Ocular contrapulsion refers to a syndrome of static ocular deviation and saccadic hypermetria toward the intact side, and saccadic hypometria and impaired smooth pursuit toward the lesion side. It has been reported in patients with lesions in the rostral cerebellum and caudal medullary hemorrhge. We report a 60-year-old man who showed ocular contrapulsion with unilateral upper medial medullary infarction. Ocular contrapulsion may be a sign of medial medullary infarction. In our patient, the climbing fibers may be damaged before crossing the midline in the upper medulla.
Cerebellar Ataxia ; Cerebellum ; Humans ; Infarction* ; Middle Aged ; Pursuit, Smooth

OBJECTIVES: We investigated the association of Val108/158Met polymorphism on catechol-O-methyl transferase(COMT) gene with smooth pursuit eye movement(SPEM) abnormality in Korean schizophrenia patients. METHODS: We measured SPEM in 217 Korean schizophrenia patients(male 116, female 101) and divided them into two groups, one was a good SPEM function group and the other was a poor SPEM function group. Then we analyzed Val108/158Met polymorphism on COMT gene. We compared the differences of genotype and allele distributions of the polymorphism on COMT gene between the two groups. RESULTS: The natural logarithm value of signal/noise ratio(Ln S/N ratio) of the good SPEM function group was 4.39+/-0.33(mean+/-s.d.) and that of poor SPEM function group was 3.17+/-0.71. There were no statistically significant differences of age and male/female ratio between the two groups. There were no significant differences of genotype or allele distributions of the Val108/158Met polymorphism on COMT gene between the two schizophrenic groups. CONCLUSIONS: The results suggest that Val108/158Met polymorphism on COMT gene is not related to SPEM function abnormality in schizophrenia.
Alleles ; Eye ; Female ; Genotype ; Humans ; Polymorphism, Genetic ; Pursuit, Smooth ; Schizophrenia

Biomechanical Phenomena ; Eye Movements ; Neurons/physiology* ; Pursuit, Smooth ; Saccades

During natural viewing, we often recognize multiple objects, detect their motion, and select one object as the target to track. It remains to be determined how such behavior is guided by the integration of visual form and motion perception. To address this, we studied how monkeys made a choice to track moving targets with different forms by smooth pursuit eye movements in a two-target task. We found that pursuit responses were biased toward the motion direction of a target with a hole. By computing the relative weighting, we found that the target with a hole exhibited a larger weight for vector computation. The global hole feature dominated other form properties. This dominance failed to account for changes in pursuit responses to a target with different forms moving singly. These findings suggest that the integration of visual form and motion perception can reshape the competition in sensorimotor networks to guide behavioral selection.
Animals ; Pursuit, Smooth ; Macaca mulatta ; Motion Perception/physiology* ; Photic Stimulation

Ocular motor apraxia has been reported in bilateral frontoparietal lesions. We report a case of ocular motor apraxia after bilateral striatal infarctions. The patient had impaired voluntary saccades and smooth pursuits in the vertical and horizontal planes with an intact vestibulo-ocular reflex. Magnetic resonance imaging showed an old left putaminal infarction and an acute infarction in the right caudoputaminal area. This case demonstrates that ocular motor apraxia may occur in bilateral basal ganglia lesions.
Apraxias* ; Basal Ganglia ; Humans ; Infarction* ; Magnetic Resonance Imaging ; Pursuit, Smooth ; Reflex, Vestibulo-Ocular ; Saccades

BACKGROUND AND OBJECTIVES: Perverted head-shaking nystagmus (HSN) refers to nystagmus that develops in the plane other than that being stimulated by head oscillation, i.e., downbeat or upbeat HSN after head oscillation in the yaw plane. However, the mechanism of perverted HSN is unknown. To elucidate the mechanism of perverted HSN by measuring tilt suppression of the vestibule-ocular reflex (VOR). MATERIALS AND METHOD: Twenty two consecutive patients with perverted HSN from cerebellar lesions (13 circumscribed and 9 diffuse) and 50 normal volunteers underwent recording of spontaneous, head-shaking and positional nystagmus, smooth pursuit, saccades, and the VOR. Tilt suppression method was to pitch patients' head forward further at the end of the step rotation stimuli. RESULTS: HSN was pure downbeat in nine and mixed horizontal-downbeat in 13 patients. The mean VOR time constants did not differ between normal controls and patients. However, tilt suppression of the post-rotatory nystagmus was impaired in the patients (p<0.01). Downbeating (n=12) and central positional nystagmus (n=12) were frequently accompanied findings. CONCLUSION: Uvulonodular dysfunction was frequently observed in patients with perverted HSN from cerebellar lesions. Uvulonodulus may be involved in the spatial organization of the velocity storage mechanism and uvulonodular dysfunction may be responsible for developing perverted HSN in cerebellar lesions.
Cerebellum ; Head* ; Healthy Volunteers ; Humans ; Nystagmus, Physiologic ; Pursuit, Smooth ; Reflex ; Saccades

