MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction.Abstract
We evaluated objective diagnostic methods for patients with possible upper cervical spine instability caused by trauma and correlated them with subsequent neurosurgical findings and outcomes. Between November 1995 and May 1998, we investigated 420 patients with functional magnetic resonance imaging functional magnetic resonance imaging
n. Abbr. fMRI
Magnetic resonance imaging that provides three-dimensional images of the brain based on changes in blood flow and that can be correlated with brain functions. (MRI 1. (application) MRI - Magnetic Resonance Imaging.
2. MRI - Measurement Requirements and Interface. ) of the craniocervical junction. We evaluated the extracranial extracranial
external to the cranial vault.
when the cause of the convulsions is external to the brain, e.g. hypocalcemic tetanic convulsions. vertebral ver·te·bral
1. Of, relating to, or of the nature of a vertebra.
2. Having or consisting of vertebrae.
3. Having a spinal column. circulation by MRI angiography angiography
X-ray examination of arteries and veins with a contrast medium to differentiate them from surrounding organs. The contrast medium is introduced through a catheter to show the blood vessels and the structures they supply, including , with focus on the position of the dens and on the subarachnoid space sub·a·rach·noid space
The space between the arachnoid membrane and pia mater that is filled with cerebrospinal fluid and contains the large blood vessels that supply the brain and spinal cord. during entire rotational maneuvers. We documented 72 cases (17.1%) of injuries to the alar ligaments that were accompanied by signs of instability. Twenty patients (4.8%) had a complete alar ligament rupture, and 52 (12.4%) had an incomplete rupture with coexisting instability. We referred these patients to a neurosurgeon neurosurgeon
a physician who specializes in neurosurgery.
neurosurgeon A surgeon specialized in managing diseases of the brain, spine and peripheral nerves Meat & potatoes diseases Brain tumors, spinal cord disease Salary $245K + 15% bonus. . Surgery was eventually chosen for 42 patients (10.0%) with the intention of obtaining dorsal occipitocervical stabilization. The duration of time between the MRI evaluation and surgery ranged from 1 week to 1.5 years (me an: 3.5 mo). After the fifth postoperative day, almost all symptoms had disappeared. One year following surgery, 34 of the 42 patients (80.9%) still demonstrated successful fusion and an alleviation of their sensation of instability. Twenty-five of these patients (59.5 %)--all of whom were unemployed before surgery--were able to resume a professional activity. In the eight patients (19.0%) who still had a loss of stability during the second and 14th weeks, we noticed that there were some negative effects of rehabilitation. Six of these patients developed pseudarthrosis or osteolysis osteolysis /os·te·ol·y·sis/ (os?te-ol´i-sis) dissolution of bone; applied especially to the removal or loss of the calcium of bone.osteolyt´ic
n. of their bone grafts during the first 3 months after fusion, and three required a repeat operation. We conclude that functional MRI functional MRI Fast MRI Imaging A brain imaging technique that measures ↑ blood flow–BF which, like PET, relies on changes in BF and oxygenation due to brain activity; aerobic metabolism in some neurons creates a local ↑ in deoxyHb, which triggers with lateral tilting and rotatory ro·ta·to·ry
1. Of, relating to, causing, or characterized by rotation.
2. Occurring or proceeding in alternation or succession. evaluation is a useful tool for investigating craniocervical instability. For patients who are recalcitrant to following a program of conservative therapy, surgical stabilization of the craniocervical junction appears to be justified.
Patients who experience an injury to their cervical spine cervical spine Clinical anatomy The region of the vertebral column encompassing C1 through C7 after an acceleration trauma often present problems with respect to the correct diagnosis. Particularly difficult to recognize are injuries to the cervicocephalic area because there is currently a lack of objective diagnostic criteria. The craniocervical ligaments and fibrous capsules are not visible on plain radiographs. A widened or uneven atlantodental distance implies that the alar ligaments are disrupted or dysfunctional.
