Reflex anoxic seizures

• Reflex anoxic seizures:

  • Paroxysmal, spontaneously-reversing brief episodes of asystole
  • Triggered by pain, fear or anxiety
  • Non-epileptic events caused by reflex asystole due to increased vagal responsiveness
  • Often misdiagnosed as epilepsy
• Epidemiology:

  • Occur mainly in young children
  • Peak age group is from 6 months to 2 years
  • Increased vagal tone tends to familial
• Presentation:

  • Child suddenly pale and limp, will fall if standing and lose consciousness
  • Followed by stiffening and clonic jerking of the limbs
  • Episode is usually brief (30-60 seconds) and recovery is rapid
  • May be upward eye deviation and urinary incontinence
  • Child may feel tired for some time
• Investigations:

  • Often diagnosed on the basic of the history and normal EEG
  • ECG - exclude a long QT interval, pre-excitation, heart block or ventricular hypertrophy
• Management:

  • Can usually be managed with just reassurance
  • Parents should be advised to place the child in the recovery position
  • Pacemaker insertion is the only definitive treatment and is only used for frequent, severe cases
• Prognosis:

  • Reflex anoxic seizures in childhood are usually benign such that the child grows out of it.