Carotid Artery Dissection Clinical Presentation

Patients with internal carotid artery dissection can present with nonspecific complaints and in all settings. Maintaining a high index of suspicion for carotid dissection is critical whenever a patient presents with unusual focal neurologic complaints, particularly if the cranial nerves are involved and of the patient has sustained major mechanism trauma, minor mechanism stress, or a direct impact on the neck. Failure to consider the diagnosis in young patients presenting with neurologic symptoms is a potential medicolegal pitfall.

In cases of high-impact trauma, a history of cervical hyperextension, flexion, or rotation should alert the physician to the possibility of dissection. In patients with multiple traumatic injuries, the appearance of these nonspecific symptoms may be delayed for 1-5 days after the injury.

Even patients with seemingly minor trauma can develop dissection of the internal carotid artery. Symptoms may range from headache to hemiparesis. Precipitating events should be sought and may include chiropractic manipulation, yoga, gymnastics, sports injuries (including direct impact of high-velocity ball or other direct impact to the neck), overhead painting, coughing, or sneezing.

Typical presenting symptoms are as follows:

• Headache, including neck and facial pain – This can be constant, instantaneous, gradual, throbbing, or sharp
• Transient episodic blindness (amaurosis fugax) – This is caused by decreased blood flow to the retina
• Ptosis with miosis (partial Horner syndrome) – This is usually painful when caused by internal carotid artery dissections
• Neck swelling
• Pulsatile tinnitus – This can occur in as many as 25% of patients with dissection of the internal carotid artery
• Decreased taste sensation (hypogeusia)
• Focal weakness
• Migrainelike symptoms (eg, a scintillating scotoma, which is loosely defined as a transient visual field disturbance in the form of shimmering or arcs of light)

Pain is the initial symptom of a spontaneous internal carotid artery dissection presenting to a physician. Headache (including neck and facial pain) is usually described as constant and severe and is commonly ipsilateral to the dissected artery. It usually precedes a cerebral ischemic event, unlike headache associated with stroke, which usually follows or accompanies the ischemic event. Recurrence of neck pain suggests extension or recurrence of the dissection.

Unilateral facial or orbital pain is also common, and 25% of patients have isolated ipsilateral neck pain. Cluster-like headache with pain centered in or around the eye has been described in a case of spontaneous internal carotid artery dissection.^[9]

Hypogeusia, or decreased taste sensation, may also be a presenting symptom.

In fewer than half of patients presenting with a carotid artery dissection, unilateral oculosympathetic palsy (partial Horner syndrome), may develop, and these patients will experience miosis, visual disturbance, and mild ptosis that may not be detected clinically. Isolated transient vision loss may also be a presenting complaint. Irreversible blindness from an ischemic optic nerve injury is rare. As many as 20% of patients may present with an ischemic stroke without any warning signs.

In the setting of high-impact trauma, a history may be unobtainable; consequently, it is essential to identify physical signs indicating a possible internal carotid artery dissection. Furthermore, signs may be masked in patients with concomitant head trauma, coma, or multiple traumatic injuries, making careful examination crucial.

Signs that should be looked for when the diagnosis of internal carotid artery dissection is being entertained include the following^{[10, 11]} :

• Focal neurologic deficit and frank stroke occurring hours to days after injury – These may be present in as many as 93% of patients at the time of diagnosis of internal carotid artery dissection secondary to high-impact blunt trauma
• Hemiparesis
• Oculosympathetic palsy (partial Horner syndrome; ptosis with miosis) – This may be present in fewer than 50% of patients; when accompanied by ipsilateral pain and retinal ischemia, it suggests an internal carotid artery dissection
• Cranial nerve palsy – This can be present in as many as 12% of patients, with the lower cranial nerves affected more often than the facial, trigeminal, and oculomotor nerves
• Cervical bruit
• Cervicothoracic seat belt sign (ecchymosis to the neck and chest) – This raises the incidence of cerebrovascular injuries (to internal carotid or vertebral arteries) to 3%
• Neck hematoma or ecchymosis
• Cervical spine injuries, maxillofacial trauma, or basilar skull fractures
• Massive epistaxis
• Evidence of near-hanging injury or strangulation injury

The term partial Horner syndrome (see above) is used for the oculosympathetic palsy because anhydrosis is absent. The sympathetic fibers innervating the facial sweat glands are anatomically located on the external rather than the internal carotid artery; thus, anhydrosis is not a finding in the setting of internal carotid dissection.