M02.01.07 The spinal cord

The spinal cord is a vital part of the central nervous system (CNS) that extends from the base of the brain, through the vertebral column, down to the lower back. It serves as a communication pathway between the brain and the peripheral nervous system. Here’s a detailed overview of the spinal cord’s anatomy, blood supply, and clinical relevance:

Anatomy:

• Segments: The spinal cord is divided into segments, typically grouped into cervical, thoracic, lumbar, sacral, and coccygeal regions. There are 31 pairs of spinal nerves that emerge from these segments.
• Grey Matter: The inner portion of the spinal cord consists of grey matter, which is butterfly-shaped in cross-section. It contains neuronal cell bodies, interneurons, and synapses.
• White Matter: Surrounding the grey matter, the white matter is composed of myelinated nerve fibers that transmit signals up and down the spinal cord. These fibers are organized into ascending (sensory) and descending (motor) tracts.
• Central Canal: Running through the center of the spinal cord is the central canal, which contains cerebrospinal fluid (CSF). The CSF provides nourishment and protection to the spinal cord.

Blood Supply:

• Anterior Spinal Artery: Arises from branches of the vertebral arteries and supplies the anterior two-thirds of the spinal cord, including the grey and white matter.
• Posterior Spinal Arteries: Arise from branches of the posterior cerebral arteries and supply the posterior one-third of the spinal cord.
• Segmental Arteries: Arise from various sources, including the vertebral, intercostal, and lumbar arteries. These arteries supply the spinal cord at specific levels along its length.

Clinical Relevance:

• Spinal Cord Injury: Trauma to the spinal cord can result in various degrees of injury, leading to loss of motor function, sensory deficits, and potential paralysis. The level and severity of the injury determine the extent of functional impairment.
• Spinal Cord Compression: Conditions such as herniated discs, spinal tumors, or spinal stenosis can cause compression of the spinal cord, leading to symptoms such as pain, weakness, sensory changes, and loss of bladder or bowel control.
• Spinal Cord Disorders: Various disorders can affect the spinal cord, including spinal cord tumors, syringomyelia (cyst formation within the spinal cord), myelitis (inflammation of the spinal cord), and spinal cord infarction (stroke). These conditions can cause neurological deficits and require appropriate diagnosis and treatment.
• Spinal Cord Vascular Malformations: Abnormalities of blood vessels in the spinal cord, such as arteriovenous malformations (AVMs), can lead to bleeding or restricted blood flow, resulting in spinal cord dysfunction.
• Spinal Cord Syndromes: Certain conditions, such as anterior spinal artery syndrome or Brown-Séquard syndrome, are characterized by specific patterns of neurological deficits due to damage or interruption of specific spinal cord tracts.
• Spinal Cord Surgery: Surgical interventions, including decompression procedures, tumor removal, or stabilization of spinal fractures, may be necessary to address specific spinal cord conditions and restore function.

Understanding the detailed anatomy, blood supply, and clinical relevance of the spinal cord is crucial for diagnosing and managing spinal cord injuries, disorders, and related conditions. Diagnostic techniques such as MRI, CT scans, and neurological assessments are used to evaluate spinal cord health and identify abnormalities. Treatment approaches may involve medications, physical therapy, rehabilitation, or surgical interventions, depending on the underlying condition and its impact on spinal cord function.