DOI
https://doi.org/10.1136/vetreccr-2017-000448
原文网址
https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vetreccr-2017-000448
Successful medical management of an epidural
abscess in a dog
一例犬的硬膜外脓肿的成功保守治疗
Nora Romero-Fernandez, Roberto José-López, Alexane Durand, Rodrigo Gutierrez-Quintana
First published: 13 June 2017
https://doi.org/10.1136/vetreccr-2017-000448
Abstract 摘要
A seven-month-old entire male dobermann presented with acute onset neck pain and left thoracic limb lameness. The dog had a similar episode eight weeks before presentation that responded to meloxicam. A cervical spinal epidural abscess secondary to Staphylococcus pseudintermedius bacteraemia was diagnosed following investigations, including MRI of the cervical vertebral column and blood cultures. Treatment with cephalexin, gabapentin and meloxicam was started. The dog was doing clinically well one month later. A control MRI and radiographs of the cervical vertebral column showed evidence of discospondylitis and resolution of the primary lesion, therefore the treatment course with cephalexin was continued. Three months after initial presentation the clinical signs had resolved, radiographs showed improvement of the discospondylitis and antibiotics were stopped. Seven months later the dog continued doing well with no relapse.
SUMMARY 总结
A seven-month-old entire male dobermann presented
with acute onset neck pain and left thoracic limb
lameness. The dog had a similar episode eight weeks
before presentation that responded to meloxicam.
A cervical spinal epidural abscess secondary to
Staphylococcus pseudintermedius bacteraemia was
diagnosed following investigations, including MRI of the
cervical vertebral column and blood cultures. Treatment
with cephalexin, gabapentin and meloxicam was started.
The dog was doing clinically well one month later. A
control MRI and radiographs of the cervical vertebral
column showed evidence of discospondylitis and
resolution of the primary lesion, therefore the treatment
course with cephalexin was continued. Three months
after initial presentation the clinical signs had resolved,
radiographs showed improvement of the discospondylitis
and antibiotics were stopped. Seven months later the
dog continued doing well with no relapse.
Back ground 背景
Spinal epidural abscesses (SEAs) are rarely reported
in veterinary medicine (Cherrone and others 2002,
Schmiedt and Thomas 2005, Linon and others
2014). Infection results from haematogenous bacterial spread or direct local extension (Cherrone and
others 2002, Lavely and others 2006, Song and
others 2015, Monteiro and others 2016). The most
common bacteriae isolated as the causative agent
for spinal epidural infections in human beings and
dogs are Staphylococcus and Streptococcus species
(Linon and others 2014, Cherrone and others
2002, Monteiro and others 2016, Schmiedt and
Thomas 2005). Epidural infections can present as a
diffuse purulent exudate in a natural cavity without
a capsule (empyema) or in a newly formed cavity
(abscess) (Lavely and others 2006, Remedios and
others 1996). The former is uncommonly reported
in the veterinary literature and the latter has only
rarely been described (Cherrone and others 2002,
Linon and others 2014, Nykamp and others 2003,
Schmiedt and Thomas 2005, Lavely and others
2006, De Stefani and others 2007, Granger and
others 2007, Escriou and others 2011, Linon and
others 2014, Song and others 2015, Monteiro and
others 2016). Although both terms are distinct,
they are usually used interchangeably in the literature. Clinical signs are commonly non-specific, and
neurological signs may initially be absent (Linon
and others 2014). The imaging test of choice for the
diagnosis of SEA is MRI (Remedios and others 1996,
Cherrone and others 2002, Nykamp and others
2003). Although historically myelography has been
the most widely used diagnostic tool (Schmiedt and
Thomas 2005). The current treatment of choice is
surgical drainage and decompression (Lavely and
others 2006, Granger and others 2007), although
medical management has recently been described
(Escriou and others 2011, Song and others 2015,
Song and others 2015, Monteiro and others 2016)
suggesting non-surgical treatment should also be
considered an option.
This case report describes the successful medical
management and MRI features at initial presentation and follow-up of a cervical SEA in a dog.
Case presentation 病例就诊表现
A seven-month-old entire male dobermann
presented to the Neurology Service of the University of Glasgow for investigation of acute onset
neck pain and left thoracic limb lameness. The dog
had one episode of left thoracic limb lameness two
months before presentation that responded well to
meloxicam.
