“low-frequency, high-amplitude, posture-induced proximal arm tremor, elicited by sustained abduction of the arms, with flexed elbows and palms facing downward”
“one half-cycle of elevation&intorsion of one eye
and
synchronous depression&extorsion of the other eye.
Next half-cycle,
vertical&torsional components are reversed”
- waveform: pendular (seesaw) & jerk (hemi-seesaw)
- hemi-seesaw: only one half-cycle
2/
Pathophysiology
Jerk (hemi-seesaw)
- lesion in the interstitial nucleus of Cajal