Canadian J Neurological Sciences 2000 (Nov); 27 (4): 292–296 ~ FULL TEXT
Saeed AB, Shuaib A, Al-Sulaiti G, Emery D
Department of Medicine,
University of Alberta, Canada
BACKGROUND AND OBJECTIVES: Internal carotid artery dissection has been extensively studied and well-described. Although there has been a recent increase in the number of reported cases of vertebral artery (VA) dissection, the clinical variety of presentation and the early warning symptoms have not been well-described before. Our objectives in this study include: (1) To determine the early symptoms and warning signs which may help the clinician in the early identification and treatment of patients with VA dissection. (2) To explore the variety of clinical presentation of VA dissection and its relation to prognosis.
DESIGN AND SETTING: Retrospective analysis of hospital records in a tertiary academic centre for the period 1989-1999.
RESULTS: Twenty-six patients were identified (13 men and 13 women). The mean age was 48. Possible precipitating factors were identified in 14 patients (53%). Sporting activity and chiropractic manipulations were the most common (15% and 11% respectively). Headache and/or neck pain was the prominent feature in 88% of patients and was a warning sign in 53%, preceding onset of stroke by up to 14 days. The most common clinical features included vertigo (57%), unilateral facial paresthesia (46%), cerebellar signs (33%), lateral medullary signs (26%) and visual field defects (15%). Bilateral VA dissection presented in six patients (24%). The most common region of dissection was the C1-C2 level (16 arteries, 51%). Intracranial VA dissection was found in eight arteries (25%). The majority of patients (83%) had favorable outcome. Poor prognosis was associated with (1) bilateral dissection; (2) intracranial VA dissection accompanied by subarachnoid hemorrhage. Only two patients reported stroke recurrence.
CONCLUSIONS: Our findings show that VA dissection affects mainly middle age persons and involves both sexes equally. Headache and/or neck pain followed by vertigo or unilateral facial paresthesia is an important warning sign that may precede onset of stroke by several days. Although the majority of patients will have excellent prognosis, this was less likely in patients presenting with subarachnoid hemorrhage or bilateral VA dissection. Recurrence rate was low.
From the FULL TEXT Article:
The incidence of cervical artery dissection is unknown. In
some series of young patients with stroke, dissection accounts
for one fifth to one tenth of cases.  Internal carotid artery
dissections are widely-known and as a diagnosis are more often
sought. [2, 3] Although there has been a recent increase in the
number of reported cases of vertebral artery (VA) dissection, a
study of the patients presented in this report show that VA
dissection diagnosis is frequently not considered in the younger
patient with typical symptoms. In many instances, the diagnosis
in patients with multiple suggestive symptoms is missed until
after stroke develops. Our objectives of presenting this series
include identifying the early symptoms that should raise
suspicion of VA dissection, explore the variety of clinical
presentation of VAdissection, and to evaluate the prognosis and
frequency of recurrence.
SUBJECTS AND METHODS
We reviewed and studied medical records of all patients less
than age 60 with stroke and all patients who underwent cerebral
angiography between 1989-1999 at the University of Alberta
Hospital, Edmonton. We excluded patients with traumatic
arterial dissection and patients with only occlusion of a VA on
angiograms without angiographic evidence of dissection in the
other VA. Twenty-six consecutive patients with VA dissection
were identified. We studied their demographic features; presence
or absence of warning symptoms; cumulative symptoms and
signs; the presence of predisposing factors; the prevalence of
diabetes mellitus, hypertension or migraine; neuroimaging and
angiographic findings and type of treatment received. All
patients, except one, had standard four vessel cerebral
angiography within five days of stroke onset. One patient was
diagnosed with magnetic resonance angiography. Follow-up was
possible in twenty patients. The duration of follow-up ranged
from four weeks to five years.
For the purpose of classification we used a simple four category outcome scale:
(1) Patients without neurological deficit;
(2) Patients with mild deficits, which did not prevent the patient from performing work and/or major daily activities; for example, slight unsteadiness;
(3) Patients with significant neurological deficit preventing from the performance of work and/or other major activities;
Age and Sex
Of the 26 patients identified, there were 13 men and 13
women. Age ranged between 29 and 76 (mean age 48).
