Transcerebellar ventriculoperitoneal shunt for management of presumed arachnoid diverticulum in the fourth ventricle of a dog.

OBJECTIVE: To describe the approach for placement of a transcerebellar fourth ventriculoperitoneal shunt for management of presumed fourth ventricle arachnoid diverticulum and secondary obstructive hydrocephalus of a dog. To describe the outcome of this procedure. STUDY DESIGN: Case report. ANIMALS: Male entire English springer spaniel, 3 years 9 months of age. METHODS: The dog was initially presented for management of acute, progressive, and multifocal brainstem and forebrain dysfunction. Magnetic resonance imaging revealed internal obstructive hypertensive hydrocephalus. The dog was managed via ventriculoperitoneal shunting from the left lateral ventricle and made an excellent recovery. The dog acutely deteriorated 18 months after initial discharge and follow-up magnetic resonance imaging confirmed the ventricular shunt remained in situ with normal-sized lateral ventricles but revealed a cystlike lesion within the fourth ventricle, presumed to be a fourth ventricle arachnoid diverticulum. The diverticulum was causing mass effect and resultant compression of adjacent neuroparenchyma. A second ventriculoperitoneal shunt was subsequently placed into the fourth ventricle via the caudal cranial fossa and cerebellum. This was attached to a three-way connector, to which the existing shunt (within the left lateral ventricle) was also attached, and then secured to the existing medium-pressure valve. RESULTS: Postoperatively, the dog immediately developed mild vestibular-cerebellar ataxia, with a marked improvement after 3 months. There were no shunt-associated complications. Long-term follow up at 40 months after the second surgical procedure revealed a normal neurological examination. CONCLUSION: Transcerebellar ventriculoperitoneal shunt placement for treatment of a presumed fourth ventricle arachnoid diverticulum was performed and was associated with a favorable long-term outcome.

Early CT in dogs following traumatic brain injury has limited value in predicting short-term prognosis.

Traumatic brain injury is associated with a high risk of mortality in veterinary patients, however publications describing valid prognostic indicators are currently lacking. The objective of this retrospective observational study was to determine whether early CT findings are associated with short-term prognosis following traumatic brain injury (TBI) in dogs. An electronic database was searched for dogs with TBI that underwent CT within 72 h of injury; 40 dogs met the inclusion criteria. CT findings were graded based on a Modified Advanced Imaging System (MAIS) from grade I (normal brain parenchyma) to VI (bilateral lesions affecting the brainstem with or without any foregoing lesions of lesser grades). Other imaging features recorded included presence of midline shift, intracranial hemorrhage, brain herniation, skull fractures, and percentage of total brain parenchyma affected. Outcome measures included survival to discharge and occurrence of immediate onset posttraumatic seizures. Thirty dogs (75%) survived to discharge. Seven dogs (17.5%) suffered posttraumatic seizures. There was no association between survival to discharge and posttraumatic seizures. No imaging features evaluated were associated with the study outcome measures. Therefore, the current study failed to identify any early CT imaging features with prognostic significance in canine TBI patients. Limitations associated with CT may preclude its use for prognostication; however, modifications to the current MAIS and evaluation in a larger study population may yield more useful results. Despite this, CT is a valuable tool in the detection of structural abnormalities following TBI in dogs that warrants further investigation.

Neurological signs and MRI findings in 12 dogs with multiple myeloma.

Vertebral lesions and associated neurological signs occur in dogs with multiple myeloma, however, veterinary literature describing MRI findings is currently lacking. The objective of this multicenter, retrospective, case series study was to describe neurological signs and MRI findings in a group of dogs that presented for spinal pain or other neurological deficits and had multiple myeloma. Electronic records of four veterinary referral hospitals were reviewed. Dogs were included if they had a pathologically confirmed diagnosis of multiple myeloma, had presented for spinal pain or other neurological signs, and had undergone MRI of the vertebral column. The MRI studies were evaluated and the anatomical location of lesion(s), signal intensity, presence of extra-dural material, degree of spinal cord compression, extent of vertebral lesions, and contrast enhancement were recorded. Twelve dogs met inclusion criteria. Most dogs (n = 8) had a chronic progressive history, with varying degrees of proprioceptive ataxia and paresis (n = 11), and spinal pain was a feature in all dogs. The MRI findings were variable but more consistent features included the presence of multiple expansile vertebral lesions without extension beyond the outer cortical limits of affected vertebrae, and associated extradural material causing spinal cord compression. The majority of lesions were hyper- to isointense on T2 (n = 12) and T1-weighted (n = 8) sequences, with variable but homogeneous contrast-enhancement (n = 12). These described MRI characteristics of multiple myeloma may be used to aid early identification and guide subsequent confirmatory diagnostic steps, to ultimately improve therapeutic approach and long-term outcome.

Outcomes of nonsurgical treatment for congenital thoracic vertebral body malformations in dogs: 13 cases (2009-2016).

OBJECTIVE To characterize outcomes following nonsurgical treatment of congenital thoracic vertebral body malformations causing neurologic deficits in dogs. DESIGN Retrospective case series. ANIMALS 13 client-owned dogs treated nonsurgically for congenital thoracic vertebral body malformations at 3 veterinary referral hospitals from June 2009 through May 2016. PROCEDURES Data were extracted from the medical records regarding dog signalment, duration and type of clinical signs before referral, general physical and neurologic examination findings, radiographic and MRI findings, and treatments provided after diagnosis. Follow-up data were obtained from records of recheck examinations and via a standardized owner questionnaire. RESULTS All included dogs were screw-tail brachycephalic breeds with a median age of 6 months. All dogs had ambulatory paraparesis and ataxia, and in 1 dog, signs of spinal hyperesthesia could be elicited. Nonsurgical treatments consisted of restricted exercise without (n = 5) or with (3) physiotherapy, physiotherapy without restricted exercise (3), and no exercise modification (2). Seven dogs received additional nonsurgical treatment consisting of prednisolone (n = 5) or gabapentin (2). Four dogs were eventually euthanized because of progressive neurologic deterioration, 2 underwent surgery for the same reason, and the remaining 7 dogs survived for ≥ 170 days after diagnosis, despite progressive neurologic deterioration. CONCLUSIONS AND CLINICAL RELEVANCE Nonsurgical treatment of congenital thoracic vertebral body malformations was associated with an unfavorable outcome in this group of dogs. Despite this treatment, all dogs had progression of clinical signs.