ABSTRACT
BACKGROUND: Although not typically considered as part of the clinical phenotype of migraine, cranial autonomic symptoms, such as lacrimation or conjunctival injection, can certainly occur. Their appearance can lead to the common misdiagnosis of sinus headache in clinical practice. CASE: The patient presented developed post-ganglionic sympathetic denervation at the level of the superior cervical ganglion/carotid plexus. Her subsequent partial Horner's syndrome symptoms intensified during subsequent migraine attacks indicating increasing sympathetic autonomic dysfunction. At the time of the pain, recruitment and activation of the trigeminal autonomic reflex were demonstrated by lacrimation. CONCLUSION: The clinical picture suggests peripheral unmasking of the underlying central trigeminal autonomic reflex that is active in migraine. Recognition of cranial autonomic symptoms in migraine is a key to confident differential diagnosis from trigeminal autonomic cephalalgias and from sinus-related headache disorders.