These were categorized into warning symptoms and
cumulative symptoms, Fourteen patients reported having
symptoms before onset of stroke. The delay between onset of
warning symptoms and stroke onset ranged between 1 to 14
days. The most common warning symptom was headache and
neck pain. This was usually of sudden onset, severe and, though
not accompanied by other symptoms or signs, persistent until the
onset of stroke. With respect to cumulative symptoms assessed in
each patient, pain was again the most frequent symptom (22
patients, 84%). Thirteen patients presented with headache only,
four patients with neck pain only and five patients presented with both symptoms. Table 1 summarizes the location of headaches in those patients.
Dissection risk factors
The history revealed a possible link between the onset of
dissection and specific predisposing factor in 14 of the patients in this series. This was related to sports activities (four patients), chiropractic maneuvers (three patients) and possible neck injuries in seven patients. The details of the precipitating factors are summarized in Table 2.
Clinical signs on presentation
Cerebellar signs were the most common objective finding on
neurological examination (nine patients). This was unilateral in
five patients. Gait ataxia was evident in the remaining four
patients. Lateral medullary syndrome signs were present in seven
patients, these were partial in five of them. Four patients had
visual field abnormalities (two had homonymous hemianopia
and two had homonymous quadranopia). Three patients presented with basilar artery syndromes, all had decreased level of consciousness, one of them had Parinaud syndrome and one
presented with quadriparesis. There were no clinical findings in
three patients – all of them came to medical attention because of vertigo or headache.
In nine patients neuroimaging was normal. Infarction was
noted in 17 patients. The most common radiological finding in
these patients was cerebellar infarction which was evident in ten patients. The second most common site of involvement was the
occipital lobe, which was involved in four patients.
Subarachnoid hemorrhage (SAH) was noted in three patients.
The dissection was found to be intracranial in all three patients with SAH. Cerebral angiography findings are summarized in Table 3. Two representative images are shown in Figure 1 and 2.
Different treatment modalities were used in our patients
according to clinical situation and physician judgment. All three patients who presented with intracranial VAdissection associated with SAH were treated with endovascular occlusion. This was followed by surgical clipping of the pseudo-aneurysm in one patient. Two patients (7%) were treated with intra-arterial
thrombolysis. One of these patients presented with signs of
basilar artery thrombosis. Cerebral angiography revealed
extracranial VA dissection with thrombosis extending to basilar
artery. She was treated with intra-arterial t-PA and made an
excellent recovery. The other patient had dissection with
occlusion of one extracranial VA and hypoplasia of the other
artery and developed subacute progressive brain stem signs. She
was unsuccessfully treated with intra-arterial Urokinase. Eight
patients (30%) received antiplatelet agents as the only treatment and 13 patients (50%) received anticoagulation treatment. The duration of anticoagulation was very variable. This was for less than a week in four patients, for two months in two patients and for six months in another three patients. The duration of anticoagulation could not be identified in four patients.
Of the 20 patients who were available for follow-up, eight
(40%) had no residual neurological deficit. Eight patients (40%)
had mild residual symptoms. These consisted of mild imbalance
and dizziness in six patients, partial visual field defects in two and difficulty with fine motor movements in one patient. Two
patients (10%) were left with disabling deficits. Two other
patients in our series died in the acute stage. Only two patients (10%) have had recurrent neurological symptoms that were transient in both cases.
VA dissection is an important cause of stroke in young
patients. The incidence of VA dissection is not known precisely.  Once thought to be relatively uncommon, it is now being recognized more frequently. In our series, more than 60% of the cases studied were diagnosed in the last two years compared to only one patient diagnosed before 1995. During 1998, ten patients with VA dissection were identified in our institute. Although some earlier reports suggested a predominance of VA dissection in females, [5, 6] our data did not show any significant difference in incidence between women and men. With a mean age of 48, the present study also confirmed that VA dissection mainly affects middle-aged adults.
We found a precipitant factor in 53% of our patients. Sports
activity and chiropractic manipulation were again prominent
precipitating factors. After reviewing 90 reported cases of VA
dissections in the literature, we found that a similar percentage (49%) was associated with minor trauma or neck
manipulation. [2, 5, 7, 8-12] It is important to inquire in detail about recent physical activities if arterial dissection is suspected as the
etiology of a stroke.
