Is it reasonable to delay a neurology referral for a patient with worsening migraines and recent episodes of dizziness until CT results are available?

Delaying Neurology Referral While Awaiting CT Results

Your approach is reasonable only if the patient has no red flag features and you can ensure close follow-up within 1-2 weeks, but you should have a low threshold to expedite the referral if symptoms persist or worsen after CT results return. 1

Key Decision Points

When Waiting for CT is Acceptable

• If the neurological examination is completely normal, the yield of finding clinically significant pathology is extremely low (approximately 0.2-0.4%), making a brief observation period reasonable while awaiting imaging results. 2

• However, this patient has concerning features that increase the likelihood of significant intracranial pathology:

  • Worsening migraines (progressive pattern) 2
  • New episodes of dizziness 1
  • Rapid increase in headache frequency is specifically identified as a red flag that increases the odds of finding abnormalities on neuroimaging 3

Critical Limitations of Your Current Plan

• CT has significant limitations - it detects acute brain lesions in only 6% of cases compared to 11% with MRI in patients with dizziness and atypical features. 3, 1

• A normal CT does not exclude serious pathology including:

  • Early cerebral venous thrombosis 1
  • Spontaneous intracranial hypotension 1
  • Small posterior fossa lesions 1
  • Multiple sclerosis 3

• If CT is normal but symptoms persist or worsen, MRI brain with contrast should be ordered as it is significantly more sensitive for detecting clinically significant pathology. 1

What You Must Do Now

Establish Clear Safety Parameters

Instruct the patient to return immediately to the emergency department for any of the following: 1

• Sudden severe headache ("worst headache of my life")
• New focal neurologic deficits
• Altered mental status or confusion
• Seizure activity
• Persistent vomiting
• Headache awakening from sleep
• Worsening with Valsalva maneuver
• Fever with headache

Schedule Definitive Follow-Up

• Ensure follow-up within 1-2 weeks with either neurology or yourself to review CT results and reassess symptoms. 1

• Do not delay neurology referral beyond 2 weeks if symptoms continue, as the combination of worsening migraines and dizziness represents a concerning pattern that warrants specialist evaluation. 3, 4

If CT Returns Normal

• Consider ordering MRI brain with and without contrast if:

  • Symptoms continue to worsen over the next 1-2 weeks 1
  • Patient develops any new neurologic symptoms or signs 1
  • Dizziness has atypical features (not clearly positional, not responding to repositioning maneuvers) 3, 1

• Proceed with neurology referral regardless of normal CT given the progressive nature of symptoms and presence of dizziness. 3, 1

Common Pitfalls to Avoid

• Do not assume a normal CT excludes all serious pathology - CT can miss early cerebral venous thrombosis, spontaneous intracranial hypotension, and small posterior fossa lesions that may be causing the patient's symptoms. 1

• Do not dismiss the dizziness as purely vestibular without specialist evaluation, as vestibular migraine is now recognized as the most common cause of spontaneous episodic vertigo and requires specific management. 5, 6

• Do not delay the neurology referral indefinitely - only 20% of patients who fulfill criteria for chronic migraine are properly diagnosed, and PCPs play an essential role in appropriate specialist referral. 3