Med. Weter. 2013, 69 (1) 56
Opis przypadku Case report
Spinal epidural empyema (SEE) in cats is a very rare
condition. Till now, two such cases have been
descri-bed (5, 8) (Tab. 1). This paper describes a case of
sud-den-onset paraplegia with no deep pain perception due
to an epidural empyema associated with the suspected
penetrating trauma of the lumbar region in an
imma-ture cat.
Case description
A 5-month-old and 2 kg body weight male domestic shorthaired cat was referred with a 4-day history of gait worsening. It had progressed to paraplegia by the day of admission. The cat had a history of falling from a tree with no obvious trauma 4 weeks before presentation. Apart from that, he had been treated with oral cefalexin (Kefavet, Orion
Spinal epidural empyema in an immature cat:
a case report
PIOTR TRÊBACZ, JOANNA BONECKA, JACEK STERNA Department of Small Animal Disease with Clinic, Faculty of Veterinary Medicine, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159 C, 02-786 Warsaw, Poland
Trêbacz P., Bonecka J., Sterna J.
Spinal epidural empyema in an immature cat: a case report
SummaryA 5-month-old and 2 kg body weight male domestic shorthaired cat was referred with 4 days history of gait worsening. It had progressed to paraplegia by the day of admission. The cat had a history of fall from a tree with no obvious trauma 4 weeks before presentation. CT-myelography revealed marked asymmetrical extradural compression caused by a questionable soft tissue density in the right dorsal aspect of the vertebral canal at the L4 vertebra. A right-sided hemilaminectomy centered near the base of the spinal process of the L4 vertebra was performed. After opening the spinal canal pus exuded from the epidural space, and a large amount of friable tissue compressed of the spinal cord was retrieved. The dorso-lateral part of the exposed dural sac was covered by a layer of reddish granulation tissue. The cat was ambulatory but weak with deep pain perception 3 days after surgery. Histopathological analysis of tissue retrieved from the spinal canal revealed pyogranulomatous inflammation. No etiological agents were isolated in the aerobic and anaerobic bacterial culture. A follow-up examination 6 months postoperatively showed good progress in ambulation, with mild prioprioceptive deficits in the hind limbs. Spinal epidural empyema in cats is a very rare condition. Till now, two such cases have been described. The presented case broadens the knowledge about this disease in cats. Spinal epidural empyema should be included in a list of possible causes for cats with progressive myelopathy and spinal pain.
Keywords: cat, spinal epidural empyema, penetrating trauma
Tab. 1. Comparison of described cases of epidural empyema in domestic cats and the presented case of an immature cat
Explanation: * some prioprioceptive deficits in hindlimbs r o h t u A a t a d l a c i n il C r e b m u n d e t a e rt f o s t a c e g a ) s h t n o m ( x e s cilnicalpresentaiton locailsaitonofempyema rteatment f o e s u a c a m e y p m e resutls .l a t e r e g n a r G ) 7 0 0 2 ( 1 24__ tneertcakplpeagiina t c e p s a l a r e t a l-o s r o d tf e l r a e n l a n a c l a r b e tr e v e h t f o l a r b e tr e v r e t n i 4 C -3 C e h t n e m a r o f d e d i s -t f e l 4 C -3 C y m o t c e n i m a li m e h y p a r e h t o c it o i b it n a l a r e n e g s k e e w 3 r o f f o n o it a r g i m n w a s s a r g a verygood .l a t e a t e a M ) 0 1 0 2 ( 1 24__ s i s y l a r a p b m il c i v l e p n i s s e n r d n e t e r e v e s n o i g e r r a b m u l e h t e h t f o t c e p s a l a s r o d tf e l 4 L -2 L l a n a c l a r b e tr e v 4 L -3 L y m o t c e n i m a l l a s r o d y p a r e h t o c it o i b it n a l a r e n e g s k e e w 3 r o f unknown good* .l a t e z c a b ê r T ) e s a c d e t n e s e r p ( 1 5__ o n h ti w a i g e l p a r a p n o it p e c r e p n i a p p e e d n i a p r a b m u l e r e v e s t c e p s a l a r e t a l-o s r o d t h g ir r a e n l a n a c l a r b e tr e v e h t f o 4 L f o s s e c o r p l a n i p s e h t d e d i s -t h g ir 4 L y m o t c e n i m a li m e h y p a r e h t o c it o i b it n a l a r e n e g s k e e w 3 r o f f o n o i c i p s u s g n it a rt e n e p a m u a rt good*