Approximately 25% of all patients with cervical distortion and injury to the soft tissues of the neck experience cervical and/or neck pain up to 4 to 7 years later--pain that requires continual orthopedic, manual, pharmacologic, or other therapy. [1,2] Several authors have postulated that cervical spine instability is a consequence of injury to the ligaments. [3-6] Conventional x-ray studies and functional computed tomography Computed tomography (CT scan)
X rays are aimed at slices of the body (by rotating equipment) and results are assembled with a computer to give a three-dimensional picture of a structure. (CT) can be helpful in determining the various angles of anatomic markers in the spine. [4,7,8] However, the usefulness of these imaging studies is dependent on the degree of the patient's relaxation and do not always correspond with the degree of functional impairment. It is known that the atlanto-occipital plane and therefore the socle so·cle
1. A plain square block higher than a plinth, serving as a pedestal for sculpture, a vase, or a column.
2. A plain plinth supporting a wall. joint (C2 vertebral body) are especially vulnerable to indirect trauma.  Also, the horizontally oriented facet joints and capsules between the atlas and axis can be affected by accentuated axial rotation, which can injure the alar ligaments.
Since the introduction of functional magnetic resonance imaging (fMRI) on an open magnet, it has been possible to observe the functional condition of the ligaments and the atlantoaxial joints on a video loop. One study attempted to classify alar-atlantoaxial joint instability and the related regional injuries in order to better understand the result of biomechanical damage to the ligaments during overstretching. 
Saternus found that among 397 victims of high-speed trauma, 340 (85.6%) had evidence of upper cervical ligamentous lesions, while only 57 (14.4%) had bone fractures. 
Functional MRI video diagnosis does not focus on injuries to the ligamentous microstructure mi·cro·struc·ture
The structure of an organism or object as revealed through microscopic examination.
a structure on a microscopic scale, such as that of a metal or a cell as does high-resolution MRI. Instead, it directly visualizes instability of the craniocervical junction.  It is generally accepted that increased axial rotation instability of the upper cervical spine can cause symptoms such as severe occipital occipital /oc·cip·i·tal/ (ok-sip´i-t'l) pertaining to the occiput; located near the occipital bone.
Of or relating to the occipital bone.
n. headache and pain and tenderness in the adjoining neck muscles. Other concomitant complaints can include dizziness, tinnitus Tinnitus Definition
Tinnitus is hearing ringing, buzzing, or other sounds without an external cause. Patients may experience tinnitus in one or both ears or in the head. , paresthesia paresthesia /par·es·the·sia/ (par?es-the´zhah) morbid or perverted sensation; an abnormal sensation, as burning, prickling, formication, etc.
par·es·the·sia or par·aes·the·sia
n. , visual disturbance, cognitive impairment, sleep disturbance, vegetative vegetative /veg·e·ta·tive/ (vej?e-ta?tiv)
1. of, pertaining to, or characteristic of plants.
2. concerned with growth and nutrition, as opposed to reproduction.
3. symptoms, inability to ride a bicycle, and darkness orientation disturbances. [13,14]
Patients and methods
Between November 1995 and May 1998, we studied 420 patients (228 females, 192 males), aged 17 to 55 years (mean: 37), who had a history of trauma involving the upper cervical spine. We performed fMRI with a 0.2 Tesla Magnetom Open imager (Siemens; Erlangen, Germany) that was equipped with a device that allowed for lateral tilting and transverse rotation of the cervical spine. The causes of these traumas included high-speed motor vehicle or automobile-pedestrian collisions (n = 371), falls from high elevations (n = 18), sports play (n = 16), and bicycle or motorbike accidents (n = 15). We excluded from our study patients younger than 17 years of age and patients who had open, penetrating spinal injuries, metabolic bone disease metabolic bone disease Any defect in bone absorption or deposition that alters the PTH/calcium-phosphate/vitamin D axis, often with ↑ bone fragility Etiology Fibrous dysplasia, Langerhans' cell histiocytosis/histiocytosis X, acromegaly, corticosteroid therapy, , ankylosing spondylitis Ankylosing Spondylitis Definition
Ankylosing spondylitis (AS) refers to inflammation of the joints in the spine. AS is also known as rheumatoid spondylitis or Marie-Strümpell disease (among other names). , rheumatoid arthritis rheumatoid arthritis
Chronic, progressive autoimmune disease causing connective-tissue inflammation, mostly in synovial joints. It can occur at any age, is more common in women, and has an unpredictable course. , or generalized connective tissue diseases.
