Analysis of eye movement characteristics in newly diagnosed drug-naive Parkinson′s disease / 中华神经科杂志

Objective:To explore eye movement characteristics in newly diagnosed, drug-naive Parkinson′s disease (PD) patients and their correlation with motor and non-motor symptoms.Methods:Seventy-five newly diagnosed, drug-naive PD patients and 46 healthy controls (HCs) were included in this cross-sectional study. Patients were recruited from the Department of Neurology, Shanghai Ninth People′s Hospital, Shanghai Jiao Tong University School of Medicine from November 2017 to December 2021, while HCs were recruited from the local community during the same period. For PD patients, motor severity was measured with the modified Hoehn and Yahr stage, Movement Disorder Society Unified Parkinson′s Disease Rating Scale part Ⅲ and the Freezing of Gait questionnaire. Non-motor symptoms were evaluated by serial scales such as Non-Motor Symptoms Questionnaire, 16-item odor identification test from Sniffin Sticks, 17-item Hamilton Rating Scale for Depression, Chinese version of Mini-Mental State Examination, Montreal Cognitive Assessment Basic and REM Behavior Disorder Screening Questionnaire. All subjects underwent oculomotor test including pro-saccade task and smooth pursuit eye movement (SPEM) task in the horizontal direction via videonystagmography. Visually guided saccade latency, saccadic accuracy and gain in SPEM at three frequencies (0.1, 0.2, 0.4 Hz) of the horizontal axis were compared between the 2 groups. The association between key oculomotor parameters and clinical phenotypes was explored in PD patients. The receiver operating characteristic (ROC) analyses of eye movement parameters as independent factors were also performed for detecting PD from HCs, then combining the saccadic latency, saccadic accuracy and the most significant SPEM gain (0.4 Hz) as the model to distinguish PD from HCs.Results:Relative to HCs, newly diagnosed, drug-naive PD patients showed prolonged saccadic latency [(210.4±41.3) ms vs (191.3±18.9) ms, t=-3.445, P=0.001] and decreased saccadic accuracy (88.4%±6.8% vs 92.2%±6.1%, t=3.064, P=0.003). SPEM gain in PD was uniformly reduced at each frequency(0.1 Hz: 0.68±0.15 vs 0.74±0.14, t=2.261, P=0.026; 0.2 Hz: 0.72±0.16 vs 0.79±0.16, t=2.704, P=0.008; 0.4 Hz: 0.67±0.19 vs 0.78±0.19, t=2.937, P=0.004). The ROC analyses of saccade latency, saccadic accuracy and gain in SPEM at 0.1, 0.2, 0.4 Hz as independent factors for detecting PD from HCs showed that the area under the curve (AUC) of each parameter was lower than 0.7: the AUC of saccade latency was 0.641 ( P=0.010), the AUC of saccadic accuracy was 0.681 ( P=0.001), the AUC of gain in SPEM at 0.1 Hz was 0.616 ( P=0.032), at 0.2 Hz was 0.652 ( P=0.005), at 0.4 Hz was 0.660 ( P=0.003). Combining the saccadic latency, saccadic accuracy and the most significant SPEM gain (0.4 Hz) revealed that the model could significantly distinguish PD from HCs with an 80.4% sensitivity and a 73.3% specificity (AUC=0.780, P<0.001). Prolonged saccadic latency was correlated with long disease duration ( β=0.334, 95% CI 0.014-0.654, P=0.041), whereas decreased SPEM gain was associated with severe motor symptoms in newly diagnosed drug-naive PD patients (0.1 Hz: β=-0.004, 95% CI -0.008--0.001, P=0.036; 0.4 Hz: β=-0.006, 95% CI -0.011--0.001, P=0.012). Conclusions:Ocular movements are impaired in newly diagnosed, drug-naive PD patients. These changes could be indicators for disease progression in PD.

