Saccades and smooth pursuit in myotonic dystrophy

Abstract

Reflexive saccades, remembered saccades, antisaccades, fixation and smooth pursuit were recorded in seven subjects with myotonic dystrophy (MD) and seven age-matched controls using the magnetic scleral search coil technique. Neuropsychological performance was assessed using the Wisconsin Card Sort Test and measures of verbal fluency. Subjects with MD showed significantly elevated error rates in the antisaccade and remembered saccade paradigms, consistent with prefrontal dysfunction, and these two measures of distractibility were significantly correlated with each other. Saccadic latencies, square wave jerk frequency, and smooth pursuit peak velocity gain showed no significant difference between the two groups, although the peak velocity of all classes of saccades was significantly reduced in patients with MD. These results extend the findings of previous studies of oculomotor function in MD, and provide novel evidence for a central contribution to abnormalities of eye movements in this condition.

In myotonic dystrophy type 1 reduced FDG-uptake on FDG-PET is most severe in Brodmann area 8

“…Interestingly, the area with the most severe reduced FDG-uptake in our DM1 patients was Brodmann area 8, an area involved in (or at least very near to zones implicated in) eye movement control (Brodmann area 8A corresponding to the frontal eye field and area 8B corresponding to the premotor ear-eye field, although the exact localisation of these fields are still under debate). A multitude of oculomotor abnormalities have been reported in DM1 [ 11 – 13 ]. Some of these oculomotor abnormalities are thought to be due to oculomotor muscle dysfunction (weakness and/or myotonia) whereas other abnormalities suggest brain dysfunction.…”

Orthoptic and video‐oculographic analyses in oculopharyngeal muscular dystrophy

“…In myotonic dystrophy type 1, ptosis is frequent, whereas defects in ocular motility are usually absent or mild. Observed abnormalities of ocular motility include reduced smooth pursuit gain, reduced saccadic peak velocity, increased duration and abnormal skewness of saccades, and elevated error rates in the antisaccades and remember saccade paradigms – . Some of these oculomotor abnormalities are thought to be due to oculomotor muscle dysfunction (weakness and/or myotonia), whereas other abnormalities suggest brain dysfunction.…”

“…In contrast to other muscular dystrophies (especially myotonic dystrophy type 1), few data exist on eye movement abnormalities in OPMD. [1][2][3][4][5][6][7][8] Ophthalmoparesis has only been described in a few OPMD series and was present in between 42% and 69% of the OPMD patients studied. 4,5 One study reported systematic analysis of the oculomotor deficit in OPMD.…”

Bilateral Adduction Palsy in a Patient with Myotonic Dystrophy Type 1

“…A reliable feature of the eye involvement is the presence of iridescent posterior subcapsular cataracts that are identifiable by slit lamp examination in almost all adult patients [ 1 ]. In addition to cataracts, DM1 has been associated with ptosis, slow saccades, and decreased intraocular pressure, with both central and peripheral mechanisms proposed for the eye movement abnormalities [ 3 4 ]. Regarding ocular muscle functions in DM1, ptosis is the most described deficit.…”