Thin-cut heavily T2-weighted contrast-enhanced modified balanced SSFP sequences and contrast-enhanced MRA focused on the posterior skull provide detailed imaging of the nerves within the jugular foramen and their relationship to the hypoglossal nerve as they exit the skull base, visualizing CN IX in 90% to 100% of imaged patients [24]. Various combinations of high-resolution 3-D T2-weighted imaging, MRA, and 3-D T1-weighted contrast-enhanced sequences can be used to assess for neurovascular compression [143,149-151] and have demonstrated agreement with surgical findings in all patients in two small studies [143,150]. US Neck There is no relevant literature to support the use of US neck in the initial evaluation of oropharyngeal neurogenic dysphagia or oropharyngeal pain. Variant 6: Unilateral isolated palatal or vocal cord paralysis or both (vagal nerve, CN X). Initial imaging. The vagus nerve (CN X) supplies visceral sensation to the pharynx, larynx, and viscera and general sensation to the ear. Branchial motor branches innervate muscles of the pharynx via the pharyngeal branches and the larynx via the superior and recurrent laryngeal nerves, and visceral motor branches play a predominant role in parasympathetic supply to the thorax and abdomen [2]. The vagus nerve runs the longest course in the body of any CN and is therefore vulnerable to a wide range of pathologies occurring throughout its trajectory from the posterior fossa and skull base to the neck, thorax, and abdomen. Within the neck it descends in the posterior carotid sheath. At the base of the neck, the recurrent laryngeal branch of the right vagus nerve turns upward and medial posterior to the subclavian artery, ascending in the tracheoesophageal groove. The left recurrent laryngeal nerve arises to the left of the aortic arch, turns upward in the aortopulmonary window beneath the ligamentum arteriosum, ascending in the left tracheoesophageal groove.
Cranial Neuropathy. Thin-cut heavily T2-weighted contrast-enhanced modified balanced SSFP sequences and contrast-enhanced MRA focused on the posterior skull provide detailed imaging of the nerves within the jugular foramen and their relationship to the hypoglossal nerve as they exit the skull base, visualizing CN IX in 90% to 100% of imaged patients [24]. Various combinations of high-resolution 3-D T2-weighted imaging, MRA, and 3-D T1-weighted contrast-enhanced sequences can be used to assess for neurovascular compression [143,149-151] and have demonstrated agreement with surgical findings in all patients in two small studies [143,150]. US Neck There is no relevant literature to support the use of US neck in the initial evaluation of oropharyngeal neurogenic dysphagia or oropharyngeal pain. Variant 6: Unilateral isolated palatal or vocal cord paralysis or both (vagal nerve, CN X). Initial imaging. The vagus nerve (CN X) supplies visceral sensation to the pharynx, larynx, and viscera and general sensation to the ear. Branchial motor branches innervate muscles of the pharynx via the pharyngeal branches and the larynx via the superior and recurrent laryngeal nerves, and visceral motor branches play a predominant role in parasympathetic supply to the thorax and abdomen [2]. The vagus nerve runs the longest course in the body of any CN and is therefore vulnerable to a wide range of pathologies occurring throughout its trajectory from the posterior fossa and skull base to the neck, thorax, and abdomen. Within the neck it descends in the posterior carotid sheath. At the base of the neck, the recurrent laryngeal branch of the right vagus nerve turns upward and medial posterior to the subclavian artery, ascending in the tracheoesophageal groove. The left recurrent laryngeal nerve arises to the left of the aortic arch, turns upward in the aortopulmonary window beneath the ligamentum arteriosum, ascending in the left tracheoesophageal groove.