Which initial investigations should be considered for a patient presenting with acute vertigo?

The initial investigations for a patient presenting with acute vertigo should involve a comprehensive assessment of their symptoms, medical history, and clinical findings ¹. Key considerations for initial assessment and investigation include:

• Identifying Red Flag Symptoms: It is crucial to look for features suggestive of a central cause of vertigo, which require urgent referral or admission ¹. These include:
  • Very sudden onset of vertigo (within seconds) that is not provoked by positional change and is persistent ¹.
  • Central neurological symptoms or signs, such as a new type of headache (especially occipital), gait disturbance, truncal ataxia, or vertical nystagmus ¹.
  • Acute deafness without other typical features of Meniere's disease ¹.
  • Isolated, persistent (>24 hours) vertigo of hyperacute (seconds) onset ¹.
  • Normal head impulse test ¹.
  • New onset unilateral deafness ¹.
  • Cranial nerve weakness or sensory loss, or limb weakness or sensory loss ¹.
  • Severe ataxia ¹.
• Assessing for Stroke: Always consider the possibility of a stroke in people with new onset unilateral hearing loss and vertigo ¹. For adults with sudden-onset dizziness and a focal neurological deficit (e.g., vertical or rotatory nystagmus, new-onset unsteadiness, new-onset deafness), check for and treat hypoglycaemia if the person has diabetes ³. If the person does not have diabetes, or if treating hypoglycaemia does not resolve symptoms, and benign paroxysmal positional vertigo (BPPV) or postural hypotension do not account for the presentation, refer immediately to exclude posterior circulation stroke ³.
• HINTS Test: For adults with sudden-onset acute vestibular syndrome (vertigo, nausea or vomiting, and gait unsteadiness), a HINTS (head-impulse–nystagmus–test-of-skew) test should be performed if a healthcare professional with training and experience in its use is available ³. A negative HINTS test makes a diagnosis of stroke very unlikely ³. If the HINTS test shows indications of stroke (a normal head impulse test, direction-changing nystagmus, or skew deviation), refer immediately for neuroimaging ³. If a trained professional for the HINTS test is not available, and BPPV or postural hypotension do not account for the presentation, refer immediately in line with local stroke pathways ³.
• Benign Paroxysmal Positional Vertigo (BPPV): For adults with transient rotational vertigo on head movement, offer the Hallpike manoeuvre to check for BPPV if a healthcare professional trained in its use is available ³. If BPPV is diagnosed, offer a canalith repositioning manoeuvre (such as the Epley manoeuvre) if a trained professional is available and the person does not have unstable cervical spine disease ³.
• Migrainous Vertigo: Be alert to the possibility of vestibular migraine in adults who have episodes of dizziness lasting between 5 minutes and 72 hours and a history of recurrent headache ³.
• Severity of Symptoms: Consider admission to hospital or urgent referral if the person has severe nausea and vomiting and is unable to tolerate oral fluids or symptomatic drug treatment ¹.