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Chiari Malformation
Also known as Arnold-Chiari Malformation or ACM, this is a very rare structural condition affecting the cerebellum. Essentially there is extra cerebellum crowding the outlet of the brainstem/spinal cord from the skull on its way to the spinal canal. This crowding will commonly lead to severe headaches, neck pain, loss of balance, tingling in the arms and/or legs, stiffness, and less often will cause problems such as chronic coughing, difficulties with swallowing, and choking. Often the symptoms are made worse with straining.
Untreated, the chronic crowding of the brainstem and spinal cord can lead to very serious consequences including paralysis. In addition they can lead to the development of syrinxes which may further injure the patients spinal cord and function. These malformations are very difficult to see on CT scans and impossible to see on plain x-rays.The Chiari Malformation can be seen in MRI's showing the cranio-cervical junction (either brain or Cervical Spine MRI's).  Typically, radiologists only know the "traditional" definition of Chiari, as tonsillar herniation.  Also, many neurologists and neurosurgeons haven't heard of chiari, while others have learned the "traditional" definition of CM.  All of these things contribute to the common misdiagnosis of the condition.
Chiari can present with a wide variety of symptoms, because the cerebellum and the brainstem are often compressed, which leads to a variety of neurologic symptoms. 

There are many ways to treat Chiari malformations, but all require surgery. The basic operation is one of uncrowding the area at the base of the cerebellum where it is pushing against the brainstem and spinal cord. This is done by removing a portion of bone at the base of the skull deep to the neck muscles as well as often removing a part of the back of the first and occasionally additional spinal column segments.

After so much controversy and confusion regarding chiari and it's diagnosis, this is a landmark study by Dr. Thomas Milhorat, from the Chiari Institute. If all neurosurgeons would read this, it would put an end to misdiagnosis and confusion. (Let me know if you have any trouble viewing pdf (acrobat) files.)

Here are some other sites that have good information about Chiari (some of the design/navigation is better than others, but that can't be helped).

The Chiari Institute (with overviews of Chiari Malformations, Syringomyelia, diagnosis, treatment etc)

Overview about Chiari

Chiari Syringomyelia News
They also have some pdfs of patient awareness sheets and stuff you can download and print out (Chiari Awareness sheet, Syringomyelia Awareness sheet, Chiari Patient Education sheet, Syringomyelia Patient Education sheet).

The World Arnold Chiari Malformation Association Click the onsite info link to start with...there is a lot there.

Chiari Malformation I

American Syringomyelia Alliance Project (ASAP)

Syrinx/Syringomyelia (being looked at as a matter of course)(NOTE: This was ruled out for me)

Syringomyelia, often referred to as SM, is a chronic disorder involving the spinal cord. For reasons that are only now being understood, cerebrospinal fluid enters the spinal cord, forming a cavity known as a syrinx. (Doctors sometimes use other words such as cyst, hydromyelia or syringohydromyelia) This syrinx often expands and elongates over time, destroying the center of the spinal cord. As the nerve fibers inside the spinal cord are damaged, a wide variety of symptoms can occur, depending upon the size and location of the syrinx. There are two major types of SM. In most cases it is related to a congenital malformation involving the hindbrain (cerebellum) called a Chiari I Malformation, named after the physician who first described it. This malformation occurs during fetal development and is characterized by downward displacement of the lower part of the brain (cerebellar tonsils) beneath the foramen magnum, into the cervical spinal canal. This displacement blocks the normal flow of cerebrospinal fluid. When normal flow is obstructed, a syrinx can then form in the spinal cord. Not all patients with Chiari Malformations will develop a syrinx, however.
SM can also occur as a complication of trauma, meningitis, tumor, arachnoiditis, or a tethered spinal cord. In these cases the syrinx forms in the section of the spinal cord damaged by these conditions. As more people are surviving spinal cord injuries, more cases of post-traumatic SM are being diagnosed as the syrinx can form years after the trauma.


Spina Bifida Occulta (being looked at due to red markings on my lower back and a coccygeal pit (dimple) also on my lower back)(NOTE: This was ruled out for me)

Spina bifida is a defined as any abnormal development of the bones of the spine that display a typical pattern, with or without the involvement of the brain, nerves or covering of the nerves (meninges). It is the most common congenital spine abnormality. The term spina bifida covers a range of malformations that always include deformities of certain parts of the vertebrae, the spinous process and vertebral arch. Some have described this process as a failure of these bones to fuse during early fetal development.

Most common locations are the lower thoracic, lumbar, and sacral spine. The cause behind this congenital malformation is not well understood. Data suggests that genetic factors play a predominant role, but nutritional and environmental factors may also contribute to the development of spina bifida. Spina bifida is broken down into two categories: spina bifida occulta and open spina bifida. These subtypes are distinguished by the absence or presence of nerves, fluid that surrounds the nerves (CSF), and the meninges that are included within the deformity.

Since there is no opening to the skin, spina bifida occulta can only be seen on x-ray or MRI. Certain clinical findings such as dimpling of the skin or a hairy patch at the base of the spine may trigger further investigation by a physician. Underlying spinal nerve abnormalities can be seen in these situations. There is inconclusive evidence that this type of deformity is related to back pain, scoliosis, or nighttime bed-wetting. A large study showed that in patients not complaining of back pain, almost 20% had uncomplicated spina bifida occulta. If you have an abnormality on an x-ray, it does not always mean that this is causing your pain.
A good site is the Spina Bifida Association of America.


Tethered Cord (being looked at due to red markings on my lower back and a coccygeal pit (dimple) also on my lower back)(NOTE: This was ruled out for me)

Tethered Spinal Cord Syndrome is a disorder characterized by progressive neurological deterioration that results from compression of the lowermost bundle of nerves of the spinal cord (cauda equina). It is most commonly associated with a defective closing of the neural tube (precursor of the spinal column) during embryonic development (Spina Bifida).

The spinal cord extends from the base of the brain through the boney spine to the lower back. Soon after conception, special cells come together to form a tube that will become your baby's spinal cord. If this tube does not completely close, the spinal cord can become tethered. The cord is said to be "tethered" when it is abnormally attached within the boney spine.
The spinal cord can also become tethered with spina bifida occulta. This can occur without visible outward signs although usually half the children have visible symptoms.
This may not be a problem until the child develops symptoms. Normally the spinal cord is able to move freely when your child bends or stretches but when it is tethered, it is stretched, especially with those movements. This abnormal stretching puts tension on the cord that can cause permanent damage to the muscles and nerves that control the legs, feet, bowel and bladder. Early detection and treatment is important to prevent this from occurring.

* Note the pic on this page isn't of me, just an example image.