Anterior spinal cord syndrome from a spinal epidural hematoma following removal of an epidural catheter

PURPOSE

Spinal epidural hematoma (SEH) is a rare yet significant complication associated with neuraxial anesthesia. Here, we present the case of a 74-yr-old male who underwent open repair of an abdominal aortic aneurysm. Following the removal of an epidural catheter, the patient developed anterior spinal cord syndrome due to an SEH despite having a normal coagulation profile.

CLINICAL FEATURES

This patient's neurologic presentation was marked by a loss of motor function while maintaining fine touch sensation distal to the spinal cord injury. Initial truncal computed tomography (CT) angiography failed to detect vascular compromise or diagnose the SEH. Subsequently, delayed magnetic resonance imaging (MRI) revealed a multilevel thoracic epidural hematoma, spinal cord infarction, and ischemia. Immediate surgical decompression was performed, but unfortunately, the patient had a poor outcome.

CONCLUSION

Anterior spinal cord syndrome (ASCS) represents an uncommon neurologic manifestation of SEH, which is typically characterized by a triad of back pain and sensory and motor deficits. Although the initial CT scan was necessary to diagnose the postvascular surgery complication, it did not immediately detect the SEH. In cases of ASCS subsequent to thoracic epidural placement and removal, MRI is the preferred imaging modality for precise diagnosis and assessment of the need for surgical intervention. Despite adherence to anticoagulation guidelines, patients undergoing neuraxial anesthesia may face an elevated risk of developing SEH. Health care professionals should remain vigilant in monitoring for neurologic abnormalities following epidural catheter insertion or removal, particularly in the context of vascular surgery.

Blood supply to the corticospinal tract: A pictorial review with application to cranial surgery and stroke

The corticospinal tract (CST) is the main neural pathway responsible for conducting voluntary motor function in the central nervous system. The CST condenses into fiber bundles as it descends from the frontoparietal cortex, traveling down to terminate at the anterior horn of the spinal cord. The CST is at risk of injury from vascular insult from strokes and during neurosurgical procedures. The aim of this article is to identify and describe the vasculature associated with the CST from the cortex to the medulla. Dissection of cadaveric specimens was carried out in a manner, which exposed and preserved the fiber tracts of the CST, as well as the arterial systems that supply them. At the level of the motor cortex, the CST is supplied by terminal branches of the anterior cerebral artery and middle cerebral artery. The white matter tracts of the corona radiata and internal capsule are supplied by small perforators including the lenticulostriate arteries and branches of the anterior choroidal artery. In the brainstem, the CST is supplied by anterior perforating branches from the basilar and vertebral arteries. The caudal portions of the CST in the medulla are supplied by the anterior spinal artery, which branches from the vertebral arteries. The non-anastomotic nature of the vessel systems of the CST highlights the importance of their preservation during neurosurgical procedures. Anatomical knowledge of the CST is paramount to clinical diagnosis and treatment of heterogeneity of neurodegenerative, neuroinflammatory, cerebrovascular, and skull base tumors.

Acute Myelopathy: Vascular and Infectious Diseases

Vascular and infectious causes are rare but important causes of spinal cord injury. High suspicion for these processes is necessary, as symptoms may progress over hours to days, resulting in delayed presentation and diagnosis and worse outcomes. History and clinical examination findings can assist with localization of the affected vascular territory and spinal level, which will assist with focusing spinal imaging. Open and/or endovascular surgical management depends on the associated vascular abnormality. Infectious myelopathy treatment consists of targeted antimicrobial therapy when possible, infectious source control, and again, close monitoring for systemic complications.

Collateral Circulation in Spinal Cord Injury: A Comprehensive Review

Surgery is the most common cause of spinal cord ischemia; it is also caused by hemodynamic changes, which disrupt the blood flow. Direct ligation of the spinal arteries, especially the Adamkiewicz artery is involved as well. Other causes of spinal cord ischemia include arteriography procedures, thoracic surgery, epidural and rachianesthesia, foraminal infiltration, arterial dissection, systemic hypotension, emboligenic heart disease, thoracic disc herniation, and compression. Understanding the vascular anatomy of the spinal cord is essential to develop optimal strategies for preventing ischemic injuries to the spinal cord. During ischemia, a rich network of intra and paraspinal collaterals allow enough blood flow to compensate the intensity of spinal cord ischemia. In case of interruption of flow of a main artery, the collateral artery increases its flow to maintain perfusion to the tissues. Avoiding spinal cord ischemia by using collateral circulation is necessary to prevent the establishment of hypovolemia, hyperthermia and elevations in venous pressures. The objective of this narrative review is to present the current concepts of spinal collateral circulation and its role in the setting of ischemic events, affecting the vascular supply of the spinal cord.

Anatomical study of the pial arterial network in human spinal cords

INTRODUCTION

Multiple collaterals originate from three main longitudinal vessels to perfuse the human spinal cord. Only a few classic studies published in the last century have investigated these collaterals. The current work proposes a possible classification of these vessels and analyzes their relative abundance along spinal cord segments.

MATERIALS AND METHODS

Human spinal cords (n = 30) from male and female cadavers were injected with colored latex through the vertebral, ascending cervical, costocervical trunk and segmental arteries and then fixed in formaldehyde solution. Afterwards, spinal vessels were dissected and the relative abundances of each type of collateral were quantified and compared between different spinal cord segments.

