Tapia Syndrome

Etiology

Tapia syndrome results from concurrent unilateral paralysis of the hypoglossal nerve (cranial nerve XII) and the recurrent laryngeal branch of the vagus nerve (cranial nerve X). Rare cases of concurrent bilateral paralysis of these nerves have also been reported.[4] Theoretically, injury can occur anywhere along a nerve's path, either centrally (intracranially) or peripherally (extracranially). The most common site involved in Tapia syndrome is the extracranial area in the cervical region, where the 2 nerves lie in close proximity, adjacent to the oropharynx junction and the hypopharynx.

Tapia syndrome typically manifests as unilateral peripheral nerve damage due to direct trauma to the hypoglossal and recurrent laryngeal nerves at the base of the tongue and the pyriform fossae.[5] Most cases are iatrogenic in nature, occurring during orotracheal intubation for anesthesia in any surgical procedure. Nerve injury may also occur in the intensive care setting with prolonged intubation and assisted ventilation.[6] The nerve damage may result from stretching or compression of the nerves.

Excessive neck flexion or extension during anesthesia procedures could exacerbate the nerve injury.[7] Some anatomical anomalies, such as a long styloid process or an enlarged hyoid bone, may predispose to this syndrome.[8] Other causes include any pathology in the neck region, including neoplasia, trauma, or dissection of cervical arteries.[9][10][11] Notably, Tapia syndrome is more often reported in patients with COVID-19, probably related to more frequent orotracheal intubation for assisted ventilation.[12][13]

The central type of Tapia syndrome typically forms part of a brainstem syndrome affecting the hypoglossal nucleus, nucleus ambiguus, and pyramidal tract.[6] Causes include hemorrhage, ischemia, abscess formation, malignancies, and other space-occupying lesions. Central Tapia syndrome is extremely rare, with fewer than 5 cases reported in the literature. These cases have been attributed to brainstem infarctions, meningovascular syphilis, and metastatic hemangiosarcoma.[14][15]

Epidemiology

Tapia syndrome is closely associated with surgical procedures involving general anesthesia and orotracheal intubation. The main factors affecting its incidence include the duration of intubation, neck positioning, and upper limb manipulation of the head.[16][17] This trend is supported by reports from shoulder arthroscopy, cervical spine surgery, and intensive care units.[18][19] Cases have also been recognized in cardiothoracic, otolaryngology, and maxillofacial surgeries.[20][21][22]

Pathophysiology

The hypoglossal nerve arises from the hypoglossal nucleus in the medulla and passes between the olive and pyramid of the anterior brainstem before exiting the cranial cavity through the hypoglossal canal. Later, cranial nerve XII receives contributions from cervical nerves as it enters the neck between the internal carotid artery and the internal jugular vein. Upon reaching the tongue's lateral aspect, cranial nerve XII courses close to the hyoglossus muscle and inferior to the lingual nerve. The hypoglossal nerve only has a motor function, controlling all the intrinsic and extrinsic tongue muscles.

The motor fibers to the laryngeal and pharyngeal muscles begin in the nucleus ambiguous, exit the medulla at the root of the accessory nerve, and join the vagus nerve before exiting the jugular foramen and traveling within the carotid sheath in the neck. The recurrent laryngeal nerves eventually branch off the vagus nerve, wrapping underneath the right subclavian artery on the right side and aortic arch on the left. The nerves then ascend in the groove between the trachea and esophagus to reach the larynx, supplying all the larynx's intrinsic muscles except the cricothyroid muscles.

Damage to these nerves at any point in their paths can result in neuropraxia (mild, temporary loss of function) or axonotmesis (typically permanent, irreversible damage). An injury mechanism is believed to be pressure neuropathy of the nerves secondary to a difficult laryngoscopy, endotracheal tube malpositioning or overinflation, and extubation with an inflated cuff.[23]

The hypoglossal and recurrent laryngeal nerves are adjacent to the oropharynx junction and the hypopharynx. Thus, this area is where concurrent injury and paralysis most likely arise. An excessive stretch of the hypoglossal nerve from neck manipulation can occur on the anterior surface of the first cervical transverse process as it intersects the vagus nerve, potentially causing this syndrome.[24] Other risk factors for nerve injury include placement of a throat pack or intraoperative neck manipulation.

