Accessory nerve (XI) lesions
Spinal accessory branch arises from upper cervical cord segments and passes through the foramen magnum to join the cranial accessory branch. They leave the skull separately through the jugular foramen.
Cranial nerves join the pharyngeal plexus and supply the muscles of the palate, pharynx and larynx. The spinal part supplies trapezius and sternocleidomastoid.
Polio, syringomyelia, tumours near the jugular foramen.
Weakness of lifting ipsilateral shoulder and turning head against resistance towards the contralateral side.