RESULTS

Collaterals of the anterior longitudinal pathway can be classified as central arteries and arteries for the anterior and lateral columns. Collaterals for the anterior column can be classified into two types: anteromedial and anterolateral. Arteries for the lateral column can be classified, according to their relationship with the dentate ligament, as either preligamentous or post-ligamentous. The collaterals of posterior longitudinal pathways can be divided between those for the posterior and those for the lateral column. In turn, the arteries for the posterior column can be classified into three types: median posterior, posteromedial and posterolateral. The collaterals for the lateral column were also classified as either pre- or post-ligamentous.

CONCLUSION

The relative abundance of the various types of collateral and anastomoses between longitudinal pathways was inhomogeneous along the spinal cord, with several statistically significant differences observed between spinal segments.

Spinal cord

We first present a brief historic review of developments in the understanding of spinal cord clinical neuroanatomy and neurophysiology over the past 200 years. We then discuss the technical aspects that apply to the examination of the human spinal cord giving details on the interrelations between the spinal cord and the overlying structures, including the meninges and vertebrae. The subsequent discussion focuses on diseases of the spinal cord. Diseases that affect the spinal cord are vascular disease, diseases of spinal column, trauma, developmental abnormalities, central nervous system degenerative disease, inflammatory disease, metabolic and nutritional myelopathies, and tumors. We summarize our knowledge regarding general reactions of spinal cord tissue to disease, in particular Wallerian degeneration of descending/ascending tracts and axonal reaction. Two categories of disease will be covered in depth: vascular disease of the spinal cord, including a review of normal vascular anatomy, and diseases of the vertebral column that can affect the cord secondarily.

Spinal Cord Infarcts: Risk Factors, Management, and Prognosis

OPINION STATEMENT

There are no standard guidelines for treatment of spinal cord ischemia due to how rare it is and the diverse etiology and presentations involved. In addition, to date, there have been no large clinical trials examining ideal pharmacologic treatment options for spinal cord infarct. In our practice, we rely on hemodynamic augmentation initiated as soon as possible. Otherwise, treatment is usually geared towards the etiology of spinal cord ischemia. For instance, spinal cord ischemia occurring after aortic aneurysmal repair may improve with CSF drainage through a lumbar catheter in the periprocedural setting. Vertebral artery dissection should be treated with antithrombotics. If no clear etiology is found and there is evidence of atherosclerosis in other vascular beds, then management is focused on risk factor modification with blood pressure and glucose control, statins, and antithrombotics.

Innervation of the blood vessels of the spinal cord: a comprehensive review

There is growing evidence that the nervous system influences spinal cord vasculature. However, most descriptions of the spinal cord have paid little attention to this important aspect. We reviewed the literature on the innervation of spinal cord vessels with an emphasis on findings that may be applicable to human medicine. Multiple neurotransmitters and competing theories have been implicated in the neural regulation of spinal cord blood vessels. Identifying valid mechanisms of pathogenesis could be beneficial to human patients with spinal cord lesions. We discuss the various findings on the neural mechanisms behind spinal cord blood flow. Further investigation is warranted due to the current emphasis on comparative animal studies without corresponding corroborative human findings.

Arterial variations around the atlas: a comprehensive review for avoiding neurosurgical complications

INTRODUCTION

Neurosurgical approaches often involve the atlas. Therefore, the arterial relationships and anatomical variations are of paramount importance to the neurosurgeon.

METHODS

Using standard search engines, a literature review of arterial variants near the first cervical vertebra was performed.

CONCLUSIONS

Arterial variations around the atlas are surgically significant. Awareness of their existence and course may provide better pre-operative planning and surgical intervention, potentially leading to better clinical outcomes. Three-dimensional computed tomography angiography (3D CTA) is an important tool for identifying and diagnosing such abnormalities and should be used when such vascular anomalies are suspected.

A rabbit model of lumbar distraction spinal cord injury

BACKGROUND CONTEXT

Excessive spinal distraction is a major cause of distraction spinal cord injury (SCI) during spinal deformity correction surgery. However, the lack of animal models of gradable and replicable distraction SCI has hampered research about how it occurs and how it can be prevented. The rabbit is a suitable choice for a model because it is more similar to humans than the rat, the most often used for studies of distraction SCI. The rabbit is readily acquired and reasonably affordable to maintain.

PURPOSE

The study aims to develop a gradable and replicable animal model of human lumbar distraction SCI.

STUDY DESIGN

This is an animal laboratory study.

METHODS

We built a spine distractor designed to vary the percentage of spine distraction by changing the movement between the bony landmarks of the spine. Anesthetized rabbits underwent surgery to expose the vertebral segments from T12 through L4. The distractor was mounted onto the T12 and L4 vertebral segments, and distraction was effected by turning the distractor's central screw to 0% (control), 10%, 20%, or 30% of the length from the L1 to the L4 vertebral segments, with eight rabbits in each group. Cortical somatosensory evoked potentials were recorded, and neurologic function was evaluated before the distractor was mounted and after the distractor was dismounted. The rabbits were killed, and spinal cord samples were taken for biochemical, histopathologic, and stereologic studies.

RESULTS

With increasing percentage distraction, the extent of distraction SCI increased as measured by recordings of cortical somatosensory evoked potentials, neurologic function, and biochemical, histopathologic, and stereologic studies.

CONCLUSIONS

Our model can be widely applied to studies of the causes of and treatment for distraction SCI.