II. Causes: New Onset Secondary Seizure Causes by age
- Age under 10 years
- Febrile Seizure (under age 5 years)
- Idiopathic
- Congenital
- Birth Injury
- Head Trauma (including due to Child Abuse)
- Gastroenteritis (Rotavirus, Shigella)
- Metabolic disorder
- Hypoglycemia
- Hyponatremia (most common cause in afebrile children under age 2 years)
- Hypocalcemia
- Hypomagnesemia
- Age 10 to 40 years
- Idiopathic
- Head Trauma
- Pre-existing focal brain disease
- Drug Withdrawal (e.g. Alcohol Withdrawal)
- Age 40 to 60 years
- Age over 60 years
- Prior Cerebrovascular Accident (32%)
- Brain Tumors (14%)
- Subdural Hematoma
- CNS Infection (Meningitis or Encephalitis)
- Alzheimer's Dementia
- Metabolic abnormalities
III. Causes: Non-Epileptic Causes of Seizure
- Idiopathic (most common, accounts for >70%)
- Isolated unprovoked, non-epileptic Seizure
- Neurogenic
- Brain Tumor
- Cerebral dysgenesis
- Cerebrovascular degenerative disorders
- Migraine Headache
- Movement Disorder
- Hypertensive Encephalopathy (Posterior Reversible Encephalopathy Syndrome or PRES)
- Head Trauma
- Cardiogenic
-
Electrolyte
- Hypocalcemia
-
Hyponatremia (Water Intoxication)
- Most common cause in afebrile children under age 2 years
- May also be caused by water Intoxication in adults
- Hypomagnesemia
- Hyperosmolarity
- Hypercarbia
- Metabolic disorders
- Hypoglycemia
- Adrenal Insufficiency (Addison Disease)
- Hyperthyroidism (Thyroid Storm)
- Hypothyroidism
- Vitamin B6 deficiency (Pyridoxine deficiency)
- Acute Renal Failure (Uremia)
- Acute Liver Failure
- Inborn Errors of Metabolism (infants)
- Infectious disease
- Miscellaneous
- Febrile Seizure
- Ecclampsia
- Pregnancy after 20 weeks to 6 weeks postpartum
- Most Seizures (>80%) are >2 days after delivery
- Hyperthermia
- Hypoxia
- Psychogenic Nonepileptic Seizure (or Pseudoseizure)
- Sleep Disorder
IV. Causes: Medications and Drugs (and their withdrawal)
- Subtherapeutic Antiepileptic Drug
- Medications (especially if in overdosage)
- See Toxin-Induced Seizure Causes
- Antipsychotics (esp. Clozapine, Chlorpromazine)
- Avoid high dose, or in those with Seizure Disorder or brain disorder
- Antibiotics (primarily with high doses, or if not adjusted for renal Impairment)
- Beta-lactam antibiotics (e.g. Penicillins)
- Cephalosporins
- Quinolones (e.g. Ciprofloxacin)
- Bupropion (Wellbutrin)
- Do not exceed maximum dose
- Avoid in Eating Disorder (e.g. Bulimia, Anorexia), Seizure Disorder, Electrolyte disturbance
- Cyclosporine (Sandimmune)
- Oral HypoglycemicOverdose (e.g. Sulfonylurea Overdose)
- Interferon
- Isoniazid (INH)
- Lithium
- Local Anesthetic Systemic Toxicity (LAST Reaction)
- Meperidine (Demerol)
- Tacrolimus
- Theophylline and other Methylxanthines
- Tramadol (Ultram)
- Tricyclic Antidepressants
- Quinolone antibiotics
-
Drug Withdrawal
- Alcohol Withdrawal
- Benzodiazepine Withdrawal
- Cocaine withdrawal
- Barbiturate withdrawal
- Meperidine withdrawal
- Drug or Metal toxicity
V. Differential Diagnosis: Other Events that may appear to be Seizure
- Breath Holding Spells (infants and young children)
- Parasomnias and other Sleep Disorders
- Migraine Headache
- Transient Ischemic Attack
- Vertigo and other vestibular disorders
- Syncope
- Movement Disorder
- Psychogenic Nonepileptic Seizure (or Pseudoseizure)
- Gastroesophageal Reflux disease
- Attention Deficit Disorder
- Hallucinations or other Psychosis
- Panic Attacks
VI. References
- Nocera, Valente, Amanullah (2018) Crit Dec Emerg Med 32(11): 3-9
- (2017) Presc Lett 24(8): 47-8
- Liu (2017) Am Fam Physician 96(2): 87-96 [PubMed]