First Unprovoked Seizure Evaluation in Adults

Algorithm Steps

1. ▶

   Start

   First Apparent Seizure

   Patient presents after possible first seizure

   1. ◆

      Decision

      Was This a Seizure?

      Differentiate from mimics

      • Syncope (most common mimic)
      • Psychogenic non-epileptic seizure
      • Migraine with aura
      • Movement disorders
      • Transient global amnesia
      1. ●

         Action

         Not a Seizure

         Evaluate for alternative diagnosis

         • Syncope workup if indicated
         • Cardiac evaluation (ECG, holter)
         • Psychiatric evaluation if PNES suspected
         • No AED indicated
      2. ◆

         Decision

         Provoked or Unprovoked?

         Identify acute symptomatic causes

         • Provoked: metabolic (Na, glucose, uremia)
         • Provoked: acute CNS insult (<7 days)
         • Provoked: drug/alcohol withdrawal
         • Unprovoked: no acute precipitant
         1. ●

            Action

            Acute Symptomatic Seizure

            Treat underlying cause

            • Correct metabolic abnormality
            • Treat CNS infection/injury
            • Usually no long-term AED needed
            • Risk of epilepsy lower than unprovoked
         2. ●

            Action

            Brain Imaging

            MRI preferred over CT

            • MRI with epilepsy protocol (preferred)
            • CT if MRI unavailable or contraindicated
            • Look for structural causes
            • Tumors, vascular malformations, cortical dysplasia
            1. ●

               Action

               EEG

               Standard or prolonged EEG

               • Routine EEG within 24-48h if possible
               • Yield higher if sleep deprived
               • Epileptiform activity increases recurrence risk
               • Normal EEG does not rule out epilepsy
               1. ◆

                  Decision

                  Assess Recurrence Risk

                  High vs low risk features

                  • Overall recurrence: 21-45% in 2 years
                  • HIGH RISK: prior brain insult (Level A)
                  • HIGH RISK: EEG epileptiform (Level A)
                  • HIGH RISK: abnormal MRI (Level B)
                  • HIGH RISK: nocturnal seizure (Level B)
                  1. ●

                     Action

                     High Recurrence Risk

                     Consider AED initiation

                     • Risk may be 50-90% in 2 years
                     • AED reduces recurrence by ~35%
                     • Shared decision-making essential
                     • Discuss driving, employment, safety
                     1. ◆

                        Decision

                        To Treat or Not?

                        Shared decision-making

                        • AED does NOT prevent epilepsy development
                        • AED reduces recurrence risk short-term
                        • Consider patient preferences, occupation
                        • Discuss side effects, teratogenicity
                        1. ●

                           Action

                           Start AED

                           Select appropriate medication

                           • Levetiracetam (LEV) - broad spectrum, low interactions
                           • Lamotrigine (LTG) - good for focal, slow titration
                           • Valproate - avoid in women of childbearing potential
                           • Monotherapy at low effective dose
                           1. ●

                              Action

                              Patient Counseling

                              Safety and lifestyle

                              • Driving restrictions (typically 3-12 months)
                              • Avoid heights, heavy machinery, swimming alone
                              • Alcohol and sleep deprivation as triggers
                              • When to seek emergency care
                              1. ✓

                                 Outcome

                                 Neurology Follow-up

                                 Ongoing care plan

                                 • Reassess in 1-3 months
                                 • If second seizure: epilepsy diagnosis
                                 • Long-term AED if recurrence
                                 • Consider epilepsy specialist referral
                        2. ●

                           Action

                           Observation

                           Watchful waiting approach

                           • Seizure precautions
                           • Driving restrictions (varies by state)
                           • Return for recurrence
                           • Follow up in 1-3 months
                  2. ●

                     Action

                     Lower Recurrence Risk

                     Observation reasonable

                     • Normal EEG, normal MRI
                     • No prior CNS injury
                     • ~20-30% recurrence risk
                     • Can defer AED treatment
                     • Close follow-up
            2. ●

               Action

               Laboratory Studies

               Rule out provoking factors

               • Glucose, electrolytes (Na, Ca, Mg)
               • Renal function, LFTs
               • Toxicology screen
               • Lumbar puncture if infection suspected