Raeder's paratrigeminal neuralgia secondary to internal carotid artery dissection mimicking trigeminal autonomic cephalalgia: a case report.

Raeder's paratrigeminal neuralgia is a rare clinical syndrome characterized by ipsilateral periorbital pain, partial Horner syndrome (ptosis and miosis without anhidrosis), and sensory disturbances in the ophthalmic division (V1) of the trigeminal nerve1. The syndrome results from involvement of sympathetic fibers traveling along the internal carotid artery (ICA), often in association with vascular or parasellar pathologies2. Among its etiologies, ICA dissection is particularly important, as it may present with unilateral headache and cranial autonomic features that closely mimic trigeminal autonomic cephalalgias (TACs)2,3. This overlap may lead to misdiagnosis and delay in the identification of potentially serious vascular conditions4. Recognition of distinguishing clinical features is therefore critical.