Diagnostics

History

• History of present illness: description of the event by the patient (aware seizure) and/or witnesses (seizure with impaired awareness)

  • Potential triggers (e.g., sleep deprivation, excessive alcohol intake)

  • Prodromal symptoms (e.g., aura)

  • Ictal symptoms

  • Postictal symptoms

• Past medical history

  • History of epilepsy (including current antiepileptic drugs and adherence)

  • History of other potential underlying conditions (e.g., head trauma, stroke, tumor, CNS infection)

Physical examination: attention should be paid to visual inspection (e.g., for bruises from falls, tongue bites, phakomatosis-specific skin manifestations) and evaluation for cardiovascular disorders

EEG

• Performed in individuals who present with first seizure, with insufficient information for seizure classification, and/or treatment-refractory seizures

• Characteristic EEG findings help to establish the diagnosis of epilepsy; the absence of such findings cannot, however, rule out epilepsy.

  • During the seizure (ictal)

    • Epileptiform discharges (e.g., spikes, sharp waves, spike waves) are usually detected.

    • Certain types of conditions characterized by seizures have characteristic discharge patterns (e.g., hypsarrhythmia in West syndrome, 3 Hz spike-and-wave in typical absence seizures, burst suppression in anoxic encephalopathy or barbiturate administration)

    • If no epileptiform discharges are detected during a seizure, alternative diagnoses (e.g., psychogenic nonepileptic seizures) should be considered.

  • After a seizure or between seizures (postictal or interictal)

    • Often normal findings (even after provocation via sleep deprivation, hyperventilation, or visual stimuli)

    • May show epileptiform activity (bursts of abnormal discharges featuring spikes and/or sharp waves, hypsarrhythmia in West syndrome)

  • Video-EEG telemetry in hospitalized patients

  • Continuous EEG in ambulatory patients

ECG: Rule out cardiogenic causes (e.g., cardiac arrhythmias resulting in cerebral hypoxia) in all patients with loss of consciousness during a seizure.

MRI: Modality of choice for investigating potential underlying structural abnormalities. [24]

• All patients with first-time focal seizures

• Exception: children with history and examination suggestive of benign seizure or characteristic epilepsy syndrome

CT: May be used if MRI is not available, but is less sensitive for identifying soft-tissue lesions [24]

Angiography: if vascular cause (e.g., cerebral arteriovenous malformation) is suspected

Laboratory screening: to identify metabolic disorders and infectious diseases, if suspected

• Blood

  • CBC

  • Glucose

  • Electrolytes

  • Prolactin

  • Toxicology screening

  • ESR

  • Rapid plasma reagin

  • Creatine kinase

  • Renal and liver function tests

  • Antiepileptic drug levels (e.g., phenytoin, carbamazepine, phenobarbital) [25]

• Urinalysis

• Bacterial cultures

• Cerebrospinal fluid analysis

• Endocrine studies

  • Thyroid function tests

  • Adrenal function tests

  • Pituitary function tests