz threshold
- induction w/ propofol 1.5mg/kg IV (anti-epileptic), but if HoTN, use Ketamine 2mg/kg
- Paralytics – use succinylchoine – watch out for hyperkalemia; rocuroniym increase the risk of nonconvulsive status epilepticus
- Consult neuro for EEG to r/o nonconvulsive status epilepticus
- Phenobarbital 20mg/kg – respiratory depression, HoTN, long half life
- some guideline recommends skip phenobarbital and right to propofol
- Obtain CT head and consider LP
5. In a patient who has had a first seizure, counsel regarding high-risk activities and initiate the appropriate procedures for reporting to authorities (e.g., driving/sports/occupation).
No driving, swimming, Bath, other high risk activities
6. Given a patient with a first seizure, investigate to establish the underlying etiology in a timely fashion (e.g., CT, lumbar puncture, EEG, metabolic, toxicologic).
DDx: syncope, dysrhythmia, psychiatric illness, migraines, CVA, SAH
First Time Seizure
- check Na, Glucose, Ca, Mg, bHCG, urine toxicology
- CT if any suspicion for serious structural lesion
- LP if any suspicion for meningitis, SAH, hx of cancer ? mets to brain
- HIV pt – CT with contrast / MRI
- EEG during event confirms diagnosis if diagnosis is in question; Out paitent follow up for MRI/EEG if no cause found in ED.
- Defer initiation of antiepileptics to outpatient neurology unless CNS lesion present
7. In a known epileptic who has had a seizure, investigate appropriately but do not over-investigate without specific indication (e.g., verify compliance and check anticonvulsant levels, consider contributing causes).
Precipitating factors
- missed medications
- substance abuse or withdrawal
- sleep deprivation
- infection
- electrolyte disturbances
Recurrent Seizures
- check glucose and anticonvulsant levels – supratherapeutic level of phenytoin and carbamazepine can result in Sz
- More extensive evaluation if change in Sz pattern, prolonged postictal or fever
- Consider medication adjustment
8. In a child with a typical febrile seizure, including a complete recovery, make a diagnosis based on history and physical exam alone, and do not over-investigate.
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