Seizure, Differential Diagnosis

Fever in children (Febrile seizures)
Breath holding spells (children)
Epilepsy (idiopathic)
Metabolic disorders
Electrolyte abnormalities
Inborn errors of metabolism
Liver or kidney failure
Pyridoxine deficiency
Hypoglycemia
Hyponatremia
Uremia
Hypomagnesemia
Hypocalcemia
Hypoxia (cerebral anoxia from any cause)
Brain Vessels, Infection, Neoplasm
Stroke (Cerebrovascular); Acute hemorrhagic stroke, Acute ischemic stroke.
Transient ischemic attack
Acute venous thrombosis
Vascular malformation
Carotid sinus sensitivity
CNS infections; Brain abscess
Cysticercosis
Encephalitis
Meningitis
Brain tumor
Vasculitis (systemic lupus erythematosus)
Drugs and drug withdrawals
Illicit drug use and withdrawal
Alcohol and alcohol withdrawal
Drug withdrawal (benzodiazepines)
Drug intoxication (cocaine, amphetamines)
Analgesics (e.g., local anesthetics, meperidine, tramadol
Antibiotics (e.g., beta-lactam antibiotics, isoniazid, quinolones, some HIV medications)
Immunomodulators (e.g., cyclosporine, interferons, tacrolimus)
Psychotropics (e.g., antidepressants, antipsychotics, lithium, stimulants)
Theophylline
Toxic Exposures
Brain Trauma
Head trauma
Peri- or prenatal brain injury
Iatrogenic: Contrast agents
Neuropsychiatric and others
Psychogenic nonepileptic seizures (pseudoseizures)
Cerebral dysgenesis,
degenerative disease
inflammatory/autoimmune diseases
Genetic disorders
Sandifer’s syndrome
Parasomnias
Movement disorders (Tics, hemiballismus)
Imitators:
vasovagal syncope,
psychogenic nonepileptic seizures (pseudoseizures),
TIA,
arrhythmia,
Hemiplegic Migraine (Hemiparetic migraine)
Tetany

Thinking through the Differential diagnosis

Classification of causes of seizures and seizure mimics

The differential diagnosis of a seizure can be broken down nicely as follows (AFP 2012)

A) Nonepileptic
-Psychogenic
-Syncope (see differential diagnosis of syncope)

B) Epileptic
Provoked (acute symptomatic; caused by underlying disease or event): The above list of causes including brain vessels, infections, neoplasm, metabolic disorders, drugs, brain trauma, etc are all things that provoke seizures.

Unprovoked:
1) Remote symptomatic (caused by previous static brain disease): Perinatal injury, Remote stroke, Remote trauma
2) Progressive symptomatic (caused by progressive brain disease): Degenerative disorder, Movement disorder, Tumor

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** The above differential diagnosis for seizures can also be ordered using VINDICATED MEN mnemonic for the mechanisms of disease

Further Reading

Am Fam Physician. 2007 May 1;75(9):1342-1347. https://www.aafp.org/afp/2007/0501/p1342.html