Cs. Helmchen et al., PATHOLOGICAL TORSIONAL EYE DEVIATION DURING VOLUNTARY SACCADES - A VIOLATION OF LISTINGS LAW, Journal of Neurology, Neurosurgery and Psychiatry, 62(3), 1997, pp. 253-260
Background-Under normal conditions, there are no torsional eye movemen
ts during voluntary saccades when the head is stationary (Listing's la
w). Methods and results-Using dual search coils for three dimensional
eye movement recordings, a patient is reported who had direction speci
fic rapid deviations of torsional eye position (up to 10.5 degrees) du
ring voluntary saccades followed by a slow exponential torsional drift
after the end of the saccade (''blip'') towards the initial torsional
eye position. In the absence of spontaneous nystagmus, this transient
torsion means a violation of Listing's law for voluntary saccades and
was associated with a lesion involving the cerebellar vermis, its dee
p nuclei, and the dorsolateral medulla. Amplitudes of the blip were la
rger for ipsilesional (hypermetric) than contralesional (hypometric) h
orizontal saccades. For comparison transient torsion, during and after
saccades was also examined in six normal subjects. Using the same in
vivo calibration, there were no blips larger than 1.2 degrees in any o
f them. Conclusion-Transient torsion with large amplitudes can be clin
ically seen on bedside examination and might thus be a new clinical si
gn in the diagnosis of saccadic disorders.