TY - JOUR

T1 - Evidence for the occurrence of myotonia in the extraocular musculature in patients with dystrophia myotonica

AU - Hansen, H. C.

AU - Lueck, C. J.

AU - Crawford, T. J.

AU - Kennard, C.

AU - Zangemeister, W. H.

PY - 1993

Y1 - 1993

N2 - Dystrophia myotonica (DM) is a multisystem disorder which has been reported to affect eye movements. There is, however, disagreement in the literature as to whether the observed slowing of saccadic eye movements is due to a central abnormality or due to abnormalities of the extraocular muscles themselves. A ‘warm-up’ effect is well known to occur in the peripheral muscles in DM. This effect involves a progressive decrease in the degree of myotonia observed with each successive relaxation during a period of repetitive contraction and relaxation of a given muscle. The authors have studied seven patients using two different paradigms to provide evidence that the ‘warm-up’ phenomenon can be demonstrated in extraocular musculature in patients with DM. Such an effect is not seen in controls. The observation of a ‘warm-up’ phenomenon suggests that the disorder of saccadic eye movements is likely to be due to an abnormality of the extraocular muscles themselves rather than a central mechanism.

AB - Dystrophia myotonica (DM) is a multisystem disorder which has been reported to affect eye movements. There is, however, disagreement in the literature as to whether the observed slowing of saccadic eye movements is due to a central abnormality or due to abnormalities of the extraocular muscles themselves. A ‘warm-up’ effect is well known to occur in the peripheral muscles in DM. This effect involves a progressive decrease in the degree of myotonia observed with each successive relaxation during a period of repetitive contraction and relaxation of a given muscle. The authors have studied seven patients using two different paradigms to provide evidence that the ‘warm-up’ phenomenon can be demonstrated in extraocular musculature in patients with DM. Such an effect is not seen in controls. The observation of a ‘warm-up’ phenomenon suggests that the disorder of saccadic eye movements is likely to be due to an abnormality of the extraocular muscles themselves rather than a central mechanism.

KW - dystrophia myotonica

KW - saccades

KW - peak velocity

KW - ‘warm-up’ phenomenon

U2 - 10.3109/01658109309036998

DO - 10.3109/01658109309036998

M3 - Journal article

VL - 13

SP - 17

EP - 24

JO - Neuro-Ophthalmology

JF - Neuro-Ophthalmology

IS - 1

ER -