"What Does Cervical Enlargement of the Spinal Cord Mean?"
The spinal cord, a complex network of organs in our bodies, is often unfamiliar to the average individual unless issues arise. One such aspect is the cervical enlargement of the spinal cord, also known as the neck enlargement. This enlargement can lead to syndromes such as cervical enlargement disease syndrome or spinal cord ischemia syndrome, but it often goes unnoticed until health problems arise. Let's delve deeper into what the cervical enlargement of the spinal cord is and the related diseases.
The cervical enlargement, also referred to as the neck enlargement, is an enlargement in the upper portion of the spinal cord, corresponding to segments 4 of the cervical cord to segment 1 of the thoracic cord, with segment 6 being the most prominent. This enlargement is related to the well-developed upper limb function of humans. The spinal cord has two enlargements, one being the cervical enlargement located between the fourth segment of the cervical cord and the first segment of the thoracic cord. This enlargement is formed due to the abundance of cells and nerve fibers within it, linked to the motor functions of the upper limbs. The other enlargement, known as the lumbar enlargement, is found in the waist region of the spinal cord, extending from the 12th segment of the thoracic cord to the 3rd segment of the lumbar cord. This enlargement also contains a significant number of nerve cells and nerve fibers, and its formation is associated with the formation and function of the lower limbs. Damage to this enlargement can affect lower limb function.
2.1 Cervical Enlargement Disease Syndrome
Clinical manifestations of this syndrome can be divided into mid-cervical cord lesions and lower cervical cord lesions. The initial symptoms of mid-cervical cord lesions (C5-C7) often include spontaneous pain in the lower neck, scapular region, or upper limbs, which can be localized or radiating. If the lesion is centered around C5, diaphragmatic paralysis may be evident, along with muscle weakness and atrophy commonly affecting the deltoid, biceps brachii, triceps brachii, radialis, and extensor carpi radialis longus muscles. Patients often present with a characteristic posture of abducted upper limbs, extended wrists, and flexed fingers. Hyperreflexia of upper limb tendons may be observed in lesions above C5, while loss of biceps brachii reflex and normal triceps brachii reflex may be seen in C5-C6 lesions. Lower cervical cord lesions (C8-T1) primarily manifest as weakness and atrophy of small hand muscles such as the interosseous and lumbrical muscles, flexion of the 3rd to 5th fingers resulting in a claw-like hand due to ulnar nerve paralysis, disappearance of the triceps brachii reflex, and the appearance of Horner's syndrome in C8-T1 lesions.
2.2 Spinal Cord Ischemia Syndrome
Spinal cord vascular diseases are not uncommon in clinical practice. The blood supply to the spinal cord originates from the vertebral arteries, which branch into anterior and posterior spinal arteries that descend along the anterior median fissure and posterior lateral sulcus of the spinal cord, respectively. Additional blood supply comes from the deep cervical, intercostal, lumbar, iliac, and sacral external arteries. The lumbar region of the spinal cord (lumbar enlargement) has a particularly large anterior root artery called the Ad-amkiewicz anterior radicular artery (Lazorthes' lumbar enlargement artery). These vessels penetrate the dura mater, enter the spinal cord along the anterior and posterior roots, and anastomose on the surface of the spinal cord to form a reticulate pattern of coronal arteries that communicate with the anterior and posterior spinal arteries. The coronal arteries branch off to supply the lateral funiculus of the spinal cord. The anterior spinal artery gives rise to central arteries that supply the anterior horn, central gray matter, lateral horn, basal posterior horn, Clare's column, and most of the anterior funiculus and anterior part of the posterior funiculus. The posterior spinal arteries supply the majority of the posterior funiculus, posterior part of the posterior funiculus, and posterior part of the lateral funiculus. It is evident that the anterior spinal artery plays a crucial role in spinal cord blood circulation. Occlusion of this artery can lead to circulatory disturbances in the anterior two-thirds of the spinal cord. Within the spinal cord, the terminal branches of the anterior and posterior spinal arteries are end arteries with limited anastomoses. In the thoracic segment of the spinal cord, blood supply to
