Seizure (Adults)


Classification

Primary Seizure: those without a clear cause

Secondary Seizures: Result from another identifiable neurologic condition such as mass or stroke.

Generalized Seizures

Cause by nearly simultaneous activation of entire cerebral cortex. The attacks begin w/ abrupt loss of consciousness.

  • Non-convulsive (absence or petit mal)
    • Alteration in mental status without motor activity
    • Most frequent in 5- to 10-year-olds
    • Rarely postictal
  • Convulsive (grand mal)
    • Abrupt loss of consciousness at onset (except with myoclonic)
    • Can be clonic (jerking of trunk), tonic (rigid), tonic-clonic, myoclonic or atonic
    • Followed by postictal state (postictal confusion may persist for hours).
  • Todd’s paralysis: Focal paralysis, typically following a generalized seizure; usually lasts 1-2 hours but may last 1-2 days

Partial (Focal) Seizures

Electrical discharges beginning in a localized region of the cerebral cortex, often a brain lesion.

  • Simple partial
    • Brief event without alteration of consciousness
    • If involving motor neurons → unilateral focal clonic movements.
    • May also manifest as isolated sensory, autonomic, or psychic symptoms
  • Complex partial (temporal lobe or psychomotor)
    • Partial seizure with impairment of consciousness and postictal state
    • Commonly manifests as mental and psychological symptoms, including changes in affect, confusion, hallucinations, automatisms (eg, lip smacking)
  • Secondary generalized: Partial seizure that spreads to both hemispheres (eg, generalized seizure preceded by aura)

Status Epilepticus:

  • Continuous or intermittent seizure for more than 5 min. without recovery or consciousnes.

Eclampsia:

  • Combination of seizures, hypertension, edema, & proteinuria in pregnant women > 20 wk gestation or up to 3 week postpartum

Differential Diagnosis

Paroxysmal Disorders: Differential Diagnosis
  • Seizures
  • Syncope
  • Pseudoseizures
  • Hyperventilation syndrome
  • Complex Migraine headache
  • Movement disorders
  • Narcolepsy/cataplexy

Etiology

Metabolic
  • Electrolyte abnormality
    • Na, Ca, Mg
    • Hypoxia
    • Hepatic failure
    • Renal failure/post dialysis
  • Endocrine
    • DKA, hyperosmolar coma, thyrotoxicosis
Toxin
  • Drug withdrawal
    • EtOH, anticonvulsants, barbiturates
  • Drug induced
    • TCAs, theophylline
    • Amphetamine, cocaine, PCP
    • Lead
    • Lidocaine
Vascular
  • CVA, TIA, thrombosis, vasculitis
  • Hypertensive encephalopathy
  • Arrhythmia
Traumatic
  • Can be an early & late result
  • Subdural hematoma, contusion, laceration, hemorrhage, birth injury
  • 75% within first yr post trauma
Infectious
  • Meningitis/encephalitis
  • Abscess
  • Slow virus (SSPE, Jakob-Creutzfeld)
  • Febrile
Neoplastic
  • Primary & metastatic
  • <1% of all childhood seizures
  • Approximately 10% of all new adult seizures
Congenital
  • Sturge-Weber, Tuberous sclerosis
Primary epilepsy

Causes of Seizures in the HIV Patient

Mass lesion
  • Toxoplasmosis
  • Lymphoma
Meningitis/encephalitis
  • Cryptococcal
  • Bacterial/aseptic
  • Herpes zoster
  • Cytomegalovirus
HIV encephalopathy/acquired immunodeficiency syndrome dementia complex
Progressive multifocal leukoencephalopathy
CNS tuberculosis
Cysticercosis
Neurosyphilis

Differential etiology relative to age

  1. Neonatal (<1 mth)
    • 90% birth injury (anoxia, hemorrhage) or metabolic disorder (glucose, Ca)
    • Infection, congenital
  2. Infant (1-6 mth)
    • Same as neonates
    • Inborn errors of metabolism
  3. Early childhood (6mo-3yrs)
    • Birth injury, trauma
    • Metabolic, toxic ingestion
    • Febrile, infectious
  4. Childhood/adolescence
    • Trauma, birth injury, infection
    • Idiopathic
    • Toxins
  5. Young adult
    • Trauma, tumor, idiopathic, toxin, eclampsia
  6. Elderly (>55yo)
    • Vascular disease, trauma, tumor

Workup

Labs:
  • Finger-Stick sugar : Treat if < 80 or unable to determine
  • CMP, Ca, Mg
  • Antiepileptic drug level
  • UDS, UA, Urine Pregnancy
  • Consider ETOH, ASA, APAP, TCA screen
  • Consider CSF studies if CNS infection suspected

- Non-Contrast head CT for NEW seiuzure or NEW focal neurological Sx
- Consider ED EEG to assess ongoing seizure activity despite use of heavy sedation or paralytic.

