Introduction
Spinal cord infarction is a rare but often devastating disorder caused by many pathologic states. Patients typically present with acute paraparesis (inability to move the lower limbs) or quadriparesis (paralysis from the neck down), which depends on the level of the spinal cord involved. The diagnosis is generally made clinically, with neuroimaging to confirm the diagnosis and exclude other conditions.
What Is the Blood Supply of the Spinal Cord?
The posterior intercostal and lumbar arteries from the descending aorta give off the segmental arteries. These further subdivide into radiculo-medullary arteries. They enter the neural foramen and form radicular arteries. These supply the nerve roots or medullary arteries. The medullary arteries supply one midline anterior spinal artery (ASA). The two posterolateral spinal arteries (PLSA) are also supplied by this branch. The cervical cord is the segment with the maximum amount of blood supply. There are contributions to the ASA from either one or both of the vertebral arteries. The contributions are also from the PLSA from the posterior inferior cerebellar arteries (PICA). The mid-thoracic cord is associated with a very delicate arterial supply. Adamkiewicz is the dominant segmental artery that supplies the thoracolumbar spinal cord. The artery enters between the T5 and L2. In 85 percent of cases, it is from the right side, and from the left side in 80 percent of cases. The Conus and Cauda equina usually have a median and a lateral sacral artery that contribute to the blood supply.
What Are the Onset and Precipitating Factors for Spinal Cord Infarction?
The onset of spinal cord infarction is abrupt, similar to cerebral infarction. However, many patients experience a decline over a few to several hours.
What Are the Neurologic Syndromes Associated with Spinal Cord Infarction?
The neurologic presentation of a spinal cord infarction is primarily defined by the involved blood vessels. The severity of the impairment varies widely. It ranges from paraplegia to minor weakness. The involved cord level can be anywhere along the cord's length, depending on the underlying etiology. Pain in the back or neck often accompanies spinal cord ischemia, which is a lack of blood supply to the region. Several studies have reported in as many as 70 percent of patients, it typically occurs at the lesion level.
What Is Anterior Spinal Artery Syndrome?
A spinal cord infarction's most common clinical presentation is anterior spinal artery (ASA) syndrome. Consistent with its functional neuroanatomy, ASA infarct typically exhibits a loss of motor function. The pain and temperature sensations are also impaired. A relative sparing of proprioception and vibratory sensation is seen below the lesion level. The acute stage is characterized by flaccidity and loss of deep tendon reflexes, spasticity, and hyperreflexia that progress with time. Moreover, autonomic dysfunction leads to low blood pressure (either orthostatic or frank hypotension), sexual dysfunction, or bowel and bladder dysfunction. Chest pain with electrocardiogram (ECG) changes has been reported in a patient with C7 to T1 spinal cord infarction. A critical evaluation of patients shows that hypotension is the cause of spinal cord ischemia. In this case, the lesion in the rostral cervical cord causes the compromisation of respiration.
How Is Spinal Cord Infarction Treated?
In order to relieve the symptoms and the complications associated with the spinal cord, spinal fusion surgery is one of the best options. It not only supports to cure of the symptoms but also manages the back pain associated with routine activity. During this procedure, the vertebrae's mobility is restricted, which also reduces the flexibility of the spine. This procedure manages the disorders connected with the spine along with pain management. The following are the disease that requires this procedure:
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Tumors or Growths: These are found on the vertebral column of the spinal cord.
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Stenosis: It is the narrowing of the nerve roots of cranial and spinal nerves, which in turn causes extra pressure on the spinal cord.
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Disk Hernias: It is a condition caused by disk degeneration due to age, where the flexibility of the disk is reduced.
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Degeneration of the Intervertebral Disks: It can be caused by many conditions.
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Fracture: Vertebrae fracture that affects the stability of the spine.
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Scoliosis: It is a condition that causes a hump-like curve of the vertebral column.
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Kyphosis: It is the condition that causes a forward rounding of the upper back.
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Weakness of the Spine: Due to disease or age spine undergoes many structural changes, such as disk degeneration, which affects its flexibility and also causes weakness.
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Spondylolisthesis: It is the condition where a vertebra slips onto the vertebra located below it. This causes extra pressure on the spinal cord or nerves, which further causes excruciating pain.
Spinal fusion surgery can be the only required procedure or it might be done along with a diskectomy. Diskectomy is the removal of the injured or affected disk. After diskectomy, bone grafts are placed into the empty disk space to maintain the proper height between the two bones. Moreover, two vertebrae adjacent to both sides of the removed disk are connected across the bone grafts, which gives stability to the spine.
A procedure on the cervical spine, along with a diskectomy, is known as cervical fusion surgery. During this, the disks or bone spurs from the cervical spine located in the neck are removed instead of the vertebra.
What Is the Long-Term Prognosis of Spinal Cord Infarction in Neurology?
There have been relatively few studies on long-term outcomes after spinal cord infarction. One study included 115 patients, of whom 60 percent had perioperative infarctions or infarctions caused by aortic aneurysm or dissection. Another study included 54 patients with mixed spontaneous and non-spontaneous infarctions.
Only one study has focused on long-term prognosis in spontaneous spinal cord infarction in 30 patients with a mean follow-up time of 7.1 years. An important finding in this study was that long-term mortality was lower among spinal cord infarction patients (23 percent after a mean follow-up of 7.1 years) than among cerebral infarction patients (hazard ratio 0.2) after adjusting for age and functional scores in the acute phase. A possible explanation is that the frequencies of traditional risk factors, such as myocardial infarction (heart attack), atrial fibrillation (quivering heartbeat), and hypertension (increased blood pressure), are lower in spinal cord infarction patients.
Many spinal cord infarction patients experience significant improvement with time; up to half of the patients who could not walk one week after spinal cord infarction onset can walk on follow-up. Of all spinal cord infarction patients, two-thirds can walk on follow-up. The long-term prognosis as to functional state is better than previously reported. Almost all surviving patients less than 60 years at the onset of their spinal cord infarction return to their jobs in the long term.
By contrast, re-employment is lower among patients younger than 60 years at the beginning of their cerebral infarction, even when their functional scores are better than those of spinal cord infarction patients. Cerebral infarction patients often have cognitive deficits, whereas cognitive deficits are rare among spinal cord infarction patients and probably do not differ from those in hospitalized patients with equally severe conditions. The difference in re-employment probably reflects this dissimilarity in cognitive functioning.
Conclusion
Spinal cord infarction patients are younger and, more often, women than cerebral infarction patients. Traditional cerebrovascular risk factors are less relevant in spinal cord infarction. Spinal cord infarction patients are more likely to be discharged home and show better improvement after initial treatment than cerebral infarction patients. They have lower mortality and higher emotional well-being scores than cerebral infarction patients on long-term follow-up. Despite more chronic pain, the frequency of re-employment is higher among spinal cord infarction patients than cerebral infarction patients, who are more often afflicted with cognitive function deficits.
