Monday, February 2, 2009

TUBERCULOSIS OF THE UPPER CERVICAL SPINE (A must know how for physiotherapists in independent first-hand practice)


Introduction:

Tuberculosis is still common in underdeveloped countries. The overall higher incidence of cervical spine incidence being more common in children. Any part of the spinal column may be affected with tuberculosis but it is commonly found in the lower thoracic and the thoraco-lumbar region. The order of frequency in Paus’ series (1964) being lumbar, dorsal, dorso-lumbar, lumbo-sacral, cervicodorsal, sacral and cervical.
Its occurrence in the upper cervical spine is rare but the consequences are very serious. Bright (1837) described a case of spinal caries with insidious paralysis beginning in the hand and spreading to the whole body. Necropsy revealed extensive abscess formation in the upper cervical vertebrae and compression of the medulla from the “processus dentatus”. Smith (1871) reported 15 postmortem cases of fractures of the dens, at least three of which resulted from spinal caries. Death was due to atlanto-axial dislocation causing compression of the cord in each case. Recently, Wang (1981) reported 15 cases of atlanto-axial involvement in 5393 cases of tuberculous spondylitis.

Prominent features of the disease included pain and stiffness with painful range of movements, paralysis, swelling of the retropharyngeal soft tissue reveal fullness in the retropharyngeal area (example: left side more than the right), osteolytic erosions, and atlanto-axial subluxation. The anterior type of involvement of vertebral bodies seems to be due to extension of an abscess beneath the anterior longitudinal ligament and the periosteum. The infection may spread up and down stripping the anterior or posterior longitudinal ligament and the periosteum from the front and the sides of the vertebral bodies. Cure is usually obtained with antibiotics, transoral decompression and C1-2 fusion.
The duration of prodromal symptoms is extremely long in most case of TB. Since the symptoms are non-specific and there are no obvious radiographic findings in the early stage, these cases are often misdiagnosed or go undetected for a very long time. Consequently, the disease is usually at an advanced stage before the patient seeks medical attention. This is one reason why it is important to keep the diagnosis of TB in mind for any patient with and to do a laboratory work-up for TB for either neck pain or back pain. Magnetic resonance imaging should also be performed if there is suspicion of this infection. Once a case of spinal TB is diagnosed, percutaneous transpedicular biopsy should be carried out under local anesthesia and fluoroscopic guidance. To minimize treatment time and costs, and to avoid surgical complications, it is better to spend time and money on diagnosis when a patient first presents with symptoms. Delay of diagnosis leads to more severe bone destruction, which can result in kyphosis, cord compression, and even neurological deficits.
Clinical presentation.
1. All patients complain of neck pain and stiffness lasting three to eight weeks. Few have severe torticollis and few other patient hold his/her neck in flexion. Patient may have occipital headache and hoarseness followed by acute dysphagia.
2. patients may have constitutional symptoms of fever, anorexia and loss of weight.
3. Neurologically patients may be normal but may report with weakness and hypoaesthesia of an upper limb. Patients also report with hemiparesis and tetraparesis.
4. Blood investigations may reveal moderate leucocytosis (1 1 300-1 1 600 cells per microlitre) and raised erythrocyte sedimentation rate (40-90 millimetres in the first hour).
5. Radiology.
The spinal cord at the medullary cervical junction is threatened by tuberculosis in one of three ways: by atlanto-axial subluxation or upward translocation of the dens; by compression by a tuberculous abscess ; and by direct tuberculous invasion.
The radiological finding common to all cases are
a. increased width of the retropharyngeal soft-tissue space on the lateral view. According to Wholey, Bruwer and Baker (1958) this space should normally measure less than seven millimetres at the lower margin of the axis (focus to film distance of I .5 metres).

b. Anterior atlanto-axial dislocation presents with atlantodental interval exceeding five millimetres.

Rotary fixation of the atlas on the axis was seen in one patient in whom all movements of the cervical spine failed to alter the rotary relationship. Anterior rotary subluxation of one lateral atlantal mass is usually confirmed at transoral surgery.

c. Osteolytic erosions were present in all cases. In the axis lytic lesion involve the body and the dens. Destruction in the atlas may be located in the anterior arch, lateral masses & also the posterior arch which can also be partly destroyed.

d. Other vertebrae: Erosions also involve C3 body or bodies of both C3 and C4. Inter-vertebral disc narrowing may be very evident in these cases.

e. Chest radiographs may show unmistakable pulmonary tuberculosis in many cases.

f. Aspiration Biopsy: Human Mycobacterium tuberculosis may be isolated few patients from material obtained at transoral debridement.