BACKGROUND AND OBJECTIVES: Perverted head-shaking nystagmus (HSN) refers to nystagmus that develops in the plane other than that being stimulated by head oscillation, i.e., downbeat or upbeat HSN after head oscillation in the yaw plane. However, the mechanism of perverted HSN is unknown. To elucidate the mechanism of perverted HSN by measuring tilt suppression of the vestibule-ocular reflex (VOR). MATERIALS AND METHOD: Twenty two consecutive patients with perverted HSN from cerebellar lesions (13 circumscribed and 9 diffuse) and 50 normal volunteers underwent recording of spontaneous, head-shaking and positional nystagmus, smooth pursuit, saccades, and the VOR. Tilt suppression method was to pitch patients' head forward further at the end of the step rotation stimuli. RESULTS: HSN was pure downbeat in nine and mixed horizontal-downbeat in 13 patients. The mean VOR time constants did not differ between normal controls and patients. However, tilt suppression of the post-rotatory nystagmus was impaired in the patients (p<0.01). Downbeating (n=12) and central positional nystagmus (n=12) were frequently accompanied findings. CONCLUSION: Uvulonodular dysfunction was frequently observed in patients with perverted HSN from cerebellar lesions. Uvulonodulus may be involved in the spatial organization of the velocity storage mechanism and uvulonodular dysfunction may be responsible for developing perverted HSN in cerebellar lesions.
Cerebellum ; Head* ; Healthy Volunteers ; Humans ; Nystagmus, Physiologic ; Pursuit, Smooth ; Reflex ; Saccades

Electrooculography (EOG or ENG) is the simplest and most readily available diagnostic tool for recording and quantitatively analysing the pathologic nystagmus, visually guided eye movements (saccades, pursuits, OKN) and Vestibular-ocular reflexes. By using our standard method, we analyzed the normal ranges of smooth pursuit velocity and its gain, slow component velocity of OKN, and the bitherrnal caloric response. Our results of ENG tests for normal controls would be used as a basic quantitative data in evaluating vestibular dysfunction, and ocular motility disorders.
Caloric Tests* ; Electrooculography ; Eye Movements ; Nystagmus, Pathologic ; Ocular Motility Disorders ; Pursuit, Smooth* ; Reference Values ; Reflex

OBJECTIVE : We investigated the relationship between the severity of the disease and the abnormality of some ocular movements in parkinson's disease. BACKGROUND: Disorders of eye movements have been described in diseases of the basal ganglia for over a century and ocular motor deficits of the saccadic and pursuit system have been reported in parkinsonian patients. METHOD : We studied the electro-oculography of the eye tracking and saccadic movement in 26 patients (11 males, 15 females) with Parkinson's disease. The severity of the disease was divided into two groups by Hoehn & Yahr(H-Y) staging, H-Y stage 1, 2(group A) and H-Y stage 3, 4 (Group B). Some patients antiparkinsonian drugs of L-dopa, dopamine agonist and anticholinergics. RESULT : The velocity of smooth pursuit and the velocity and latency of saccade were calculated and compared between two groups. Eye tracking test revealed decreased pursuit velocity leading to catch-up saccades, but normal phase relationship between eye and target movement, while saccadic eye movement had increased latency. These results showed more profound severity in more advanced stages of the disease. CONCLUSION : We suggest that ocular movement be often chosen as a simple but relevant example of general motor function, as well as criteria for staging of Parkinson's disease and basal ganglia play significant role in ocular movement.
Basal Ganglia ; Cholinergic Antagonists ; Dopamine Agonists ; Eye Movements ; Humans ; Levodopa ; Male ; Parkinson Disease* ; Pursuit, Smooth ; Saccades

Eye alignment is related with binocular connection in the visual cortex during critical period between postnatal 3 and 5 months. Authers examined horizontal pursuit and latent fixation nystagmus using electronystagmogram(ENG)in 6 year old female patient, who was diagnosed a congenital esotropia showing V patten esodeviation, both inferior oblique overaction, dissociated vertical deviation and head turn. In the pursuit examination, symmetric pursuit was observed under binocular viewing. However asymmetric pursuit was observed with smooth pursuit toward temporo-nasal direction and irregular saccade toward naso-temporal direction under monocular viewing. We could observe jerky nystagmus with decelerating velocity under monocular viewig, direction of which was toward fixating eye and degree of which was increased in abduction and decreased in adduction. The direction of pursuit asymmetry and nystagmus were instantaneously reversed when changing occluding eye. The results of ENG were not changed after successful strabismus surgery. We report a typical case of congenital esotropia as one of oculomotor disorders showing asymmetric pursuit and latent fixation nystagmus, which findings were proved by ENG.
Child ; Critical Period (Psychology) ; Esotropia* ; Female ; Head ; Humans ; Pursuit, Smooth ; Saccades ; Strabismus ; Telescopes ; Visual Cortex