# Seizures and Epilepsy Across Ages

## Introduction

Seizures represent one of the most common neurologic emergencies encountered by medicine-pediatrics physicians. The spectrum of epilepsy spans from **neonatal seizures** to **new-onset epilepsy in the elderly**, with age-specific etiologies, classification systems, and treatment strategies. A med-peds clinician must understand these differences to provide seamless care across the lifespan.

## Definitions and Classification

### ILAE 2017 Classification
**Focal onset**: Arising from networks limited to one hemisphere. **Generalized onset**: Engaging bilateral networks from onset. **Unknown onset**: Insufficient information to classify. **Focal to bilateral tonic-clonic**: Previously called secondary generalization.

### Key Terminology
**Seizure**: A transient occurrence of signs/symptoms due to abnormal excessive or synchronous neuronal activity. **Epilepsy**: Defined by any of the following: two unprovoked seizures >24 hours apart, one unprovoked seizure with >60% recurrence risk, or a diagnosed epilepsy syndrome. **Status epilepticus**: Continuous seizure activity lasting >5 minutes or recurrent seizures without return to baseline.

## Age-Specific Etiologies

### Neonatal Period (0-28 days)
**Hypoxic-ischemic encephalopathy** (most common); Intracranial hemorrhage; Metabolic disturbances (hypoglycemia, hypocalcemia); Neonatal infections (meningitis, encephalitis); Inborn errors of metabolism (pyridoxine-dependent epilepsy).

### Infancy and Early Childhood (1 month - 5 years)
**Febrile seizures** (most common; simple vs. complex); Genetic epilepsy syndromes (Dravet syndrome, infantile spasms); CNS infections; Structural abnormalities (cortical dysplasia).

### School Age and Adolescence (6-18 years)
**Childhood absence epilepsy** (peak 4-8 years); **Juvenile myoclonic epilepsy** (peak 12-18 years); Benign epilepsy with centrotemporal spikes; Autoimmune encephalitis.

### Adults and Elderly
Traumatic brain injury; **Cerebrovascular disease** (most common cause in adults >35); Brain tumors; Neurodegenerative diseases; Alcohol withdrawal seizures.

![Diagram showing age-specific seizure etiologies across the lifespan](images/seizure-etiologies-by-age.jpg)

## Diagnostic Workup

### First Seizure Evaluation
Detailed history: semiology, duration, preceding aura, postictal state; **EEG**: Standard, sleep-deprived, or continuous monitoring. **Neuroimaging**: MRI preferred over CT (except in acute setting) Laboratory studies: glucose, electrolytes, toxicology screen; Lumbar puncture when infection is suspected.

### Pediatric-Specific Considerations
Developmental history and regression assessment. Genetic testing for suspected epilepsy syndromes. Metabolic workup for neonatal and infantile seizures.

### Adult-Specific Considerations
Cardiac evaluation to exclude syncope. Alcohol and substance use assessment. Occupational and driving implications.

![EEG patterns showing generalized 3-Hz spike-and-wave in absence epilepsy](images/eeg-absence-epilepsy.jpg)

## Treatment Principles

### When to Start Antiseizure Medications (ASMs)
After a second unprovoked seizure (standard recommendation) After a first seizure with high recurrence risk (abnormal EEG, structural lesion) Immediate treatment for status epilepticus.

### First-Line ASMs by Age and Seizure Type

| Population | Focal Seizures | Generalized Seizures |
|---|---|---|
| Neonates | Phenobarbital, levetiracetam | Phenobarbital |
| Children | Oxcarbazepine, levetiracetam | Ethosuximide (absence), valproate |
| Adults | Lamotrigine, levetiracetam | Valproate, lamotrigine |
| Elderly | Lamotrigine, levetiracetam | Lamotrigine, levetiracetam |

### Special Considerations
**Valproate**: Avoid in women of childbearing potential (teratogenicity) **Carbamazepine/phenytoin**: May worsen generalized epilepsy. **Ketogenic diet**: Effective in refractory pediatric epilepsy. Surgical evaluation for drug-resistant epilepsy (failed two adequate ASM trials)

## Transition of Care

Adolescents with epilepsy need structured transition to adult neurology. Address medication adherence, driving laws, reproductive counseling. Update seizure action plans for school, work, and independent living.

![Flowchart for epilepsy transition from pediatric to adult care](images/epilepsy-transition-care.jpg)

## Clinical Pearls

Febrile seizures do not require chronic ASM therapy; parental education is paramount. Juvenile myoclonic epilepsy typically requires lifelong treatment due to high relapse rates. Always consider **autoimmune encephalitis** (anti-NMDA receptor) in young patients with new-onset seizures and psychiatric symptoms. In the elderly, levetiracetam and lamotrigine are preferred due to fewer drug interactions. Med-peds physicians are uniquely positioned to manage epilepsy transitions from childhood through adulthood.

## References

1. Fisher RS, Cross JH, French JA, et al. Operational classification of seizure types by the International League Against Epilepsy. *Epilepsia*. 2017;58(4):522-530.
2. Kwan P, Arzimanoglou A, Berg AT, et al. Definition of drug resistant epilepsy: Consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. *Epilepsia*. 2010;51(6):1069-1077.
3. Shellhaas RA, Wusthoff CJ, Tsuchida TN, et al. Profile of neonatal epilepsies: Characteristics of a prospective US cohort. *Neurology*. 2017;89(9):893-899.
4. Subcommittee on Febrile Seizures, American Academy of Pediatrics. Neurodiagnostic evaluation of the child with a simple febrile seizure. *Pediatrics*. 2011;127(2):389-394.