Collet-Sicard syndrome due to cervical artery dissection disclosed by high-resolution magnetic resonance imaging

Cervical artery dissection (CAD) represents a leading cause of unilateral lower cranial nerve IX-XII palsy, known as Collet-Sicard syndrome (CSS). High-resolution magnetic resonance imaging (HR-MRI) is widely used in the evaluation of patients with CAD, providing information regarding vessel wall abnormalities and intraluminal thrombus.

We present a patient with palsy of multiple lower cranial nerves in the context of CSS, attributed to unilateral spontaneous internal carotid artery dissection.

We describe a 68-year-old man with unremarkable previous history, who presented with subacute, gradually worsening dysphagia and hoarse voice. Clinical examination revealed right-sided palsy of cranial nerves IX-XII. Three-dimensional fat-saturated black-blood T1-weighted high-resolution vessel wall imaging disclosed spontaneous dissection with intramural hematoma along the distal right internal carotid artery. Neck MRI showed inward displacement of right aryepiglottic fold, right pyriform sinus dilatation, and right true vocal cord in middle position, indicative of right vagus nerve palsy, atrophy of right trapezius and sternocleidomastoid muscles, due to right spinal accessory nerve palsy, and unilateral tongue atrophy with fatty infiltration, characteristic for right hypoglossal nerve palsy.

This case highlights the utility of high-resolution vessel wall imaging and especially fat-saturated T1-weighted black-blood SPACE (sampling perfection with application-optimized contrast using different flip-angle evolutions) sequences in the accurate diagnosis of CAD, revealing the characteristic mural hematoma and intimal flap. HR-MRI is also valuable in the recognition of indirect signs of lower cranial nerve compression.