In 15 sitting volunteers with eyes covered the vestibulo- and cervico-ocular reflexes were tested with sinusoidal movements around the vertical axis of the body, at frequencies of 0.05, 0.1 and 0.2 s-1 and a total amplitude of 40 degrees. When the trunk was moved against the fixed head, the subjects described mainly an illusionary head movement at 0.05 s-1, while, at 0.2 s-1 only the trunk movement was perceived. Subjects asked to imagine head motion during COR showed increased eye shifts and total saccadic amplitudes. With concentration on trunk movement perception these values decreased.

Adult↗

PubMedDate not supplied

Eye movements during active head turning with different vestibular and cervical input.

Eye movements were measured in 15 volunteers during vestibulo-ocular reflex (VOR), cervico-ocular reflex with the head fixed from the ceiling (passive COR), during voluntary stabilization of the head in space while the trunk was moved sinusoidally (active COR) and active head movements with and without additional vestibular or cervical stimuli. The subjects were sitting with eyes covered on a rotating chair swinging sinusoidally at 40 degrees peak to peak amplitude at 0.05, 0.1 and 0.2 Hz. The saccadic activity during passive COR is below the VOR and increases slightly during active COR. During voluntary head movements it shows a marked increase and is further activated if cervical or vestibular stimuli are added. The amplitudes of eye shifts of passive and active COR are not different. During active head movements and more with additional cervical or vestibular input, they increase significantly. The phase of the maximum eye shifts to head position is anticompensatory during passive COR and compensatory during VOR. The phase lead of about 45 degrees during active head movements is less during active COR but is larger with additional cervical and vestibular stimuli reaching 90 degrees.

Adult↗

PubMedDate not supplied

Modulation of vestibulo-ocular reflex (VOR) by active stabilization of head to trunk.

Horizontal vestibulo-ocular reflex (VOR) with covered eyes was tested in 15 healthy subjects sitting on a rotation chair (40 degrees, 0.05, 0.1, 0.2, 0.33 Hz) under two conditions: (a) head fixed to chair by a neck support; (b) with instruction to turn the head together with the passively moved trunk. In situation (b), saccadic amplitudes/sec, nystagmus frequency, gain of nystagmus slow phase velocity and amplitudes of maximum eye shift were enhanced significantly. The phase of maximum eye shift changed from 180 degrees up to 270 degrees with respect to stimulus position. The distribution of nystagmus saccades over the stimulus period showed enhanced peak values and a slight phase shift.

Adolescent↗

PubMedDate not supplied

Experience with dorsal column stimulation (DCS) in the operative treatment of chronic intractable pain.

The results of DCS in 50 patients are altogether favourable; they are better for the group of amputation and phantom pain than for the group of peripheral nerve lesions. For patients with malignoma pain no valid comment can be given. The influence of DCS is mostly immediate in bouts of acute pain, slower in chronic permanent pain, where a longer period of stimulation is needed. The observation of such longer stimulation periods together with the experience that during DCS there is a shift in the pain threshold, even in segments above the stimulus including also the face, seems to indicate a participation of higher neuronal centers in the assumed gate control.

Amputation Stumps↗