The role of trivial, unnoticed trauma producing dissection is
not clear. It has been suggested that patients with “spontaneous” VA dissection may have had un recognized trauma or sudden neck motion that was forgotten or considered insignificant by the patient and thus not reported to the physician. 
Pain in our series was a crucial symptom seen in the majority
of patients (88%). This was mainly headache with or without
neck pain. Typically, the headache was occipital and severe in
nature. Our data are consistent with previously reported cases of reported neck pain or headache in 76-100% of VA dissection
Headache and neck pain were also an important warning sign
before the onset of stroke. This was reported by 53% of the
patients, one day to two weeks before the onset of their stroke.
Some of the patients had sought medical advice for these early
signs. One patient, who presented initially with acute neck pain
and vertigo, underwent lumbar puncture to rule out SAH and
then was discharged from hospital, presented later with brain
The extracranial cerebral arteries are known to be pain
sensitive  and the pain may be a signal of mural hemorrhage. According to Sturzenegger,  who studied warning symptoms in 44 patients with internal carotid artery dissection, this pain seems to be a key symptom with regard to starting anticoagulation before cerebral infarction has occurred. This may be of similar importance in VA dissection, especially with the observation in our study that 12% of patients had no abnormal signs on presentation and many presented with minimal signs. Some patients repeatedly presented to the emergency room before developing brainstem or cerebellar strokes. Four other important symptoms reported by about half of our patients were:
(2) nausea or vomiting;
(3) unilateral facial numbness (this symptom was subjective and no abnormality was found by sensory testing);
Three of our patients presented with SAH due to intracranial
segment VA dissection. Their age was relatively older than the
other patients (54, 55 and 76-years-old). Two were diabetic and
one was hypertensive. Two patients had a favorable outcome
with no significant deficit. However, one patient died due to
hydrocephalus and other complications. SAH as a complication
of intracranial VA dissection has been reported before in the
literature. [15-18] The proposed mechanism is a dissecting hematoma that originates between the media and adventitia. This is more likely to happen in intracranial arteries which lack a well-developed external elastic membrane and have muscularis and adventitial layers that are only about two-thirds as thick as extracranial arteries. [17-19]
Bilateral VA dissection was found in six patients (23%). This
was also found in previous reports in a range between 15%-
61%. [6, 8, 10, 11] Compared to patients with unilateral VA dissection, patients with bilateral VA dissections tended to have a more severe presentation. Two such patients developed bilateral
pontine infarction signs, while another two had cerebellar
infarction. One had lateral medullary syndrome and one patient
had posterior cerebral artery territory infarction. Multi-vessel
involvement in the absence of a history of trauma raises the
possibility that an underlying arteriopathy may predispose the
vessels to dissection. Only two patients had angiographic
evidence of fibromuscular dysplasia. No other vascular
abnormalities could be identified. The possibility of an as yet
unknown arteriopathy in some of the cases cannot be entirely
Cerebral angiography was not used as a diagnostic modality
in one of our patients. This patient was diagnosed on the basis of his typical clinical presentation, as well as evidence of dissection on MR angiography (Figure 3). Some recent reports suggested that new noninvasive methods, like vertebral Doppler, magnetic resonance imaging and angiography, are useful in detection and monitoring of VAdissection. [9, 20, 21]
The overall prognosis was good on clinical follow-up in the
majority of patients. Almost 80% made complete or near complete
recovery. The most important factors associated with unfavorable
prognosis (disabling outcome or death) were (1) bilateral
dissection; (2) dissection associated with subarachnoid
The recurrence rate of strokes or transient ischemic attacks
was very low, occurring in two patients during the available
In conclusion, VA dissection is increasingly being diagnosed.
It mainly affects middle-aged persons and both sexes are equally
affected. Headache and/or neck pain are prominent features that
may precede onset of stroke by several days. Although the
majority of patients will have excellent prognosis, this was less likely in patients presenting with SAH or bilateral VA dissection. Recurrence rate was low.
The authors thank Heather Richardson; Research Co-ordinator,
Clinical Trials, University of Alberta Hospital in data collection and Dr. Muzaffar M Siddiqui; Research Fellow, Stroke Research Unit, University of Alberta Hospital for editing this manuscript.
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