Could the patient's symptoms be attributed to migraine alone, rather than multiple sclerosis (MS)?

Could This Be Migraine Alone?

Yes, the patient's symptoms could be attributed to migraine alone, particularly given the pattern of visual aura without subsequent headache, the episodic nature (7-8 attacks per year over 4 years), and the complete reversibility of symptoms. 1

Key Diagnostic Features Supporting Migraine

The clinical presentation strongly suggests migraine based on several characteristic features:

• Visual aura without headache is a recognized migraine variant and remains part of the migraine spectrum, as confirmed by diagnostic criteria 1
• Visual phenomena such as bright scintillating lights, zigzag lines, scotomas, or gradual spreading of visual disturbances over 5-20 minutes are highly characteristic of migraine aura 1
• Symptoms that develop gradually over at least 5 minutes and last 5-60 minutes with complete resolution strongly support migraine over vascular events like TIA 1
• The episodic frequency (averaging 7-8 per year) falls within episodic migraine category, not chronic migraine which requires ≥15 headache days per month 1, 2

Critical Red Flags That Would Argue Against Migraine Alone

However, certain features would immediately exclude migraine as the sole diagnosis:

• Loss of consciousness is never a symptom of migraine and should prompt immediate evaluation for alternative diagnoses 1
• Persistent neurological deficits that do not completely resolve suggest alternative diagnoses and require urgent neuroimaging 1
• New focal neurological signs that don't fit the typical aura pattern 2

The MS-Migraine Relationship: When to Suspect Both

While migraine can explain the symptoms, the relationship between MS and migraine warrants careful consideration:

• Migraine prevalence is twice as high in MS patients compared to the general population 3, 4
• Migraine onset typically starts years before the clinical diagnosis of MS, suggesting either a unidirectional relationship with migraine predisposing to MS, or a shared underlying factor 5
• MS can present initially with worsening of pre-existing migraine symptoms, particularly when periaqueductal grey matter is involved 6
• A predominance of brainstem inflammatory lesions is described on MRI in MS patients with migraine 4

Practical Diagnostic Approach

To determine if this is migraine alone versus MS with migraine:

Document the specific symptom pattern using ICHD-3 criteria:

• Onset pattern (gradual over ≥5 minutes supports migraine) 1
• Duration (5-60 minutes typical for migraine aura) 1
• Complete reversibility (essential for migraine diagnosis) 1
• Associated symptoms like photophobia, phonophobia, nausea, or motion intolerance 1

Implement a headache diary to track attack frequency, duration, associated symptoms, and any evolution in pattern 1, 2

Consider MRI if:

• The patient shows any change in headache pattern or poor response to migraine treatment 6
• Episodes of focal neurological deficit occur beyond typical aura 6
• New-onset symptoms don't fit the established migraine pattern 1

Be particularly vigilant in young women showing changes in headache pattern, as failure to recognize MS may lead to inappropriate treatment and worse prognosis 6

When Migraine Diagnosis is Sufficient

The diagnosis of migraine alone is appropriate when:

• All symptoms completely resolve without persistent deficits 1
• The pattern is consistent and stereotyped across episodes 2
• No red flags are present (loss of consciousness, persistent deficits) 1
• Response to migraine-specific treatment is appropriate 6

The key distinction is that migraine symptoms must be fully reversible and stereotyped - any deviation from this pattern, particularly in a young woman with episodic neurological symptoms, should prompt consideration of MS as a differential diagnosis even if migraine is also present. 6, 1