The acute onset of neck pain and arm weakness is most commonly due to cervical radiculopathy or inflammatory brachial plexopathy. Rarely, extracranial vertebral artery dissection may cause radiculopathy in the absence of brainstem ischemia. We describe a case of vertebral artery dissection presenting as cervical radiculopathy in a previously healthy 43-year-old woman who presented with proximal left arm weakness and neck pain aggravated by movement. Cervical magnetic resonance imaging (MRI) and angiography revealed dissection of the left vertebral artery with an intramural hematoma compressing the left C5 and C6 nerve roots. Antiplatelet treatment was commenced, and full power returned after 2 months. Recognition of vertebral artery dissection on cervical MRI as a possible cause of cervical radiculopathy is important to avoid interventions within the intervertebral foramen such as surgery or nerve root sleeve injection. Treatment with antithrombotic agents is important to prevent secondary ischemic events.
In patients presenting with neck pain and arm weakness a multitude of pathologies, ranging from the benign to those potentially fatal, must be considered in the differential diagnosis. On cervical magnetic resonance imaging (MRI), the absence of discogenic or other structural causes for compression provides clinical direction to consider other causes such as inflammatory brachial plexopathy or the more recently recognised entity of vertebral artery dissection (VAD)-associated cervical radiculopathy. The typical presentation of VAD is with neck pain and occipital headache, which is often misinterpreted as musculoskeletal in nature until focal neurological signs appear [
A 43-year-old woman awoke with left cervical discomfort 10 days before presentation. The discomfort radiated to the trapezius and scapular region, and was aggravated by neck movement. 4 days after awakening with cervical discomfort, she noted the inability to abduct her left arm. In retrospect, she recalled mild left upper cervical discomfort on neck rotation to the left while reversing her car about 4 days before the symptoms began. On examination, she had weakness involving the left deltoid, supraspinatus, infraspinatus and biceps muscles (4/5), with milder weakness of left forearm pronation and supination (4+/5). The left biceps reflex was absent and the left brachioradialis reflex reduced. The remainder of the neurological examination including left upper limb sensory examination and cranial nerve examination was normal.
Cervical MRI revealed an intramural haematoma in the left vertebral artery from mid-C7 to C2 (
Acute onset of neck pain associated with arm weakness is most often due to an acute disc protrusion or uncovertebral/osteophytic disc ridge complex root compression. Less often an inflammatory brachial plexopathy may be the cause. We present an unusual case of compression of the C5 and C6 nerve roots by expansion of the vertebral artery wall within the intervertebral foramina associated with vertebral artery dissection.
Arterial dissection occurs when a tear in the intima of the vessel wall allows blood to enter the tunica media. The expanding hematoma dissects along the vessel wall; subintimal expansion stenoses the vessel lumen whereas subadventitial dissection causes aneurysmal dilatation of the vessel with the potential to compress closely related anatomical structures. The etiology of arterial dissection is not fully understood. Genetic factors such as connective tissue disorders and evidence of arteriopathy such as cystic medial degeneration and aortic root dilatation are commonly found post-mortem [
VAD usually presents with upper cervical pain associated with clinical evidence of brainstem or cerebellar ischemia. Presentation with acute onset neck pain and upper limb symptoms has been described less commonly [
The vertebral artery enters the transverse foramina of the cervical vertebrae at C6 and ascends adjacent to the ventral (motor) spinal nerve roots, supplying corresponding spinal roots via radicular arteries at each vertebral level. VAD-associated radiculopathy primarily affects the ventral spinal roots; the dorsal (sensory) spinal roots may be compressed by larger dissections or their vascular complications. Impaired perfusion of vasa nervorum and occlusion of radicular arteries by intramural hematoma (inducing neural ischemia) may also contribute [
MRI/A is the investigation of choice, showing an enlarged vertebral artery with a spiralling crescentic rim of hyperintense signal (intramural hematoma) surrounding an eccentric hypointense signal representing the stenosed lumen [
Treatment with antithrombotic agents should be commenced immediately to prevent secondary ischemic events. The irregular vessel wall, false lumen and intimal flap provide a surface for thrombus formation which may then embolise or occlude the lumen. The choice between antiplatelet or anticoagulant agents is dependent on many factors including the state of the intimal lining of the vessel lumen and the presence of thrombus or embolic events [
VAD may present with symptoms suggestive of a cervical radiculopathy with acute onset of neck pain, a history of minor trauma and arm weakness. Diagnostic clues may be evident even on a standard cervical MRI. Recognition of VAD associated radiculopathy is essential to avoid interventions within the intervertebral foramen such as surgery or nerve root sleeve injection, and to ensure antithrombotic treatment before secondary thromboembolic events occur.
No potential conflict of interest relevant to this article was reported.
Axial T1 section through the C4/5 intervertebral foramen. The left vertebral artery (in cross-section) demonstrates marked high signal intensity anteriorly (arrowheads) with a lesser degree of high signal posteriorly. This is due to a combination of extra-cellular and intracellular methemoglobin in the vessel wall. The expanded vessel fills the foramen compressing the exiting C5 root (arrow).
Axial T2 section through nerve level in
Magnetic resonance angiogram study. The left vertebral artery demonstrates an irregular lumen (arrowheads) due to the spiral intramural hematoma underlying the intima. The hematoma of slightly lesser signal intensity is shown along the length of the dissected segment. The proximal and distal segments of the artery are normal.