Abnormal eye movements in patients with idiopathic rapid eye movement sleep behavior disorder / 浙江大学学报·医学版

OBJECTIVE@#To analyze the characteristics of eye movements in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD).@*METHODS@#Twenty two patients with iRBD and 20 controls were enrolled between January 2017 and May 2019 from Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. Clinical data including polysomnogram (PSG) results were collected. Videonystagmography (VNG) including spontaneous nystagmus, gaze, saccade, tracking and optokinetic test were performed. The difference of VNG results between iRBD patients and controls were analyzed. The factors related to the abnormal VNG results were analyzed by using logistic regression analysis.@*RESULTS@#No significant differences were found between the iRBD and control groups in the spontaneous nystagmus, gaze nystagmus, square wave jerk, involuntary eye movement, saccade and optokinetic nystagmus (all >0.05). In smooth pursuit of 0.4-0.5 Hz and 0.6-0.7 Hz, iRBD patients had more type Ⅲ-Ⅳ curve than controls (=5.177 and 5.301, both <0.05). Logistic regression analysis indicated that less sleep time of N3 stage was related to the abnormal results in smooth pursuit of 0.4-0.5 Hz (=0.963, <0.05). iRBD patients with Ⅲ-Ⅳ type curve in smooth pursuit of 0.4-0.5 Hz had less N3 sleep time than iRBD patients with Ⅰ-Ⅱ type curve (52±28 min vs. 76±23 min, =2.197, <0.05).@*CONCLUSIONS@#Abnormal smooth pursuit was found in iRBD patients, which might be related to the pathological mechanism of iRBD.

Impaired Smooth Pursuit During Transient Global Amnesia

BACKGROUND AND PURPOSE: During transient global amnesia (TGA), selective impairment of episodic memory is assumed to occur due to alteration in the neuronal network between the hippocampus and parietooccipital cortices that also include a hub for smooth pursuit (SP) eye movements. This study aimed to determine whether SP is impaired during TGA, and to identify any anatomical and functional linkage present between the oculomotor and memory systems. METHODS: Within a median of 1.0 day of TGA, horizontal SP was evaluated in 145 patients with a target moving at peak velocities of 10°/s and 20°/s. The average SP gains of patients were compared with those of the age-matched controls. RESULTS: The patients with TGA showed lower SP gains in both directions for both peak target velocities. While the normal controls showed symmetric SP in the rightward and leftward directions, in the TGA patients the SP gain was lower during rightward than leftward SP regardless of bilaterality or the side of the lesions. CONCLUSIONS: The cortical regions processing information about visual motion appeared to be affected during or soon after an amnestic episode of TGA, and more so in the right hemisphere. This means that disturbed processing of dynamic visual information may be related to the impaired spatial orientation observed during TGA.

Two Cases of Myasthenia Gravis Showing Fatigibility Presenting with Decreased Gain of Smooth Pursuit / 대한평형의학회지

Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies to the acetylcholine receptors of the neuromuscular junction characterized by weakness and abnormal fatigability of the muscles. Therefore, the diagnosis of MG depends on the recognition of this distinctive pattern of fatigable weakness. Previous studies presented the diagnostic efficacy of saccadic eye movements in patients with ocular MG. We here in report 2 patients of ocular MG showing the fatigue effects during repetitive sustained smooth pursuit, and the effects of the administration of edrophonium on myasthenic smooth pursuit. Changes in smooth pursuits reflecting peripheral and secondary central mechanisms were demonstrated.

Association Analysis between Chromogranin B Genetic Variations and Smooth Pursuit Eye Movement Abnormality in Korean Patients with Schizophrenia

OBJECTIVES: According to previous studies, the Chromogranin B (CHGB) gene could be an important candidate gene for schizophrenia which is located on chromosome 20p12.3. Some studies have linked the polymorphism in CHGB gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) abnormality has been regarded as one of the most consistent endophenotype of schizophrenia. In this study, we investigated the association between the polymorphisms in CHGB gene and SPEM abnormality in Korean patients with schizophrenia. METHODS: We measured SPEM function in 24 Korean patients with schizophrenia (16 male, 8 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated genotypes of polymorphisms in CHGB gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of polymorphism. RESULTS: The natural logarithm value of signal/noise ratio (Ln S/N ratio) of good SPEM function group was 4.19 ± 0.19 and that of poor SPEM function group was 3.17 ± 0.65. In total, 15 single nucleotide polymorphisms of CHGB were identified and the genotypes were divided into C/C, C/R, and R/R. Statistical analysis revealed that two genetic variants (rs16991480, rs76791154) were associated with SPEM abnormality in schizophrenia (p = 0.004). CONCLUSIONS: Despite the limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may be associated with SPEM abnormality and provide useful preliminary information for further study.

Clinical significance of saccade test, smooth pursuit test, and optokinetic nystagmus test in nystagmography / 영남의대학술지

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo.METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo.RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo.CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.