 

ED care and Disposition

  1. Goal: prevent prolonged or recurrent seizures to reduce CNS damage
  2. ABC's: IV, O2, monitor
    • O2
    • IV access
  3. Quick scan for trauma, remove glasses, dentures (unless seizing)
  4. Glucose & thiamine
  5. Little is required during the course of a seizure other than to protect the pt from injury. IV anticonvulsants are not indicated during an uncomplicated seizure.
  6. In pt with a known seizure disorder whose anticonvulsant levels are low, supplemental doses may be appropriate.
    • Phenytoin (18 mg/kg PO as a single dose or divided into 3 doses given over 12 hr) will achieve therapeutic concentration in 2 to 24 hrs. Alternatively, 10-20 mg/kg of IV phenytoin at a rate of 25 mg/min achieves anticonvulsant effects in 1-2 hrs.
    • Fosphenytoin 10-20 mg/kg Phenytoin Equivalent at a max IV rate of 150 mg/min. Loading dose of other entiepileptics may be guided by the pt's neurologist.
  7. Administer Magnesium sulfate 4-6 g IV, to eclamptic pt followed by an infusion of 1-2 g/h. Consult an Obstetrician early in the pts care.
  8. Pt in Status Epilepticus require: [Adult Seizure Calc]
    • Large-bore IV access, cardiac monitor, & pulse Ox.
    • ET intubation is recommended.
    • If a paralytic agent is used, a short-acting agent is preferred so seizure activity can be monitored.
       
    • Lorazepam  2-4 mg IV repeated to max 0.1 mg/kg -OR-
      Diazepam 5-10 mg IV repeated to max 0.15 mg/kg
      -AND-
      Phenytoin
      20-30 mg/kg at 50 mg/min IV -OR-
      Fosphenytoin
      20-30 mg/kg at 150 mg/min IV  

  9. Refractory Status:
    • Phenobarbital 20 mg/kg at 50-75 mg/min IV -OR-
      Valproic acid
      20-40 mg/kg at 5mg/kg/min IV

      Propofol 2-5 mg/kg IV then 2-15 mg/kg/hr (5.0-200 mcg/kg/min) -OR-
      Midazolam
      0.2 mg/kg IV then 0.05-2 mg/kg/hr -OR-
      Pentobarbital
      5-15 mg/kg IV then 0.5-10 mg/kg/hr

      Consider general anesthesia
      Neuromucular blocking agents may be necessary in which case EEG monitoring is mandatory.
  • Pts with first seizure who have a normal neurologic examination, acute or chronic medical co-morbidities, normal diagnostic testing including neuro-imaging, and a normal mental status can be discharged from the ED. Initiation of antiepileptic medication and further testing may be deferred to the outpt. setting.
  • Consider admission for pt. who do not meet the above criteria. Instruct discharge pts to take precautions to minimize risk of injury from further seizures. Swimming, working with hazardous tools or machines and working at heights should be prohibited. Driving is prohibited until cleared by the neurologist or PCP, and driving privileges should conform to state laws.

 

 

Notes
  • Consider Pyridoxine (Vitamin B6) 5g IV over 3-5 min for possible INH toxicity
  • Consider Thiamine 100mg IV & Mg Sulfate 1-2g for alcoholic or malnourished pts
  • Consider Ceftriaxone 2g IV + Vancomycin 1g IV is suspected CNS infection.
 

Drugs

Properties of Commonly Used Anticonvulsant Drugs
Drug Oral Dose, MG per Day Therapeutic Level, MG per mL Days to Reach Steady State Serum Half-Life, Hours
Carbamazepine (Tegretol)
 
400-1200, divided 3 or 4 times a day 4-12 2-4 12-17
Felbamate (Felbatol)
 
1200-2400, divided 3 or 4 times a day 20-100 2-5 13-23
Gabapentin (Neurontin)
 
900-3600, TID 1-2 1-2 5-7
Lamotrigine (Lamictal)
 
25-500, BID 2-5 6-10 25-33
Levetiracetam (Keppra)
 
1000-3000, BID 5-45 1-2 6-13
Oxcarbazepine (Trileptal)
 
600-1200, BID 10-30 1-3 9
Phenytoin (Dilantin)
 
300-600, TID 10-20 2-10 7-42
Topiramate (Topamax)
 
200-400, BID 2-5 4-8 21
Valproic acid (Depakene)
 
15-60 mg/kg, BID or TID 50-150 2-4 12-18
 

Admit Orders: Seizure

1. Admit to:

2. Diagnosis: Seizure

3. Condition:

4. Vital Signs: q6h with neurochecks. Call physician if BP >160/90, <90/60; P >120, <50; R>25, <10; T >38.5°C; or any change in neurological status.

