Spinal cord injury Flashcards
What are the common causes of acute spinal cord injuries in dogs?
Acute intervertebral disc extrusions, fibrocartilagenous embolism (FCE), trauma
Trauma is more common in cats than intervertebral disc extrusions, and thrombo-embolic events are much more common than FCE.
What are the two main types of damage caused by acute spinal cord injury?
Primary damage, secondary damage
Secondary damage develops over acute (0-48 hours), subacute (48 hours to 2 weeks), and chronic phases.
What is primary damage in the context of acute spinal cord injury?
Mechanical damage to the spinal cord causing contusion, shearing, acceleration/deceleration, and laceration
This results in physical disruption of cell membranes causing hemorrhage and ischemia.
What are the effects of compression on the spinal cord?
Limits arterial supply, occludes venous drainage, causes direct damage to myelin and axons
Compression can occur due to herniated disc material, displaced vertebrae, or epidural hematomas.
What happens during the secondary damage phase after acute spinal cord injury?
Expansion of tissue destruction, including hemorrhage, rapid changes in ion concentration, excitotoxicity, free radical production, inflammation
This phase can lead to apoptosis.
How does vascular injury affect spinal cord perfusion?
Causes hemorrhage and ischemia, leading to increased interstitial pressure and decreased perfusion
Petechial hemorrhages can form over 24 hours after injury.
What role does the Trpm4 gene play in spinal cord injury?
Upregulation causes ion entry, oncotic swelling, and cell death
Antisense Trpm4 administration reduces post-injury hemorrhage and lesion volume.
What are the effects of ionic disturbances following spinal cord injury?
Influx of chloride and cations, increased extracellular glutamate, cytotoxic edema, necrosis, and apoptosis
Excitotoxicity plays a significant role in neuronal and oligodendroglial cell death.
What are reactive oxygen species (ROS) and their role in spinal cord injury?
Produced by ischemic conditions and damage membranes, leading to glial, neuronal, and endothelial damage
ROS production peaks within the first 12 hours of injury.
What is the effect of methylprednisolone sodium succinate (MPSS) in spinal cord injury?
Believed to exert neuroprotective effects through inhibition of lipid peroxidation
Controversy exists regarding the benefits and significant side effects of high doses in humans.
What is the role of inflammatory mediators like TNFα and IL1β in spinal cord injury?
Increase permeability of blood spinal cord barrier, produce toxic chemicals, recruit inflammatory cells
MMP-9 activity has been linked to poor recovery outcomes.
What is apoptosis and its significance in spinal cord injury?
Cell death by necrosis or apoptosis, with oligodendrocyte death contributing to demyelination and loss of function
Activation of the Fas receptor triggers apoptosis in oligodendrocytes.
What are the challenges of axonal regeneration after spinal cord injury?
Weak intrinsic response and non-permissive environment due to inhibitory factors from myelin and astrocytes
Strategies targeting these inhibitory proteins are in clinical trials.
What is the importance of maintaining blood flow to the injured spinal cord?
Close relationship between perfusion and outcome, with loss of autoregulation worsening perfusion
Hypertension at the time of injury predicts a worse outcome.
Fill in the blank: The initial traumatic injury causes _______ to the spinal cord.
mechanical damage
True or False: Secondary injury mechanisms can continue long after the initial injury.
True
What are the potential consequences of a glial scar following spinal cord injury?
Disturbances in CSF flow, development of syringomyelia, or subarachnoid cysts
These can lead to further neurological deterioration months to years after injury.
What is the significance of excitotoxicity in spinal cord injury?
It is relevant in neuronal and oligodendroglial cell death and is a potential pharmacological target for therapy
Elevated CSF glutamate levels have been documented in dogs with naturally occurring SCI.
