Acute aseptic tendinitis of the longus colli muscle (retropharyngeal tendinitis) is extremely rare and was first described by Hartley and Fahlgren in 1964.1 Due to the typically sub-acute onset of extremely severe neck pain—and more seldom headache—painful restriction of movement in the cervical spine and increased body temperature, retropharyngeal tendinitis is an important differential diagnosis in patients with secondary headaches and neck pain.
Retropharyngeal tendinitis is a rare cause of intense neck pain and occipital headache. It is caused by an aseptic inflammatory process in the longus colli tendon, triggered by deposition of calcium hydroxyapatite crystal. Clinically, it can be misdiagnosed as retropharyngeal abscess, traumatic injury, infectious spondylitis, cervical artery dissection, or even meningitis. The diagnosis is made radiographically by a nearly pathognomonic amorphous calcification anterior to C1-C2 and prevertebral soft tissue swelling. We present a new case of this uncommon condition exhibiting some unusual features.
A 38-year-old female patient was admitted to hospital following the occurrence of progressive complaints over the course of only a few days. She reported continual, sharp and diffuse pain at the nape of the neck, which radiated up into the back of the head and was aggravated by head movement. The patient also complained of swallowing difficulties.
No incident of cervical spine trauma was recalled. An infection of the upper respiratory tract, the pharynx or teeth prior to symptom onset was negated. The patient had been operated on 5 years earlier due to a herniated disc at level C5/C6. A Bryan cervical disc prosthesis had been inserted.
Clinical assessment revealed painful restriction of cervical movement. Neurological status was normal. An elevated leukocyte count 12.8/nL (4.0–9.0/nL) and CRP 91.3 mg/L (<5.0 mg/L) was established. Extensive laboratory analyses, eg, rheumatoid factor, ANCA, ANA, revealed normal results.
Normal results were also found in the ENT examination for the oral cavity, pharynx, and larynx, ruling out a retropharyngeal abscess.
Cervical spine x-rays showed that the Bryan disc prosthesis was correctly positioned and also revealed kyphosis at C5/C6. Calcification ventral to C2 inferior to the anterior arch of the atlas and a widening of the prevertebral soft tissue shadow was observed (Fig. 1B). In comparison with outpatient x-rays taken 1 year earlier (Fig. 1A; current symptoms were not present, x-rays were taken in order to check the position of the inserted Bryan prosthesis), an increase in the amount of calcification was evident.
In accordance with the x-ray images, computer tomography revealed a narrow, band-like and moderate calcification to the right and ventral anterior to the first and second cervical vertebrae (Fig. 2). The calcification was located in the very area of the longus colli muscle. MRI revealed hypointensity ventral to C2 and a thin prevertebral hyperintense rim of edema (Fig. 3).
Altogether, the findings resulted in a diagnosis of “acute calcifying prevertebral tendinitis.” The patient received antiphlogistic treatment with ibuprofen (500 mg/d t.i.d.). Due to the severity of pain experienced, initial treatment with opioids (100 mg tramadolol/d) and the muscle relaxant benzodiazepine tetrazepam (50 mg/d) was also necessary. This treatment led to a rapid alleviation of symptoms, so that it was possible to discharge the patient only a few days later.
Both the longus colli muscle and the longus capitis muscle are paired in form and constitute a large proportion of the prevertebral musculature of the cervical spine, which is separated from the retropharyngeal space by the prevertebral layer of cervical fascia. These muscles extend from the inferior cervical vertebrae and the superior thoracic vertebrae and are attached to the superior cervical vertebrae and the anterior tubercle of atlas. Their main function lies in the bending forward or tilting sideways of the cervical spine. As is the case, for example, in calcifying inflammation of tendons in the shoulder area, above all in periarthritis humeroscapularis, calcifying tendinitis of the longus colli and longus capitis muscle induces considerable discomfort.2
Symptoms usually consist of extremely intense neck pain with a sub-acute onset over the period of a few days. This pain often radiates up into the back of the head and is described as sharp or pulsating, or sometimes also as dull and heavy.3 As a result, movement of the cervical spine is painfully restricted. As seen in our patient, the clinical picture of acute calcifying prevertebral tendinitis is characterized by sub-febrile to febrile temperatures and elevated inflammation parameters.4 The diagnosis must be differentiated from retropharyngeal abscesses, cervical osteomyelitis, spondylodiscitis, cervical disc herniation, cervical artery dissection, and meningitis. A correct diagnosis can only be made on the basis of radiological findings. Typical is a calcification of the myotendinous junction of the longus colli muscle, primarily observable anterior to C2 in x-rays and CT scans.5,6
Somewhat unusually, results of 2 x-ray examinations carried out at 2 different points in course were available in the case of our patient. These show that radiological changes can remain asymptomatic for a long period of time and be subject to acute exacerbation given an increase in size of the calcification. Severe calcification leads, as seen in the MRI of our patient, to a signal loss for all weightings, accompanied by a edema of the surrounding tissue which often induces a hyperintense signal change in water-sensitive sequences.6,7
The etiology of the disease is not fully understood. It is, however, assumed that excessive mechanical strain coupled with pre-existing degenerative damage to the spine can result in exsudative and subsequently calcifying inflammatory reactions. Histological evidence of hydroxyapatite crystals, which are suspected to have played a role in triggering inflammatory responses, was found.8
Our patient also had pre-existing damage to the cervical spine; due to a herniated disc at level C5/C6, a nucleotomy had earlier been performed and a Bryan cervical disc prosthesis subsequently inserted. The association between operative treatment of the cervical spine and a retropharyngeal tendinitis is remarkable given that no such association—as far as we are aware—has previously been described. The question therefore arises as to whether cervical disc resection with insertion of foreign bodies can damage the movement mechanism of the cervical spine to such an extent that retropharyngeal tendinitis emerges.
Retropharyngeal tendinitis tends to disappear spontaneously. Non-steroidal anti-inflammatory drugs and corticosteroids have an analgetic effect and accelerate the healing process.4,5 Opioids can be indicated in the case of persistent pain.7 Chronic courses are rare. Radiological changes can persist over an extended period of time, can, however, also regress within weeks to months. Following alleviation of all symptoms, our patient refrained from undergoing any further radiological examinations.