several patients show signs of deterioration. Regarding motor function

there is high variability, several of the patients increase their motor func-

tion while others show a deteriorating pattern. The deterioration does not

seem to be related to either age or severity of the disorder. The number of

patients with foot deformities and scoliosis seem to increase over time in

the group with more pronounced muscle weakness. The results are still

preliminary and will be further analysed.

http://dx.doi:10.1016/j.nmd.2013.06.671

P.18.3

Test –retest reliability of strength measurements of the long finger flexors

(LFF) in patients with myotonic dystrophy type 1

K. Eichinger, N. Dilek, J. Dekdebrun, W. Martens, C. Heatwole,

C.A. Thornton, R.T. Moxley, S. Pandya

University of Rochester, Department of Neuromuscular Disease, Rochester,

United States

Patients with myotonic dystrophy (DM1) have distal upper extremity

weakness which initially focuses on the long finger flexors. Grip strength

using a Jamar dynamometer with the handle in the second position has

provided reliable measurement of hand strength in patients with DM1.

Grip strength however, is a measure of intrinsic and extrinsic hand muscle

strength and does not isolate the LFF. The use of the Jamar dynamometer

with the handle in the furthest position, contacting the distal phalanx, iso-

lates the flexor digitorum profundus. Pinch also relies on long finger flexor

strength. There are no established testing procedures in DM1 to specifi-

cally examine the LFF. To pursue this goal, this study investigates test–

retest reliability of strength measurements of the LFF in patients with

DM1. We measured strength of the LFF by manual muscle testing

(MMT) and quantitative muscle testing (QMT) in 26 patients with

DM1. MMT was performed bilaterally on the LLF of the thumb, first

and second digits using standard MRC procedures and grading. QMT

was performed using a Jamar hand dynamometer on the furthest setting

and the palmar pinch was measured using a pinch gauge (B & L Engineer-

ing). These testing procedures were performed twice in a 24 h period (rang-

ing from 18–24 h apart). The weighted kappa statistic for LFF’s using

MMT were 0.84 (right) and 0.92 (left). The ICC for the LFF using the

Jamar dynamometer was 0.95 (right) and 0.92 (left). The ICC for palmar

pinch was 0.95 (right) and 0.96 (left). Strength testing of the LFF demon-

strated excellent intra-rater reliability over a 24 h period. Tests of sensitiv-

ity to change over longer periods of time are necessary to establish the

usefulness of these tests as outcome measures for clinical trials.

http://dx.doi:10.1016/j.nmd.2013.06.672

P.18.4

Physical activity profile and barriers to physical activity in individuals with

myotonic dystrophy

K. Eichinger 1, J. Dekdebrun 1, N. Dilek 1, D. Chen 2, S. Pandya 1

1 University of Rochester, Department of Neuromuscular Disease, Roches-

ter, United States; 2 University of Rochester, School of Nursing, Rochester,

United States

Individuals with myotonic dystrophy (DM) type 1 are less active than

healthy individuals, which may result in secondary complications and

decreased functional abilities. Therefore, the purpose of this study was

to document the physical activity profile and barriers to physical activity

in persons with DM. Individuals with DM were recruited during the

Empower 2011 patient and family conference sponsored by the Myo-

tonic Dystrophy Foundation. Participants were asked to complete a sur-

vey that included a Demographic/Clinical profile, the Barriers to

Physical Activity and Disability Survey and the International Physical

Activity Questionnaire. Physical activity in terms of number of days

and time (in 10 min increments) over the past 7 days was reported. A

multiple regression model including age, number of current clinical prob-

lems, and the number of barriers reported was used to predict the

amount of sedentary time (sitting time). 107 (53% male) participants with

DM (65% DM1) reported finger and hand weakness, fatigue, day time

sleepiness, gastrointestinal issues, and leg weakness as the most common

clinical problems. Participation in at least 1 day of activity was reported

by 15% of the participants for gardening, 69% for household activities,

42% for leisure time walking, and 22% for moderate intensity level lei-

sure time activities. Lack of energy and motivation were the most com-

mon barriers to physical activity reported. Number of barriers was a

significant predictor of the amount of time spent sitting. Persons with

DM have decreased physical activity and spend a significant time seden-

tary and are limited by a lack of energy and motivation. Administration

of this survey at the conference may have influenced the report of phys-

ical activity as it may have been modified due to travel and conference

participation. Further investigation is needed to better understand addi-

tional factors that contribute to inactivity.

http://dx.doi:10.1016/j.nmd.2013.06.673

P.18.5

The value of short exercise and short exercise with cooling tests in the

diagnosis of myotonic dystrophies (DM1 and DM2)

M. Gawel 1, E. Szmidt-Salkowska 1, A. Lusakowska 1, M. Nojszewska 1,

A. Sulek 2, W. Krysa 2, M. Rajkiewicz 2, A. Seroka 1, A.M. Kaminska 1

1 Medical University of Warsaw, Neurology, Warsaw, Poland; 2 Institute of

Psychiatry and Neurology, Genetics, Warsaw, Poland

Despite clinical and genetic similarities, myotonic dystrophy type 1

(DM1) and type 2 (DM2) are distinct disorders requiring different diag-

nostic and management strategies. Although the standard quantitative

EMG is useful in diagnosis of myotonic syndromes, it does not differenti-

ate between DM1 and DM2. Other electrophysiological methods such as

the short exercise test (SET) and the short exercise test with cooling

(SETC), which seem to be more sensitive, have recently been recom-

mended in DM1/DM2 differentiating diagnosis. The aim of our study

was to analyze the results of SET/SETC in myotonic dystrophies and to

estimate their usefulness in differentiating between DM1 and DM2. Mate-

rial and method: 60 patients with genetically proven myotonic dystrophy:

32 patients with DM1, (mean age 35.8 ± 12.7yrs) and 28 patients with

DM2 (mean age 44.5 ± 12.5 yrs). For every patient a short exercise test

(SET) and short exercise test with cooling (SETC) were performed.

Results: In DM1 with SET as well as with SETC a significant decline of

compound motor action potential (CMAP) amplitude immediately after

effort was observed (mean value CMAP amplitude decline was about

20%). In DM2 there was no marked change of CMAP amplitude with

either SET or SETC. Conclusions: Electrophysiological tests such as the

short exercise test and short exercise test with cooling, may serve as useful

tools for differentiating between DM1 and DM2 and in clinical practice as

a guide for molecular testing. In contrast to DM2, in DM1 a marked

decline of CMAP amplitude was observed in SET as well as in SETC.

The mechanism of these opposites remains unclear. Hypothetically the dif-

ferent pattern of response to SET/SETC in DM1 and DM2 could be

explained by multifactorial disabilities of muscle ion channels of different

intensity in these two diseases.

http://dx.doi:10.1016/j.nmd.2013.06.674

Abstracts / Neuromuscular Disorders 23 (2013) 738–852 833