Med. Weter. 2013, 69 (1) 57
Pharma Animal Health) because of otitis externa. Gait disturbances had been observed since the cats external ear canal cleaning was performed by the referring veterinarian. Initial neurological examination showed paraplegia with rigidity of the hind limbs, absence of deep pain perception and intense pain of the lumbar spine. A spinal cord lesion between Th3-L3 spinal segments was suspected. The cat was normothermic. Complete blood count and serum bio-chemical values were within the reference ranges. The FeLV and FIV tests were negative. Survey radiographs of the thoracolumbar spine were obtained under general anesthesia. There was only a small cleft in the spinal process of L4 vertebra. The cleft was also visualized in computed tomo-graphy (CT). It was 6.2 mm long with smooth margins and it reached the spinal canal (Fig. 1). No other abnormalities were found. Subsequently a lumbar myelography was per-formed by the injection of a 1 ml iohexol (Omnipaque 300, Amersham) via lumbar puncture at L5-L6. On a lateral and ventrodorsal view, a poor filling on the subarachnoid space over L4 body was detected. Therefore, CT myelography was performed, which revealed marked asymmetrical extra-dural compression caused by a questionable soft tissue density in the right dorsal aspect of the vertebral canal at L4 (Fig. 2, 3).
The cat was classified to surgical exploration of the suspected area of the spinal canal. Perioperatively, 0.4 mg meloxicam (Metacam, Boehringer Ingelheim), 36 mg cefalexin (Ceporex, Shering-Plough Animal Health) and 0.01 mg buprenorphine (Bunondol, Polfa) were injected subcutaneously. While preparing the surgical field, a small round skin scar was found near the spinal process of the L4. There were no noticeable abnormalities in the subcuta-neous tissue and paravertebral muscles. A right-sided hemilaminectomy centered near the base of the spinal process of L4 vertebra was performed. After opening the spinal canal, pus exuded from the epidural space (Fig. 4) and a large amount of friable tissue compressed of the spi-nal cord was retrieved. The dorso-lateral part of exposed dural sac was covered by a layer of reddish granulation tissue (Fig. 5). The area of the lesion was flushed with
a large amount of sterile saline solution and closed in layers in a standard manner. The cat recovered from anesthesia uneventfully. He was ambulatory but weak with deep pain
Fig. 3. CT myelography of the 5-month-old male domestic shorthaired cat: coronal reconstruction of spinal canal. Compres-sion of the spinal cord at the level of L4 vertebra is clearly visible (black arrows)
Fig. 1. CT scan of the lumbar part of spine of the 5-month-old male domestic shorthaired cat: sagittal reconstruction of spinal canal. The cleft in the body of the spinal process L4 vertebra is clearly visible (white arrow)
Fig. 2. CT myelography of the 5-month-old male domestic shorthaired cat: transverse image at the level of L4. The spinal cord is severely compressed by the extradural mass (black arrow). The cleft in the body of the spinal process L4 (*)
Fig. 5. Intraoperative view (L4 hemilaminectomy in of the 5-month-old male domestic shorthaired cat): dorso-lateral part of exposed dural sac is covered by a layer of granulation tissue (black arrow)
Explanation: head on the right
Fig. 4. Intraoperative view (L4 hemilaminectomy in of the 5-month-old male domestic shorthaired cat): a free flow of a purulent material after opening of the spinal canal (black arrow)
Med. Weter. 2013, 69 (1) 58
perception 3 days after surgery. Histopathological analysis of tissue retrieved from the spinal canal revealed pyogra-nulomatous inflammation. No etiological agents were iso-lated in the aerobic and anaerobic bacterial culture.