Characteristics of smooth pursuit eye-movement in subjects at clinical high risk for psychosis / 中国神经精神疾病杂志

Objective To investigate the eye-movement features of smooth pursuit in subjects at clinical high risk for psychosis.Methods sixty subjects at clinical high risk for psychosis and sixty healthy controls were recruited.The smooth pursuit tasks were assessed in both horizontal (0.4 Hz) and Lissajous (0.2 or 0.4 Hz) condition.The Wechsler Memory Scale-third edition and spatial span subtest were used to assess working memory.The difference of the smooth pursuit performance between the two groups and the relationship between smooth pursuit and working memory were analyzed.Results Subjects at clinical high risk for psychosis showed significantly lower Horizontal components for pursuit gain [Lissajous 0.2 Hz task (0.82±0.12) vs.(0.89±0.09),Lissajous 0.4 Hz task (0.78±0.13) vs.(0.84±0.14)],lower vertical components for pursuit gain [Lissajous 0.2 Hz task (0.80±0.14) vs.(0.86±0.12),Lissajous 0.4 Hz task (0.71±0.15)vs.(0.77±0.16)] and higher mean positional error [Lissajous 0.2 Hz task (37.00±19.10) vs.(30.45± 16.18),Lissajous 0.4 Hz task (44.18±19.70) vs.(37.61±16.26)] compared to healthy controls (P＜0.05).There was a significant correlation between pursuit gain and performance on Spatial Span (Horizontal components:r=0.361,P=0.005;vertical components:r=0.327,P=0.01 1) in the Subjects at clinical high risk for psychosis.Conclusions Subjects at clinical high risk for psychosis showed deficits in smooth pursuit,and the deficits were related to the working memory.

Clinical significance of saccade test, smooth pursuit test, and optokinetic nystagmus test in nystagmography / 영남의대학술지

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo. METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo. RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo. CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.

Isolated Infarction of Anterior Cerebellar Vermis / 대한평형의학회지

The anterior cerebellar vermis has been known to act in coordination of gait and postural adjustment of the trunk and legs. However, oculomotor abnormalities in an isolated anterior vermian lesion have not been described in the literature. A 59-year-old man presented with acute non-rotatory dizziness and disequilibrium. Neuro-ophthalmologic examination found impaired smooth pursuit and hypometric saccades in the contralesional direction, and disconjugate ipsiversive ocular torsion, but without spontaneous or gaze-evoked nystagmus. Imaging study showed an infarction restricted to the rostral end of right cerebellar vermis involving the lingual and central lobules. The anterior cerebellar vermis participates in the maintenance of axial posture and gait, and also in the control of ocular motor and vestibular systems.

No Association between (AAT)n Repeat Polymorphisms in the Cannabinoid Receptor 1 Gene and Smooth Pursuit Eye Movement Abnormality in Korean Patients with Schizophrenia

OBJECTIVES: According to previous studies, the cannabinoid receptor 1 (CNR1) gene could be an important candidate gene for schizophrenia. Some studies have linked the (AAT)n trinucleotide repeat polymorphism in CNR1 gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) has been regarded as one of the most consistent endophenotypes of schizophrenia. In this study, we investigated the association between the (AAT)n trinucleotide repeats in CNR1 gene and SPEM abnormality in Korean patients with schizophrenia. METHODS: We measured SPEM function in 167 Korean patients with schizophrenia (84 male, 83 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated allele frequencies of (AAT)n repeat polymorphisms on CNR1 gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of (AAT)n trinucleotide repeats. RESULTS: The natural logarithm value of signal/noise ratio (Ln S/N ratio) of the good SPEM function group was 4.34 ± 0.29 and that of the poor SPEM function group was 3.21 ± 0.70. In total, 7 types of trinucleotide repeats were identified, each containing 7, 10, 11, 12, 13, 14, and 15 repeats, respectively. In the patients with (AAT)₇ allele, the distributions of the good and poor SPEM function groups were 18 (11.1%) and 19 (11.0%) respectively. In the patients with (AAT)₁₀ allele, (AAT)₁₁ allele, (AAT)₁₂ allele, (AAT)₁₃ allele, (AAT)₁₄ allele and (AAT)₁₅ allele, the distributions of good and poor SPEM function groups were 13 (8.0%) and 12 (7.0%), 4 (2.5%) and 6 (3.5%), 31 (19.8%) and 35 (20.3%), 51 (31.5%) and 51 (29.7%), 36 (22.2%) and 45 (26.2%), 9 (5.6%) and 4 (2.3%) respectively. As the number of (AAT) n repeat increased, there was no aggravation of abnormality of SPEM function. CONCLUSIONS: There was no significant aggravation of SPEM abnormality along with the increase of number of (AAT)n trinucleotide repeats in the CNR1 gene in Korean patients with schizophrenia.

