Tevald: MSK changes and respiration with SCI

Question 1

Diaphysis is made of what kind of bone?

Answer 1

cortical which is hard

Question 2

Epiphysis is made of what kind of bone?

Answer 2

trabecular/cancellous/spongey

Question 3

What happens to bone with SCI
Epiphysis ?
Diaphysis?
Spine?

Answer 3

Epiphysis: BMD loss

Diaphysis: thinning of the cortex from the inside

Spine: BMD stays the same because they’re still able to load through it

Question 4

Does bone stiffness increase or decrease at the dipahysis with SCI?

Answer 4

decrease it thins from the inside out.

Question 5

two phases of the bone getting weaker

what % per month initially?

What % overall?

Answer 5

1) initial rapid decline in the first 2 years. 2-4% per month during this phase
2) persistent decline over decades. 60% decline overall

Question 6

_____ fold increase in risk of fracture compared to age matched norms for able bodied individuals

Answer 6

5-23

Question 7

Cumulative fracture rate for SCI?

What does it mean and what %

Answer 7

Number of fractures by the number of people across time

> 40%

Question 8

What is the big deal with weak bone?

Answer 8

risk of fractures with minimal trauma

Question 9

What are the most commonly fractured bones?

Answer 9

distal femur, proximal tibia, ankle

Question 10

What is a risk for skin breakdown with fractures for SCI that is not a concern in able bodied individuals

Answer 10

casts on an insensate body part

Question 11

Resorption and formation of bone with SCI. And what is the catalyst?

Answer 11

Resorption&raquo_space;> formation and this occurs because there is no loading going on!

Question 12

osteoclast resorption or formation?

Answer 12

resorption = breaking down

Question 13

Two things that happen to muscle after SCI

Answer 13

1) atrophy

2) fat and CT infiltration

Question 14

CSA of muscles with SCI

Answer 14

goes way down over 25 week period, and its possible that acutely its even more, the study we looked at took data 6 weeks after injury

Question 15

name positive and negative regulators of muscle

Answer 15

+ regulators: growth factors, anabolic horomones, mTORC1. These are DECREASED

• regulators: inflammation, protein breakdown FoxO. These are INCREASED

Question 16

Type one vs. type two fibers

Kind of activity and fatiguability

Answer 16

Type one: endurance, fatigue resistant, running

Type two: power, quick movements

Question 17

what is the fiber type change in muscle post SCI?

Consequences of this?

Answer 17

type one –> type two; muscles start forming cross bridges more rapidly, it takes a lot higher frequency to get a fully fused tetanic contraction/the amount of torque

Question 18

Does type one or type two fibers need a higher frequency for tetanic contractions?

why do we care?

Implications for practice?

Answer 18

type two

We care: after SCI muscle fiber type changes from type one to type two therefore cross bridges are forming more rapidly and it takes a higher frequency to get a tetanic contraction.

implications for practice: you have to set the stimulator at a higher frequency to get the same % of peak torque/relative force

Question 19

Muscle fatiguability with stimulation post SCI vs. control

Answer 19

the control didn’t even have a 10% drop in force

The SCI had a crazy drop in force

MUSCLE BECOMES MORE FATIGUABLE.

Question 20

T2 weighted image what color is water? What does water suggest?

Answer 20

T2 weighted image water is white and suggests inflammation

Question 21

Describe control vs. SCI T2 weighted images 72 hrs post activation?

Answer 21

control looks about the same at baseline, only a little white suggesting inflammation

SCI looks very bright, inflammation stemming from contraction induced muscle damage.

Question 22

What do the T2 weighed images of the muscles 72 hours post tell us about SCI muscles?

Answer 22

there is prolonged force loss and damage (1/4 of individuals after 72 hours)

Question 23

What are the three factors of total energy expenditure and what is compromised in SCI

Answer 23

total energy expenditure = resting + PA + diet

In SCI resting (due to muscle atrophy) and PA is influenced

Question 24

How do muscle changes in SCI affect how we think about treatment if a cure for SCI was developed

Answer 24

they still wouldn’t be good candidates because their muscles have already undergone physiologic changes

Question 25

how do muscle changes with SCI affect use of FES

Answer 25

higher frequency needed to get same contraction. This may cause muscle damage and fatiguability

Question 26

Why do we care about energy expenditure in SCI population?