During postoperative period oral meloxicam and cefa-lexin were administered for 5 and 21 days respectively. A follow-up examination 6 months postoperatively showed good progress in ambulation, with mild prioprioceptive deficits in the hind limbs.
Discussion
SEE is characterized by the accumulation of pus in
the epidural space of the spinal canal. Although there
are several reports of this condition in dogs (several
dozen cases) (1-4, 6, 7, 9-11), there have been only
2 reports of epidural empyema in domestic cats (5, 8).
In dogs, epidural empyema is usually caused by
mi-grating plant material (grass awn and wooden sticks).
In cats only the case reported by Granger et al. (5) was
caused by plant material (grass awn). In the case
reported by Maeta et al. (8) the reason of epidural
empyema was unknown. In the presented case SEE
might be caused by penetrating trauma. A small round
scar of the skin found near the spinal process of
L4 and cleft in the body of the spinal process of L4
visualized on survey radiographs and CT scans could
confirm this theory. The cat fell from a tree 4 weeks
before the presentation and it probably was the cause
of lumbar trauma. A definitive source of infection was
not identified in this case. The negative aerobic and
anaerobic culture results might be influenced by the
use of a broad-spectrum antibiotic preoperatively. SEE
could be associated with ear infection and immaturity
of the immune system. A similar mechanism of
epidural empyema in a young dog is postulated by
Cherrone et al. (2).
Clinical signs of SEE are non specific. The
classi-cal triad of signs for this condition in humans and dogs
are fever, localized spinal pain and progressive
neuro-logical deficits. In the presented case lumbar pain and
progressive neurological deficits were obvious. No
elevation of body temperature was noted before
surgery. In cases described by Granger et al. (5) and
Maeta et al. (8) the body temperature of treated cats
was raised. In the presented cat a normal body
tempe-rature could be caused by use of an antibiotic in the
preoperative period.
Animals suffering progressive neurological deficits
caused by compression of the spinal cord should be
treated surgically. Pre-operative diagnostics are intended
to confirm the diagnosis, localize the lesion and
ex-clude other differential diagnoses. Clinical signs allow
gross lesion localization. Conventional radiography is
unreliable in the diagnosis of SEE, but could exclude
other differential diagnoses, e.g. trauma or vertebral
neoplasia. Myelography locates the lesion more
relia-bly than clinical signs and survey radiography. This
method does not differentiate the cause of
compres-sion of the spinal cord, e.g. empyema, neoplasia,
inter-vertebral disc extrusion or protrusion. According to
De Stefani et al. (3), MRI is a non invasive modality
of choice in the detection of spinal empyema.
Compa-red to the CT scan, it is able to form multiplanar
ima-ges and scan deep structures without bone artifacts.
Unfortunately MRI is not available in our Clinic. In
the treated cat myelography did localize the site of
compression, but did not lateralize it. CT-myelography
did localize and lateralize the lesion. Maeta et al. (8)
reached similar results.
Surgery is the treatment of choice for SEE because
it allows decompression of the spine, drainage of the
purulent material from epidural space and collecting
samples for histopathological and microbiological
examination. General antibioticotherapy ameliorates
results of surgery. In the presented case, after
right--sided hemilaminectomy and decompression of the
spinal cord a fast resolution of neurological symptoms
was observed. Similar results were reached by Granger
et al. (5) and Maeta et al. (8).
Although SEE is rare, it should be suspected in cats
with progressive myelopathy. Myelography and
CT--myelography are valuable methods in the detection
of the compression site of the spinal cord caused
by epidural empyema in cats. Quick diagnosis and
decompressive surgery are required to allow recovery.
References
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