History and Physical

Tapia syndrome is a diagnosis of exclusion made principally upon clinical grounds. The onset of manifestations often occurs quickly after extubating patients who have undergone orotracheal intubation. Signs and symptoms typically include hoarseness, speech and swallowing difficulties, and ipsilateral tongue deviation upon protrusion.

Obtaining a detailed history and performing a thorough neurological examination are crucial to exclude other findings and confirm whether the cause is central or peripheral. Intracranial brainstem lesions are extremely uncommon. Ipsilateral vagal and hypoglossal involvement with long sensory and motor tract signs affecting the contralateral body, arm, and leg are often noted.

Intracranial nerve lesions outside the brainstem may involve multiple cranial nerves without long-tract signs and symptoms. Basal meningeal processes, including chronic or granulomatous meningitis or neoplasia, generally cause these lesions. Isolated involvement of the hypoglossal nerve and the recurrent laryngeal branch of the vagus nerve is rare. Extracranial injuries generally result in isolated nerve palsies. Any additional localizing signs should be discussed and referred to relevant specialists for further investigation and management. 

In 2010, Aktas and Boga proposed a classification and treatment protocol for Tapia syndrome that has not yet been validated. This classification provides a practical framework for diagnosis but should be used for guidance purposes only.

Table. Aktas and Boga Classification

Evaluation

Computed tomography (CT) scanning and magnetic resonance imaging (MRI) are essential for ruling out central causes of Tapia syndrome. CT is the initial imaging modality of choice despite being inferior to MRI, as CT is readily available in many facilities. Neurology input and electromyography may provide additional information but are unlikely to alter the diagnosis or management.

Visual confirmation of nerve paralysis can also be obtained using airway endoscopy on swallowing tests. Saliva is often observed pooling in the piriform sinus.[25] Depending on the degree of clinical suspicion, airway endoscopy may offer a safe and reliable diagnosis, thereby eliminating the unnecessary use of CT, MRI, barium swallow, or electromyography.

Treatment / Management

The mainstays of management for Tapia syndrome are supportive treatment and active rehabilitation. The recovery process can take many months. Early involvement in speech and language therapy and establishing a structured swallowing rehabilitation program are crucial for a good outcome. The consensus is that an interprofessional approach is required to manage this syndrome correctly.

The role of steroids in treating Tapia syndrome remains controversial, without any clear evidence, and should be guided by neurologists.[26] Without contraindications, early steroid therapy may reduce nerve swelling and enhance recovery based on the disease mechanism. No steroids are recommended in mild (grade I) cases. Moderate (grade II) cases are managed with 15 days of corticosteroid treatment. The steroids are administered intravenously in the first 3 days and shifted afterward to the oral route. Severe (grade III) cases can be treated with 1 week of intravenous corticosteroids at a dose of 1 mg/kg/d.(A1)

Differential Diagnosis

Tapia syndrome is almost always associated with orotracheal intubation and surgical intervention. Therefore, any presentation that lacks a history of direct trauma should be a cause for concern. The main pathologies to exclude are space-occupying lesions and infections, some of which are listed below:

• Lung cancer, specifically left-sided tumors causing left recurrent laryngeal nerve compression
• Ortner syndrome, a left recurrent laryngeal nerve palsy due to structural expansion within the heart and major blood vessels
• Malignant lymph nodes
• Head and neck tumors
• Abscess formation

A thorough clinical evaluation and appropriate diagnostic testing can help rule out these causes and manage the case accordingly.

Prognosis

Recovery time ranges between 3 and 22 months with a median of 9 to 12 months. Recovery is complete in approximately 30% of patients, incomplete in 39%, and not achieved in over 26%.

Complications

Tapia syndrome is not always reversible and can lead to significant morbidity. Incomplete recovery may lead to permanent speech and swallowing difficulties, resulting in poor feeding, inadequate nutrition, and a high risk of aspiration. Severe bilateral vocal cord paralysis in Tapia syndrome may present as an airway emergency, necessitating tracheostomy.