Prenatal exposure to maternal anxiety is associated with less developed smooth pursuit eye movements in six-month-old infants: An initial study.

Aims: There are an increasing number of reports suggesting an association between maternal anxiety experienced during pregnancy and adverse outcomes of the offspring. However, exploration of the biological changes in the brain that mediate that relationship has been hampered by the lack of appropriate biomarkers. This report represents an initial step exploring whether a potential infant biomarker, smooth pursuit eye movements, may be associated with prenatal exposure to maternal anxiety. Study Design: Blinded cross-sectional study. Place and Duration of Study: Department of Psychiatry, University of Colorado School of Medicine. Data collected from July 2011 to May 2012. Methodology: Forty-three infants including 34 whose prenatal maternal anxiety status were identified (12 with a known maternal prenatal anxiety diagnosis and 22 without) had eye movements recorded during a smooth pursuit eye movement task at four and/or six months of age. Results: At 6 months of age, infants with prenatal exposure to maternal anxiety, compared to infants without such exposure, spent a higher percentage of time utilizing smooth pursuit (t=2.7, df=24, P=.013), had longer duration of smooth pursuit uninterrupted by saccades (t=2.5, df=24, P=.019), and had decreased frequency of forward saccades (t=3.8, df=24, P=.001). No differences between groups were identified at 4 months of age. Conclusion: Smooth pursuit abnormalities may, at six months of age, be a potential biomarker for prenatal maternal anxiety exposure.

Initiation of Smooth Pursuit in Acute Cerebellar Infarction: A Preliminary Study / 대한평형의학회지

BACKGROUND AND OBJECTIVES: The cerebellar lesion causes an initiation deficit of smooth-pursuit eye movement depending on the location of the lesion. We investigated the initiation of smooth pursuit in patients with cerebellar infarction and in healthy subjects, using step-ramp stimuli. MATERIALS AND METHODS: Ten patients with cerebellar infarction documented by brain magnetic resonance imaging and fifty healthy subjects are recruited. To estimate the initiation of smooth pursuit, the onset latency and initial acceleration during the first 100ms of the horizontal smooth pursuit were estimated using the step-ramp target stimuli (5degrees/sec, 10degrees/sec, and 20degrees/sec). RESULTS: In healthy subjects, onset latency of pursuit was shortened and initial acceleration was increased as target velocity was increasing. In patients with unilateral cerebellar infarction, the onset latency of ipsilesional smooth pursuit was significantly delayed at the target velocities of 10degrees/sec and 20degrees/sec. For the fast target velocity of 20degrees/sec, there was significant decrease of the initial acceleration of contralesional pursuit. CONCLUSION: In comparison with the healthy subjects, the patients with unilateral cerebellar lesions showed significant delay of pursuit onset and decrease of initial eye acceleration in the fast target velocity. These results support that the cerebellar lesions affect not only steady-state smooth pursuit gain but also the processing time required to initiate smooth pursuit, i.e., onset latency and initial acceleration. More extensive study is needed to confirm the role of cerebellum for parametric adjustment of each component of smooth pursuit.

Sacadas, anti-sacadas e perseguição lenta neurossemiologia / Saccades, antisaccades and smooth pursuit neurosemiology

Diversos aspectos do exame neurológico envolvem conhecimentos oriundos de especialidades afins. Os objetivos principais deste artigo são: tornar manifesto ao exame à beira-do-leito, três tipos de movimento ocular considerados do domínio da neuro-oftalmologia e da neuro-otologia - sacadas, anti-sacadas e perseguição lenta - mas que devem fazer parte do exame neurológico de rotina, além de ressaltar as muitas mazelas relacionadas às suas alterações.

Several parts of the neurological exam utilize knowledge derived from related specialties. This article aims to unveil three ocular movements usually observed in the neuro-ophthalmological and neuro-otological s which can be perfectly used to enhance the routine neurological bedside examination, also uncovering the numerous illnesses related to these ocular movements: saccade, antissacade, and smooth pursuit.

