Stroke 1

• Define stroke.


  A neurological deficit of cerebrovascular cause that persists beyound 24 hours or is interrupted by death within 24 hours (WHO)
• What are the types of stroke?

  Ischaemic

  Haemorrhagic

  TIA
• What is an ischaemic stroke?

  Blockage cuts off blood supply to brain

  Most common type of stroke
• What are the different types of ischaemic stroke?

  Large artery atherosclerosis

  Cardioembolism

  Small vessel occlusion

  Stroke of other determined aetiology

  Stroke of undetermined aetiology
• What is a haemorrhagic stroke?

  Bleeding in or aroud the brain

  Types -> intracranial haemorrhage, subarachnoid haemorrhage
• What is a TIA?

  Same as stroke (mini-stroke)

  Symptoms only last for a short amount of time (temporary blockage)
• What are the non-modifiable RFs of stroke?

  Previous stroke or TIA

  Age

  FHx

  Ethnicity

  Gender (male?)

  Pregnancy
• What are the modifiable RFs of stroke?

  HTN

  Smoking

  Diabetes

  Diet

  Physical inactivity

  Obesity

  High cholesterol

  Alcohol

  Heart disease
• Why should we care about disease frequency?

  Understand size of problem

  Spotting outbreaks

  Assess risks & management of conditions

  Aids planning of resources
• Define prevalence.


  Proportion of a population who have a specific (existing) disease at a given time
• How can you calculate the point prevalence?

  Number of cases of disease / total population
• Define incidence.


  Occurence of new cases in a population at risk at a specific time
• How can incidence proportion be calculated?

  Number of new cases of disease during a specified time period / total population at risk during that time
• What is incidence rate?

  Speed that new cases develop during a specificed time period
• How can incidence rate be calculated?

  Number of new cases / person-time at risk during study period (follow-up)
• Fill in the blanks

  A) Incidence

  B) Prevalence

  C) Death

  D) Recovery

  
• What is absolute risk (AR)?

  Prevalence & incidence rates

  Number of events (good/bad) in a treated (exposed) or control(non-exposed) group, divided by the number of people in that group
• What is relative risk (RR)?


  Risk of outcome among exposed/risk of outcome among non-exposed
• What is attributable risk difference?

  Risk of outcome among exposed-risk of outcome among non-exposed