Antrochoanal polyps arise from the maxillary sinuses and are the much less common; ethmoidal polyps arise from the ethmoidal sinuses. Symptoms of polyps include nasal congestion, sinusitis, anosmia (loss of smell), and secondary infection leading to headache.
Relationship of internal jugular vein to the spinal accessory nerve (SAN). Spinal accessory nerve (SAN) posterior to the internal jugular vein. As the nerve approaches the sternocleidomastoid muscle (SCM), it may perforate the cleidomastoid portion of the SCM (80%) or run posterior to it (20%).
Causes of spinal accessory nerve injury. A spinal accessory nerve injury can be caused by trauma or damage during surgery, such as a lymph node biopsy or jugular vein cannulation. Symptoms of spinal accessory nerve injury. Shoulder pain. Scapular winging. Weakness or atrophy of the trapezius muscle.