• Proportion of patients who were discharged pain free that have a recurrence of headache within 48 hours.
  
• Proportion of patients who were not pain free at discharge whose headache is worse or unchanged within 48 hours.
  

• Severity of any headache experienced.
  
• Proportion of patients experiencing adverse events and their type.
  
• Proportion of patients requiring additional analgesia within 48 hours for headache.
  
• Proportion of patients seeking additional treatment from GP or hospital.
  
• Proportion of patients who had returned to normal activity within 48 hours.
  

Migraine headache can be a debilitating condition. A small but significant proportion of sufferers seek treatment in emergency departments [ED], accounting for 2-5% of ED visits.Available data suggests that up to 66% of these patients may experience rebound headache after discharge that affects their ability to function normally [eg work, social, etc].It appears that inflammation plays a key role in recurrences. A number of small studies suggest that a single dose of corticosteroids at the time of discharge might prevent rebound headache. To date these studies have used intravenous dexamethasone. The aim of this project is to determine if a single dose of oral dexamethasone at the time of discharge from the ED [after successful treatment] prevents rebound headache.

Hypothesis: That single dose oral dexamethasone 8mg reduces the proportion of patients who suffer rebound headache after treatment for migraine in the ED.

Aims: The primary aim is to compare the proportion of patients who experience rebound headache within 48 hours after ED treatment of migraine between a group treated with single dose oral dexamethasone 8mg and a group treated with placebo. Secondary aims are to compare headache severity, analgesia/ health service use, adverse events and return to normal functioning between the groups.

Methods:

Study design: Double blind, randomised placebo controlled clinical trial. Setting: Emergency Department, Western Hospital. Participants: Adult patients [age >17 years] with physician-diagnosed migraine treated in the ED.

Inclusion criteria: Consenting adult patients [age >17 years] with physician-diagnosed migraine treated in the ED who are willing and able to be contacted between 48-72 hours after discharge for follow-up.

Sample size: 76 patients