Craniocervical instability (CCI) is a

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

characterized by excessive movement of the

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

at the

atlanto-occipital joint The atlanto-occipital joint (''Articulatio 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 joint is an ...

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, that can start from C2 To C7. Structure The atlanto-axial joint ...

located between the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

and the top two vertebra, known as C1 and C2. The condition can cause neural injury and compression of nearby structures, including the

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 ...

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

vagus nerve The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

, and

vertebral artery The vertebral arteries are major artery, 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, m ...

, resulting in a constellation of symptoms. Craniocervical instability is more common in people with a

connective tissue disease Connective tissue diseases (also termed connective tissue disorders, or collagen vascular diseases), are medical conditions that affect connective tissue. Connective tissues protect, support, and provide structure for the body's other tissues a ...

, including Ehlers-Danlos syndromes,

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

, and

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

. It is frequently co-morbid with

instability,

Chiari malformation In neurology, the 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 cau ...

, or

tethered spinal cord syndrome Tethered cord syndrome (TCS) refers to a group of neurological disorders that relate to malformations of the spinal cord.physical trauma Injury is physiology, physiological damage to the living tissue of any organism, whether Injury in humans, in humans, Injury in animals, in other animals, or Injury in plants, in plants. Injuries can be caused in many ways, including mechanic ...

, including whiplash, 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 in which patients are bed-bound. The constellation of symptoms caused by craniocervical instability is known as "cervico-medullary syndrome" and includes: *

Anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...

* Bobble-head doll syndrome, a sensation that the skull may fall off the cervical spine *

Clumsiness Clumsy or clumsiness may refer to: Behaviour *Accident-proneness *Developmental coordination disorder, a motor skills disorder which brings about chronic clumsiness Music * ''Clumsy'' (Our Lady Peace album), 1997 ** "Clumsy" (Our Lady Peace song ...

and motor delay *

Cognitive Cognition is the "mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...

and

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...

decline *

Double Double, The Double or Dubble may refer to: Mathematics and computing * Multiplication by 2 * Double precision, a floating-point representation of numbers that is typically 64 bits in length * A double number of the form x+yj, where j^2=+1 * A ...

or blurred vision *

Dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

, or the sensation of being choked *

Dyspnea Shortness of breath (SOB), 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 discomfort that ...

Fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

* Lhermitte's sign *

Migraine Migraine (, ) is a complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea, and light and sound sensitivity. Other characterizing symptoms may includ ...

headaches *

Nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

Neck The neck is the part of the body in many vertebrates that connects the head to the torso. It supports the weight of the head and protects the nerves that transmit sensory and motor information between the brain and the rest of the body. Addition ...

, shoulder, and jaw pain *

Occipital The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone lies over the occipital lobes of the cere ...

headaches A headache, also known as cephalalgia, 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. Head ...

Orthostatic intolerance Orthostatic intolerance (OI) is the development of symptoms when standing upright that are relieved when reclining. There are many types of orthostatic intolerance. OI can be a subcategory of dysautonomia, a disorder of the autonomic nervous ...

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 o ...

* Syncope *Tenderness at base of skull *

Tinnitus Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely ...

Tremor A tremor is an involuntary, somewhat rhythmic muscle contraction and relaxation involving neural oscillations, oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the h ...

s *

Palpitations Palpitations occur when a person becomes aware of their heartbeat. The heartbeat may feel hard, fast, or uneven in their chest. Symptoms include a very fast or irregular heartbeat. Palpitations are a sensory symptom. They are often described as ...

Vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

or dizziness *Weakness of 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, as if blowing up a balloon. Variations of the maneuver can be ...

, or by being upright for long periods of time. The reason that being upright is problematic is that gravity allows increased interaction between the brain stem and the top of the spinal column, increasing symptoms. Lying in the

supine position The supine position () means lying horizontally, with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it grants access to the peritoneal, thoracic, and pericardium, pericardial ...

can bring short-term relief. Lying supine eliminates the downward gravitational pull, reducing symptoms to some degree. Lying with the feet somewhat higher and head lower allows gravity can be helpful in symptom reduction.

Diagnosis

Craniocervical instability is usually diagnosed through neuro-anatomical measurement using

radiography Radiography is an imaging technology, 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 ("diagnostic" radiog ...

. 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 body or a road sign. The most common ones are: left and right; forward and backward; up and down. They fo ...

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

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 ...

CT scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

, 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, a subluxation is a "significant structural displacement" and is therefore visible on static imaging studies, such as X-rays. ...

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 Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

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, although they should not be rou ...

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

References

{{reflist Human diseases and disorders Medical terminology Syndromes affecting the nervous system

Symptoms and signs

Diagnosis

Treatment

See also

References