The duration of time between the trauma and the MRI ranged from 4 months to 5 years (mean: 2.7 mo). Most patients had earlier undergone plain radiography, and some had undergone thin-section CT or high-resolution MRI under static conditions. Before undergoing fMRI, all patients underwent MRI angiography of the cervical vertebral arteries. When necessary, we monitored heart rate and respiratory function during the imaging process with an MR-fiberoptic pulse oximeter pulse oximeter
A device, usually attached to the earlobe or fingertip, that measures the oxygen saturation of arterial blood.
pulse oximetry n. (Nonin 8600 FO, Mediquip; Kirchzarten, Germany). There was continuous, direct-view visual monitoring of the patient. Our decision to use an open magnet was based on our familiarity with clinical manual therapy--specifically, tilting the neck step by step to the right and left as a single investigation and rotating the neck to the right and left as a separate investigation. No anesthesia was necessary. Under our protocol, the procedure could be interrupted if the patient lost consciousness or developed a blockage in the upper cervical spine that co uld irritate the vertebrobasilar circulation. The details of the MRI parameters and characteristics have been reported elsewhere.  Circular surface coils of different diameters were used to improve the anatomic resolution at the target point. We obtained thin slices, mostly between 4 and 5 mm, that were oriented to the exact location of the alar ligaments, either horizontally or off-axis.
We used several pulse sequences, including fast-spin echo (for the motion video loop) and gradient echo as T1-and T2-weighted images. No three-dimensional gradient sequences with secondary reconstruction were used. In order to characterize the instability patterns of the craniocervical joint, especially in the dens and the alar ligaments, we established two criteria to indicate the local motion of the dens: the left-to-right tumbling of the dens ("dancing dens") and the anterior-to-posterior movement during MRI video documentation (figures 1 and 2). In order to identify instability of the craniocervical junction, it is necessary to keep attention focused on the position of the dens, the surrounding dens capsula capsula /cap·su·la/ (kap´su-lah) pl. cap´sulae [L.] capsule.
n. pl. cap·su·lae
1. , and the dimension of the subarachnoid space during the entire rotational maneuver. The types of ligamentous lesions and the identification of instability were documented with respect to the patient's neurotologic and orthopedic presentation, to the operative treatment, and to the patient's outcome.
We found that 72 patients had documented signs of instability, including ligamentous injuries, fibrous capsule ruptures of C1-C2, or trauma to the dens-related capsula. These patients were referred to a neurosurgeon. Surgery was chosen for 42 patients (10.0%) with the intention of obtaining dorsal occipitocervical stabilization. The duration of time between the MRI evaluation and surgery ranged from 1 week to 1.5 years (mean: 3.5 mo). Under the surgical plan, it was initially decided to insert only the bone transplant between C0 and C2 and fix it with a titanium wire. Rotating movements between C1 and C2 were still possible.
Because pseudarthrosis can occur as a result of a recurrence of instability and clinical symptoms, we decided to insert an additional screw, thereby reintroducing an old method described by Magerl.  Essentially, this involved a posterior surgical approach to the craniocervical junction. With fluoroscopic Fluoroscopic (fluoroscopy)
An x-ray procedure that produces immediate images and motion on a screen. The images look like those seen at airport baggage security stations.
Mentioned in: Hypotonic Duodenography guidance, we placed titanium screws into predrilled holes, starting at the arch of C2 and proceeding in the direction of the lateral mass of C1 (figure 3). We paid careful attention to avoiding the intravertebral artery. We achieved further stabilization from C0 to C2 over the spinous process spinous process
1. See sphenoidal spine.
2. The dorsal projection from the center of a vertebral arch.
spinous process with cortical and spongy spongy /spon·gy/ (spun´je) of a spongelike appearance or texture.
