Outcome comparison in dogs with a presumptive diagnosis of thoracolumbar fibrocartilaginous embolic myelopathy and acute non‐compressive nucleus pulposus extrusion

Abstract

Dogs with fibrocartilaginous embolic myelopathy (FCEM) or acute non-compressive nucleus pulposus extrusion (ANNPE) are reported to have a fair prognosis; however, persistent motor/autonomic deficits are possible. Specific MRI patterns have been suggested to differentiate these diseases although never been validated with histopathology in large studies. The aim of this retrospective study was to evaluate if these MRI patterns are associated with different clinical outcomes in dogs with peracute non-progressive T3-L3 myelopathy. Two hundred and one dogs were included. Outcome data were obtained via medical records and telephone questionnaires. MRIs were blindly reviewed by three board-certified observers, obtaining substantial to almost perfect interobserver agreement on diagnoses (κ=0.635-0.828). Presumptive ANNPE and FCEM were diagnosed in 157 and 44 dogs , respectively. Ambulatory function was regained in 99 per cent of cases, with persistent motor deficits in 83.6 per cent and 92.5 per cent of dogs with presumptive ANNPE and FCEM, respectively. The presumptive diagnosis was not associated with motor function recovery, recovery times or urinary continence. Faecal incontinence was five times more likely in dogs with presumptive ANNPE (23 per cent) compared with presumptive FCEM (7.5 per cent).Distinguishing between MRI patterns of presumptive ANNPE or FCEM in dogs with peracute non-progressive T3-L3 myelopathy may help predict the risk of developing faecal incontinence.

Predictors of urinary or fecal incontinence in dogs with thoracolumbar acute non‐compressive nucleus pulposus extrusion

“…Considering the nonsurgical nature of the disease, histological confirmation of the diagnosis is rarely obtained; however, the MRI signal characteristics of extradural hydrated nucleus pulposus have been histopathologically validated in 2 studies and can support the diagnosis together with history and clinical signs . Successful functional recovery, defined as recovery of unassisted ambulation and complete urinary and fecal continence, occurs in 66% to 81% of dogs with a MRI‐ or myelography‐based diagnosis of ANNPE . However, in cases with unsuccessful outcome, this was mainly related to persistently impaired micturition or defecation rather than inability to walk unassisted .…”

“…Successful functional recovery, defined as recovery of unassisted ambulation and complete urinary and fecal continence, occurs in 66% to 81% of dogs with a MRI‐ or myelography‐based diagnosis of ANNPE . However, in cases with unsuccessful outcome, this was mainly related to persistently impaired micturition or defecation rather than inability to walk unassisted . In a large study including 157 dogs with MRI consensus diagnosis of T3‐L3 ANNPE 99% of cases recovered ambulatory function (although most often with a degree of persistent motor deficits), 92.5% were urinary continent and 77% were fecally continent at long‐term follow‐up .…”

“…However, in cases with unsuccessful outcome, this was mainly related to persistently impaired micturition or defecation rather than inability to walk unassisted . In a large study including 157 dogs with MRI consensus diagnosis of T3‐L3 ANNPE 99% of cases recovered ambulatory function (although most often with a degree of persistent motor deficits), 92.5% were urinary continent and 77% were fecally continent at long‐term follow‐up . More specifically, fecal incontinence (FI) occurred in 100% of dogs that were paraplegic without nociception, 61% of dogs paraplegic with nociception, 20% of nonambulatory paraparetic or monoplegic dogs and in 9% of dogs that were ambulatory without assistance at the time of presentation …”

Perilesional photobiomodulation therapy and physical rehabilitation in post-operative recovery of dogs surgically treated for thoracolumbar disk extrusion

“…Hansen described two types of canine IVD herniation (IVDH): type 1 IVDH, extrusion of the IVD, and type 2 IVDH, protrusion of the IVD [3,4]. More recently, a non-compressive subtype of IVD extrusion has also been proposed [5,6]. Compressive IVD extrusion occurs when there is total rupture of the dorsal annulus and massive extrusion of the nucleus pulposus into the spinal canal [7].…”

Acute hydrated non‐compressive nucleus pulposus extrusion: what do we know so far?

“…Male dogs seem to be affected more commonly than females. The age at diagnosis in dogs is usually around six years (range two to 12 years) 2,5,10,11. The T3-L3 spinal cord segments and, in particular, the T12-T13, T13-L1 and L1-L2 intervertebral disc spaces are most commonly affected.…”