Craniocervical instability (CCI) is a

medical condition A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

where there is excessive movement of the vertebrae at the

atlanto-occipital joint The atlanto-occipital joint (''Capsula articularis atlantooccipitalis'') is an articulation between the atlas bone and the occipital bone. It consists of a pair of condyloid joints. It is a synovial joint. Structure The atlanto-occipital join ...

and the

atlanto-axial joint The atlanto-axial joint is a joint in the upper part of the neck between the atlas bone and the axis bone, which are the first and second cervical vertebrae. It is a pivot joint. Structure The atlanto-axial joint is a joint between the atlas ...

, that is, between the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

and the top two

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...

( C1 and C2). This can cause

neuronal A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. No ...

injury and compression of nearby structures including the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

brain stem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is co ...

vertebral artery The vertebral arteries are major arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, midline ba ...

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

, causing a constellation of symptoms. It is frequently co-morbid with atlanto-axial instability,

Chiari malformation Chiari malformation (CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum (the opening at the base of the skull). CMs can cause headaches, difficu ...

and tethered cord syndrome. It is more common in people with a

connective tissue disease A connective tissue disease (collagenosis) is any disease that has the connective tissues of the body as a target of pathology. Connective tissue is any type of biological tissue with an extensive extracellular matrix that supports, binds togeth ...

, notably Ehlers-Danlos Syndrome,

osteogenesis imperfecta Osteogenesis imperfecta (; OI), colloquially known as brittle bone disease, is a group of genetic disorders that all result in bones that break easily. The range of symptoms—on the skeleton as well as on the body's other organs—may b ...

and

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are invol ...

. It can be brought on by a trauma, frequently

whiplash Whiplash may refer to: * The long flexible part of a whip * Whiplash (medicine), a neck injury ** Whiplash Injury Protection System (WHIPS), in automobiles Film and television * ''Whiplash'' (1948 film), a US film noir about a boxer * ''Whiplas ...

; laxity of the ligaments surrounding the joint; or other damage to the surrounding connective tissue.

Symptoms and signs

The impact of craniocervical instability can range from minor symptoms to severe disability, with some patients being bed-bound. The constellation of symptoms caused by craniocervical instability has been labelled the cervico-medullary syndrome. Common symptoms include: * Occipital

headaches Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

* Migraine Headaches * neck, shoulder and jaw pain * difficulty swallowing, or the sensation of being choked * tenderness at base of skull * feeling of 'bobble-head', where the skull may 'fall off' the spine *

photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...

* double or blurred vision *anxiety *

tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...

* tremors * orthostatic intolerance * vertigo or dizziness * palpitations *

shortness of breath Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

* fatigue *

Lhermitte's sign Lhermitte phenomenon, also called the barber chair phenomenon, is an uncomfortable "electrical" sensation that runs through the back and into the limbs. The sensation can feel like it goes up or down the spine. It is painful for some, although oth ...

* cognitive and memory decline * clumsiness and motor delay *

fainting Syncope, commonly known as fainting, or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from ...

* weakness of the limbs Symptoms are frequently worsened by a

Valsalva maneuver The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air out as if blowing up a balloon. Variations of the maneuver can ...

or by being upright for long periods of time. Lying

supine In grammar, a supine is a form of verbal noun used in some languages. The term is most often used for Latin, where it is one of the four principal parts of a verb. The word refers to a position of lying on one's back (as opposed to ' prone', l ...

can bring short-term relief. The reason that being upright is problematic is that gravity is allowing increased interaction between the brain stem and the top of the spinal column, increasing symptoms. Lying supine eliminates the downward gravitational pull, reducing symptoms to some degree. Lying with the feet somewhat higher and head lower (Trendelenberg) allows gravity to work somewhat in the patient's favor.

Diagnosis

Craniocervical instability is usually diagnosed through neuro-anatomical measurement using

radiography Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeu ...

. Digital Motion X-ray is considered the most accurate method.

Upright Body relative directions (also known as egocentric coordinates) are geometrical orientations relative to a body such as a human person's. The most common ones are: left and right; forward(s) and backward(s); up and down. They form three pairs ...

magnetic resonance imaging,

magnetic resonance imaging, CT scan, and flexion and extension x-rays may also be used but are far less accurate and have a much higher potential for false negatives. The measurements to diagnose craniocervical instability are: * Clivo-Axial Angle equal or less than 135 degrees * Grabb-Oakes measurement equal or greater than 9 mm * Harris measurement greater than 12mm * Spinal

subluxation A subluxation is an incomplete or partial dislocation of a joint or organ. According to the World Health Organization (WHO), a subluxation is a "significant structural displacement", and is therefore always visible on static imaging studies, suc ...

Alternatively, craniocervical instability can be diagnosed if a trial of cervical traction, typically using a halo fixation device, results in a significant alleviation of symptoms.

Treatment

Conservative treatment of craniocervical instability includes physical therapy and the use of a

cervical collar A cervical collar, also known as a neck brace, is a medical device used to support and immobilize a person's neck. It is also applied by emergency personnel to those who have had traumatic head or neck injuries, and can be used to treat chronic ...

to keep the neck stable. Cervical spinal fusion is performed on patients with more severe symptoms.

Prolotherapy Prolotherapy, also called proliferation therapy, is an injection-based treatment used in chronic musculoskeletal conditions. It has been characterised as an alternative medicine practice. Medical uses A 2015 review found no evidence that prolother ...

, including with

stem cells In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of ...

, is another treatment option used, but there is limited scientific evidence on this approach.

References

{{reflist

External links

Ehlers Danlos Society

Bobby Jones Chiari & Syringomyelia Foundation
Human diseases and disorders Medical terminology

Symptoms and signs

Diagnosis

Treatment

See also

References

External links