Saccadic Eye Movements In Patients Research Articles

迷路性固視機能検査装置の開発とその臨床的利用

A new apparatus capable of recording head and eye movements was devised to examine the vestibulo-ocular system. Horizontal and vertical head movements were recorded with a sensor of terrestrial mgnetism. Eye movenments were recorded by an electronystagmographic technique. The transmitted data were stored on a floppy disc and analyzed with a microcomputer in a specially designed program.1. The apparatus was useful as a tool for recording spontaneous and gaze nystagmus and pursuit and saccadic eye movements in patients with labyrinthine and central disturbances.2. Transfer function (gain and phase) of the vestibulo-ocular system was calculated with head and eye movements obtained from pseudo-random head oscillation in the dark. In normal subjects, gain with head movements as input signal and eye movements as output signal indicated a frequency-dependent gain enhancement;the phase difference between head eye movements was 180°.3. The vestibulo-ocular reflex (VOR) induced by the right and left labyrinth were examined with velocity recording of head and eye movements induced by quick head movements to the right and left at intervals of 1 second in the dark. Patients with unilaterl labyrinthine disturbance showed a low amplitude response in head movements toward the affected labyrinth.4. The integration mechanism in the pursuit system was examined from the velocity recording of eye movements during vertical head oscillation with fixation on a visual target. A patient with primary position upbeat nystagmus caused by nutritional deficiency encephalopathy showed a disturbance of the up neural integrator from velocity signal to position signal in the visual vestibular oculomotor system.The apparatus was usuful for the examination of the vestibulo-ocular system of patients with vertigo and equilibrium disturbances.

Flumazenil and saccadic eye movements in patients with panic disorder and normal controls

AbstractThe effects of the benzodiazepine receptor antagonist flumazenil on saccadic eye movements were studied in patients with panic disorder and in controls. Compared with vehicle, flumazenil displayed slight partial agonist effects in that it significantly reduced peak deceleration of eye movements, with a similar but non‐significant trend for peak velocity, in both groups. In controls flumazenil had little in the way of subjective effects whereas in panic patients it produced marked anxiety. The paradoxical responses to flumazenil in panic disorder (partial agonist effects on saccadic eye movements but partial inverse agonist effects on mood) may be due to different receptor subtypes controlling these variables.

Voluntary control of saccadic eye movements in patients with schizophrenic and affective disorders

We have examined visually guided saccade and antisaccade tasks in 32 schizophrenics, 13 patients with affective disorders and 36 normal controls. Latencies of saccades were within the normal range in all patients examined. In the antisaccade task, 26/32 schizophrenics showed more errors and/or longer latencies, whereas 11/13 patients with affective disorders showed normal results. One manic patient showed significantly longer latency, and one bipolar patient showed a borderline error rate (15%). These results indicate that the antisaccade abnormalities are commonly found in schizophrenics but not in patients with affective disorders. The abnormalities in schizophrenics were not correlated with age, duration of illness, length of education or quantities of medication. None of the schizophrenics with normal antisaccades showed abnormalities in CT scans, while 73% of the schizophrenics who showed both higher error rate and longer latencies showed atrophy of the frontal cortex. The scores of conceptual disorganization and motor retardation in Brief Psychiatric Rating Scale (BPRS) were significantly higher in schizophrenics with abnormal antisaccades, while acute symptoms such as delusions and hallucinations were not correlated with the abnormalities.

Saccades in Huntington's disease: initiation defects and distractibility.

We recorded saccadic eye movements in patients mildly affected with Huntington's disease. Most showed an increase in saccade latencies that was greater for saccades made on command than to the sudden appearance of a visual target. All patients showed excessive distractibility during attempted fixation. They had particular difficulty suppressing a saccade to a suddenly appearing visual target when simultaneously trying to initiate a saccade in the opposite direction. Our results are compatible with a posited role of the basal ganglia in both the initiation of volitional saccades and in the maintenance of fixation. Saccade abnormalities--especially distractibility--are sensitive but probably not specific indicators of Huntington's disease.

Visually stimulated saccadic eye movements in patients treated with lithium.

Saccadic eye movements were stimulated with the aid of 11 light spot stimuli, 10 of which were arranged at 3 degrees, 6 degrees, 9 degrees, 12 degrees, and 15 degrees to the left and right of the central stimulus. The parameters average and maximal eye movement velocity and latency were precisely investigated. 19 patients averaging 6.6 years on lithium prophylaxis were compared with 23 healthy controls. Significant differences between the two groups could not be found at this level of function.