Unilateral right occipital condyle to C2 level spinal cord infarction associated with ipsilateral vertebral artery stenosis and contralateral vertebral artery dissection: a case report

Abstract

Objectives

To illustrate the clinical presentation, diagnosis, management, and outcome of unilateral right occipital condyle to C2 level spinal cord infarction.

Setting

A teaching hospital in Taiwan.

Findings

A 37-year-old man presented with acute-onset severe right neck pain before weakness developed in both right limbs. Early diagnosis was delayed due to mild intervertebral herniation of the C4–C5 disk. Magnetic resonance imaging revealed unilateral right occipital condyle to C2 level infarction. Angiography showed stenosis of the right vertebral artery (foraminal and intradural segments), and dissection of the left vertebral artery at the C1–C2 level. At discharge, he walked with assistance; 2 weeks later, he walked independently.

Conclusions

An early diagnosis is difficult but important, as it facilitates appropriate treatment for better functional and survival outcomes. Accurate early diagnosis can be made with adequate knowledge of spinal cord infarction and high index of suspicion for this condition.

Introduction

Spinal cord infarction is an uncommon disease with a heterogonous etiology, and a shared etiology with cerebral stroke.^1,2 Anterior spinal cord infarction occurs relatively more frequently compared to posterior spinal cord infarction. Moreover, unilateral is exceedingly rare.^1–3 We report a case of right unilateral occipital condyle to C2 level infarction with acute onset of severe neck pain preceding the neurological insult.

Case report

A 37-year-old man without history of having any systemic diseases who had mild dyslipidemia. He experienced acute onset of severe right neck pain and was sent to our emergency room (ER). Numbness and weakness of both limbs on his right side developed and progressed to total paralysis within 2 hours of entering the ER. Computerized tomography (CT) of the brain revealed nothing unusual, but magnetic resonance imaging (MRI) of the cervical spine revealed mild central disc herniation at level C4–C5. He was admitted to the Department of Neurosurgery for further management. On examination, sensory impairment at the C2 level was noted and a lesion higher than C5 was highly suspected. MRI and magnetic resonance angiography of the brain and cervical regions were performed 2 days after the onset of pain. A lesion with T1-hypointensity, T2-hyperintensity, and water diffusion restriction under diffusion-weighted imaging in the right lateral and posterior spinal column within the cervical spinal cord extended from the occipital condyle to the C2 level; the lesion was compatible with spinal cord infarction (Figs. 1 and 2). Carotid and vertebral angiography also revealed focal narrowing at the foraminal and intradural segments of the right vertebral artery, along with a left vertebral arterial dissection at the C1–C2 level (Fig. 3). Under the impression of unilateral right occipital condyle to C2 level infarction conservative treatment was determined due to vertebral arterial lesions without hemorrhage and aspirin was given for ischemic stroke prevention.

Figure 1.

T2-weighted transverse magnetic resonance image (left panel) obtained 2 days after the onset of neck pain demonstrates a hyperintense area in the spinal cord (arrow), and the corresponding level on the coronal view (right panel), suggesting spinal cord infarction.

Figure 2.

Diffusion-weighted transverse MRI (left panel) shows the hyperintense area of the spinal cord (arrow), suggesting spinal cord infarction, and the corresponding level on the coronal view (right panel). The lesion extends from occipital condyle to the C2 level.

Figure 3.

Vertebral arteriography reveals focal narrowing of the right vertebral artery (arrow in left panel) and left vertebral artery dissection (arrow in right panel).

On examination in the rehabilitation department, the patient had Brown–Séquard syndrome, with right-side weakness (manual muscle testing grade 4 in the upper extremity, grade 3 in the lower extremity) and sensory impairment at the C2 level. Urinary retention was resolved after a short course of intermittent catheterization. After 3 weeks of inpatient rehabilitation, the patient ambulated with aid. Two weeks after discharge, he ambulated without aid.

Discussion

Spinal cord infarction is rare although it shares etiologies with cerebral infarction and systemic vascular diseases. The vascular territories of the cervical spinal cord must be considered in the diagnosis of spinal cord infarction, including the vertebral, ascending cervical, deep cervical, and radicular arteries.³ The causes of vascular insufficiency could be related to trauma, hypertrophic degenerative spine, or invasive procedures that risk compromising the spinal circulation.^1,2 This patient had bilateral, high-level vertebral arteries lesions that compromised blood flow to the spinal cord at the right occipital condyle to C2 level.

Acute pain is a common and important symptom of spinal cord infarction. The pain occurs adjacent to the level of infarction level and its cause is thought to result from nerve root ischemia.² In our patient, right neck pain without radiation developed, because his corresponding lesion was located at the level of the occipital condyle to C2 instead of middle or lower cervical level in most cervical spinal cord infarctions.² Unilateral spinal cord infarction is rare, and unilateral occipital condyle to C2 level infarction associated with ipsilateral stenosis and contralateral dissection of vertebral arteries is not previously reported.

Imaging study for the diagnosis of spinal cord infarction is MRI, and the best sequence to reveal early spinal cord infarction is diffusion-weighted imaging.^4,5 The concomitant vertebral body infarction is an important confirmatory sign of spinal cord infarction. Angiography can then be done to reveal the occlusion or stenosis of the corresponding arteries.²

Current practice for spinal cord infarction management is to search for a surgically treatable spinal cord compression⁴ and apply medical control of vascular risk factors or antiplatelet therapy. The benefits of thrombolysis for early diagnosis of acute cerebral infarction are also potentially useful for the very early diagnosis of spinal cord infarction under emergency care, although studies and observation are needed.⁵

In experienced hands, endovascular stenting for both vertebral artery stenosis (VAS) and non-hemorrhagic vertebral dissection is technically successful with few periprocedural complications.^6,7 The most effective treatment for symptomatic VAS and non-hemorrhagic vertebral dissection has not yet been proven.^7,8

Conclusion

It is important to have awareness and knowledge of spinal cord infarction and include it in the differential diagnosis of acute pain accompanied by paralysis. Early diagnosis of spinal cord infarction is easily delayed when it is associated with nearby spinal disorders. Unilateral spinal cord infarction is rare and the outcome is good.