What are the red flags of dizziness?

Red Flags of Dizziness

Red flags for dizziness include sudden severe headache, new neurological symptoms, inability to walk or stand, persistent vomiting, and altered mental status, which require urgent evaluation. 1

Key Red Flags to Identify

When evaluating a patient with dizziness, the following red flags should prompt immediate concern and urgent evaluation:

• Sudden severe headache - May indicate subarachnoid hemorrhage or other intracranial pathology
• New neurological symptoms - Including:
  • Diplopia (double vision)
  • Dysarthria (slurred speech)
  • Dysphagia (difficulty swallowing)
  • Facial numbness or weakness
  • Limb weakness or numbness
  • Ataxia (uncoordinated movements)
• Inability to walk or stand - Suggesting severe vestibular dysfunction or cerebellar involvement
• Persistent vomiting - Particularly when unresponsive to antiemetics
• Altered mental status - Including confusion, drowsiness, or decreased level of consciousness

Clinical Context and Assessment

The American Academy of Otolaryngology-Head and Neck Surgery guidelines emphasize that understanding the timing and triggers of dizziness is more important than the specific descriptor a patient uses 2. When assessing dizziness, categorize it into one of these vestibular syndromes:

1. Acute Vestibular Syndrome (AVS) - Acute persistent continuous dizziness lasting days to weeks

   • Red flag: Abnormal HINTS examination (Head-Impulse, Nystagmus, Test of Skew)
   • Red flag: Associated neurological deficits
   • Concerning causes: Posterior circulation stroke, demyelinating diseases

2. Triggered Episodic Vestibular Syndrome - Episodic dizziness triggered by specific actions

   • Red flag: Central paroxysmal positional vertigo (different from benign BPPV)
   • Red flag: Symptoms lasting longer than expected for BPPV (>1 minute)

3. Spontaneous Episodic Vestibular Syndrome - Episodic dizziness without triggers

   • Red flag: Associated with posterior circulation TIA symptoms
   • Red flag: New-onset severe headache with vertigo (vertebrobasilar insufficiency)

4. Chronic Vestibular Syndrome - Dizziness lasting weeks to months

   • Red flag: Progressive symptoms with posterior fossa signs
   • Red flag: Associated with new headache pattern

Diagnostic Approach for Red Flags

When red flags are present, the following diagnostic approach is recommended:

• HINTS examination - More sensitive than CT for detecting posterior circulation stroke 1

  • Head Impulse: Abnormal (central) if preserved VOR during rapid head rotation
  • Nystagmus: Bidirectional or pure vertical nystagmus suggests central cause
  • Test of Skew: Vertical misalignment suggests central pathology

• Neuroimaging:

  • MRI brain (without contrast) is preferred when central causes are suspected 1
  • CT head has low sensitivity (~10%) for posterior fossa strokes but can exclude hemorrhage in emergency settings

Additional Red Flags by Patient Population

Elderly Patients

• Falls or near-falls associated with dizziness (12-fold increased risk) 1
• New dizziness with polypharmacy (especially sedatives, antihypertensives)
• Orthostatic hypotension with significant drop (>20 mmHg systolic or >10 mmHg diastolic)

Patients with Vascular Risk Factors

• Dizziness with concurrent neck pain or manipulation
• Dizziness with history of recent trauma
• High vascular risk profile with acute vestibular syndrome

Common Pitfalls to Avoid

1. Relying solely on symptom quality - Focus on timing and triggers instead
2. Missing stroke in AVS - CT has poor sensitivity; use HINTS examination
3. Attributing all positional vertigo to BPPV - Central causes can mimic BPPV
4. Overlooking medication side effects - Particularly in elderly patients
5. Failing to recognize persistent symptoms - Reassessment within 1 month is recommended for persistent symptoms 1

By recognizing these red flags and avoiding common pitfalls, clinicians can identify potentially serious causes of dizziness requiring urgent evaluation and intervention, ultimately improving patient outcomes.