Key-words:
Brucella - spinal brucellosis - spinal epidural abscess - spinal instrumentation
Introduction
Brucellosis usually presents as a fever of unknown origin, and it was initially discovered
by David Bruce in 1887 from troopers with Malta fever. It is a Gram-negative bacillus
that is oxygen consuming and nonmotile facultative intracellular, having a place in
the genus Brucella.[[1]] People can be infected by Brucella by direct contact with meat or tissue of infected
animals, consumption of unpasteurized dairy products, or exposure in laboratory.[[2]] Vertebral brucellosis is relatively common in patients who have musculoskeletal
infection. Early diagnosis and appropriate treatment is needed for better prognosis.
The lumbar spine is the most commonly involved region in spinal brucellosis, followed
by thoracic spine.[[3]],[[4]],[[5]] The cervical spine is rarely involved in spinal brucellosis.[[6]] Spondylodiscitis is the most common form of infection in spinal brucellosis. Epidural
abscess formation is rare and is considered a complication of spinal brucellosis.[[6]]
Conventionally, spinal epidural abscess was treated with immobilization and antibiotics.[[7]] There is now increasing evidence that the unstable spine in the presence of acute
infection can be safely stabilized with instrumentation.[[8]],[[9]],[[10]] Only a few cases of cervical spinal epidural abscess caused by Brucella and treated
with spinal instrumentation in the acute setting have been reported in the literature.
Here, we present a rare case of cervical spinal brucellosis manifesting as C5 vertebral
osteomyelitis and epidural abscess and treated with antibiotics and spinal instrumentation.
We have also reviewed similar cases reported in the literature.
Case Report
Our patient is a 29-year-old male from Sudan and a veterinary doctor by occupation.
He presented to the emergency department of the hospital, complaining of neck and
shoulder pain and numbness in the upper limbs for 8 days. He also had cough with fever
for 3 days before the presentation. His numbness gradually progressed and developed
weakness of the bilateral hand. While under investigation in emergency, the patient
started having urinary retention, and hence, a urinary catheter was inserted.
On examination, the patient was febrile and had weakness of the bilateral upper limb
and lower limb. The power of his hand grip was 0/5, elbow flexion and extension were
3/5, shoulder was 4/5, and both lower limbs were 4/5. The patient had hyperreflexia
and lax anal tone, and the sensory level was at C4. Magnetic resonance imaging (MRI)
of the cervical spine was done that showed osteolytic lesions involving C5 vertebral
body and spondylodiscitis of C4 body and C4–5 disc. There was an epidural abscess
extending from C4–C6 level compressing the adjacent spinal cord with associated intramedullary
early T2 bright cord edema extending from C3 down to C6 [[Figure 1]].
Figure 1: Preoperative magnetic resonance imaging (a) T2. (b) Postcontrast T1 sequences showing
the epidural abscess at C4/C5 level with compression of the spinal cord
As the surgery was done on emergency basis to quickly decompress the spinal cord,
initially only anterior cervical fusion was done, posterior spinal fixation was planned
later on during follow-up if the patient has progressive kyphosis. The patient underwent
emergency C5 corpectomy and evacuation of epidural abscess with interbody titanium
cage fusion (ADDplus™, Ulrich Medical, Ulm, Germany). Intraoperatively, there was
a frank pus with granulation tissue seen compressing the cord. C5 vertebra was soft
in consistency and relatively avascular. The procedure was uneventful with no complication.
Postoperatively, the patient's neurological symptoms improved significantly and were
completely recovered at 6 weeks.
Pus was sent for bacterial, tuberculosis (TB), and fungal cultures. All cultures were
negative; TB polymerase chain reaction was negative. The histopathological examination
showed granulation tissue, and the tissue sample was negative for acid-fast bacilli.
Brucella serology was positive with immunoglobulin G (IgG) and IgM titer of 1:640.
On the basis of serology, a diagnosis of spinal brucellosis was made, and he was started
on rifampicin and doxycycline for 3 months and gentamycin for 1 week.
He completed 3 months of antibiotics, and his last follow-up was after 9 months of
surgery. There were no neurological deficits. He underwent a dynamic C-spine X-ray
which showed good alignment of implant, and there was no evidence of instability in
the flexion and extension X-rays. There was kyphosis in the X-ray which is one of
the drawbacks of anterior-only approach, but the patient was asymptomatic and there
was no neck pain, the patient is planned for follow-up, and in case kyphosis worsens,
posterior fixation will be considered He also underwent follow-up MRI that shows complete
resolution of the spinal collection and normal spinal cord [[Figure 2]].