Physical examination showed mild to moderate
prescapular lymphadenomegaly and was otherwise
unremarkable. Orthopaedic examination was unremarkable. Neurological examination showed normal
mentation. The dog was ambulatory with intermittent
left thoracic limb lameness. Cranial nerve examination was within normal limits. Proprioception was
normal in all four limbs. A reduced withdrawal reflex
was noted on the left thoracic limb when assessing the
spinal reflexes. Marked pain was elicited on manipulation of the neck. The neuroanatomical localisation
was left brachial plexus or lateralised C6-T2 spinal
cord segments.
Investigations 检查
Complete blood count, biochemistry profile, clotting times and buccal mucosal bleeding time were
unremarkable. MRI of the cervical vertebral column
was performed using a 1.5-Tesla unit (Siemens
Magnetom Essenza; Frimley). T2-weighted (T2w)
and T1-weighted (T1w) images were acquired
in the sagittal plane. Transverse T2w, T1w and
T2* images were also obtained. Postcontrast T1w
images were acquired in the sagittal and transverse planes after intravenous administration of
gadolinium (0.1mmol/kg; Gadovist, Bayer). MRI
showed a left-sided well defined small and ovoid
extradural (epidural) T2w and T2* hyperintense mass lesion outlined by a hypointense halo, dorsal to mid-C6
vertebral body (Fig 1). The lesion was isointense to hypointense
in the centre relative to spinal cord parenchyma on T1w images,
with a surrounding mildly hyperintense peripheral rim, which
was markedly enhancing on T1w postcontrast sequences. The
lesion was causing a moderate mass effect with moderate spinal
cord compression and right dorsolateral displacement. The
caudal half of the C6 vertebral body and the left C6 transverse
process were hypointense on T1w sequences relative to adjacent
normal vertebrae and showed marked diffuse contrast enhancement. There was marked enhancement of C6 and cranial C7
hypaxial muscles just adjacent to the ventral vertebral bodies,
more pronounced on the left.
FIG 1: Parasagittal T2w (a), T1w (b), T1w postcontrast (c), and transverse T2w (d), T1w (e) and T1w postcontrast (f) MRIs demonstrating a T2w
hyperintense and T1w isointense to slightly hypointense extradural mass with a contrast medium-enhanced peripheral rim (arrows), moderately
compressing the spinal cord at the level of the mid-C6 vertebral body. Note also the enhancement of the caudal half of the C6 vertebral body, C6 left
transverse process and the hypaxial muscles from C6 to C7 on T1w postcontrast images.
A cerebrospinal fluid (CSF) sample was obtained but marked iatrogenic blood contamination precluded reliable interpretation of analysis results. Two blood sample cultures taken from different veins (right and left saphenous veins, 10minutes apart) were positive for Staphylococcus pseudintermedius and serologies for Toxoplasma gondii and Neospora caninum were negative.
Differential diagnosis 鉴别诊断
Differential diagnoses after general and neurological examination included inflammatory/infectious process (eg, meningitis,
neuritis, discospondylitis), traumatic injury, congenital vertebral
malformation or haemorrhage causing spinal cord or nerve root
compression, and less likely neoplasia (eg, lymphoma).
An infectious condition was considered most likely following
MRI (ie, epidural abscess with early physitis/osteomyelitis), likely
secondary to haematogenous spread infection or to unidentified foreign body migration. Less likely differential diagnoses
included focal epidural haemorrhage or an epidural cystic lesion.
Treatment 治疗
The patient was admitted and treated with meloxicam (0.1 mg/
kg orally every 24 hours), methadone (0.26 mg/kg intramuscularly every 6 hours) and gabapentin (10.5 mg/kg orally every
8 hours). After MRI, CSF analysis and sampling for blood
cultures, a course of cephalexin (19.7 mg/kg, orally every 8
hours), metronidazole (15.8 mg/kg orally every 12 hours)
and omeprazole (1 mg/kg orally every 12 hours) was started
in addition to the former treatment. After 12 days the dog
was discharged and continued on gabapentin, cephalexin and
meloxicam.
