Departments of Neurology,
Otorhinolaryngology ,
Anesthesiology,
Mayo Clinic and Mayo
Foundation, Rochester, Minnesota.
A clinical pain syndrome similar to
"carotidynia"
developed in a patient several years after
undergoing carotid endarterectomy. The pain was
reversed by superior laryngeal nerve block,
followed by supenor lamygeal neurectomy. A
diagnosis of superior laryngeal neuralgia was
suggested by several characteristic features:
(1) pain along the anterior cervical triangle,
with extension to the ipsilateral ear and eye,
(2) hoarseness, and (3) paralysis of the
ipsilateral cricothyroid muscle on laryngoscopy.
Carotidynia usually refers to neck pain arising
from the carotid artery in the neck and is often
viewed as a migraine variant. Our observations
suggest that carotidynia may not be a migraine
variant and that "carotidynia" may not be an
accurate term for all pains in the anterior
cervical triangle. We suggest that evaluation of
neck pain include speech pathology and
otolaryngologic consultations (including
laryngoscopy) if any voice disorder is reported
or noted. Since the superior laryngeal nerve is
the neural structure most contiguous to the
bifurcation of the carotid artery, the superior
laryngeal nerve may have become entrapped in a
fibrotic process that developed after carotid
endarterectomy. Such pain may be a rare
complication of carotid endarterectomy. When
other causes have been excluded and pain
continues, a superior laryngeal nerve block
should be considered.
INTRODUCTION
Carotidynia usually refers to neck pain
arising from the carotid artery in the anterior
cervical triangle. The pain is often an
episodic, throbbing neck pain, frequently
associated with carotid artery tenderness and
adjacent swelling. As described, the pain
usually is considered to be a migraine variant.
However, any abnomiahty of the wall of the
carotid artery may cause pain about the head,
face, and neck, as evidenced by reports of
similar pain with carotid artery aneurysms,
carotid arteritis, and dissection of the carotid
artery.
Recently, we evaluated a 60-year-old man
whose description of pain resembled carotidynia.
Careful voice analysis and laryngoscopy
indicated a lesion of the superior laryngeal
nerve on the symptomatic side. Pain was relieved
after successful block of the nerve and superior
laryngeal neurectomy.
REPORT OF A CASE
A 60-year-old man was first seen in July
1979 with a complaint of right anterior neck
pain. He reported a 6-to 12-month history of
episodic then constant "burning" in the right
anterior aspect of his neck. The pain began as a
muscle "cramping" initiated by opening his
mouth,
yawning, or
turning his head. The pain, initially located in
the anterior cervical triangle, would extend to
the right shoulder, cheek, maxilla, and
retroauricular and retro-orbital regions. Except
fur occasional tearing with intense pain, no
vasomotor or neurologic signs were apparent. He
became aware of tenderness from palpation or
pressure and resorted to sleeping on his left
side so that he would avoid compressing the
right side of his neck during sleep. Prolonged
talking or singing would intensify the pain as
much as turning his neck. His voice became
lower-pitched, rough, and easily fatigued. He
eventually abandoned singing.
Pertinent past medical history included
bilateral carotid endarterectomies done 9 (right
side) and 7 (left side) years before evaluation.
Soon after the operations, he began to notice
occasional cramping discomfort across his
neck.
When the patient was first seen, he had
moderate tenderness along the course of the
right carotid artery in the neck. A right
carotid angiogram revealed only slight deformity
of the right internal carotid artery at its
point of origin from the common carotid artery.
At speech pathology consultation, a low-pitched
hoarseness was noted during contextual speech
and a tremorlike voice unsteadiness was noted
toward the end of vowel prolongation.
indomethacin, amitriptyline, propranalol,
carbamazepine, methysergide, and diazepam (at
maximal recommended dosages) produced no change
in symptoms. The patient returned 4 months after
initial evaluation, with intense pain that would
extend to his forehead. Pain could be triggered
by pressure over the right carotid artery near
the tip of the hyoid bone and at the angle of
the mandible. No further change in his speech
was noted. Otorhinolaryngologic consultation
demonstrated an oblique larynx with the
posterior commissure deviated to the left,
consistent with contracture of the right
cricothyroid muscle. A computed tomographic (CT)
study of the neck demonstrated the relationships
in the anterior cervical triangles. Appropriate
distortion of the laryngeal image, on section
through the level of the arytenoid cartilages,
was consistent with the laryngoscopic
impression.
Complete block of the superior laryngeal
nerve was achieved by injection of a 0.25%
solution of bupivacaine HCI, followed by
instillation of a 5% phenol-water solution near
the tip of the right hyoid bone. Pain returned
approximately 2 months after injection. Similar
blocks produced pain relief of successively
shorter duration. Superior laryngeal neurectomy
was then performed, with nearly complete
resolution of the pain. A small region of
"burr-like" discomfort remained at the tip of
the hyoid bone.
DISCUSSION
The earliest descriptions of carotidynia by
Fay suggested that sensitivity of the carotid
artery may be a cause of facial and neck pain.
Some of his patients were improved by
denervation of the artery and interruption of
the cervical sympathetic fibers. Electrical
stimulation of the wall of the carotid artery
near its bifurcation caused pain in the teeth,
gums, eye, nose, cheek, and jaw, depending on
the precise area of the artery stimulated. He
noted that digital pressure over the carotid
arteries near their bifurcation elicited a
similar pain and was a helpful diagnostic
feature.
Subsequent literature suggests two basic
categories of carotidynia: one a migrainous
disorder and the other a structural disease of
the carotid artery.
