ACUTE HEADACHE
(this section does not consider traumatic causes of headache)
- Consider early CT brain if rapid onset of headache to rule out expanding space-occupying lesion particularly if there is altered mental state or focal neurological deficit
- In severely depressed conscious state then early airway protection is required
- Abrupt onset of severe (‘thunderclap’) should be considered a sub-arachnoid haemorrhage until proven otherwise
- Do not send a patient with rapidly deteriorating conscious state unescorted for imaging
- Note that a normal plain CT brain does not rule out a number of important causes of acute headache
- Consider important non-intracranial sources of headache
Red flags
- Rapid onset
- Altered mental state
- Focal deficit
- Meningism
- Severe hypertension
- Anticoagulation
- Signs of Raised Intracranial Pressure
ASSESSMENT
- There are many causes for acute headache so it important to follow the Principles of a Systematic Assessment
- Focus on the chronology which gives an indication of urgency alongside location of pain. This and the associated symptoms greatly assists at narrowing down the possibilities to the likely culprit organ, the pathological process and best investigative strategy
- Consider non intra-cranial causes of headache
- Consider pre-eclampsia in late pregnancy as a cause
See Acute Headache Assessment Form (printable form)
Examination
- Vital signs especially fever or Cushing’s reflex
- GCS
- A careful neurological examination including gait, coordination and reflexes
- A test of higher cortical functions e.g. speech
- Evaluate cognition via the mini-mental state examination
- Examine the head for non-intracranial pathology
COMMON TRAPS
- Ignoring any headache in an anti-coagulated patient
- Considering a normal plain CT brain rules out all serious pathology
INVESTIGATIONS
Depending on clinical assessment, severity of symptoms and likelihood of acute pathology
Routine blood tests are usually not helpful unless there are specific suspicion
- WCC/CRP (if infective process suspected)
- ESR/CRP (if temporal arteritis suspected)
High patient risk groups
- Anticoagulated patients
- Immuno-compromise
DISPOSITION
Immediate CT brain
- Rapidly deteriorating conscious state
- Focal deficit
Early CT brain
- Rapid onset of acute headache
- Headache different or ‘worst ever’ from previous episodes
Prolonged observation
Moderate headache with
- Fever
- Immuno-compromise (e.g. AIDs patients)
Discharge Criteria
- Afebrile
- Normal GCS
- No focal deficit or other neurological symptoms
- No signs of Raised Intracranial Pressure
- Mild symptoms
- Normal CT brain if high-risk patient