Rodolfo Cappello

Background: Orthostatic tremor (OT) is a rare movement disorder characterized by high-frequency (>12 Hz) involuntary, rhythmic, sinusoidal movements affecting predominantly the limbs while standing. Objective: To describe the signalment, presenting complaints, phenotype, diagnostic findings, treatment, and outcome of a large sample of dogs with OT. Animals: Sixty dogs diagnosed with OT based on conscious electromyography. Methods: Multicenter retrospective case series study. Dogs were included if they had a conscious electromyography consistent with muscle discharge frequency >12 Hz while standing. Results: Fifty-three cases were diagnosed with primary OT (POT). Giant breed dogs represented most cases (83%; 44/53). Most dogs (79%; 42/53) were younger than 2 years of age at onset of signs, except for Retrievers which were all older than 3.5 years of age. The most common presenting complaints were pelvic limb tremors while standing (85%; 45/53) and difficulty when rising or sitting down (45%; 24/53). Improvement of clinical signs occurred in most dogs (85%; 45/53) treated medically with phenobarbital, primidone, gabapentin, pregabalin or clonazepam, but it was mostly partial rather than complete. Orthostatic tremor-plus was seen in 7 dogs that had concurrent neurological diseases. Conclusions and Clinical Importance: Primary OT is a progressive disease of young, purebred, giant/large-breed dogs, which appears to begin later in life in Retrievers. Primary OT apparently responds partially to medications. Orthostatic tremor-plus exists in dogs and can be concomitant or associated with other neurological diseases.

Background: Although thoracic hemivertebra can cause neurological signs, they occur commonly in neurologically normal dogs. Objectives: To evaluate whether computed tomography (CT) findings and factors associated with signalment can be used to differentiate between dogs with and without neurological signs associated with hemivertebra. Animals: One hundred sixty dogs with ≥1 hemivertebrae were retrospectively studied. This group consisted of 40 dogs with clinical signs caused by hemivertebra and 40 French Bulldogs, 40 Pugs, and 40 English Bulldogs that underwent CT for reasons unrelated to neurological disease. Methods: All dogs underwent CT and affected dogs also underwent magnetic resonance imaging. All CT studies were randomly evaluated by an observer blinded to signalment and clinical status. The following variables were evaluated: presence, number, location, and subtype of hemivertebra; presence of vertebral subluxation; severity of vertebral canal stenosis; presence, location, and severity of kyphosis, and number of vertebrae involved in the kyphotic segment. Statistical modeling was performed to identify factors associated with clinical status. Results: Pug breed (odds ration [OR], 10.8; P = .01), more severe kyphosis (OR, 1.1 per grade increase; P < .001), fewer instead of more observed hemivertebrae (OR, 0.8; P = 0.03), and ventrolateral hypoplasia hemivertebra subtype (OR, 4.0; P = .011) were associated with higher likelihood of neurological disease. A Cobb angle of 34.5 degrees corresponded with the highest combined sensitivity and specificity to differentiate between clinically affected and unaffected dogs. Conclusions and Clinical Importance: The variables identified could aid in differentiating between clinically relevant and irrelevant hemivertebra in small breed brachycephalic dogs.

Objective: To describe a novel vertebral body stabilization and report its outcome in dogs with thoracic kyphosis and secondary myelopathy.Study design: Case series.Animals: Six pugs with thoracic kyphosis and secondary myelopathy.Methods: Medical records (2012‐2017) of dogs with chronic progressive pelvic limb ataxia and ambulatory proprioceptive paraparesis due to thoracic kyphosis were reviewed. Dogs were evaluated via MRI and computed tomography. A 3‐dimensional print of the kyphotic vertebral segment was used to precontour the SOP (String of Pearls) plates. Bilateral double, dorsal intercostal thoracotomies were performed to place precontoured SOP on the vertebral bodies. Long‐term (6‐16 months) clinical outcome was determined on the basis of neurological scoring (NS) and owner questionnaire.Results: The only intraoperative complication consisted of a lung laceration due to preexisting adhesions. Postoperative complications included seroma formation (n = 2) and incidental radiographic evidence of screw breakage (n = 2). NS at presentation ranged between 2 and 4 and improved to 1 at long‐term follow‐up in all dogs but 1 (NS = 2). All owners felt that their dog had excellent quality of life at follow‐up.Conclusion: In spite of the challenging local anatomy, all dogs undergoing vertebral stabilization with SOP placement experienced a good clinical outcome.Clinical significance: Stabilization of vertebral bodies with precontoured SOP placed through bilateral thoracotomies may be considered as a treatment option for dogs with thoracic kyphosis and secondary myelopathy.

Objective This case series describes the clinical presentation, management and outcome of three cats diagnosed with cervical intervertebral disc disease that underwent decompressive ventral slot surgery. Methods This is a retrospective case series evaluating client-owned cats undergoing a ventral slot surgical procedure to manage cervical intervertebral disc disease (n = 3). Results A routine ventral slot surgery was performed in each case without complication, resulting in postoperative neurological improvement in all three cases. Clinical Significance Ventral slot surgery can be used to achieve effective cervical spinal cord decompression with a good long-term outcome in the management of feline cervical intervertebral disc herniation. To avoid creating an excessively wide slot with the potential for postoperative complications including vertebral sinus haemorrhage, vertebral instability or ventral slot collapse, careful surgical planning was performed with preoperative measurement of the desired maximum slot dimensions.

A five‐year eight‐month‐old Maltese terrier was presented with a 3‐week history of progressive paraparesis and pelvic limb ataxia. Neurological examination was consistent with a lesion involving the T3‐L3 spinal cord segments. Myelogram and magnetic resonance imaging revealed a spherical, intradural‐extramedullary mass lesion at T13/L1. A dorsal laminectomy, durotomy and debulking of the mass were performed. Histopathologic examination revealed a highly cellular tissue, most likely of mesenchymal origin, infiltrated by many lymphocytes, macrophages and neutrophils. The pathological diagnosis of an inflammatory pseudotumour was made. Postsurgical analgesia was achieved with opioids and 2 mg/kg carprofen twice daily for 5 days. When the histopathological diagnosis was made, a tapering course of 1 mg/kg prednisolone twice daily was prescribed, with dose reduction by approximately 50% every 4 to 6 weeks over a 4‐month period. Magnetic resonance imaging was repeated at 22, 32 and 85 weeks postsurgery; no signs of regrowth could be detected and the patient recovered with residual mild paraparesis. Inflammatory pseudotumour has not been documented previously at this site in dogs and, although rare, should be considered in the differential diagnosis of a focal mass lesion affecting the spinal cord. Surgical debulking and immunomodulatory therapy can be curative.

A 6‐year‐old neutered male Rottweiler had chronic episodic signs of thoracolumbar pain and inability to stand that did not improve after rest and nonsteroidal antiinflammatory medication. In magnetic resonance images, an extradural mass was identified between the spinal cord and the T13/L1 intervertebral disc; the mass was compressing the cord in a dorsoventral direction. The lesion had a low signal intensity rim that enhanced slightly after gadolinium administration, and contents with similar signal intensity to cerebrospinal fluid. The lesion was removed surgically by severing its attachments to the annulus fibrosus. The histologic diagnosis was degenerative intraspinal cyst. The origin of such cysts, and their relationship to synovial and ganglion cysts is discussed.