Is facial palsy associated with migraines?

Facial Palsy and Migraine: A Recognized but Uncommon Association

Facial palsy can occur in association with migraine, though it is not a typical or common manifestation of migraine itself. The relationship exists primarily through two distinct mechanisms: migraine-triggered hemifacial spasm and a proposed entity called "migrainous facial palsy."

Primary Mechanisms of Association

Migraine-Triggered Hemifacial Spasm

• Hemifacial spasm (HFS) can develop during migraine attacks, with muscle spasms beginning after pain onset and occurring ipsilateral to the headache 1
• This represents facial nerve hyperexcitability rather than true paralysis, with electromyographic evidence showing facial nerve involvement in affected patients 1
• The mechanism likely involves central hyperexcitability from nociceptive inputs on the trigeminal nucleus caudalis and/or dilation of vessels compressing the facial nerve at the root exit zone 1

Migrainous Facial Palsy (Lower Motor Neuron Type)

• A case series identified 12 patients who developed true lower motor neuron facial palsy following migraine attacks, predominantly affecting the occipital and posterior auricular regions 2
• The palsy occurred ipsilateral to the headache in 83.33% of cases, and in bilateral headaches (16.67%), it lateralized to the side with more severe pain 2
• The proposed mechanism involves neurogenic inflammation of the facial nerve trunk caused by proximity to dilated posterior auricular, stylomastoid, occipital, and superficial temporal arteries during migraine attacks 2
• Most cases (75%) achieved complete clinical recovery within 6 months 2

Genetic Link Between Migraine and Recurrent Facial Palsy

• A missense variant in the TRPM8 gene (c.304G>A, p.Ala102Thr) has been identified in a family with autosomal dominant facial palsy associated with migraine, diplopia, facial swelling, and eye conjunctivitis 3
• This gene was previously linked to migraine through genome-wide association studies, suggesting a shared genetic susceptibility 3

Critical Distinction: Facial Palsy is NOT Bell's Palsy When Associated with Migraine

When facial palsy occurs in the context of migraine, it should NOT be diagnosed as Bell's palsy, which is strictly a diagnosis of exclusion requiring no identifiable cause 4, 5. The American Academy of Otolaryngology-Head and Neck Surgery explicitly states that Bell's palsy can only be diagnosed after excluding all other medical etiologies 4.

Red Flags Excluding Bell's Palsy Diagnosis

• Temporal relationship to migraine attacks indicates an identifiable cause 2
• Recurrent episodes on the same side require workup for structural lesions, sarcoidosis, or other underlying pathology 5
• Additional neurologic symptoms (diplopia, other cranial nerve involvement) exclude idiopathic Bell's palsy 4, 5

Differential Diagnosis Considerations

Distinguishing from Stroke

• Stroke typically spares forehead muscles (upper motor neuron pattern) and presents with additional neurologic deficits such as dizziness, dysphagia, or diplopia 6, 4
• Migraine-associated facial palsy affects the entire ipsilateral face including the forehead (lower motor neuron pattern) 2

Pontine Lesions with Concurrent Facial Palsy

• Lesions involving the pons can cause both 6th nerve palsy and facial palsy because the 7th nerve curves over the 6th nerve nucleus 6
• These cases present with additional neurologic findings beyond isolated facial weakness 6

Management Approach

Acute Phase

• Document the temporal relationship between migraine onset and facial palsy development 2
• Perform comprehensive cranial nerve examination to exclude other neurologic involvement 6, 4
• Consider MRI with and without contrast if presentation is atypical, symptoms progress beyond 3 weeks, or other neurologic findings are present 6, 7

Treatment Considerations

• Oral corticosteroids within 72 hours may be considered, though evidence specific to migraine-associated facial palsy is limited 7
• Implement mandatory eye protection measures including lubricating drops, ointments, and nighttime taping to prevent corneal damage 4, 7
• Address migraine prophylaxis to potentially reduce recurrence risk 2

Follow-Up Protocol

• Reassess at 3 months if facial recovery is incomplete 7
• Refer to facial nerve specialist for persistent weakness or recurrent episodes 7
• Monitor for development of new neurologic symptoms requiring urgent evaluation 7

Common Pitfalls to Avoid

• Do not reflexively diagnose Bell's palsy when facial palsy occurs with migraine—this represents premature closure and anchoring bias 8
• Do not miss the temporal relationship between migraine attack and facial palsy onset, as this indicates a non-idiopathic etiology 2
• Do not overlook recurrent episodes, which warrant imaging for structural lesions or alternative diagnoses 5
• Do not delay eye protection, as corneal exposure can cause permanent damage regardless of etiology 4, 7

Prognosis

Most patients with migraine-associated facial palsy achieve complete recovery within 6 months, similar to idiopathic Bell's palsy 2. However, the recurrent nature in some patients and potential genetic predisposition suggest the need for long-term monitoring and migraine management 3.