In atypical histopathology show: epithelioid cells, Langhans’ giant cells and caseation but no acid-fast bacilli. Few patients may show neither bacteriological nor histopathological proof.

Where there is no bacteriological or radiological proof:
Diagnosis is based on the radiologically demonstrated presence of pulmonary tuberculosis, on the macroscopic nature of pus from a large retropharyngeal abscess, the involvement of four cervical vertebrae and the good response to antituberculous drugs.

Treatment before operation.
Antituberculous drugs- once the disease had been diagnosed radiologically.
2. Halo traction or head-halter traction for five weeks or treated by bed rest alone for one to six months. Atlanto-axial subluxation may be reduced in halo traction.
Tuberculous atlanto-axial subluxation should be treated urgently by skull traction; we recommend the halo device for its control of rotation and convenience of after-management. Traction alone may be sufficient in reducing an early subluxation but when adhesions have already formed reduction can only be achieved after excision of the disease focus together with overlying parts of the lateral atlantal masses.


Operative treatment.
1. Operation is undertaken for anterior debridement of the diseased area (all diseased bone, synovium and granulation tissue was excised) and for stability by atlanto-axial fusion is advocated. Anterior fusion is usually performed by the insertion of homologous iliac or rib grafts into oblique troughs across the lateral facet joints. A standard posterior C1-2 fusion may be done eight weeks after through debridement.

2. Debridement is by the transoral route as described by Fang and Ong (1962).

After-care.
Method 1. Bed rest with sandbags guarding the head and one patient’s neck was extended over a shortened mattress. These patients were allowed up after three months and were then given a soft collar.

Method 2. Nursing on a turning frame with halo traction for three months and then given a Minerva jacket or a collar for another two months.

Clinical Monitoring.

For each patient re-check exams should be done at 1, 3, 6, 9, 12, 18, and 24 months after surgery. At each of these time points, ESR and serum CRP were recorded to evaluate disease status. Liver enzyme levels, BUN, creatinine testing were also done every 2 months during anti-tuberculosis drug treatment. Radiological assessments were done preoperatively, immediately after surgery, and at the last follow-up check. At each assessment the angulations between, the superior end-plate of the proximal healthy vertebra to the inferior end-plate of the distal healthy vertebra on lateral spinal X-ray is looked at.

RESULTS
Neurological status.
Neurological symptoms such as monoparesis, hemiparesis and tetraparesis were completely relieved immediately after transoral decompression. There may also be a gradual recovery over the next nine months. Neck symptoms such as a slight torticollis, persistent neck pain and stiffness despite radiological evidence of disease healing and posterior fusion may be reported at final follow-up. These symptoms can probably be accounted for the unreduced anterior subluxation.
Fusion rate.
Solid bony fusion are achieved in almost all cases. Anterior fusion was achieved at 8 to 17 weeks while the posterior fusions took 12 to 16 weeks.

Quality of life.
Many patients resumed normal activities but mental sub-normality in children has been reported (attend special school). Few could not return to work because of persistent neck pain and stiffness.

Complications.
Anterior bone grafts may became displaced in patients treated solely by bed rest after their operation. These grafts may present in the oropharynx. Reduction of atlanto-axial subluxation is partially lost in this kind of patients.

Caution for surgery:

Although transoral reduction of chronic subluxations is a major surgical undertaking, transoral debridement, which gives access to the median and both lateral atlanto-axial joints, has proved to be a straightforward and safe procedure with low morbidity.

Transoral surgery in severe upper cervical myelopathy must be under caution against routine open reduction. Besides compressing the cord a large retropharyngeal abscess may cause acute dysphagia and asphyxia. Treatment of a tuberculous abscess in this strategic area by drugs alone is hazardous even in the absence of myelopathy.

Wang (1981) reported good results after transoral debridement and prolonged recumbence with the neck extended. Few other surgeons prefer anterior fusion at the time of surgical debridement. But alternatively one can perform posterior fusion at a second stage. Patients may be allowed to get up soon after the operation but in the case of transoral fusion external immobilisation in a halo. One should aim at early healing and stability by jacket is necessary until radiological union has occurred.

References:
Six patients, aged between 3 and 51 years, with tuberculosis of the upper cervical spine were studied by D. FANG et al (1983, British Editorial Society of Bone and Joint Surgery, VOL. 65-B. No. I).

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