Spinal cord blood supply

Williams GM, Perler BA, Burdick JF et al. (1991) Angiographic localization of spinal cord blood supply and its relationship to postoperative paraplegia. J Vase Surg 13 23-33 discussion 33-25... 

Segmental arteries supply the spine with blood, including the vertebral bodies, paraspinal muscles, dura, nerve roots, and spinal cord. All these tissues, with the exception of the spinal cord, receive their blood supply from segmental arteries (one on each side) or their equivalents. In particular, the segmental supply of the thoracolumbar region is derived from intercostal and lumbar arteries arising from... 

Thus, acute, subacute, or chronic impairment of spinal blood supply can result from a deficient arterial supply and from venous circulatory problems (Mull and Thron 2004). Spinal vascular malformations like spinal dural arteriovenous (AV) fistulas and AV malformations (AVM) of the perimedullary fistula type are the typical disorders associated with venous congestion of the spinal cord. On the other hand, AVM of the glomerular type are seldom combined with a venous outflow disorder. 

The posterior cerebral artery supplies the occipital lobe and portions of the medial and inferior temporal lobe. The arterial supply of the spinal cord is derived from the vertebral arteries and the radicular arteries. The brain is supplied by the internal carotid arteries (the anterior circulation) and the vertebral arteries, which join at the pon tomedullary junction to form the basilar artery (collectively termed the posterior circulation). The brainstem is supplied by the posterior system. The medulla receives blood from branches of the vertebral arteries as well as from the spinal arteries and the posterior inferior cerebellar artery (PICA). The pons is supplied by paramedian and short circumferential branches of the basilar artery. Two major long circumferential branches are the anterior inferior cerebellar artery (AICA) and the superior cerebellar artery. The midbrain receives its arterial supply primarily from the posterior cerebral artery as well as from the basilar artery. The venous drainage of the spinal cord drains directly to the systemic circulation. By contrast, veins draining the cerebral hemispheres and brain stem drain into the dural sinuses. Cerebrospinal fluid also drains into the dural sinuses through unidirectional valves termed arachnoid villi. 

CSF, produced within specialized chambers deep inside the brain, flows over the surface of the brain and spinal cord. This fluid serves to cushion these relatively delicate structures, as well as supplying important nutrients for brain cells. CSF is reabsorbed by blood vessels which are located within the meninges. 

Usually it is the skeletal or striated muscles that will require therapy for painful spasm or will need to be relaxed to allow the surgeon to gain access to the abdomen easily. Muscle spasm may be associated with a trauma or may be brought on by multiple sclerosis, cerebral palsy, stroke, or an injury to the spinal cord. Severe cold, an interruption of blood supply to a muscle, or over exertion of the muscle also can lead to spasms. A muscle spasm actually is an increase in muscle tone brought on by an abnormality in motor control by the spinal nerves. 

The arterial blood supply of the spinal cord is provided by the unpaired anterior spinal artery (ASA) and the paired posterior spinal arteries. These vessels constitute a longitudinally orientated arterial system that is interconnecting with numerous arteries entering transversely and resembling the segmental embryology of the spine (Gillilan 1958 Lasjaunias and Berenstein 1990). 

Neiurosarcoidosis may present as an acute explosive illness or in a slow, chronic fashion (143). Any part of the nervous system may be affected including the cranial nerves, meninges (Fig. 11), pituitary gland, hypothalamus, parenchyma of the brain, brainstem (Fig. 12), spinal cord (Fig. 13), subependymal layer of the ventricular system, peripheral nerves, and blood vessels supplying the nervous structures (143). 

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