spinal cord injury Flashcards
what are some causes of spinal cord injury?
- accidents
- falls
- violence
- neoplasm
- disease ( e.g transverse myelitis an autoimmune disease of long fiber tracts usu. in the thoracic spine –> paralysis in the legs)
- degenerative spine ( myelopathy: slow motion spinal cord injury over yrs.)
if you have a fracture dislocation at c3/ c4 what will happen w/o immediate medical attention
death w/in 5 minutes because of suffocation due to phrenic nerve not being able to work.
what are some acute consequences of spinal cord injury?
weakness: ( qudriparesis/plegia, neck injury, paraparesis/plegia, injury to caudal T1)
sensory loss: (touch, proprioception, pain, temperature)
sensory abnormalities: (parasthesia, pain ( neuropathic)
hypotension ( spinal cord ischemia)
urinary retention ( can’t relay info so you can ‘t release the pee)
orthopedic pain ( broken neck/back, multiple fractures)
why is it BAD to give pain meds when someone has a spinal cord injury?
because they will likely have low BP due to spinal ischemia and meds like OPIOIDS will further lower BP causing their breathing to decrease even further
what are some chronic consequences of spinal cord injury?
- involuntary movements ( spasticity i.e. hyperreflexia, and myocolonus:recurrent stretch reflex in gastrocnemus
- bladder problems : either spastic( can’t relax external sphincter ) or flaccid ( external sphincter is completely relaxed)
- decreased bowel motility
- male sexual dysfunction ( women don’t get infertility)
- increased risk for: blood clot, pressure ulcer, cutaneous ischemia- ( repositioning is vital to prevent this), autonomic dysfunction
- mostly absent thermoregulation ( no sweating( overly over heat,), limited vasoconstriction ( conserving heat)
- autonomic dysreflexia
-metabolic disorders ( diabetes, heart disease)
-psychosocial issues
musculoskeletal breakdown
a spinal injury at what level would cause spastic ( can’t relax sphincter) bladder injury?
at or above t10
a spinal injury at what level would cause flaccid (relaxed sphincter) bladder injury?
below t12
what is the thing that people with spinal cord injury would like to regain?
control of their urination
in spastic bladder problem due to Spinal cord injury what happens to the external sphincter as the detrussor muscle contracts with continued filling?
the external sphincter contracts stronger as well
*** ( prob on test) overly full bladder is the most common cause of _______ ________?
autoimmune dysreflexia
what symptoms would be exhibited with autonomic dysreflexia?
episodes of crazy high BP
HR drop to 40 beats per/min ( these two are paradoxical b/c usu increase BP is accompanied by increase heart rate)
what can trigger autonomic hypereflexia?
- overly full bladder** ( biggest cause)
- bladder emptying ( if neurogenic bladder)
- strong cutaneous inputs
what demographic does spinal cord injury affect most?
males and people over 40
at what level do more than 50% of spinal cord injuries occur
cervical spine
are more than 50% of the spinal cord injuries neurologically complete or incomplete and what does this mean?
neuroogically incomplete ( i.e. the patient has either sensory or motor function at s4 or s5)
what is the american spinal injury association (ASIA) scale?
a scale for classification of a spinal cord: A is COMPLETE i.e no motor or sensory fnc below the injury.
E is normal ( sensory and motor fnc is normal ) B-C are varying degrees of incomplete injury
what is a B on the ASIA scale?
sensory ( only) below injury, including S4- S5 segment ( anal segment)
what is a C on the ASIA scale?
sensation and LIMITED motor fnc below the injury level
What is a D on the ASIA scale?
sensation and significant motor fnc below the injury level
can nerve cell bodies crushed in the traumatic injury be healed?
no they are permanently gone and so are the connections they made.
what are the 3 broad approaches to spinal cord injury treatment?
NEUROPROTECTION: of surviving cells/axons from toxic environ. caused by injury
NEURORESTORATION:replace cells, provide neurotrophinc, reestablish a growth permissive environment
NEUROREHABILITATION ( strengthen existing systems, retain circuits, develop alternative strategies to accomplish desired tasks)
what did the pt who had been quadraplegic for 17 years start spontaneous stepping while sleeping 3 days after he started intense lower limb training 5 hours per day?
because although he couldn’t feel it his right hip was subluxed and that afferent stimulus that we would normally feel as pain triggered the spinal cord and especially when he was laying down the stimulus had a greater effect.
what improved for the pt who had been quadraplegic for 17 years start spontaneous stepping while sleeping 3 days after he started intense lower limb training 5 hours per day?
he was able to voluntarily walk better.
what muscle shows a double burst in the EMG contractions?
tibialis anterior
what evidence is there for Central pattern generators in humans?
increased involuntary double bursts in tibialis anterior
can the central pattern generator in humans be trained to improve voluntary walking in persons with incomplete spinal cord injury?
NO, there is no evidence. the involuntary improvement is neuroplasticity. it’s due to the increase in balance and increase in leg muscles
what is interlimb reflex?
when stimulate the knee for example and the contralateral hand innervated
what are characteristics of the interlimb reflex?
most common in distal upper limb muscles, rare in proximal upper limb muscles, response is almost always excitatory in nature, minimum latency suggests (near) direct pathway btw sensory afferent and cervical motorneuron
*** not evident in able-bodied pts.
what is the basis for the interlimb reflex?
regenerative sprouting: new connections in the spinal cord are made caudal to the jury post- injury
when do interlimb reflexes appear after a spinal cord injury?
days to weeks ( they are established but not functional)
months to years later novel connections develop or existing connections strengthen dramatically
once internal lomb reflexes what happens to them do the get stronger, weaken, disappear?
they get stronger for 1-2 years and never disappear
interlimb reflexes are probably the basis for ________ _________?
autonomic dsyreflexia but decrease at the presynaptic sympathetic interneurons at the thoracic level not the motor neurons on the cervical enlargement.
