Unilateral Headache as a Presentation of Spontaneous Internal Carotid Artery Dissection: A Case Report

Spontaneous internal carotid artery (ICA) dissection is a rare but potentially serious cause of ischemic stroke, with a frequently heterogeneous clinical presentation that poses a diagnostic challenge, particularly in primary care settings.We report a case of a 46-year-old female with a history of migraine, resolved thyrotoxicosis, and oral contraceptive use, who presented to her family health unit with a 15-day history of left-sided hemicranial headache preceded by ipsilateral neck pain without identifiable trauma.Associated findings included left ptosis, ipsilateral scalp hyperesthesia, and taste disturbance affecting the posterior third of the tongue, in the absence of motor deficits, aphasia, or visual changes.She was referred to the emergency department, where CT angiography revealed narrowing of the left ICA at the post-bulbar segment, raising suspicion of dissection, subsequently confirmed by cervical Doppler ultrasound and magnetic resonance angiography, which demonstrated a minimally opacified false lumen with mild-tomoderate stenosis and no cerebral ischemia.An extended etiological workup was negative.Dual antiplatelet therapy was initiated, and the patient achieved complete neurological recovery, being discharged on hospital day 7. Follow-up imaging identified the development of a pseudoaneurysm at the post-bulbar segment of the left ICA without hemodynamic significance.The patient remains under neurology and family medicine follow-up with persistent headache and cervicalgia under pharmacological management.This case highlights the importance of maintaining a high index of clinical suspicion in primary care when faced with persistent unilateral headache associated with cranial nerve signs, even in the absence of overt stroke, and underscores the role of the general practitioner in the early recognition of warning signs, timely referral, and continuity of care.