Raskin and Prusiner described an episodic,
throbbing pain with tenderness and swelling of
the carotid artery which sometimes was
associated with vascular headache, nausea, and
vasomotor phenomena. Eight patients responded to
antimigrainous drugs. They further noted that
nearly 40% of patients with frequent migraine
had tender carotid arteries, which almost
invariably were ipsilateral to the hemicranial
headache.
The carotid arteries were nontender in 100
controls. Similar experience has been cited by
Lovshin in a review of 100 cases. Others,6
however, have remarked on the resistance of
carotidynia to parenterally administered
ergotamine. Whether this responsiveness is
itself an indicator of functional (that is,
migraine) versus structural disease of the
carotid artery is unknown.
Pain in the carotid artery may be caused by
various pathologic processes, such as arteritis,
dissection of the carotid artery, thrombosis,
aneurysm, or direct trauma to the artery. These
causes probably constitute a category of carotid
artery pain less common than migrainous
carotidynia. Nevertheless, such pain is a
valuable indicator that significant disease may
be present in the neck. The pain in these
disorders is less often episodic or accompanied
by a typical hemicrania. The pain is usually a
stabbing or pulling type and is
characteristically aggravated by head and neck
movements; swallowing, chewing,
yawning, and
sneezing may be poorly tolerated. A benign,
self-limited form, occasionally bilateral, has
been considered to represent a viral cause.
The clinical findings in our case resembled
those associated with this second type of
carotidynia. Our patient lacked the prior
migraine history, the coexistent hemicrania, and
the episodic, throbbing neck pain with
interictal normalcy, and he had no response to
antimigrainous drugs. A structural lesion was
suggested. The observation of coexistent voice
change led to the consideration that the larynx
was participating in the pathologic process.
Speech evaluation by a speech pathologist and an
otorhinolaryngologist confirmed chronic
paralysis of the ipsilateral cricothyroid
muscle, thus suggesting a lesion of the superior
laryngeal nerve.
The cricothyroid muscle is the only
intrinsic muscle of the larynx supplied by the
superior laryngeal nerve; all other muscles are
supplied by the recurrent laryngeal nerve. The
cricothyroid muscle approximates the thyroid and
cricoid cartilages. It lengthens, stretches, and
tenses the vocal cord - actions that are
essential to the production of sounds of higher
pitch. It also functions as an adductor of the
vocal cord. Acute paralysis of one of the
cricothyroid muscles produces a unilateral
failure of tensing and adducting of the cord.
The voice will be weak, rough, and easily
fatigued. Pitch will be lowered, and most high
tones will be lost, as will the singing voice.
The intact cricothyroid muscle rotates the
cricoid, producing an oblique deviation of the
glottis toward the unaffected side. Thus, in
acute palsy of the right superior laryngeal
nerve, the posterior commissure is rotated to
the right. In chronic palsy, contracture of the
ipsilateral cricothyroid probably rotates the
posterior larynx to the left. The internal
branch of the superior laryngeal nerve also is
the sensory supply to the larynx above the
glottis. Hence, the superior laryngeal nerve
functions as a mixed nerve.
The superior laryngeal nerve is the neural
structure most contiguous to the carotid
bifurcation and must be carefully protected
during carotid endarterectomy. Typically, the
bifurcation of the superior laryngeal nerve lies
medial to the crotch formed by the internal and
external carotid arteries. Hoarseness, typically
without pain, may develop after carotid
endarterectomy, probably by damage to the
external branch of the superior laryngeal nerve.
The strain involved in using a voice that tires
easily and requires effort to maintain pitch,
however, may cause considerable annoyance. If
the sensory branch is also involved, minor
problems of swallowing and coughing may be
transient phenomena. The exact frequency of
injury to the superior laryngeal nerve during
carotid artery surgery is unknown, but probably
occurs more frequently than is recognized
(Piepgras DG: Personal communication). Similar
injury to the superior laryngeal nerve has been
described during neck dissection for carcinoma
and during thyroid surgery.1° Face pain,
neck tenderness, and pain on swallowing were
described in a patient 6 years after carotid
endarterectomy. Other than this report, we are
unaware of carotidynia after carotid artery
surgery.
Observations on our patient may be unrelated
to his prior carotid artery surgery and may
represent superior laryngeal neuralgia. An
earlier publication from our institution
described two patients with pain cured by
resection of the superior laryngeal nerve.
Echols and Maxwell first described surgical cure
of this neuralgia after the injection of
procaine HCI gave transient relief. These
reports, as well as other, differentiated
superior laryngeal neuralgia from the more
common glossopharyngeal neuralgia by the
latter's tendency to extend to the ear from the
tonsillar region, which is the trigger zone.
None of these reports utilized speech pathologic
analysis of voice and laryngoscopic examination.
The superior laryngeal neuralgia was inferred by
a trigger spot above and lateral to the thyroid
cartilege, the radiation of pain, and the
response to blocks or resection of the superior
laryngeal nerve.
In summary, a clinical pain syndrome
similar to "carotidynia" developed in our
patient several years after carotid
endarterectomy. The pain was reversed initially
by block of the superior laryngeal nerve and by
resection of the nerve. A diagnosis of superior
laryngeal neuralgia was suggested by several
characteristic features: pain along the anterior
cervical triangle, with extension to the
ipsilateral ear and eye, hoarseness, and
paralysis of the ipsilateral cricothyroid muscle
on laryngoscopy. We suggest that evaluation of
neck pain include speech pathology and
otolaryngologic consultations if any speech
disorder is reported or noted.
