Appendix
Definitions for CMTNS
1. Sensory symptoms include neuropathic pain and symptoms (burning, tingling) as well as numbness. Does not include radicular symptoms.
2. Motor symptoms in the legs: for grade 1 –patient describes mild or minor or intermittent evidence of weak ankles but has not been using ankle support or AFO’s. Shoe inserts would still be grade 1. Wearing boots or high tops to support ankles would be considered grade 2. Ankle surgery is meant to be triple arthrodesis or other surgery designed to stabilize the ankle due to CMT. It would not include surgery for ankle fracture
3. Motor symptoms in the arms: Grade 1 is used if the patient recognizes difficulty with finger dexterity but is still able to perform tasks without aids. Grade 2 is used if unable to perform activities requiring finger dexterity including buttons, zippers, utensils, pens, keys. Poor handwriting is too non-specific and by itself does not warrant a grade of 2. Grade 3 is used for difficulties from severe weakness of finger movement and grip but not weakness of muscles above the elbow. Grade 4 is for weakness of muscles above the elbow, typified by inability to raise hands over head
4. Pin sensibility: The reduction in pin sensation must be moderate (greater than 50% reduction compared to an uninvolved proximal site) to severe (unable to distinguish sharp from dull). There should be no doubt in the examiner’s mind that the sensation is abnormal.
5. Vibration: The deficits must be pronounced so that there is no question that there is reduction at the levels mentioned (greater than 5 second difference between examiner and patient at the same site).
6. Leg strength: The parameter being measured is foot dorsiflexion (not toe). If eversion or inversion weakness reduces foot dorsiflexion to 4 MRC, then this would count towards a grade of 1. Proximal weakness would include any clear-cut weakness of muscles above the knee along with 3 or less strength of the dorsi and plantar flexors of the foot.
7. Arm strength: The grade is dependent on the weakest muscle tested so if the ADMQ is a 4 but the APB is a 3, the grade is 2. For grade 4 there must be weakness of at least one muscle above the elbow as well as wrist extension weakness
8. Ulnar sensory amplitudes are based on antidromic testing with amplitudes from baseline to peak. Orthodromic normals can also be used.
9. Ulnar CMAP is baseline to peak amplitudes