Serum Calcitonin Gene-Related Peptide Is Elevated in Patients With Migraine and Ophthalmoplegia

There is ongoing debate about whether the oculomotor (III), trochlear (IV), or abducens (VI) nerve paresis in patients with migraine is directly attributable to migraine (ophthalmoplegic migraine [OM]) or is due to an inflammatory neuropathy (recurrent painful ophthalmoplegic neuropathy [RPON]). As migraine is associated with elevated serum calcitonin gene-related peptide (CGRP) levels, we studied serum CGRP levels among patients with OM/RPON to determine whether they are elevated during and between attacks. This is the first study assessing CGRP levels in the serum of patients with OM/RPON.

The aim of this case-control study was to assess serum CGRP levels in patients with ophthalmoplegia and a headache consistent with migraine according to ICHD-3 criteria. Serum CGRP levels were measured during the ictal and interictal phases in 15 patients with OM/RPON and compared with age-matched and sex-matched controls without migraine (12 patients).

The median serum CGRP levels were significantly elevated ( P = 0.021) during the ictal phase (37.2 [36.4, 43.6] ng/L) compared with controls (32.5 [30.1, 37.3] ng/L). Serum CGRP levels during the attack correlated with the total duration of ophthalmoplegia. A CGRP level of 35.5 ng/L in the ictal phase of the attack had a sensitivity of 86.7% and specificity of 75.0% in diagnosing a patient with OM/RPON.

Elevated serum CGRP levels during the ictal phase of OM/RPON favor migraine as the underlying cause of episodic headache with ophthalmoplegia.