EPILEPSY

A chronic condition characterised by recurrent unprovoked seizures. Seizures are caused by abnormal discharges in the brain and present in two different forms: convulsive and non-convulsive forms.

  • Convulsive epilepsy has features such as sudden muscle contraction, causing the person to fall and lie rigidly,
    followed by the muscles alternating between relaxation and rigidity with or without loss of bowel or bladder control
  • Non-convulsive epilepsy has features such as change in awareness, behaviour, emotions or senses (such as
    taste, smell, vision or hearing) similar to mental health conditions, so may be confused with them

Consider a diagnosis of epilepsy if person has had at least 2 convulsive seizures in the last calendar year on two different days.

Seizures during an acute event (e.g. meningitis, acute traumatic brain injury) are not epilepsy.

Causes

  • Genetic, congenital malformation, birth asphyxia, brain tumour
  • Brain infections, cysticercosis, trauma (acute or in the past)
  • Metabolic disorders

In some cases, no specific causes can be identified.

Clinical features

Depending on the type of epilepsy:

 

TYPE OF
EPILEPSY
DESCRIPTION

Generalized
epilepsy

Seizure involves whole brain,
cosciousness is lost at the onset

Tonic Clonic

(grand-mal)
or convulsive
epilepsy
  • May commence with a warning
    sensation in the form of sound, light or
    abdominal pain (aura)
  • There may be a sharp cry followed by
    loss of consciousness and falling
  • Tonic contraction (rigidity) of muscles
    occurs followed by jerking movements
    (clonic phase)
  • There may be incontinence of urine or
    faeces, frothing, and tongue biting
  • A period of deep sleep follows

Absence
seizures

(petit mal)
  • Mainly a disorder of children
  • The attack is characterized by a brief
    loss of consciousness (5-10 seconds)
    in which posture is retained but other
    activities cease
  • The child has a vacant stare
  • Previous activities are resumed at the
    end of the attack
  • Several attacks may occur in a single day

Atonic or
tonic seizures

(drop attacks)
  • Sudden loss of muscular tone, of
    brief duration (15 seconds), with
    cosciousness maintained or
  • Sudden stiffening of muscle
Myoclonus
epilepsy
  • Abnormal jerking movements occuring
    usually in the limbs but may involve the
    whole body

Focal Epilepsy
Seizure activity starts in one area of the
brain

Simple
  • Patient remains alert but has abnormal
    sensory, motor, psychic or autonomic
    manifestation e.g. jerking of a limb,
    déjà vu, nausea, strange taste or smell,
    signs of autonomic nerve dysfunction
    i.e. sweating, flushing, and gastric
    sensation, motor contraction or sensory
    change in a particular point of the body)

Complex
  • Altered awareness and behaviour e.g.
    confusion, repetitive movements

Status
epilepticus
  • A convulsive state in which the
    convulsions last >30 minutes or
    several epileptic convulsions occur
    in succession without recovery
    of consciousness in between or
    convulsions not responsive to 2 doses of
    diazepam. It is a medical emergency.

Differential diagnosis

  • Syncope, hypoglycaemia
  • Hypocalcaemia
  • Conversion disorder, hyperventilation and panic attacks

Investigations

  • A complete medical assessment including psychiatric
    history
  • Electroencephalogram (EEG)
    • Useful in petit mal and temporal lobe epilepsy
    • To be done at specialist level (RR and NR)
  • Other investigations are guided by suspected cause

MANAGEMENT

General principles

  • All suspected cases of non-convulsive epilepsy should be confirmed and treated by a specialist
  • Convulsive epilepsy can be diagnosed at hospital level but drug refills should be available at lower level
  • One brief isolated seizure does not need further treatment but review at 3 months and re-assess. Treat patients with repeated episodes as per definition
  • Treatment can effectively control epilepsy in most cases

Commonly used antiepileptics include:

  • Generalized tonic-clonic seizures
    • Children <2 years: phenobarbital or carbamazepine
    • Children >2 years: carbamazepine or valproate
    • Avoid phenobarbital and phenytoin in children with intellectual disability and/or behavioural problems
  • Absence seizures: Valproate or ethosuximide

Acute seizure and status epilepticus

First aid for acute seizure

  • Do not restrain or put anything in the mouth
  • Protect person from injury: make sure they are in a safe place away from fire or other things that
    might injure them
  • DO NOT leave patient alone. Seek help if possible
  • After the crisis, check airway, breathing and circulation and, while uncoscious, put the person
    in recovery position (on their side)
  • Most seizures resolve spontaneously. If lasting >3 minutes, give diazepam 10 mg IV or rectal
    • Child: 0.05 mg/kg rectally, 0.02 mg/kg IV

Status epilecticus

  • Dextrose 50% 1 mL/kg adults and Dextrose 10% 5 mL/kg children
  • Diazepam as above, repeated after 5-10 min

If not responsive, consider

  • Phenobarbital 10-15 mg/kg slowly IV. Dilute the solution with 10 times its volume of water for
    injections and give VERY SLOWLY (at a rate ≤0.1 mg/minute)

