Neck pain and dizziness after a swimming accident

Clinical History

A 25-year-old healthy young woman twisted her neck while being turned over by a big wave on a summer holiday in Spain. Returning home, she went to see a doctor for diffuse right-sided neck pain and dizziness, that had started with the accident. She was referred for an MRI of the cervical spine.

Imaging Findings

Routine sagittal and transverse, T1-weighted MR images showed a bright hyperintense rim around a small eccentric flow void in the right vertebral artery (VA), which extended along all segments (Fig. 1). Contrast-enhanced MR-angiography of the supra-aortic arteries performed afterwards showed an irregular stenosis of the right VA, extending from V1 through V4 (Fig. 2). There were no intracranial aneurysms in the V4 segment. A cranial MRI including diffusion-weighted imaging was also obtained prior to the MRA to rule out ischaemic lesions of the brain.

Discussion

Cervical artery dissection (CAD) in general is a recognised cause of stroke in young adults [1]. Overall, CADs are estimated to cause 2% of all cerebral infarctions, but in patients younger than 45 years, they account for approximately 20% [2].
The typical manifestation of vertebral artery dissection (VAD) is posterior headache or neck pain followed by posterior circulation transient ischaemic attack or stroke. Less frequent features include isolated neck pain, cervical spinal cord ischaemia, or radicular symptoms. Asymptomatic VADs have also been reported. The most dreaded and often lethal complication from intracranial extension of VAD is subarachnoid haemorrhage [3].
Arterial embolism is the most probable cause for infarctions resulting from VAD, for in an otherwise healthy circle of Willis, haemodynamic alterations are normally compensated [2].
The annual incidence of spontaneous VAD lies between 1 and 1.5 per 100000 [2], but may be underestimated [1]. A "weak vessel wall" due to hereditary connective tissue disorders has been postulated as a predisposing factor. Traumatic dissection occurs in approximately 1% of all blunt neck injuries [2]. About 30% of all traumatic VA injuries are not associated with structural injuries of the spine. Neurologic deficits in trauma cases of VADs occur in 0% to 24% [4]. Cervical manipulative therapy has also been accused of causing VAD. However, the best available estimate of its incidence after manipulative therapy is 1.3 per 100000, therefore not much higher than spontaneous occurrence [5]. Although our patient had no stigmata or family history of connective tissue disease, predisposing factors could not be ruled out.
Conventional angiography is the traditional imaging standard in VAD. It may differentiate between three types of manifestation: irregular stenosis, occlusion, and pseudoaneurysm [6]. There seems to be no preferred site of dissection along the course of the vessel. CT and MRI brain scans, as in the present case, are frequently normal in patients with VADs [7]. The diagnostic importance of identifying wall haematoma as a key differentiator against other causes of VA occlusion has been stressed by several authors. Wall thickening of the VA may in fact be the only abnormality found on imaging studies. Hence, luminal-opacifying techniques such as contrast-enhanced MRA or conventional angiography provide only limited information [8]. The sensitivity of T1-weighted MR sequences (especially with fat suppression) for paramagnetic blood degradation products helps to differentiate other causes of wall thickening, e. g. arteritis. However, an advantage of MRI/MRA over CT angiography could not be demonstrated [7].
Treatment options include observation, antiplatelet drugs, anticoagulation therapy, and endovascular procedures. There is little evidence to support any of the current treatment concepts in CADs [9].
Healing or stabilisation of CADs normally occurs within three to six months, with resolution of stenosis in 90%, and recanalisation of occlusions in as many as 50%. Almost half of dissecting aneurysms resolve or decrease in size on follow-up examinations. Slightly more than half remain unchanged [2]. Ruptured dissecting aneurysms involving the V4 segment require emergency treatment (mostly by embolisation), due to a high re-bleeding rate of 33% within 10 days [10].

Differential Diagnosis List

Final Diagnosis

Traumatic vertebral artery dissection

URL:	https://www.eurorad.org/case/8245
DOI:	10.1594/EURORAD/CASE.8245
ISSN:	1563-4086