Answer 26

Energy balance is off, energy in is the same, energy out is decreasing leading to an increase in adiposity

Question 27

Increase in adiposity leads to what two things?

Answer 27

1) intramuscular adipose tissue doubles | 2) increase in visceral adipose tissue

Question 28

risk of overweight/obesity in CHRONIC SCI population?

Answer 28

66%

Question 29

BMI for assessing obesity in SCI population? How do "normal" BMI and fat mass correlate?

Answer 29

no! grossly underestimates obesity BMI and fat mass correlation: poor! half of those with "normal" BMI had 30% fat mass which is over the 20% to be qualified as obese

Question 30

what is the gold standard for assessing obesity in SCI population

Answer 30

DEXA looking at fat mass >20%

Question 31

Looking at waist dircumference with assessing obesity in SCI?

Answer 31

underestimates again bc they have a greater visceral adiposity

Question 32

Suggested SCI specific obesity cutoff for BMI? (if you're going to use it even though its not great)

Answer 32

≥ 22 kg/m2

Question 33

Describe glucose, insulin action leading to what with gluconeogenesis in response to increased adiposity. All leading to _______

Answer 33

decreased glucose uptake into liver and muscle decrease insulin action leading to increased gluconeogenesis in the liver All leading to hyperglycemia

Question 34

What two things bring about diabetes

Answer 34

hyperglycemia insulin resistance

Question 35

Insulin resistance % in chronic SCI

Answer 35

60%

Question 36

Diabetes % in chronic SCI

Answer 36

50%

Question 37

Metabolic syndrome % in chronic SCI

Answer 37

55%

Question 38

Metabolic syndome leads to what overall disease?

Answer 38

CVD

Question 39

Risk of CAD in paraplegia

Answer 39

70% higher

Question 40

____ fold risk of cerebrovascular disease in tetraplegia

Answer 40

5 fold

Question 41

What is the primary cause of death in chronic SCI

Answer 41

CV disease!

Question 42

What are three out of the four risk factors of metabolic syndrome that SCI individuals undergo?

Answer 42

Abdominal obesity, dylipidemia, hyperlglycemia the other is HTN

Question 43

Describe - how much compression load to the bone was dosed - the findings of the long term boot NMES trial. - Big picture

Answer 43

Compression to the bone =1.5xBW a lot more trabecular bone in the trained limb 31% increase at distal tibia. By loading muscle they were able to load the bone. Appropriately dosed NMES can reverse bone loss.

Question 44

What can NMES do

Answer 44

``` reverse bone loss increase muscle size reduce fatiguability - preventing loss in acute injury - reversing loss in chronic injury Reverse fiber type shift Improve metabolic profile ```

Question 45

Explain the findings of the knee extension protocol and CSA of the muscle

Answer 45

increase in muscle CSA at 6 weeks and 6 months (up to 37%)

Question 46

NMES reducing fatiguability what protocol was used and what outcome were they looking at to look at fatiguability? What did they find?

Answer 46

boot protocol they were looking at the endurance of the muscle NMES can prevent the loss of endurance in acute SCI NMES can recovery the loss of endurance in chronic SCI

Question 47

FES cycling can what in terms of muscle changes? fiber changes? thigh muscle mass? VO2?

Answer 47

reduce fiber type shift increase thigh muscle mass increase in VO2

Question 48

After 10 weeks of FES cycling how did the metabolic profile of the muscles change, two things

Answer 48

Increase in lean muscle mass Decrease in inflammatory markers

Question 49

Glucose control post FES cycling? | Insulin sensitivity?

Answer 49

Better glucose control, better insulin sensitivity

Question 50

in 8 week FES cycling literature what was used to categorize people in to normal, DM and insulin resisstance? What happened after training

Answer 50

glucose tolerance After training: None had DM, fewer were in the insulin resistance, majority were normal