Keywords
pedicle screw - cortical breach - guidewire - tapia syndrome - neuropraxia
Introduction
Postoperative neuropraxia of the lower cranial nerves (CNs) can occur as a complication
of spinal surgery, manifesting as a hoarse voice, impaired breathing, and tongue paresis.
Although these features are common immediately after extubation, their persistence
has been termed Tapia syndrome. There have been isolated reports of bilateral cases, but Tapia syndrome is a unilateral
disorder with ipsilateral paresis of the tongue and vocal cord.[1]
[2]
[3] The general consensus from the literature is that the syndrome results from a pressure
neuropathy or traction of local structures during procedures such as tracheostomy,
intubation, or thoracotomy.[4]
[5]
[6]
[7]
[8]
[9]
[10] The use of guidewires during pedicle screw insertion has not been associated with
this syndrome. We present a patient who experienced persistent difficulty breathing
and dysphagia after surgery. Subsequent review of postoperative imaging was normal,
apart from a breach in the cortex of the anterior body of the T1 vertebra that corresponded
anatomically to the path of the recurrent laryngeal nerve (RLN) on the right.[11]
Case Report
A 17-year-old male patient with a history of idiopathic scoliosis underwent a posterior
instrumentation and arthrodesis at T1–L1. General anesthesia was induced with sevoflurane
and propofol. An 8.0 endotracheal tube was placed uneventfully, and the patient was
positioned prone on a Jackson table. The surgery lasted for 10 hours and 35 minutes
with no intraoperative complications, and the patient was kept intubated because of
the length of the procedure and the time spent in the prone position. After extubation
on the first postoperative day (POD), the patient had a hoarse voice and difficulty
in swallowing (including coughing when attempting to swallow liquids). Extensive neurological
imaging, including magnetic resonance image (MRI) of the brain and the brain stem,
magnetic resonance angiograph of the neck, and MRI of the cervical spine was performed
but no abnormalities were found ([Fig. 1]). Computed tomography (CT) demonstrated a small breach of the cortex at the level
of the T1 vertebra ([Fig. 2]).
Fig. 1 (A) T1 Magnetic resonance image (MRI) of the brain. (B) T1, (C) T2, and (D) STIR
sequence MRI of the cervical spine taken after the patient's symptoms started, showing
no clear evidence of injury.
Fig. 2 Computed tomography of the thorax at the level of T1 with a breach of the cortex
of the body of T1 on the right side.
An otolaryngology review noted right vocal fold immobility, decreased sensation of
the endolarynx, and pooling of secretions on flexible laryngoscopy that indicated
a right-sided CN X injury and a left-sided tongue deviation which is suggestive of
a left-sided CN XII injury. Aspiration was noted during a modified barium swallow,
prompting insertion of a percutaneous endoscopic gastrostomy (PEG) tube. In addition,
augmentation of the true vocal cord was performed by injecting hyaluronic acid. The
patient left the hospital on POD 9 on PEG tube feeding. On POD 20, a repeat of the
barium swallow demonstrated a reduced level of aspiration, and an examination showed
complete resolution of symptoms. The PEG tube was removed, and the patient returned
to a normal diet 1 month later.
Discussion
Tapia syndrome is a posttraumatic or postsurgical ipsilateral neuropraxia that can
be unilateral[1]
[6]
[7]
[8]
[9]
[12] or bilateral.[4]
[13] Its pathophysiologic factors are not completely understood. One theory is that positioning
the patient with the neck in anterior and lateral flexion can impinge both CN X and
CN XII where the two nerves cross.[4]
[6]
[7] Cinar et al[4] reported on bilateral Tapia syndrome following rhinoplasty, and although they stated
that there was no clear etiology, they attributed the nerve injury to changing positions
of the neck, malposition of the endotracheal tube, compression by the endotracheal
tube, or a combination of these. Boisseau et al[6] described a case of Tapia syndrome after arthroscopic shoulder surgery. In this
case, marked lateral flexion may have stretched the CNs for a prolonged time or placed
increased pressure around the orotracheal tube. Other pathophysiologic theories include
overinflated endotracheal tube cuffs,[8] malpositioned endotracheal tubes,[6]
[7] carotid or vertebral artery dissection[12]
[14] aneurysm,[15] and increased pressure on the lateral roots of the tongue by the tongue blade during
intubation.[7]
[9]
[15] All published studies report resolution of symptoms within 2 years.[4]
[6]
[7]
[8]
[9]
[16]
To understand the pathophysiologic factors of Tapia syndrome, an appreciation of the
function and anatomic relationships of CN XII and CN X in the neck is required. After
exiting the base of the skull through the hypoglossal canal, CN XII travels in the
carotid sheath before exiting at roughly the C2 level and traveling anteriorly[9]
[17] ([Fig. 3]). CN XII then travels superior to the hyoid bone to terminate and provide motor
innervations to the intrinsic muscles of the tongue. CN X descends in the carotid
sheath and branches into the superior laryngeal nerve, which then divides into the
external laryngeal nerve, providing motor innervation to the cricothyroid muscle.
It then branches into the internal laryngeal nerve, providing sensory innervations
of the larynx to the level of the true vocal folds. The RLN consists of the terminal
branches of CN X after coursing around the aortic arch on the left and the subclavian
on the right. The RLN ascends the neck in the tracheoesophageal groove and terminates
at the level of the larynx, where it provides motor innervation to the remaining intrinsic
muscles of the larynx as well as sensory innervation of the larynx inferior to the
true vocal folds and the trachea ([Fig. 4]).
Fig. 3 Artistic illustration of an axial section of the head and neck at the approximate
level of C2. It shows the hypoglossal and vagus nerves as they begin to travel along
an anterior course and out of the carotid sheath to their final innervation structures.
Fig. 4 Artistic illustration showing the path of the endotracheal tube during intubation
and the sites where nerve injury could occur.
In the case presented, the etiology of the patient's symptoms seems to be the cortical
breach in the body of the T1 vertebra ([Fig. 2]). Recent anatomic dissections demonstrate the proximity of the path of the RLN to
the T1 vertebra, especially on the right side.[11] The presence of concomitant impairments in opposing CN X (right sided) and CN XII
(left sided) is intriguing because Tapia syndrome is normally unilateral[1]; when bilateral cases have been described,[4]
[13] the neuropathies have been ipsilateral and contiguous. This underlying principle
may be explained by the close proximity of CN X and CN XII, and in 10% of one cadaveric
series, the inferior ganglion of the vagus nerve was bound to the trunk of the hypoglossal
nerve.[18]
According to some researchers, Tapia syndrome is caused by stretching of the nerves,
use of endotracheal or orotracheal cuffs, positioning of the patient, or direct trauma
to the area. Regardless of the etiology, the one common theme is trauma to the upper
cervical soft tissues. Surgeons should pay particular attention to the course of the
RLN, especially on the right side, in patients undergoing spinal instrumentation.
Although it occurs very infrequently, the possibility of Tapia syndrome should inform
management and decision making in procedures involving the upper airways, especially
when symptoms of dysphonia, dysphagia, and deviation of the tongue occur immediately
after surgery or extubation. Treatment is mainly supportive and aimed at minimizing
the effect of the neuropraxia. With early recognition and appropriate support, more
severe complications can be avoided.
