Epilepsy is a chronic neurological disorder characterised by idiopathic (75%), recurrent (2 or more), unprovoked seizures. Patients with epilepsy are usually physically normal and asymptomatic between events.
It affects 1% of all people by age 20 and 3% by age 75%.
Specific epilepsy syndromes
| Syndrome | Age of Onset | Key Seizure Type(s) | Distinguishing Features | EEG Findings | Prognosis |
|---|---|---|---|---|---|
| Childhood Absence Epilepsy (CAE) | 4–10 yrs | Absence seizures | Brief staring, no postictal confusion, triggered by hyperventilation | 3 Hz spike-and-wave | Good, often resolves |
| Juvenile Myoclonic Epilepsy (JME) | Adolescence | Myoclonic, GTCS, ± absence | Morning jerks, triggered by sleep deprivation | Generalized polyspike-and-wave | Lifelong, well-controlled |
| West Syndrome | <1 yr | Infantile spasms | Developmental regression, flexor/extensor spasms | Hypsarrhythmia | Poor |
| Lennox–Gastaut Syndrome | 1–8 yrs | Tonic, atonic, atypical absence | Drop attacks, intellectual disability | Slow spike-and-wave (<3 Hz) | Poor, refractory |
| Benign Rolandic Epilepsy | 3–13 yrs | Focal (face) | Facial twitching, drooling, occurs during sleep | Centrotemporal spikes | Excellent |
| Juvenile Absence Epilepsy | Adolescence | Absence + Generalised tonic clonic | Less frequent absences than CAE | 3–4 Hz spike-and-wave | Moderate |
| Generalized Tonic-Clonic Seizures | Any | Generalized tonic clonic | Tonic → clonic → postictal confusion | Generalized discharges | Variable |
| Temporal Lobe Epilepsy | Any | Focal impaired awareness | Aura (déjà vu, fear), automatisms | Temporal lobe abnormalities | Variable |
| Frontal Lobe Epilepsy | Any | Focal motor | Brief, frequent, bizarre movements, often during sleep | Frontal lobe abnormalities | Variable |
| Dravet Syndrome | Infancy | Febrile → multiple types | Developmental delay, prolonged seizures, SCN1A mutation | Generalized abnormalities | Poor |
| Febrile Seizures | 6 mo–5 yrs | Generalized | Fever-associated, usually brief | Normal | Excellent |
- Risk factors
- Genetics
- Idiopathic epilepsy is caused bygenes affecting ion channels and neurotransmitters
- Syndromic epilepsy can occur in Dravet syndrome, Lennox-Gastaut syndrome and Tuberous Sclerosis complex
- Cerebral malformations such as cortical dysplasia or hippocampal sclerosis
- Neurocutanous syndrome such as Sturge-Weber syndrome and neurofibromatosis
- Stroke and vascular disease
- Traumatic brian injury
- Infections
- Metabolic disorder such as mtochondrial disease, pyridoxine dependency, and phenylketonuria
- Autoimmune disease such as SLE
- Chronic inflammation
- Genetics
- Pathophysiology
- Disruption of the balance between excitatory (via NMDA and AMPA receptors) and inhibitory neurotransmitters (via GABA receptors)
- Ionic channel dysfunction – affects Na+, K+, Ca2_ and Cl- channels
- Aberrant long-term potentiation (LTP) enhances excitatory synaptic transmission, while impaired long-term depression (LTD) reduces inhibitory control
- Structural abnormaliteis make it conducive for seizures to be generated
- Cytokines like IL-1B and TNF-a alter blood-brain barrier permeability, affect ion channel funciton, modify neurotransmitter systems, and cotnribute to neurodegeneration
- Differentials for epilepsy
- Migraine headache
- Stroke or transient ischaemic attack
- Febrile seizure
- Syncope
- Psychogenic non-epileptic seizures(PNES):
- Psychiatric History (OCD, PTSD)
- Female sex
- Sexual abuse history
- Investigations
- Electroencephalogram (EEG) to identify characteristic patterns such as iterictal epileptiform discharges (EEG)
- Magnetic resonance imaging (MRI) to identify structural abnormalities
- Video-EEG monitoring to correlate observed behaviour during a seizure and changes in brain electrical activity. It combines video recording with continuous EEG montiroing for 5 – 7 days.
- PET/SPECT scan to localizse the seizure focus
- Treatment after the second unexplained seizure
- Refer for an EEG
- 30-minute EEG
- 5-7 day continuous video EEG
- Antiepileptic drugs (AEDs)
- Carbamazepine or lamotrigine for focal seizures or generalised tonic-clonic seizures
- Carbamazepine or lamotrigine for focal onset seizures in children
- Levetiracetam or valproate for generalized onset seizures in children
- Dual therapy with second-line medications ( sodium valproate, lamotrigine, levetiracetam and topiramate) if treatment is refractory to a single AED
- Symptom monitoring for patients with well-documented focal lesions
- Surgery for patients with well documented focal lesions
- Patient education while on anti-epileptic drugs
- Avoid becoming drunk, especially drinking sprees during weekends
- Eat at regular intervals
- Manage stress (physical or mental) as it may precipitate fits
- Avoid sleep deprivation
- Never swim alone
- Avoid operating heavy or sharp edged machinery
- To prevent burns, make protective shields around braziers (”Jikos”)
- Considerations before starting antiepileptic drugs for women of reproductive age
- Pregnancy determination test
- Counseling (contraception, pregnancy, and breastfeeding)
- Most AEDs except Carbamazepine and Valproate are present in breast milk
- Lamotrigine is not harmful to infants
- Enzyme-inducing AEDs may make progesterone-only contraceptives unreliable
- Oestrogen-containing contraceptives lower Lamotrigine levels and dosage might need to be increased
- Strictly avoid Valporate and polytherapy before and during conception
- Do not take a pregnant woman off her antiepileptic drugs. Instead, supplement with folate 5mg/d to decrease the risk of neural tube defects.
- Refer for an EEG
- Complications
- Status epilepticus
- Sudden unexpected death in epilepsy (SUDEP) can occur in uncontrolled epilepsy as a result of nocturnal seizure-associated apnoea or asystole.
- Injury from seizures
- Drug-related complications: hepatotoxicity, teratogenicity, bone marrow suppression, and skin rashes
- Depression and axiety
- Cognitive impairment
- Social isolation
- Educational underachievement and unemployment
- Driving restriction – must be seizure-free for a year before they can apply for a driving license