Athirty-nine-year-old man was involved in a high-speed snowmobile accident
in which he was thrown off his vehicle and landed on his head. The main
symptom in the emergency room was pain in the upper part of the neck.
Radiographs of the cervical spine showed no fracture or dislocation. The
workup included a computed tomographic scan of the head and chest, which
revealed normal findings. The patient was treated with a soft cervical collar,
narcotic analgesics, anti-inflammatory agents, and muscle relaxants. He was
discharged with the diagnoses of cervical sprain, a stable compression
fracture of the fourth thoracic vertebra, a fracture of the fifth metacarpal
of the right hand, a chip fracture of the right acromion, and acute alcohol
intoxication. Acute hoarseness developed four weeks later, while the patient
was swinging an ax to cut wood. After undergoing an evaluation by an
otolaryngologist, the patient was treated with antibiotics for a probable
infection. No improvement was noted during the next seven days, and an
examination by a second otolaryngologist revealed paralysis of the vocal
cords. A magnetic resonance imaging scan of the neck suggested rotatory
subluxation of the left occipital condyle in relation to the left lateral mass
of the atlas. The patient was then sent to our facility for additional
evaluation.
When we evaluated the patient, he was alert and oriented. He reported
hoarseness and soreness in the upper part of the neck. He had been
experiencing voice changes and dysphagia that had become progressively worse;
at the time of our evaluation, he was able to swallow only liquids. On
physical examination, the patient had wasting of the left trapezius muscle,
and the tongue deviated to the right on protrusion. He had weakness of
shoulder elevation on the left and a weak left sternocleidomastoid muscle.
There was no myelopathy or upper or lower-extremity radiculopathy.
Anteroposterior and lateral radiographs of the cervical spine showed no
obvious abnormality. An open-mouth radiograph showed mild asymmetry of the
lateral masses (Fig. 1). A
computed tomographic scan of the cervical spine showed a comminuted shear
fracture involving the inferior aspect of the left occipital condyle with bone
fragments immediately inferior and lateral to the left hypoglossal canal.
There was rotatory malalignment of the atlas in relation to the axis, with
anterior subluxation of the left lateral mass of the atlas in relation to the
occipital condyle (Figs. 2-A, 2-B, and
2-C). The patient was treated with halo-vest immobilization.
Laryngeal examination confirmed a true vocal-cord paralysis on the left
side, with pooling of saliva on the cords. Video-endoscopic and fiberoptic
endoscopic evaluation of swallowing indicated notable dysphagia with frank
aspiration of contrast medium, reduced laryngeal sensitivity, and reduced
clearing of secretions in addition to associated dysphonia. Magnetic resonance
angiography confirmed a normal vertebrobasilar vascular system. Cranial nerve
electromyography showed denervation of the vocal cords on the left side,
severe left spinal accessory neuropathy, and moderately severe left superior
laryngeal neuropathy.
The patient reported immediate reduction in the neck pain following halo
application. Because of the severe dysphagia and the risk of aspiration, a
gastrostomy tube was inserted and feeding was begun through this tube. The
neurological status remained unchanged during the hospital stay. He was
discharged home after five days, and feeding was continued through the
gastrostomy tube. Oral secretions required frequent suctioning.
The patient remained in a halo vest for a total of eight weeks and then
wore a rigid cervicothoracic orthosis for an additional four weeks. Three
years later, the patient was completely asymptomatic. The neurological
symptoms had resolved, and he had regained a full and painless range of motion
of the neck. A computed tomographic scan of the neck showed a healed fracture
of the occipital condyle with mild residual subluxation of the condyle on the
lateral mass of the atlas.
Isolated injury to the cranial nerves is occasionally associated with a
fracture of the occipital
condyle2-6.
Cranial nerve deficit may be due to compression of a nerve by bone fragments,
stretching of a nerve at the time of injury, or transection of a nerve.
Collet-Sicard syndrome is a unilateral lesion of cranial nerves IX, X, XI, and
XII, without an associated Horner syndrome. The lower four cranial nerves exit
the base of the skull in close association with each other. Cranial nerve IX,
the glossopharyngeal nerve, is the afferent limb of the ipsilateral gag reflex
and provides taste sensation on the posterior one-third of the tongue. Cranial
nerve X, the vagus nerve, is the efferent limb of the gag reflex. It also
innervates most of the striated muscles of the larynx and pharynx. Cranial
nerve XI, the accessory nerve, provides innervation for the
sternocleidomastoid and trapezius muscles. Cranial nerve XII, the hypoglossal
nerve, provides innervation to the ipsilateral tongue muscles. Causes of
Collet-Sicard syndrome include occipital condyle
fracture7-9,
gunshot
injury1,10,
Jefferson fracture of the
atlas11, carotid
and vertebral artery dissections or other vascular
causes12-14,
and infiltrative
tumors15-17.
Our patient was not immobilized initially, and we believe that progressive
subluxation of the occipital condyle fragments on the lateral mass of the
atlas, coupled with the added insult of secondary trauma, resulted in
increased traction on the lower cranial nerves and the subsequent cranial
nerve deficits.
Fractures of the occipital condyle are divided into three types on the
basis of the mechanism of
injury18. Type-1
fractures are impaction fractures from an axial load. Type-2 fractures occur
as part of a basilar skull fracture. Type-3 fractures are avulsion fractures
of the occipital condyle. Our patient had a type-1 fracture, with notable
comminution. We propose that in the presence of notable comminution of the
occipital condyle fracture fragments, or with an associated cranial nerve
deficit, the potential exists for an unstable subtype of the type-1 fracture.
We believe that patients with such injuries should be treated with rigid halo
immobilization for a minimum of three months.
Sharma et al. described the results of acute surgical intervention in a
patient who had Collet-Sicard syndrome following a fracture of the occipital
condyle8. A portion
of the posterior aspect of the occipital condyle was resected to decompress
the lower cranial nerves, and the authors reported that there was a decrease
in the patient's symptoms at three months. However, most authors have agreed
that nonoperative treatment leads to good results in patients with unilateral
nerve
palsies6,7,9,11,19,20.
This case illustrates several important points regarding a fracture of the
occipital condyle with associated nerve palsies of the lower cranial nerves.
Superimposition of the overlying facial bones on plain radiographs makes it
difficult to identify a fracture of the occipital condyle, and the diagnosis
thus requires a high index of suspicion. Our patient was initially diagnosed
as having a cervical sprain. The difficulty in diagnosis is evident in many
case reports on fractures of the occipital
condyle3,6,18.
Anderson and
Montesano18
reported that, in a series of six patients with a fracture of the occipital
condyle, none of the fractures were identified on the initial radiographs. We
recommend the use of computed tomography with coronal and sagittal
reconstructions to evaluate the area more fully in any patient who has (1)
suspected injury to the craniocervical region, (2) persistent neck pain, (3)
unexplained increase in prevertebral soft-tissue swelling, or (4) loss of
consciousness with substantial head injury or cranial nerve deficit.
Examination of the cranial nerves is necessary in any patient who has
sustained an injury to the craniocervical region. If a cranial nerve injury is
present in conjunction with an occipital condyle fracture, we recommend
treatment with a halo vest. It is essential to take precautions against
aspiration, including frequent mouth suctioning and the use of medications to
increase gastric motility. Adequate nutrition must be provided through a
nasogastric tube or gastrostomy. In the management of patients with
cervicocranial trauma, a high index of suspicion should be maintained
regarding a fracture of the occipital condyle and injury to the lower cranial
nerves.