Resembling a sponge in appearance, elasticity, or porosity. autogenous autogenous /au·tog·e·nous/ (aw-toj´e-nus) autologous.
au·tog·e·nous or au·to·gen·ic
1. Of or relating to autogenesis; self-generating.
2. bone graft, which was harvested from the posterior iliac crest iliac crest
The long, curved upper border of the wing of the ilium. and fixed with titanium wiring though two occipital burr holes to the right and left of midline mid·line
A medial line, especially the medial line or plane of the body.
n the line equidistant from bilateral features of the head. . Further attachment of the bone graft was achieved with "figure 8" wiring to the spinous process of C1 and C2. With this new technique, we were able to achieve immediate and reliable stability.
During followup, we noticed that there was some instability between C0 and C2 in all patients because of the loss of some of the bone graft. We believed that the primary cause of this was the normal movement of the cervical spine. It was our recommendation that a plate be installed between C0 and C2 with fixation screws inserted into the lateral mass of C2 and into the large surface areas of the occipital bone occipital bone
A bone at the lower and posterior part of the skull, consisting of basilar, condylar, and squamous parts and enclosing the foramen magnum. . Even though this procedure prevents rotational movement of the head either to the left or right, it does guarantee that there will be no future separation of C0-C2, such as was the case with the titanium wire. Nowadays, the operative procedure consists of a complete titanium-plate fixation from the occiput occiput /oc·ci·put/ (ok´si-put) the back part of the head.occip´ital
n. pl. oc·ci·puts or oc·cip·i·ta
The back part of the head or skull. to C2 in combination with the Magerl procedure.
Followup data were obtained from hospital medical records, rehabilitation clinics, outpatient charts, and telephone interviews. The collection of followup data is still in progress.
Among the 420 patients we investigated, 20 (4.8%) had a complete rupture of the alar ligament and 52 (12.4%) had an incomplete rupture (table). Twenty-eight of these patients had a coexisting elongation of the transverse atlantal ligament and a malfunction in the contralateral contralateral /con·tra·lat·er·al/ (-lat´er-al) pertaining to, situated on, or affecting the opposite side.
adj. alar ligament. In addition, some of these patients had rupture signs of either the C1-C2 or C2-C3 fibrous capsule. Such a rupture was visible only on maximum contralateral tilting, which caused a subluxation subluxation /sub·lux·a·tion/ (sub?luk-sa´shun)
1. incomplete or partial dislocation.
2. in chiropractic, any mechanical impediment to nerve function; originally, a vertebral displacement believed to impair nerve of C2.
Eighty-one patients (19.3%) had a variation in their intraligamentous signal pattern that was probably caused by granulation tissue Granulation tissue
A kind of tissue formed during wound healing, with a rough or irregular surface and a rich supply of blood capillaries.
Mentioned in: Granuloma Inguinale
n , and their MRI videos showed evidence of instability. A total of 102 patients (24.3%) had a signal variation in their alar ligaments, but no demonstrable video instability. Another 158 patients (37.6%) showed no evidence of instability in the craniocervical junction and no loss of signal in the alar ligaments. Four patients (1.0%) had dens variations, and three others (0.7%) had elasticity syndromes, such as Ehlers-Danlos syndrome Ehlers-Danlos Syndrome Definition
The Ehlers-Danlos syndromes (EDS) refer to a group of inherited disorders that affect collagen structure and function. and Marfan's syndrome. Only 12 of the 52 patients (23.1%) who had an incomplete rupture exhibited a periosteal periosteal /peri·os·te·al/ (-os´te-al) pertaining to the periosteum.
pertaining to or emanating from the periosteum. pathology at the insertion of the alar ligaments on the dens. All 20 patients who had a ruptured alar ligament had intraligamentous signal changes in the transverse ligament.
In the 42 patients who underwent stabilization surgery, almost all symptoms had disappeared by postoperative day 5, and considerable improvement was seen in their equilibrium, especially while riding a bicycle. One patient required a repositioning of a screw prior to discharge because of severe unilateral headache.
In most cases, radiographic radiographic (rā´dēōgraf´ik),
adj relating to the process of radiography, the finished product, or its use. followup was performed 6 to 8 weeks following the operation. At the 1-year followup, 34 of the 42 surgical patients (80.9%) maintained successful fusion and alleviation of their sensation of instability. Twenty-five of these patients (59.5%)--all of whom were unemployed before surgery--were able to resume a professional activity. In the eight patients (19.0%) who still had a loss of stability during the second and 14th weeks, we noticed that there were some negative effects of rehabilitation. Six of these patients developed a pseudarthrosis or an osteolysis of their bone graft during the first 3 months after fusion, and three required a repeat operation.
