Investigations

Bedside tests should be used to assess for, and exclude, other potential causes of dizziness. These tests include:

• Blood sugar
• ECG
• Postural blood pressures

Any other specific investigations for vertigo will be guided by the clinical picture, and ED investigations may not be required.

Magnetic resonance imaging (MRI) and MR angiography (MRA) are most sensitive for:

• Brainstem infarcts
• Demyelination
• Inner ear pathology
• Acoustic neuromas

However, MRI may not be available in ED, and patients with suspected central causes such as intracranial (e.g. cerebellar) haemorrhage may initially undergo an urgent CT scan of the brain. Early neuroimaging may not be fully sensitive to detect significant central causes of vertigo,⁷ and where there is high suspicion of a central cause consider admission or urgent follow up for specialist assessment and possible delayed neuroimaging.

Specialist assessment and/or neuroimaging should also be considered in those patients with a clinical picture that is not fully consistent with a peripheral cause. This is especially relevant in patients with associated headache, risk factors for stroke or symptoms lasting more than 48 hours.

Learning Bite

Investigations are guided by clinical assessment. Consider neuroimaging in patients for whom a peripheral cause cannot be confidently positively diagnosed. Be aware that early neuroimaging may yield false negatives.