Outcome and follow-up 结果与后续跟进
A complete clinical recovery was seen at re-examination six
weeks after initial presentation and gabapentin and meloxicam
were stopped. General and neurological examinations were
within normal limits. Lateral radiography of the cervical vertebral column showed fairly well defined rounded lytic lesions in
C6/7 end plates (larger in caudal C6) with surrounding sclerosis
and narrowing of the intervertebral disc space (Fig 2). These
findings were consistent with discospondylitis, which was not
present at the time of diagnosis. Follow-up MRI including a
sagittal short tau inversion recovery (STIR) sequence, showed
complete resolution of SEA (Fig 3a). The C6/7 end plates were
hypointense on T2w and T1w sequences, hyperintense on STIR
and showed diffuse contrast enhancement (Fig 3b–d). The intervertebral disc space was markedly narrowed with mild focal
T2w and STIR hyperintensity of the intervertebral disc mildly
extending into the end plates. These findings confirmed the
radiographic changes. Follow-up radiographs of the cervical
vertebral column three months after initial diagnosis showed
improvement of the lytic changes with increased sclerotic
changes and, therefore, antibiotics were stopped. At telephonic follow-up with the owner seven months later, no further clinical
signs were reported.
FIG 2: Lateral radiographic view of the caudal cervical
vertebral column six weeks after initial presentation revealing
well defined rounded lytic lesions in C6/7 end plates, larger in caudal C6
(arrow), with surrounding sclerosis and narrowing of the intervertebral
disc space.
FIG 3: Follow-up MRI performed six weeks after initial diagnosis.
Transverse T2w image at the level of the mid-C6 vertebral body
demonstrating complete resolution of the epidural lesion (a); and midsagittal STIR (b), T1w (c) and T1w postcontrast (d) images illustrating
the observed discospondylitis. Note the C6/7 end plates appear
hyperintense on STIR, hypointense on T1w and markedly enhancing on
T1w postcontrast images. Note the narrowing of the intervertebral disc
space with focal STIR hyperintensity of the disc mildly extending into
the end plates.
Discussion 讨论
Epidural empyema is an uncommon diagnosis in dogs, and SEA
has only rarely been described (Remedios and others 1996, Schmiedt and Thomas 2005, Linon and others 2014, Song and
others 2015). Clinical signs are often non-specific and include
pyrexia, spinal pain and/or neurological dysfunction that may be
progressive, however the lesions may be subclinical (Linon and
others 2014).
MRI has recently been reported as the imaging test of choice
for the diagnosis of SEA (Nykamp and others 2003, Schmiedt
and Thomas 2005, Song and others 2015). In the present case,
a lesion consistent with SEA was identified by MRI, in addition
to positive blood cultures with a pathogen commonly involved
in this type of lesion (Staphylococcus species). Discospondylitis
has been described as a cause of SEA or diagnosed concomitantly to it. In this case, however, no obvious signs of typical
discospondylitis were observed on initial MRI, although there
were some imaging features indicative of C6 vertebral osteomyelitis and physitis (Jimenez and O’Callaghan 1995). Thus,
it could have been possible that an early stage discospondylitis
was developing at the time of initial MRI, and postcontrast
fat suppression T1w or STIR sequences would have aided its
diagnosis.
The current treatment of choice is surgical drainage and
decompression (Remedios and others 1996, Lavely and others
2006). Successful medical management has been recently
described in veterinary medicine suggesting that non-surgical
treatment should also be considered (Granger and others 2007,
Escriou and others 2011, Song and others 2015, Monteiro and
others 2016).
This case report describes a case of SEA treated medically with
complete resolution of the clinical signs and epidural lesion.
To the authors’ knowledge there are only eight previous cases
described in the veterinary literature of spinal epidural infections
and successful medical management, of which only two were
described as abscesses (Remedios and others 1996, Song and
others 2015) as opposed to empyemas/infections (Escriou and
others 2011, Monteiro and others 2016). In one case the abscess
was localised at the level of the lumbosacral junction (Remedios
and others 1996) and in the other it extended from the foramen
magnum to C2 (Song and others 2015).
Therefore, this case report supports the emerging idea that
medical treatment for SEA, as well as in spinal epidural empyemas, should be considered an option for suitable cases.
Unfortunately, there is no reported criterion in the veterinary
literature to differentiate the cases that may only be treated
medically from the ones that may require surgical treatment.
