Favorable outcome of conservative treatment in a cat with T9T10 intervertebral disk disease

Abstract

Five days before referral, a 12-year-old male neutered domestic shorthair had developed an acute onset of paraplegia. The cat lived strictly indoors and no known history of trauma or intoxication was reported by the owner. The cat had never displayed similar complaints before and he seemed to be in good general condition. The blood work and thoracic and abdominal radiographs showed no significant abnormalities, except for the narrowing of the intervertebral disk (IVD) space between T9T10 and T10T11. Treatment with dexamethasone (Rapidexon; Eurovet; 0,1 mg/kg, IM) was initiated. No improvement was observed, and in fact the condition even worsened somewhat. For this reason, the cat was referred to the Neurology Department of the Faculty of Veterinary Medicine at Ghent University.No abnormalities were detected on general physical examination. During neurological examination, the cat appeared alert, but showed severe paraparesis. The cat was unable to stand up, but it was able to walk with the support of a sling, although it had an extremely ataxic, stilted gait in de pelvic limbs. Conscious proprioceptive deficits were noted in the pelvic limbs, with diminished hopping, which were worse on the left side than on the right side. The patellar reflexes were normal, while the withdrawal reflexes in the pelvic limbs were exaggerated. A crossed extensor reflex was found in the pelvic limbs. Nociception was normal in all four limbs. No neck or back pain could be elicited. The bladder function was doubtful, as the bladder was quite small but could easily be expressed manually and the cat had not urinated spontaneously. The clinical signs were ascribed to a thoracolumbar spinal cord lesion. Differential diagnoses included fibrocartilaginous embolism, myelitis caused by Feline Infectious Peritonitis (FIP) virus, neoplasia (e.g. lymphoma) of the spinal cord, spinal trauma and disk herniation.Plain and contrast radiographs were performed under general anesthesia. The patient was preme dicated with methadone (Mephenon; Federa; 0,1 mg/kg, IV). After ten minutes, the induction of anesthesia was performed with midazolam (Dormicum; Roche; 0,2 mg/kg, IV), immediately followed by propofol (Propovet; Abbott Animal Health; 3 mg/kg, IV). The cat was intubated with a 3.5 mm internal diameter endotracheal tube after 0.2 ml of lidocaine (Xylocaine 2%; AstraZeneca) was sprayed on the laryngeal mucosa to prevent the occurrence of laryngeal spasms. Anesthesia was further maintained with isoflurane in 100 oxygen, delivered by a semi-closed anesthetic rebreathing circuit.Radiographic examination of the thoracolumbar Favorable outcome of conservative treatment in a cat with T9T10 intervertebral disk diseaseSuccesvolle conservatieve behandeling van discus hernia ter hoogte van T9T10 bij een kat

Outcomes of surgically and conservatively managed thoracolumbar and lumbosacral intervertebral disc herniations in cats

“…Signalment was similar across IVDH types, although purebred cats more commonly had a thoracolumbar neuroanatomical localization. Previous literature containing breed data reports that purebred cats account for 30% of IVDH cases (68/229), most frequently Siamese, Persians, and British shorthairs 1–5,8,12–40 . In our study, 34% of cats were purebred, which was not markedly different from the referral population during the study period.…”

“…Symptomatic IVDHs were located in the thoracolumbar or lumbosacral regions in 86% to 95% of cats in recent studies, 5,8,9 whereas few IVDHs in cats have been reported cranial to the T11 thoracic vertebra (Material S1). As in dogs, several types of IVDH are reported in cats, the majority being intervertebral disc extrusions (IVDE) and protrusions (IVDP) 1–5,8–40 . The prevalence of IVDP in cats is estimated to be high, but many cases can be subclinical 41 .…”

“…Since 1981, 242 cases of IVDH have been reported in cats, but there is no clear consensus on the best course of treatment 1–5,8–40 . Current knowledge mostly is based on the outcomes of a small number of retrospective studies and case series, or by extrapolating from studies of dogs.…”

“…As in dogs, several types of IVDH are reported in cats, the majority being intervertebral disc extrusions (IVDE) and protrusions (IVDP). 1 , 2 , 3 , 4 , 5 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 The prevalence of IVDP in cats is estimated to be high, but many cases can be subclinical. 41 Acute non‐compressive nucleus pulposus extrusions (ANNPE) increasingly have been identified as a cause of myelopathy in cats 5 , 8 , 9 , 36 , 37 , 38 , 39 ; the treatment for which is exclusively conservative given the contusive, non‐compressive nature of the herniation.…”

“… 1 , 2 , 3 , 4 , 5 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 The prevalence of IVDP in cats is estimated to be high, but many cases can be subclinical. 41 Acute non‐compressive nucleus pulposus extrusions (ANNPE) increasingly have been identified as a cause of myelopathy in cats 5 , 8 , 9 , 36 , 37 , 38 , 39 ; the treatment for which is exclusively conservative given the contusive, non‐compressive nature of the herniation. 36 Traumatic intervertebral disc extrusions (TIVDE), previously synonymous with ANNPE, now generally are defined as IVDEs that occur after a known external trauma.…”