Shy et al developed the Charcot-Marie-Tooth Neuropathy Score (CMTNS) based on the Total Neuropathy Score (TNS). The authors are from Wayne State University (Detroit), National Hospital for Neurology and Neurosurgery (London), Norfolk and Norwich University Hospital (Norwich), London Health Sciences Center, the University of Western Ontario and the University of Messina.
Parameters:
(1) sensory symptoms in the lower extremities
(2) motor symptoms in the legs
(3) motor symptoms in the arms
(4) pin sensibility in the extremities
(5) vibration sensibility in the extremities
(6) lower extremity strength
(7) upper extremity strength
(8) ulnar compound muscle action potential (CMAP)
(9) ulnar sensory nerve action potential (SNAP)
Parameter |
Finding |
Points |
---|---|---|
sensory symptoms in the lower extremities |
none |
0 |
|
limited to toes |
1 |
|
above toes up to ankles |
2 |
|
above ankles up to knees |
3 |
|
above knees |
4 |
motor symptoms in the legs |
none |
0 |
|
trips, slaps feet, catches toes |
1 |
|
ankle-foot orthosis on at least 1 leg or ankle support |
2 |
|
cane, walker, ankle surgery |
3 |
|
wheelchair most of the time |
4 |
motor symptoms in the arms |
none |
0 |
|
difficulty with buttons and/or zippers |
1 |
|
unable to do buttons or zippers but can write |
2 |
|
cannot write or use keyboard |
3 |
|
affecting proximal arms |
4 |
pin sensibility |
normal |
0 |
|
reduced in fingers or toes |
1 |
|
reduced up to wrists or ankles |
2 |
|
reduced at elbows or knees |
3 |
|
reduced above elbows or knees |
4 |
vibration sensibility |
normal |
0 |
|
reduced in fingers or toes |
1 |
|
reduced up to wrists or ankles |
2 |
|
reduced at elbows or knees |
3 |
|
reduced above elbows or knees |
4 |
lower extremity strength |
normal |
0 |
|
4+, 4 or 4- on foot dorsiflexion |
1 |
|
<= 3 on foot dorsiflexion |
2 |
|
<= 3 dorsiflexion and plantar flexion |
3 |
|
proximal weakness |
4 |
upper extremity strength |
normal |
0 |
|
4+, 4 or 4- on intrinsics or finger extensors |
1 |
|
<= 3 intrinsics or finger extensors |
2 |
|
< 5 wrist extensors |
3 |
|
weak above elbows |
4 |
ulnar CMAP |
> 6 mV |
0 |
|
4.0 to 5.9 mV |
1 |
|
2.0 to 3.9 mV |
2 |
|
0.1 to 1.9 mV |
3 |
|
absent |
4 |
ulnar SNAP |
> 9 µV |
0 |
|
6.0 to 8.9 µV |
1 |
|
3.0 to 5.9 µV |
2 |
|
0.1 to 2.9 µV |
3 |
|
absent |
4 |
total score =
= SUM(points for all 9 parameters)
Interpretation:
• minimum score: 0
• maximum score: 36
• The higher the score the more severe the neuropathy.
Total Score CMTNS |
Severity |
---|---|
0 |
none |
1 to 10 |
mild |
11 to 20 |
moderate |
21 to 36 |
severe |
Specialty: Neurology