A Case of Left Facial Pain Misdiagnosed as Migraine Headache

A 58-year-old female sought a second opinion due to a two-year duration of sporadic left facial pressure pain, along with irritation and dryness in her left eye. She has a well-documented history of episodic migraines characterized by throbbing headaches on the right side. She had been under the care of a headache specialist who attributed her symptoms to migraine headaches. Her neuro-ophthalmologic examination disclosed significant dryness in her left eye, with no other notable findings. Subsequent MRI results indicated the presence of a left facial nerve schwannoma.This case presents a scenario involving left facial pain attributed to facial nerve schwannoma, most likely due to the facial schwannoma compression of the left trigeminal nerve at the cerebropontine angle. Initially, the patient's left facial and eye pain was incorrectly diagnosed as migraine headaches by a headache specialist. This case underscores the importance of conducting neuroimaging when there is a change in the headache type. Facial nerve schwannomas are rare and usually benign with slow growth. Symptoms vary depending on the lesion's size and location, given that different portions of the nerve contribute to distinct facial functions. The common symptoms are hearing loss, facial weakness, and hemifacial spasms. (1) This patient presented with unilateral dry eye, indicating the impairment of the greater superficial petrosal nerve due to facial schwannoma, (2) which is an exceedingly rare occurrence. Hence, cases of asymmetric dry eye should prompt consideration of neurologic causes.