Ischaemic paraspinal myopathy along with myelopathy due to putative fibrocartilaginous embolism in a dog

Influence of Spinal Shock on the Neurorehabilitation of ANNPE Dogs

Acute noncompressive nucleus pulposus extrusion (ANNPE) is related to contusive spinal cord injuries, and dogs usually appear to be exercising vigorously at the time of onset. ANNPE has a characteristic peracute onset of clinical signs during exercise or following trauma, with non-progressive signs during the first 24 h and possibly signs of spinal shock. The main aim was to assess if the presence of spinal shock affects the neurorehabilitation outcomes of ANNPE dogs. This prospective controlled cohort clinical study was conducted at the Arrábida Rehabilitation Center. All of the dogs had T3−L3 injuries and were paraplegic/monoplegic with/without nociception, the study group (n = 14) included dogs with ANNPE spinal shock dogs, and the control group (n = 19) included ANNPE dogs without spinal shock. The study group was also evaluated using a new scale—the Spinal Shock Scale (SSS)—and both groups were under the same intensive neurorehabilitation protocol. Spinal shock was a negative factor for a successful outcome within less time. SSS scores > 4 required additional hospitalization days. The protocol was safe, tolerable, and feasible and accomplished 32% ambulation within 7 days, 29% in 14 days, and 29% in 30 days. The results were better than those obtained in previous studies—94% at 60 days—and 75% of the dogs without nociception recovered ambulation. Long-term follows-ups carried out 4 years later revealed a positive evolution.

Low-field magnetic resonance changes in the paravertebral musculature of dogs with acute intervertebral disc extrusion

OBJECTIVES

To describe the MRI features and prevalence of paravertebral muscle signal intensity changes in dogs with acute intervertebral disc extrusion and to search for associations between the signal changes and clinical history, signalment, neurological examination, serum creatine kinase activity and MRI characteristics of the disc herniation.

MATERIALS AND METHODS

Medical records and MRI examinations from 688 dogs with surgically confirmed acute intervertebral disc extrusion were reviewed retrospectively. T2-weighted and STIR MRI sequences were available for 276 cases and were examined for paravertebral muscle signal intensity changes. When present, extension, lateralisation and signal characteristics of these changes were recorded. Exclusion criteria were muscle injections 24 hours before MRI scan, trauma and previous spinal surgery.

RESULTS

Nineteen dogs met the inclusion criteria. There were signal changes in the multifidus muscle, mostly in the thoracolumbar region and often extending caudally from the level of the intervertebral disc herniation. Two cases had paravertebral muscle signal intensity changes in the cervical region. MRI signal changes were seen more frequently in the muscles of non-ambulatory dogs. Clinical history and neuro-examination did not allow differentiation between dogs with and without paravertebral muscle signal intensity changes.

CLINICAL SIGNIFICANCE

Paravertebral muscle signal intensity changes were observed infrequently in the epaxial musculature of 6.9% dogs with acute intervertebral disc extrusion in both the thoracolumbar and cervical regions. The pathophysiological processes responsible for these MRI changes remain unknown.