Figure 2: (a) Postoperative magnetic resonance imaging T2 showing complete resolution of the
lesion, with no mass effect on the spinal cord. (b) Postoperative X-ray cervical spine
anterior-posterior and lateral view showing good alignment of implants
Discussion
Brucellosis is a relatively common cause of vertebral osteomyelitis in geographic
areas of the world in which Brucella melitensis is endemic (e.g., the Mediterranean
Basin, the Middle East, and Latin America).[[11]],[[12]],[[13]],[[14]] However, epidural abscess is a very rare manifestation of spinal brucellosis, and
the cervical spine is least involved in brucellar spinal epidural abscess.[[3]],[[4]],[[5]] However, patients with cervical and dorsal brucellar spondylitis tend to have proportionally
more paravertebral/epidural masses than lumbar spondylitis.[[15]]
Ali Ekici et al. reported a case of brucellar cervical epidural abscess (CEA) who
was treated with anterior cervical discectomy and fusion, and the authors reviewed
all the cases of CEA reported in the literature and found only 16 reports of brucellar
CEA in the literature.[[16]] Instrumentation of the spine in acute infection was traditionally not done because
of the fear that implants may flare up the infection. However, there is now increasing
evidence that the unstable spine in the presence of acute infection can be safely
stabilized with instrumentation.[[8]],[[9]],[[10]] To the best of our knowledge, there are only six cases of cervical brucellar epidural
abscess treated with drainage and instrumentation in the literature [[Table 1]].
Table 1: Various case reports done on cervical spine, including our case from literature review
In a review by Turgut et al., the authors reviewed all the articles of spinal brucellosis
published from turkey. Of 452 cases, there were 58% of men and 42% of women. Mode
of the infection was through ingestion of raw milk or dairy products in 76% of the
cases and through contact of animals in 36% of the cases.[[22]] Our patient is a veterinary doctor who denied any history of ingestion of raw milk
and had probably acquired infection through contact with animals.
Brucellosis is diagnosed authoritatively by means of confinement of Brucella species
from blood or tissue samples in laboratory, but isolation of microbes is not generally
possible.[[23]] Isolation of Brucella from a tissue or biopsy material gives the definitive proof
of Brucella disease, yet this is accomplished in only 25% of the cases. Most of the
cases were diagnosed with increased antibody titers in the blood.[[24]]
Surgical evacuation is not routinely needed in spinal brucellosis as most of the cases
resolve rapidly with antibiotic treatment. However, the reported rate of surgical
intervention varies widely from 0% to 41% in the literature.[[5]],[[6]],[[11]],[[25]] Even when surgical intervention was required, most of the reported cases in the
literature had undergone drainage of the abscess without instrumentation. In a multicenter,
retrospective comparative study of 293 cases of spinal brucellosis, most of the cases
were cured by antimicrobial therapy, and the surgery was done only in 32 patients.[[6]]
The ideal antibiotic regimen and duration of treatment for Brucella spinal abscess
is still controversial in the literature. However, every patient with diagnosed Brucella
infection must undergo antibiotic treatment. The WHO recommends a combination therapy
of doxycycline plus streptomycin for at least 12 weeks as the first-line therapy.[[26]],[[27]] However, side effects, possible drug–drug interaction, and patient's clinical and
radiological response should be addressed when choosing the antibiotics and its duration.
UluKilic et al.[[23]] analyzed five combination regimens, and they found no difference in outcome between
them. The response to treatment can be directed by Brucella serology and radiological
findings. If treated nonsurgically, antibiotics are given until the abscess is resolved
completely in the follow-up MRI scan.
Surgical intervention is indicated if there should arise any compromise in neurological
function, spinal stability, and nonresponsiveness to medical treatment.[[24]] Choice of approach varies depending on the extent of involvement of the vertebra,
preoperative kyphosis, patient's neurological status, etc. Salzmann et al. in their
state-wise database study in New York evaluated epidemiology of spinal fusion approaches
in 87,405 patients. Anterior approach overall had fewer complications, shorter length
of stay, and lower mortalities compared to posterior or circumferential fusion.[[28]] Anterior approach is indicated when there is predominant anterior compression.
Posterior approach is indicated when there is predominant posterior compression. Circumferential
fusion is generally reserved for the cases with extensive levels of involvement or
if there is significant preoperative kyphosis. Although our patient had significant
preoperative kyphosis, he was initially planned only for anterior approach and fusion
in the acute setting. He was planned for posterior instrumentation at a latter period
depending on the postoperative clinical status and correction of kyphosis. As such,
he underwent C5 corpectomy and C4–6 fusion as there were rapid neurological deterioration
and C5 vertebral collapse. He was then treated with for rifampicin and doxycycline
for 3 months. He responded well to antibiotics and recovered completely.
Follow-up fusion rates are not reported in the any of studies that we reviewed. Our
patient had postoperative follow-up dynamic X-ray after 4 weeks which showed no evidence
of instability or implant failure. The patient was asymptomatic though there was some
postoperative kyphosis.
Conclusion
Spinal brucellosis must be considered while evaluating patients with back or neck
pain and fever in endemic areas, and there should be a high index of suspicion in
patients in contact with cattle as in our case. The lumbar region is the most common
region involved, followed by thoracic and cervical regions. Spondylodiscitis is the
most common manifestation. When patients present with neurological deficits, the presence
of epidural abscess must be considered and should be evaluated with MRI spine. Most
of the infections get resolved with antibiotics, but surgery is indicated if there
is a significant compression of neural elements. Spinal instrumentation can be safely
done in the presence of acute infection, and it will not hinder the response to antibiotic
treatment.
