• History will usually need to be obtained from third party sources such as family and friends, paramedics, GPs and existing medical records. It is important to establish:
• Tempo and pattern of onset (abrupt, gradual, fluctuating)
• Any prodromal symptoms? (fever, headache, vomiting, anorexia, altered behaviour, seizure, focal neurological deficits)
• History of trauma (head injury, neck manipulation)
• Past history (systemic, neurological, psychiatric)
• Possibility of alcohol/drug intoxication
• Current medications/immunosuppression/anti-coagulants
• History of exposure or foreign travel

Examination

• Vital signs (respiratory rate, pulse, blood pressure, temperature, oxygen saturation)
• Conscious level (using Glasgow Coma Scale score (Figure 3.2))
• Meningism?
• Signs of trauma?
• Skin colour, rash?
• Eye signs (Figure 3.3)
• Pupillary size and light reflex, corneal reflex?
• Papilloedema? (indicates raised ICP of >12h duration or malignant hypertension) Spontaneous venous pulsations? (absence more sensitive, but less specific, for raised ICP)
• Eye movements (tracking, spontaneous, oculocephalic response (OCR) to passive head turn, conjugate or dysconjugate gaze deviation?)
• Focal signs (asymmetry of tone, movement, deep tendon reflexes, extensor plantar)
• Breath odour (uraemic, hepatic, ketotic)
• General examination (murmur, bruit, pulmonary disease, evidence of liver disease, pertitonism, urinary retention)