The analysis of smooth pursuit test in unilateral vestibular peripheral vertigo / 临床耳鼻咽喉头颈外科杂志

Objective:To analyze the result of smooth pursuit test(SPT) in unilateral vestibular peripheral vertigo and investigate its influencing factors.Method:Smooth pursuit test (SPT) and spontaneous nystagmus (SN)were examined in one hundred and eighty-five patients with unilateral peripheral vertigo(case group) and 51 normal persons(control group) by Video-Nystagmography (Synapsys, France), and the gain of SPT and SN were selected as the observation parameters in order to analyze the waveform and gain of SPT and the relativity between SN and the gain of SPT.Result:Of the 185 patients, 105(56.8%),72(38.9%) and 8(4.3%) cases producedⅠ,Ⅱ and Ⅲ waveforms respectively. Of these patients, 58(31.4%) demonstrated SN and none had Ⅳ waveform. While of 51 normal persons, 38(74.5%), 13(25.5%) persons producedⅠand Ⅱwaveforms repectively and there were no Ⅲ, Ⅳ waveforms or SN. There was statistical significance between the stong and weak gain of SPT in these two groups. Weak gain was significantly different between two groups. The stong and weak gain of SPT in case group were 0.86±0.06,0.80±0.06; 0.78±0.09, 0.65±0.1; 0.68±0.13, 0.45±0.12. The relativity between SN and the gain of SPT was positive when they had same direction(r_s=-0.63,P＜0.05)and negative when opposite (r_s=0.34,P＜0.05).Conclusion:Ⅰ,Ⅱ,Ⅲ three waveforms of SPT could appear in unilateral vestibular peripheral vertigo and the corresponding gains are gradually decreasing.SN is the influencing factor of SPT.

Congenital Ocular Motor Apraxia: Clinico-Radiological Analyses

BACKGROUND: Congenital ocular motor apraxia (COMA) is characterized by impaired voluntary saccades and abnormal head thrusts. However, mechanism of this disorder remains to be elucidated. METHODS: This study analyzed the eye movements and imaging findings in 16 patients with COMA, who had been recruited from 2003 to 2009 at the Neuro-Ophthalmology Clinic of Seoul National University Bundang Hospital. RESULTS: All the children showed impaired saccades and smooth pursuit in the horizontal direction. One of them also exhibited impaired vertical saccades and smooth pursuit. Eight children showed excessive blinks in association with an attempt to generate saccades. The typical head thrust usually developed around the age of eight months and had resolved by the age of 6-7 years. History of spasmus nutans was confirmed in seven children. Fourteen children showed cerebellar vermian hypoplasia, mostly in the inferior portion, and five of them also had dysgenesis of the corpus callosum. The severity of cerebellar vermian hypoplasia was correlated with developmental delay, as determined by the age of independent walking. CONCLUSION: Cerebellar vermian hypoplasia is a frequent finding in COMA. Dysfunction of the oculomotor vermis may responsible for the impaired saccades and smooth pursuit in COMA. The occasional association of COMA with spasmus nutans indicates a common pathophysiology of these benign developmental disorders.

Cerebellar Hypoperfusion during Transient Global Amnesia: An MRI and Oculographic Study

BACKGROUND AND PURPOSE: Transient global amnesia (TGA) is characterized by sudden anterograde and retrograde amnesia lasting for up to 24 hours. Diffusion-weighted magnetic resonance imaging (DWI) in cases of TGA and ischemia demonstrates a high frequency of high signal intensities restricted to the hippocampus, and this has been proposed as an etiology of TGA. The aims of this study were to characterize the DWI and single-photon-emission computed tomography (SPECT) findings during the acute and recovered phases of TGA and to correlate the findings with oculomotor abnormalities. METHODS: Five consecutive patients with a clinical diagnosis of TGA underwent DWI and SPECT of the brain within 24 hours after symptom onset and again 3 days later. Eye movements were also recorded using three-dimensional video-oculography. RESULTS: In all patients, DWI disclosed small punctuate (1-3 mm), high-signal lesions in the lateral portion of the hippocampus. The initial SPECT also revealed hypoperfusion in the cerebellar vermis, which had recovered by the follow-up examination. Three patients showed saccadic hypermetria or impaired smooth pursuit only during the acute phase. CONCLUSIONS: Our patients with TGA showed cerebellar vermian hypoperfusion in addition to ischemic insults to the lateral hippocampus. The oculomotor abnormalities observed in our patients support the occurrence of cerebellar dysfunction during the TGA attack.