This is the first followup study based on fMRI video diagnosis to evaluate patients with craniocervical instability caused by a loss of normal function of the alar ligaments after a nonpenetrating cervical spine trauma cervical spine trauma Orthopedics A traumatic event, especially common in contact sports, resulting in cervical spine injury, see there . When one alar ligament is injured, the main mechanism of motion restriction--axial rotation--is no longer limited. During trauma, especially rear-end automobile accidents that involve a whiplash whiplash n. a common neck and/or back injury suffered in automobile accidents (particularly from being hit from the rear) in which the head and/or upper back is snapped back and forth suddenly and violently by the impact. mechanism and a rotation component, the ligaments are most vulnerable when the head is initially flexed and rotated. 
We do not perform rotational CT as described by Dvorak et al  and Penning  because patients have only a limited ability to move inside the gantry Gantry
A name for the couch or table used in a CT scan. The patient lies on the gantry while it slides into the x-ray scanner portion.
Mentioned in: Computed Tomography Scans . Also, the anatomic variants of the alar, dental, and transverse ligaments are not revealed by functional CT. In addition, some patients are unable to bend sideways or perform a physiologic maximum rotation. In patients who have vertebral artery territory insufficiency, MRI evaluation should first exclude intravertebral artery pathology because of the risk of restricted blood flow through the contralateral intravertebral artery during passive rotation to the opposite side. In this situation, we performed standby monitoring to minimize the risk of a drop attack. Through direct controlled posturing of the patient, we were able to recognize patient discomfort early.
A previous study showed that seven of 95 patients (7.4%) who underwent fMRI of the upper cervical spine experienced unilateral changes in vertebral artery blood flow, and some had hypoplasia hypoplasia /hy·po·pla·sia/ (-pla´zhah) incomplete development or underdevelopment of an organ or tissue.hypoplas´tic
enamel hypoplasia .  We concur with Willauschus et al that there is only a low incidence of complete rupture of ligaments in accident victims (4.8% of our patients).  We are also in agreement with Dvorak et al  and Dickman et al,  who suggested that the mechanism of injury in the upper cervical spine occurs first with a rupture of the alar ligaments; only after a complete separation of the alar ligaments has occurred might there be a rupture of the transverse atlantodental ligament. The alar ligaments might be more vulnerable to separation because they are composed mainly of collagenous fibers and they contain few elastic fibers.  They are relatively weak compared with other ligaments.  Restoration of the strength of these nonfunctional ligaments has not been reported.
One unresolved diagnostic imaging problem is the alteration of signals in patients who have functionally normal craniocervical ligaments. Based on the observation of incomplete rupture of other ligaments--such as those in the shoulder, knee, and ankle joint --we can anticipate that if scarring forms in the disrupted, over-stretched alar ligament, it would manifest as an inhomogeneous Adj. 1. inhomogeneous - not homogeneous
heterogeneous, heterogenous - consisting of elements that are not of the same kind or nature; "the population of the United States is vast and heterogeneous" , asymmetrical band mass. However, this has not been established with certainty. Therefore, we should endeavor to improve our understanding of the osseous osseous /os·se·ous/ (os´e-us) of the nature or quality of bone; bony.
Composed of, containing, or resembling bone; bony. , ligamentous, capsular cap·su·lar
Of, relating to, or resembling a capsule.
