Prognostic Value of Early Magnetic Resonance Imaging in Dogs after Traumatic Brain Injury: 50 Cases

Abstract

BackgroundThe prognostic value of early magnetic resonance imaging (MRI) in dogs after traumatic brain injury (TBI) remains unclear.ObjectivesDetermine whether MRI findings are associated with prognosis after TBI in dogs.AnimalsFifty client‐owned dogs.MethodsRetrospective study of dogs with TBI that underwent 1.5T MRI within 14 days after head trauma. MRI evaluators were blinded to the clinical presentation, and all images were scored based on an MRI grading system (Grade I [normal brain parenchyma] to Grade VI [bilateral lesions affecting the brainstem with or without any lesions of lesser grade]). Skull fractures, percentage of intraparenchymal lesions, degree of midline shift, and type of brain herniation were evaluated. MGCS was assessed at presentation. The presence of seizures was recorded. Outcome was assessed at 48 h (alive or dead) and at 3, 6, 12, and 24 months after TBI.ResultsSixty‐six percent of the dogs had abnormal MRI findings. MRI grade was negatively correlated (P < .001) with MGCS. A significant negative correlation of MRI grade, degree of midline shift, and percentage of intraparenchymal lesions with follow‐up scores was identified. The MGCS was lower in dogs with brain herniation (P = .0191). Follow‐up scores were significantly lower in dogs that had brain herniation or skull fractures. The possibility of having seizures was associated with higher percentage of intraparenchymal lesions (P = 0.0054) and 10% developed PTE.Conclusions and Clinical ImportanceSignificant associations exist between MRI findings and prognosis in dogs with TBI. MRI can help to predict prognosis in dogs with TBI.

Canine head trauma: an update

“…Similarly, in the study by Beltran and others (2014), unilateral and bilateral brainstem lesions were respectively classified with the higher MRI grade and had significant negative correlation with MGCS at presentation and patient follow-up scores, which is consistent with previous studies in people. This study also agreed with previous work in people in which poor outcome was significantly associated with brain herniation, skull fractures and larger intraparenchymal lesions.…”

“…Recent studies in people have demonstrated that MRI findings can be valuable predictors of clinical outcome due to their high sensitivity for the detection of lesions such as non-haemorrhagic contusions, brainstem involvement and diffuse axonal injuries (DeQuesada and Chokshi 2014). In a recent veterinary study, MRI characteristics of TBI, such as volume of parenchymal damage and midline shift of the cerebral hemispheres, appeared to have clinical relevance due to their significant correlation with outcome (Beltran and others 2014). This study used a grading system modified from human medicine, where the severity and location of the lesions were taken into account (Table 1).…”

“…This was not performed by Beltran and others (2014), but its use in veterinary medicine may also advance the ability to prognosticate and should be considered in the future.…”

“…Recent large-scale studies have reported the incidence of post-traumatic epilepsy (PTE) as being 0.55 to 2 per cent of all the dogs referred to veterinary hospitals (Friedenberg and others 2012, Steinmetz and others 2013). A study evaluating 50 dogs with TBI demonstrated that 10 per cent of them went on to develop PTE and four of these five animals did not have any immediate or early onset of seizures (Beltran and others 2014). Therefore, in contrast to what is reported in the human literature, the early onset of seizures after TBI in dogs does not appear to be an important risk factor for the development of PTE.…”

Altered States of Consciousness in Small Animals

“…[23][24][25] The major drawbacks of MRI include accessibility, cost, and time necessary to complete the scan; however, recent work suggests that it can be a valuable prognostic tool, at least in dogs with head trauma. 26 Advances in task-based functional MRI (fMRI), resting-state fMRI (rs-fMRI), and arterial spin labeling (ASL) perfusion MRI have occurred at a rapid pace in recent years in humans. 27 These techniques for measuring brain function have great potential to improve the accuracy of prognostication for patients with traumatic coma.…”