The human literature describes medical approach as a reasonable
option in the following scenarios: if decompressive laminectomy
is declined by the patient or is contraindicated due to high operative risk, if paralysis has been present for over 24–36hours
(making paralysis unlikely to be reversed), in cases of panspinal
infection in which surgery may cause instability of the vertebral
column or in neurologically intact patients (Darouiche 2006).
However, these recommendations should be carefully considered in veterinary patients, and the treatment modality should be
selected based on the history, clinical signs and imaging findings.
The authors’ criteria to decide to pursue medical instead of
surgical treatment was based on the fact that the patient was
ambulatory and that no deterioration was noted after starting
medical therapy. The authors therefore believe that selected
cases may be managed medically, mainly those with no or mild
neurological deficits, especially when the history is not rapidly
progressive and an early response to treatment with no further
deterioration is shown. In these cases, close monitoring is essential and referral to a specialist centre is indicated in progressive
or severely affected cases.
Contributors
All authors listed have contributed significantly to the work,
have read the manuscript, attest to the validity and legitimacy of the data and its
interpretation, and agree to its submission to Veterinary Record Case Reports.
Competing interests
None declared.
Provenance and peer review
Not commissioned; externally peer reviewed.
Data sharing statement
No additional data are available.
© British Veterinary Association (unless otherwise stated in the text of the article)
2017. All rights reserved. No commercial use is permitted unless otherwise expressly
granted.
References 参考文献
Cherrone K. L., Eich C. S., Bonzynski J. J. (2002) Suspected paraspinal abscess and spinal
epidural empyema in a dog. Journal of the American Animal Hospital Association 38,
149–151
Darouiche R. O. (2006) Spinal epidural abscess. New England Journal of Medicine 355,
2012–2020
De Stefani A., Garosi L. S., McConnell F. J., Diaz F. J., Dennis R., Platt S. R. (2008) Magnetic
resonance imaging features of spinal epidural empyema in five dogs. Veterinary
Radiology & Ultrasound 49, 135–140
Escriou C., Duchene L., Gibert S., Seurin M A. N. D. (2011) Spinal epidural infection
medically treated in 3 dogs: mri features and follow-up, clinical findings and outcome.
Proceedings of the European Society of Veterinary Neurology. Trier, Germany,
Granger N., Hidalgo A., Leperlier D., Gnirs K., Thibaud J. L., Delisle F., Blot S. (2007)
Successful treatment of cervical spinal epidural empyema secondary to grass awn
migration in a cat. Journal of Feline Medicine and Surgery 9, 340–345
Jimenez M. M., O’Callaghan M. W. (1995) Vertebral physitis: a radiographic diagnosis
to be separated from discospondylitis. A preliminary report. Veterinary Radiology
Ultrasound 36, 188–195
Lavely J., Vernau K., Vernau W., Herrgesell E., Lecouteur R. (2006) Spinal epidural empiema
in seven dogs. The American College of Veterinary Surgeons 35, 176–185
Linon E., Geissbühler U., Karli P., Forterre F. (2014) Atlantoaxial epidural abscess secondary
to grass awn migration in a dog. Veterinary and Comparative Orthopaedics and
Traumatology 27, 155–158
Monteiro S. R., Gallucci A., Rousset N., Freeman P. M., Ives E. J., Gandini G., Granger N.,
Vanhaesebrouck A. E. (2016) Medical management of spinal epidural empyema in five
dogs. Journal of the American Veterinary Medical Association 249, 1180–1186
Nykamp S. G., Steffey M. A., Scrivani P. V., Schatzberg S. J. (2003) Computed tomographic
appearance of epidural empyema in a dog. The Canadian Veterinary Journal 44,
729–731
Remedios A. M., Wagner R., Caulkett N. A., Duke T. (1996) Epidural abscess and
discospondylitis in a dog after administration of a lumbosacral epidural analgesic. The
Canadian Veterinary Journal 37, 106–107
Schmiedt C. W., Thomas W. B. (2005) Spinal epidural abscess in a juvenile dog. Veterinary
and Comparative Orthopaedics and Traumatology 18, 186–188
Song R. B., Vitullo C. A., da Costa R. C., Daniels J. B. (2015) Long-term survival in a dog
with meningoencephalitis and epidural abscessation due to Actinomyces species.
Journal of Veterinary Diagnostic Investigation 27, 552–557