MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction - Brief Article

Ear, Nose & Throat Journal, Jan, 2001 by Eckhard Volle, Abbas Montazem

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 (MRI) of the craniocervical junction. We evaluated the extracranial vertebral circulation by MRI angiography, with focus on the position of the dens and on the subarachnoid space 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. 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 of their bone grafts during the first 3 months after fusion, and three required a repeat operation. We conclude that functional MRI with lateral tilting an rotatory 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 appear to be justified.

Introduction

Patients who experience an injury to heir cervical spine after an acceleration trauma often prevent 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 e neck experience cervical and/or neck pain up to 4 to years later--pain that requires continual orthopedic, manual, pharmacologic, or other therapy. [1,2] Several ant ors have postulated that cervical spine instability is a consequence of injury to the ligaments. [3-6] Conventional x-ray studies and functional computed tomography (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 he atlanto-occipital plane and therefore the socle joint (C2 vertebral body) are especially vulnerable to indirect trauma. [9] 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 joins 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. [10]

Satemus 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 as does high-resolution MRI. Instead, it directly visualizes instability of the craniocervical junction. [12] It is generally accepted that increased axial rotation instability of the upper cervical spine can cause symptoms such as severe occipital headache and pain and tenderness in the adjoining neck muscles. Other concomitant complaints can include dizziness, tinnitus, paresthesia, visual disturbance, cognitive impairment, sleep disturbance, vegetative 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, ankylosing spondylitis, rheumatoid arthritis, or generalized connective tissue diseases.