SAQ 417 – Neurology – dizziness and true vertigo

Neurology – dizziness and true vertigo.

a. Differential diagnoses

• Peripheral vertigo, such as BPPV, vestibular neuritis, labyrinthitis, Meniere disease, or ear pathology.
• Central vertigo, such as posterior circulation stroke/haemorrhage, mass lesion, or demyelination.
• Cardiovascular presyncope, including arrhythmia, hypotension, or dehydration.
• Metabolic or systemic causes such as hypoglycaemia, hypoxia, sepsis, or toxin exposure.

b. Peripheral versus central features

• Sudden severe vertigo worse with head movement and nausea favours a peripheral cause.
• Tinnitus or hearing loss favours a peripheral cause.
• Other neurological symptoms or vascular risk factors raise concern for a central cause.
• Any focal neurological abnormality favours a central cause.
• Nystagmus that is vertical, direction-changing, or non-fatiguing favours central vertigo; unidirectional fatigable nystagmus favours peripheral vertigo.
• A concerning HINTS pattern, such as normal head impulse, direction-changing nystagmus, or skew deviation, favours central vertigo when performed in the right clinical setting.
• Abnormal ear examination or positive Dix-Hallpike favours peripheral pathology.

c. Investigations