Spine (Vertebral Bodies)
The spine is the bony skeleton, or building blocks, that support your head and skull. The spine is composed of many bones, or vertebral bodies. These vertebral bodies, or vertebrae, appear white on x-ray as they are composed of calcium. There are three main regions that we commonly discuss. This includes the cervical spine (neck), the thoracic spine (chest), and the lumbar spine (low back). The lowest part of your spine includes the sacrum and the coccyx bones, or your “tail bone.”
Intervertebral Discs (Discs)
The spaces between the bones of the spine (vertebral bodies) have a soft area to help spread out the forces placed upon the spine. These soft spaces are known as the discs, or intervertebral discs. These spaces appear dark or black on x-ray since they are not composed of calcium. MRI scans are used to evaluate discs.
The soft material contained within the discs can sometimes be the cause of trouble. This material can actually “spill out” or herniate and can irritate the spinal nerves (or spinal cord in the cervical and thoracic spine). If this happens, it can cause nerve symptoms such as numbness, tingling or a feeling of your leg or buttock falling asleep. If enough material is compressing the nerve, it can even cause muscle weakness.
Degenerative Disc Disease
The discs between our bones change with age, in EVERYONE. As we get older, we get stiffer and the disc heights change due to a number of reasons. Less water is stored in our discs, a natural process, and drinking more water does not change this fact as it is determined by the chemical components of the disc. As the discs undergo this natural aging process, the height between the vertebral bodies is decreased. By decreasing this height, the space available for the nerves exiting from the spine decreases and “pinched nerves” is a common occurrence.
Spinal Cord & Spinal Nerve Disorders and Injuries
The spinal cord is a bundle of nerves that connects nearly all aspects of the body to the brain. The arms, legs and organs within the chest and abdomen, all have connections to the brain by way of the spinal cord. The spinal nerves are large nerves that branch off of the spinal cord. Where the spinal nerve braches from the spinal cord is called the nerve root. The spinal nerves go to specific areas and regions of the body. These nerves are similar to an analogy of a tree; think of the main tree trunk as the spinal cord, and the branches of the tree the spinal nerves or nerve roots.
Radiculopathy (ra dik you lop oh thee) & Myelopathy (my ee lop oh thee)
The fancy name for compression of a spinal nerve or nerve root is “radiculopathy,” and the medical term for compression of the spinal cord is “myelopathy.” These two conditions, although sounding somewhat similar, are much, much different. Compression of a spinal nerve or nerve root can cause numbness, tingling, muscle weakness or a burning pain in the arm, leg or buttock. This can occur in any region of the spine (cervical = neck, thoracic = chest, lumbar = legs and buttocks). On the other hand, compression of the spinal cord (occurring within the cervical and thoracic spine) can cause complete paralysis and a loss of function below the level of compression. Patients with untreated and severe myelopathy are often restricted to a wheelchair and unable to walk.
Stenosis is a medical term meaning narrowing, and this can be applied to any field of medicine. If you put this together with the word spinal, you have “spine narrowing.” The vertebral bodies, the bones of the spine, sit on top of each other with the disc between. There is a hole that forms between the bones, called a foramen, which is where the spinal nerves exit from the spinal canal. Spinal stenosis is a pinching of the nerve root as it passes out of this hole or foramen. Stenosis can be caused from any combination of spine problems and can occur in any region of the spine.
Spondylolysis (spon di low lie sis) & Spondylolisthesis (spon di low lis thesis)
Spondylolysis is a medical term for a stress fracture to the spine. This is a common occurrence in the general population, at least 6% or more of people, and so it is not rare and likely occurs during childhood and adolescence. When a patient has one of these stress fractures, it often does not heal, and can progress to a forward slippage of one vertebral body on top of the other. This slippage is termed spondylolisthesis, and the listhesis simply means a slip. When one vertebrae slips on top of another, there can be a narrowing of the foramen (hole between the bones), and this can be a cause of spinal stenosis.
Any lateral curvature of the spine greater than a certain amount (10 degrees) is termed scoliosis. When a spine curves it also rotates around on itself and can cause a patient to have a prominence that can be seen or felt over their ribs. Many people have some degree of curvature to their spine, and often this is not a problem. However, when the curve becomes severe enough, it can cause compression of nerves and can continue to get bigger and bigger (curve progression). These larger curves can be a source of back pain.
Kyphosis, Lordosis, and Sagittal Balance
Our spines have a natural flow when looking at them from the side. The neck area and the low back have an area that is concave, which is termed lordosis, while the chest and buttock area have a rounded appearance, termed kyphosis. If there is too much or too little of this natural flow to the spine, pain and deformity can develop.
Fractures are “breaks” in bone. Vertebral bodies can fracture just like any other bone in the body. Some fractures are severe and caused by bad traumatic events such as a car accident or a fall from high heights, while other fractures occur from having less bone density (compression fractures from osteoporosis). Some of these spine fractures require surgery to help the bones keep their position while they are healing, while other fractures can be treated with medications to build bone strength, or with bracing to help with pain.
Cauda Equina Syndrome
The lowest spinal nerves exit from the spinal cord and have the appearance of a horses tail, which is where this Latin term originates. When there is severe compression to these lower spinal nerves, those that go to the legs and bowel/bladder, this is termed “cauda equina syndrome.” Symptoms include being unable to control your urine, complete numbness or tingling in your genital area, loss of bowel control, among others. Compression to these nerves, if left untreated, can cause permanent loss of function to the bowel, bladder, legs and possible sexual dysfunction. Prompt diagnosis of this condition and surgical treatment is required.
A collection of blood is called a ‘hematoma’. You are probably familiar with this already, as any skin bruising is a form of a hematoma or collection of blood beneath the skin. When this occurs around the spinal cord or nerves, it is called an ‘epidural hematoma’. These blood collections around the nerves can occur after spine surgery, or these can occur for no particular reason at all, and can happen in patients who are taking blood thinning medications. This condition is potentially very dangerous, and requires prompt diagnosis and treatment. Similar to cauda equina syndrome that is explained above, epidural hematomas can cause permanent loss of function to the bowel, bladder, legs, and possible sexual dysfunction.
Spine Infections (Osteomyelitis, Diskitis, & Epidural Abscess)
Bacteria live all around us and even on our skin. Sometimes, for unknown reasons, these bacteria or other infectious things can get into our bones or disks and form an infection. Infections of the bone are termed osteomyelitis and infections of the disk are called diskitis. These infections are treated mainly with antibiotics through an IV and then with pills by mouth when infectious disease specialists feel it is appropriate and safe to do so. Occasionally, these infections will not improve with medication alone, or even get bigger, causing an abscess (which is a collection of pus) and may require surgical treatment. An epidural abscess is a collection of pus within the spinal canal space where the spinal cord and spinal nerves are located. This can cause permanent and severe damage depending on the location. Surgery could be needed to relieve pressure on the nerves and help clear the infection.
A protective membrane called the dura mater covers the spinal cord and nerves. This means “tough mother” in Latin. This protective covering can be explained to be like layers of cellophane or plastic wrap, encircling the spinal cord and nerves. Contained by this membrane is the spinal cord and nerves that are “floating” in a fluid material called CSF, or cerebrospinal fluid that is produced in the brain. As we get older and age, this tough mother of a membrane isn’t so tough anymore, and it becomes thinner and more friable or delicate. During surgery, this membrane can “spring a leak” so-to-speak, and efforts are made to repair it. If the leaking fluid forms a pocket, it is called a pseudomeningocele. The majority of these pockets of fluid do not require any further treatment, as long as the fluid is contained underneath the skin.