    • Monitor BP and respiration, be ready to administer IV fluids if hypotension develops and
      ventilate with Ambu bag in case of respiratory depression
  • Or phenytoin 15-18 mg/kg over 1 hour
  • It is very caustic so use a good IV line. Extravasation will cause tissue damage

If not responsive

  • Give another drug (if available) or add phenytoin 10 mg/kg in 30 minutes
    • Monitor for respiratory depression

Chronic epilepsy

General principles

  • Start with monotherapy. The effective dose must be reached progressively and patient monitored
    for tolerance and side effects. Aim at the lowest  dose able to control (prevent) the seizures
  • If treatment is ineffective (less than 50% reduction in crisis) try another monotherapy
    (slowly reduce the current antiepileptic and introduce the new one)
  • If high doses with side effects are required and seizures are anyway infrequent, less than
    complete control can be the goal
  • Follow up monthly until stable, then every 3 months
  • Warn patient that treatment interruptions can trigger seizures or even status epilepticus
  • If no seizure for 2 years and no known cause like head trauma or infection, consider possibility of
    stopping treatment (over 2 months). Discuss with the patient
  • If 2 monotherapy trials fail, refer to specialist

Carbamazepine

Effective in all generalized tonic-clonic seizures, focal seizures

  • Given twice daily, steady state reached in 8 days
  • Adult: starting dose of 100-200 mg daily and increased in 100 mg increments every 1-2 weeks
    to a maintenance dose of 400 to 1400 mg daily
  • Child: starting dose of 5 mg/kg/day and maintenance dose of 10-30 mg/kg/day in divided
    doses

    • Side effects: skin rash, diplopia, blurred vision, ataxia (staggering gait), nausea

Phenobarbital

Effective for tonic-clonic seizures and focal seizures but is sedative in adults and cause behavioural
disturbances and hyperkinesia in children. It may be tried for atypical absences, atonic and tonic
seizures

  • Given once a day in the evening to reduce drowsiness
  • Adult: starting dose of 1 mg/kg (60 mg) daily for 2 weeks, if not controlled increase to 2 mg/kg (120
    mg) for 2 months, if not controlled increase to 3 mg/kg (180 mg)
  • Child: starting dose of 2 mg/kg/day for 2 weeks, if not controlled increase to 3 mg/kg for 2 months,
    if not controlled increase until maximum of 6 mg/kg/day
  • It takes 2-3 weeks for the drug to achieve steady blood levels so assess effect only after this period
    • Side effects: drowsiness, lethargy, hyperactivity and irritability in children, skin rash, confusion in
      elderly, depression

Phenytoin

Effective in all forms of epilepsy except absences.

  • Adult: starting dose of 150-200 mg daily as single dose or 2 divided doses and maintenance dose of
    200-400 mg daily
  • Child: starting dose of 3-4 mg/kg and maintenance dose of 3-8 mg/kg/day (max 300 mg
    daily)
  • Increase slowly by 25-30 mg every 2 weeks
    • Side effects: drowsiness, ataxia, slurred speech, blurred vision, twitching, confusion, gum
      hyperplasia, blood abnormalities, rash, hepatitis

Sodium valproate

Effective in tonic clonic seizures, absences and myoclonic seizures. It may be tried for atypical
absences, atonic and tonic seizures.

  • Given 2 times daily
  • Adult: starting dose of 600 mg daily and maintenance does of 400-2000 mg daily
  • Increase by 200 mg every 3 days until control is achieved
  • Child: starting dose of 15-20 mg/kg/day and a maintenance dose of 15-30 mg/kg/day
  • Increase by ¼ to ½ of initial dose every 3 days until control is achieved
    • Side effects liver toxicity, blood disorders, gastrointestinal disorders, weight gain, transient
      hair loss. Monitor liver function and full flood count.

Ethosuximide

Effective in absence seizures.

  • Child >6 years: initially 500 mg daily in 2 divided doses, increase if necessary by 250 mg every 5-7
    days up to a usual daily dose of 1-1.5 g in 2 divided doses
  • Child 1 month to 6 years: Initially 250 mg single dose at night increased gradually every 5-7 days as
    required to usual dose of 20 to 40 mg/kg daily in 2 divided doses

    • Side effects: gastrointestinal disorders, blood disorders, gum hyperplasia, drowsiness
Note
  • In children, look for presence of associated intellectual disability or behavioural problems. If present, consider
    carbamazepine or valproate. (avoid phenobarbital and phenytoin) and manage associated intellectual disability
    or behavioural problem
  • All pregant women with epilepsy should be referred to specialist for appropriate management (most
    antiepileptic drugs have an increased risk of congenital malformations)

Health education

  • Health education to patients, carers and community
  • Advice on management of seizures and safety precautions
  • In children, look for and manage presence of associated intellectual disability or behavioural problems

Prevention

  • Good antenatal care and delivery
  • Avoid causative factors