How to manage migraine patients with Susceptibility-Weighted Imaging (SWI) abnormalities on Magnetic Resonance Imaging (MRI)?

Management of Migraine Patients with SWI Abnormalities on MRI

In migraine patients with Susceptibility-Weighted Imaging (SWI) abnormalities on MRI but normal neurological examination and typical migraine features, no change in management is warranted as these findings are likely incidental and do not indicate a need for additional intervention beyond standard migraine treatment. 1

Understanding SWI Abnormalities in Migraine

SWI is a high-resolution MRI technique that is particularly sensitive for detecting blood products, venous structures, and mineralization. In migraine patients, SWI may show:

• Prominent hypointense draining sulcal veins during attacks 2
• Transient perfusion abnormalities that resolve after the attack 2
• Changes that can help differentiate migraine from stroke mimics 3

Clinical Significance

These SWI findings in migraine patients typically:

• Are transient and resolve after the migraine attack 2
• Do not represent pathological changes requiring specific intervention
• May be part of the normal physiological response during a migraine attack

Diagnostic Algorithm for SWI Abnormalities in Migraine

1. Determine if red flags are present:

   • Abnormal neurological examination
   • Sudden severe (thunderclap) headache
   • Progressive or worsening pattern of headache
   • Headache with persistent vomiting
   • New onset headache after age 50
   • History of cancer or immunocompromised state

2. If no red flags and typical migraine features:

   • Continue standard migraine management
   • No additional imaging or testing needed

3. If red flags present or atypical features:

   • Consider additional imaging (MRA/MRV)
   • Neurological consultation
   • Further diagnostic workup based on specific concerns

Standard Migraine Management

For patients with SWI abnormalities but otherwise typical migraine:

1. Acute treatment:

   • First-line for mild to moderate attacks: NSAIDs or acetaminophen
   • First-line for moderate to severe attacks: Triptans
   • Second-line options: Antiemetics, ergot alkaloids, or combination analgesics 4

2. Preventive treatment (if indicated by frequency/severity):

   • Consider preventive therapy for frequent episodic migraine to prevent progression to chronic migraine 5
   • Options include antihypertensives, antidepressants, antiepileptics, and CGRP antagonists
   • For menstrual migraine: Consider hormonal interventions 3

Special Considerations

When to Be Concerned About SWI Findings

Be alert for SWI abnormalities that might indicate secondary causes:

• Multiple, bilateral white matter hyperintensities in specific patterns may suggest CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), especially with family history of early stroke or dementia 6
• Persistent (non-resolving) SWI abnormalities
• SWI abnormalities accompanied by progressive neurological deficits

Follow-up Recommendations

• Routine follow-up imaging is not necessary for typical migraine patients with incidental SWI findings 1
• Clinical follow-up should focus on migraine symptom control rather than imaging findings
• Evaluate treatment response within 2-3 months after initiation or change in treatment 3

Pitfalls to Avoid

1. Overimaging and overdiagnosis:

   • The yield of neuroimaging in primary headache disorders without red flags is extremely low 1
   • Unnecessary imaging can lead to anxiety and further unnecessary testing

2. Misinterpreting incidental findings:

   • SWI is highly sensitive and may detect clinically insignificant abnormalities
   • White matter hyperintensities are common in migraineurs but usually of unclear clinical significance 6, 7

3. Failure to recognize true pathology:

   • While most SWI abnormalities in migraine are benign, persistent abnormalities or those associated with neurological deficits warrant further investigation
   • Consider specialist referral when diagnosis is uncertain or treatment fails 3

By following this approach, clinicians can avoid unnecessary interventions while ensuring appropriate management of migraine patients with SWI abnormalities on MRI.