Disorders of the Central and peripheral nervous systems Flashcards
1
Q
Traumatic Brain injury
A
- Primary TBI: caused by the direct impact or injury
- secondary: is the indirect consequence of the primary injury; includes a cascade of cellular and molecular brain events as well as systemic responses
2
Q
Primary brain injury
A
- focal: affects one area of the brain (more than 2/3 of head injury deaths)
- diffuse axonal injury (DAI): Affects more than one area of brain
- -account for greatest # of severely disabled survivors
3
Q
TBI: Closed blunt trauma
A
- head strikes a hard surface, or a rapidly moving object strikes the head
- dura remains intact; brain tissues aren’t exposed to the environment
- causes focal (local) or diffuse (general) brain injuries
- more common than open trauma injuries
4
Q
TBI (Open) penetrating trauma
A
- injury breaks the dura and exposes the cranial contents to the environment
- causes primary focal injuries
5
Q
Glasglow coma scale
A
- mild: GCS of 13-15 (mild concussion)
- moderate GCS: 9-12 (structural injury such as hemorrhage or contusion)
- severe GCS: 3-8 (cognitive/physical disability or death)
- hallmark of severe brain injury: Loss of consciousness for 6 or more hours
6
Q
Focal brain injury
A
- coup injury: injury at site of impact
- contrecoup injury: injury from brain rebounding and hitting opposite side of skull
7
Q
Focal brain injury manifestations/tx
A
- force of impact usually produces contusions
- contusions: blood leaks from an injured vessel bruising brain
- loss of consc. usually less than 5 minutes
- tx; control ICP, and surgery
- smaller the area of impact the greater the severity of injury
8
Q
Contusions
A
- epidural (extradural) hematoma: bleeding between dura matter and skull, usually arterial and w/ skull fracture
- subdural hematoma: blood between dura and brain, usually venous
- intracerebral hematoma: bleeding w/in brain
9
Q
Spinal cord injury
A
- individuals at risk are young adult men
- causes: MVAs, falls, violence, sports
- extent of injury: in order of occurance (incomplete quad, complete paraplegia, incomplete para, complete quad)
10
Q
Primary spinal cord injury
A
- initial mechanical trauma and immediate tissue destruction
- damaged by shearing, compression or penetration
- may occur in absence of vertebral fracture or dislocation
- occurs when an injured spine is not adequately immobilized immediately following injury
11
Q
Secondary spinal cord injury
A
- pathophys cascade of vascular, cellular and biochemical events
- begins w/in a few minutes after injury an continues for weeks
12
Q
Mechanisms of secondary SCI
A
- microscopic hemorrhages, edema, ischemia, extitotoxicity, inflammation, oxidative damage, an activation of necrotic an apoptotic cell death
- cord swelling makes it hard to determine which changes are permanent
- -if injury cervical area then it can become life-threatening
13
Q
Manifestations of SCI
A
- normal activity of spinal cord ceases at and below level of injury
- spinal shock
- neurogenic shock
14
Q
spinal shock
A
- loss of continuous discharge from brain or brainstem and inhibition of suprasegmental impulses
- complete loss of reflex function, flaccid paralysis, sensory deficit, loss of bladder and rectal control
- transient drop in BP and poor venous circulation
- loss of thermal control, causes body to assume air temp
- resolving when reflexes return and bladder relaxes
15
Q
Neurogenic shock
A
- loss of sympathetic outflow
- vasodilation
- Hotn
- brady
- hypothermia
- loss of supraspinal control and unopposed parasympathetic tone mediated by the intact vagus nerve