Adj. 1. capsular - resembling a capsule; "the capsular ligament is a sac surrounding the articular cavity of a freely movable joint and attached to the bones" , and facet-joint variations at the craniocervical junction. [5,9] Before performing an fMRI study in an open system with controlled movements, physicians must be cognizant of the embryologic em·bry·ol·o·gy
1. The branch of biology that deals with the formation, early growth, and development of living organisms.
2. The embryonic structure or development of a particular organism. vascular anatomy and its variants, as well as the defined elasticity syndromes. In our series of 420 patients, we identified 267 (63.6%) with intact stability; 158 of them (37.6% of the total) had signal continuity of the alar ligaments. Moreover, these 267 patien ts might have experienced a nociceptive no·ci·cep·tive
1. Causing pain. Used of a stimulus.
2. Caused by or responding to a painful stimulus. input failure between the fibrous capsule, the facet-joint synovial membranes, and the interaction of the muscles of the cervicocephalic region. [2,9]
Before considering invasive stabilization surgery, it is imperative that the surgeon scrutinize the MRI signal-intensity patterns of the alar ligaments in order to clearly identify functional as well as anatomic instability. In order to define instability of the craniocervical junction, attention should be given to the position of the densrelated region and the dimensions of its subarachnoid space during the entire rotational maneuver.  However, what is truly at the basis of instability will have to be clarified in prospective, controlled, and coordinated outcomes studies by the investigating physicians and the surgeons. Controlled, double-blind outcomes research would be difficult to design for patients who undergo such invasive surgery.
We must not overlook the fact that a cervical disk herniation herniation /her·ni·a·tion/ (her?ne-a´shun) abnormal protrusion of an organ or other body structure through a defect or natural opening in a covering, membrane, muscle, or bone. might be the cause of severe pain, and that significant alleviation of symptoms can be obtained for most of these patients with anterior cervical fusion. Before operating on the upper cervical spine, the surgeon should obtain a routine MRI and, if possible, an anterior-to-posterior MRI under flexion flexion /flex·ion/ (flek´shun) the act of bending or the condition of being bent.
1. The act of bending a joint or limb in the body by the action of flexors.
2. and extension. 
In conclusion, fMRI video analysis is a noninvasive investigation to establish instability of the craniocervical junction, especially of the alar ligaments. Routine evaluation of the extracranial vertebral circulation by MRI angiography is an additional preinvestigative recommendation. The mechanism of alar-craniocervical junction instability might be consistent with a severe rotatory-type trauma to the upper cervical spine, such as might occur in an acceleration-deceleration strain to the neck or head while it is in a rotated and flexed position. This type of injury is different from the more typical whiplash event. Surgery is indicated for established unstable injuries when the patient experiences intractable neck pain that has failed to respond to conservative management. In our study, 42 patients with unstable alar ligament injuries and contralateral joint rupture were stabilized by dorsal fusion of CO-Cl-C2. Functional MRI video was able to identify those patients who experienced instability following a severe, traumatic, soft tissue rupture, and it helped direct the most appropriate neurosurgical intervention. Dorsal fusion can correct the underlying instability of the alaratlantoaxial joint and bring about considerable clinical improvement.
We thank Daniela Koch for her excellent technical help and Holger Koch for his assistance in preparing the figures.
From the Functional MRI Unit, Institute of Pediatric pediatric /pe·di·at·ric/ (pe?de-at´rik) pertaining to the health of children.
Of or relating to pediatrics. and Neuroradiology neuroradiology /neu·ro·ra·di·ol·o·gy/ (-ra?de-ol´ah-je) radiology of the nervous system.
1. The branch of radiology that deals with the nervous system. , Kempten, Germany (Dr. Volle), and the Spine Surgery Outpatient Clinic, Ulm, Germany (Dr. Montazem).
Reprint requests: Eckhard Volle, MD, Functional MRI Unit, Institute of Pediatric and Neuroradiology, Poststrasse 16. Hofapotheke, D-87439, Kempten, Allgau, Germany. Phone: +49-831-18470; fax: +49-831-18556; e-mail: email@example.com
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Analysis of MRI and MRI video findings in craniocervical instability pathology of 420 patients with clinical symptoms consistent with possible spinal instability Findings Patients n (%) Complete alar ligament rupture [*] 20 (4.8) Incomplete alar ligament rupture, [*] 52 (12.4) Alar signal-pattern variation; instability 81 (19.3) Alar signal-pattern variation; no instability 102 (24.3) Normal alar signal pattern; no instability 158 (37.6) Dens variation 4 (1.0) Elasticity syndromes 3 (0.7) Total 420 (100) (*.)These 72 patients (17.1%) were referred to a neurosurgeon. Of them, 42 (10.0%) underwent posterior spinal fusion.