Functional stages in AMN
United Leukodystropphy Foundation
July 19, 2013
Kathy Zackowski, PhD, OT
Motion Analysis Laboratory
Kennedy Krieger Institute
Johns Hopkins University School of Medicine
What we know:
Central nervous system changes
Our past studies show
• Sensory loss (vibration)
feet >> hands
• Progressive weakness
legs >> arms
secondary disuse
• Spasticity, legs
• Difficulty walking
• Poor balance
This is what we did:
Purpose:
To quantify symptom characteristics of AMN in men and
women and determine which characteristic(s) have the
greatest impact on function.
Subjects: 60 men, 80 women with AMN
• Single test session
• In the motion analysis laboratory at
Kennedy Krieger
• Clinical exam
• Individualized exercise program
What impairment effects movement
performance most?
Functional Tests
Impairments
Vibration
sensation
Range of
motion
Static Balance
Dynamic
Balance
Strength
Walking
Speed
Age
Walking
endurance
Sit to Stand
Gravity
Lessened
Antigravity
Resistive
Demographics
Variable
Men
Women
Strength
group
Gravity
Lessened
Anti-gravity
Resistive
Gravity
Lessened
Anti-gravity
Resistive
Flexor
strength,
kg
2.0
15.6
24.3*
0
11.2
17.0*
Sample size
5
24
31
2
25
53
Age, y
39
41
40
50
54
44
Vibration
19.9
13.3
10.4
19.9
8.4
6.0
Ankle DF
ROM
-7
2
7
-4
2
7
*40 y/o male norm: 29.0 kg
*50 y/o female norm: 18.1 kg
Sit to Stand
slower
Standing Balance: eyes open feet apart
Men
40%
91%
Gravity Lessened
100%
Anti-gravity
100%
94%
Resistive
100%
Women
Percentage values are those per group able to stand for 20 seconds
Standing Balance: eyes closed feet together
Men
26%
83%
Gravity
Lessened
Anti-gravity
Resistive
50%
96%
Women
Percentage values are those per group able to stand for 20 seconds
Dynamic Standing Balance
slower
slower
slower
Endurance
Exercises must match your ability
Gravity
Lessened
Antigravity
Resistive
Strength can be improved over one year
Women
(kg)
Strength(lbs)
ExtensionStrength
Hip
HipExtension
Hip Extension
18.0
40.0
16.0
35.0
14.0
30.0
12.0
25.0
10.0
20.0
8.0
15.0
6.0
10.0
4.0
5.0
2.0
0.0
Exercse Group
Control Group
0
1
(kg)
Strength(lbs)
ExtensionStrength
Knee
KneeExtension
Visit
Knee Extension
70.0
30.0
60.0
25.0
50.0
20.0
40.0
15.0
30.0
10.0
20.0
5.0
10.0
Exercse Group
Control Group
0.0
0
1
Visit
Men
(kg)
Strength(lbs)
ExtensionStrength
Hip
HipExtension
Hip Extension
50.0
25.0
40.0
20.0
30.0
15.0
Exercse Group
20.0
10.0
Control Group
10.0
5.0
0.0
0
1
(kg)
Strength(lbs)
ExtensionStrength
Knee
KneeExtension
Visit
Knee Extension
45.0
90.0
80.0
40.0
70.0
35.0
60.0
30.0
50.0
25.0
40.0
20.0
30.0
15.0
20.0
10.0
10.0
5.0
0.0
Exercse Group
Control Group
0
1
Visit
Functional Measures
Get Up And Go Time (s)
Velocity (m/s)
Velocity
1.5
1
Men
0.5
Women
0
0
1
Visit
Get Up And Go
15
10
5
Men
0
Women
0
1
Visit
EOFA
Standing Amplitude
(mm)
4
3
2
Men
1
Women
0
0
1
Visit
15
10
5
Men
0
Women
0
600
400
Men
200
Women
0
0
1
Visit
1
Visit
6-Min Walk Distance
Distance (m)
Sit To Stand Time (s)
Sit To Stand
Summary
• Of all the impairments, weakness is the most
prevalent feature effecting movement
performance
• Weakness affects both men and women
• Strength varies from person to person
• Preliminary data shows strength is changeable
• Important to individualize an exercise program
Acknowledgements
Neurogenetics:
Jerry Raymond
Kim Hollandsworth
Katy Gibbons
Lena Bezman
Motion Analysis Lab:
Jennifer Keller
Rhul Marasigan
Joe Wang
* All the people with AMN (and their families)
who enthusiastically participated in this study