5. Activity: Bed rest

6. Nursing: Seizure precautions with padded bed rails up. EEG monitoring.

7. Diet: NPO for 24h, then regular diet if alert.

8. IV Fluids: to heparin lock with flush q shift.

9. Special Medications:

Status Epilepticus:

1. Maintain airway.

2. Position the patient laterally. The head and extremities should be cushioned to prevent injury.

5. Secure IV access and draw blood for glucose analysis. Give thiamine 100 mg IV push, then dextrose 50% 50 mL IV push.

6. Initial Control:

Lorazepam (Ativan) 6-8 mg (0.1 mg/kg; not to exceed 2 mg/min) IV at 1-2 mg/min. May repeat 6-8 mg q5-10min (max 80 mg/24h) OR

Phenytoin (Dilantin) 15-20 mg/kg load in NS at 50 mg/min. Repeat 100-150 mg IV q30min, max 1.5 gm; monitor BP.

Fosphenytoin (Cerebyx) 20 mg/kg IV/IM (at 150 mg/min), then 4-6 mg/kg/day in 2 or 3 doses (150 mg IV/IM q8h). Fosphenytoin may be given IM.

If seizures persist, administerphenobarbital 20 mg/kg IV at 50 mg/min, repeat 2 mg/kg q15min; additional phenobarbital may be given, up to max of 30-60 mg/kg.

7. If seizures persist, intubate and give:

Midazolam (Versed) 0.2 mg/kg IV push, then 0.045 mg/kg/hr; titrate up to 0.6 mg/kg/hr OR

-Propofol (Diprivan) 2 mg/kg IV push over 2-5 min, then 50 mcg/kg/min; titrate up to 165 mcg/kg/min OR

-Induce coma with pentobarbital 10-15 mg/kg IV over 1-2h, then 1-1.5 mg/kg/h continuous infusion. Initiate continuous EEG monitoring.

Maintenance Therapy for Epilepsy:

Primary Generalized Seizures – First-Line Therapy:

-Carbamazepine (Tegretol) 200-400 mg PO tid [100, 200 mg]. Monitor CBC.

-Phenytoin (Dilantin) loading dose of 400 mg PO, followed by 300 mg PO q4h for 2 doses (total of 1 g), then 300 mg PO qd or 100 mg tid or 200 mg bid [30, 50, 100 mg].

-Divalproex (Depakote) 250-500 mg PO tid-qid with meals [125, 250, 500 mg].

-Valproic acid (Depakene) 250-500 mg PO tid-qid with meals [250 mg].

Primary Generalized Seizures -- Second Line Therapy:

-Phenobarbital 30-120 mg PO bid [8, 16, 32, 65, 100 mg].

-Primidone (Mysoline) 250-500 mg PO tid [50, 250 mg]; metabolized to phenobarbital.

-Felbamate (Felbatol) 1200-2400 mg PO qd in 3-4 divided doses, max 3600 mg/d [400, 600 mg; 600 mg/5 mL susp]; adjunct therapy; aplastic anemia, hepatotoxicity.

-Gabapentin (Neurontin), 300-400 mg PO bid-tid; max 1800 mg/day [100, 300, 400 mg]; adjunct therapy.

-Lamotrigine (Lamictal) 50 mg PO qd, then increase to 50-250 mg PO bid [25, 100, 150, 200 mg]; adjunct therapy .

Partial Seizure:

-Carbamazepine (Tegretol) 200-400 mg PO tid [100, 200 mg].

-Divalproex (Depakote) 250-500 mg PO tid with meals [125, 250, 500 mg].

-Valproic acid (Depakene) 250-500 mg PO tid-qid with meals [250 mg].

-Phenytoin (Dilantin) 300 mg PO qd or 200 mg PO bid [30, 50, 100].

-Phenobarbital 30-120 mg PO tid or qd [8, 16, 32, 65, 100 mg].

-Primidone (Mysoline) 250-500 mg PO tid [50, 250 mg]; metabolized to phenobarbital.

-Gabapentin (Neurontin), 300-400 mg PO bid-tid; max 1800 mg/day [100, 300, 400 mg]; adjunct therapy.

-Lamotrigine (Lamictal) 50 mg PO qd, then increase to 50-250 mg PO bid [25, 100, 150, 200 mg]; adjunct therapy.

-Topiramate (Topamax) 25 mg PO bid; titrate to max 200 mg PO bid [tab 25, 100, 200 mg]; adjunctive therapy.

Absence Seizure:

-Divalproex (Depakote) 250-500 mg PO tid-qid [125, 250, 500 mg].

-Clonazepam (Klonopin) 0.5-5 mg PO bid-qid [0.5, 1, 2 mg].

-Lamotrigine (Lamictal) 50 mg PO qd, then increase to 50-250 mg PO bid [25, 100, 150, 200 mg]; adjunct therapy.

10. Extras: MRI with and without gadolinium or CT with contrast; EEG (with photic stimulation, hyperventilation, sleep deprivation, awake and asleep tracings); portable CXR, ECG.

11. Labs: CBC, chem 7-12, glucose, Mg, calcium, phosphate, VDRL, anticonvulsant levels. UA.