No Association between Val108/158Met Polymorphism on Catechol-O-Methyl Transferase(COMT) Gene and Smooth Pursuit Eye Movement(SPEM) Abnormality in Korean Schizophrenia Patients

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.

Relationship between SNP A and P1763 Polymorphisms on Dystrobrevin Binding Protein 1(DTNBP1) Gene and Smooth Pursuit Eye Movement(SPEM) Abnormality in Korean Schizophrenic Patients

OBJECTIVES: We investigated the association of SNP A and P1763 polymorphisms on dystrobrevin binding protein 1(DTNBP1) gene with smooth pursuit eye movement(SPEM) abnormality in Korean schizophrenic patients. METHODS: We measured SPEM function in 217 Korean schizophrenics(male 116, female 101) and divided them into two groups, one is a good SPEM function group and the other is a poor SPEM function group. We then analyzed SNP A polymorphism and P1763 polymorphism on DTNBP1 gene from their DNAs extracted from their blood. We compared the differences of genotype and allele distributions of the two polymorphisms on DTNBP1 gene between the two groups. RESULTS: The Ln S/N ratio(mean+/-SD) of the good SPEM function group was 4.39+/-0.33 and the ratio 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 SNP A polymorphism and P1763 polymorphism on DTNBP1 gene between the two schizophrenic groups divided by SPEM function. CONCLUSION: The results suggest that SNP A polymorphism and P1763 polymorphism on DTNBP1 gene might not be related to SPEM function abnormality in schizophrenia.

Association Analysis between P1635 and P1655 Polymorphisms on Dystrobrevin Binding Protein 1(DTNBP1) Gene and Smooth Pursuit Eye Movement(SPEM) Abnormality in Korean Schizophrenia Patients / 대한정신약물학회지

OBJECTIVE: We investigated the association of P1635 and P1655 polymorphisms on dystrobrevin binding protein 1 (DTNBP1) gene with smooth pursuit eye movement (SPEM) abnormality in Korean schizophrenia patients. METHODS: We measured SPEM function in 216 Korean schizophrenia patients (male 116, female 100) and divided them into two groups, one is a good SPEM function group and the other is a poor SPEM function group. We then analyzed P1635 polymorphism and P1655 polymorphism on DTNBP1 gene from their DNAs extracted from their blood. We compared the differences of genotype and allele distributions of the two polymorphisms on DTNBP1 gene between the two groups. RESULTS: The Ln S/N ratio (mean+/-sd) of the good SPEM function group was 4.39+/-0.33 and the ratio of poor SPEM function group was 3.18+/-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 P1635 polymorphism and P1655 polymorphism on DTNBP1 gene between the two schizophrenia groups divided by SPEM function. CONCLUSION: The results suggest that P1635 polymorphism and P1655 polymorphism on DTNBP1 gene might not be related to SPEM function abnormality in schizophrenia.

Ictal Nystagmus by Epileptic Activation of Cortical Smooth Pursuit System: Electrophysiological and Neuroimaging Study

BACKGROUND: Epileptic nystagmus is rare. There is no report in Korea about epileptic nystagmus by the activation of cortical smooth pursuit area. We studied a 29-year-male patient with nonconvulsive simple partial status epilepticus presenting as pure ictal nystagmus. METHODS: The EEG including electrooculogram and electronystagmogram during ictus was done. Brain MRI including (99m)Tc-ECD SPECT and 18F-FDG PET were also done during ictus and repeated after complete relief from symptom. Subtraction images obtained from each of SPECT and PET were coregistrated onto MRI. Humphrey visual field test was done for documentation of visual field defect. RESULTS: EEG was compatible with nonconvulsive status epilepticus arising from right mesial occipital area with 9-10 Hz frequency. Compensatory left beating nystagmus with midline crossing feature was noted and characteristic ipsiversive linear slow phase was presented in electronystagmogram. Brain neuroimages from MRI, (99m)Tc-ECD SPECT, and 18F-FDG PET revealed that the right parietotemporooccipital area was relevant area, but the right frontal eye field area was spared, which was much clear in SISCOM image. CONCLUSIONS: Clinical feature and electronystagmogram in this case showed typical epileptic nystagmus by activation of cortical smooth pursuit regions in which the relevant regions was posterior parietotemporooccipital area. The sparing of the frontal eye field area in this case suggested clearly that the epileptic nystagmus by the activation of cortical smooth pursuit regions could occur without involvement of frontal eye field area.