- Email: [email protected]
Transient global amnesia: Is cranial atherosclerosis the risk factor to transient global amnesia ?
Poster Presentations P1 tests: Local Speed Discrimination (LSD), Structure-From-Motion (SFM) perception and a Contrast Sensitivity (CS) test with eye movement measurements to control for fixation and saccadic patterns potentially evoked by visual pre-cues. Patients were also assessed with motor, neuropsychiatric and fluctuation scales. Results: When compared with the control group, both groups of patients (DLB and AD) performed globally worse in cognitive and visual tasks. DLB patients showed less positional accuracy in RTI task than AD patients. Regarding eye movement patterns, DLB patients were less able to maintain fixation in the CS task, in the presence of target precues. Conclusions: DLB and AD patients demonstrated similar cognitive performance and equivalent impairment in early and dorsal visual functions. These results do therefore suggest that both diseases affect occipital networks involved in contrast sensitivity and motion perception in a similar manner. However, in what concerns to eye movement control, DLB patients are characterized by a significant inability to sustain fixation, which was the biomarker that differentiated the two groups.
P1-025
ALTERED EXPRESSION OF SYNAPTIC PROTEINS IN THE NEOCORTEX OF PARKINSON’S DISEASE WITH DEMENTIA (PDD) AND DEMENTIA WITH LEWY BODIES (DLB)
Nur-Ezan Mohamed1, Jasinda Lee1, Paul Francis2, Mitchell Lai3,1, Christopher Chen1, 1National University of Singapore, Singapore, Singapore; 2Wolfson Centre for Age-Related Disease, King’s College London, London, United Kingdom; 3Singapore General hospital, Singapore, Singapore. Contact e-mail: [email protected] Background: Neurodegenerative diseases are often characterized by synaptic dysfunction. In Alzheimer’s Disease, significant down regulation of presynaptic proteins such as synaptotagmin, synaptophysin and GAP43 have been observed in frontal and entorhinal cortex whereas postsynaptic protein PSD95, is significantly increase in the frontal cortex. Here we aim to characterize synaptic changes in PDD and DLB patients and age-matched controls. Methods: Neocortical tissues from subjects (14 PDD, 13 DLB and 7 agematched controls) were obtained from established longitudinal studies. Immunoblotting was performed on post-mortem brain tissue homogenates from the parahippocampus gyrus (Brodmann area 36) to measure pre and post synatic markers (synaptophysin, synaptotagmin, synapsin, Rabphilin 3A, syntaxin, SV2A, GAP 43 and PSD 95). Immunoblot densities were analyzed using one-way ANOVA with post-hoc Bonferroni correction. Results were considered statistically significant if p < 0.05. Results: We found a significant reduction of synapsin, Rabphilin3A and synaptophysin in PDD (p ¼ 0.030, 0.003 and 0.003 respectively) compared to control. Rabphilin 3A, synaptophysin and synaptotagmin were significantly reduced in DLB (p ¼ 0.003, 0.035 and 0.004 respectively) compared to controls. No significant changes observed between PDD and DLB. Conclusions: SNARE complex, which is formed prior to neurotransmitter release, involved the specific docking of V-SNARE (Vesicle) and its respective targeted T-SNARE (Target). Interestingly, presynaptic proteins, that formed the V-SNARE (synaptotagmin, synapsin, synaptophysin) but not those involved in the T-SNARE (syntaxin) are significantly reduced in PDD and DLB. Significant down regulation of Rabphilin 3A, a GTPase which assists and regulates the efficiency of docking and matching of V-SNARE and T-SNARE is also observed in both PDD and DLB. These findings confirm a distinctive pattern of presynaptic changes which are likely linked to impairment of neurotransmitter release and points to further investigation of synaptic changes in various brain regions of PDD and DLB.
P1-026
TRANSIENT GLOBAL AMNESIA: IS CRANIAL ATHEROSCLEROSIS THE RISK FACTOR TO TRANSIENT GLOBAL AMNESIA ?
Hee-Jeong Jeong, Heeyoung Kang, Kyusik Kang, Ki-Jong Park, NackCheon Choi, Oh-Young Kwon, Byeong Hoon Lim, Department of Neurology, Gyeongsang National University School of Medicine, Jinju, Korea. Contact e-mail: [email protected]
S181
Background: The pathomechanism of transient global amnesia (TGA) was uncertain. The carotid atherosclerosis is more in TGA group than normal healthy adults in one study. In other previous studies, TGA had no correlation to risk factor of cerebral ischemia. However, there are no report between TGA and cranial atherosclerosis. Methods: 49 patients with TGA, 61 agematched lacune infarct and 62 normal controls were enrolled. We examined brain MR images and angiography and vascular risk factors including diabetes, hypertension, hyperlipidemia, systolic blood pressure, and smoking. The cranial atherosclerosis divided into six parts (anterior, middle, posterior cerebral, vertebral, basilar, and internal carotid artery). We examined the difference of risk factors and atherosclerosis among three groups. Results: 15 TGA patients (30%) shown hippocampal hyperintensity on diffusion weighted MRI. The atherosclerosis on middle cerebral artery and internal carotid artery were more prevalent in lacune group than TGA and normal group. However, there was no difference of cranial atherosclerosis and vascular risk factors between TGA and normal group. Conclusions: TGA seems to have no correlation with cranial atherosclerosis and it reject the cerebral ischemia as cause of TGA. P1-027
VISUAL INFORMATION PROCESSING FUNCTIONS ARE SELECTIVELY IMPAIRED IN LEWY BODY DISEASE WITH DEMENTIA, BUT NOT IN ALZHEIMER’S DISEASE
Akira Kurita1, Masahiko Suzuki2, Maiko Murakami2, Satoshi Takagi3, Kazutaka Matsui3, 1Kashiwa Hospital, Jikei University School of Medicine, Kashiwa, Chiba, Japan; 2Aoto Hospital, Jikei University School of Medicine, Katsushika, Tokyo, Japan; 3Jikei University School of Medicine, Minato-ku, Tokyo, Japan. Contact e-mail: [email protected] Background: Visual hallucinations (VHs) are common in Lewy body disease with dementia (LBD-D) including dementia with Lewy bodies (DLB) and Parkinson’s disease (PD) with dementia (PDD), while those are not so frequently observed in Alzheimer’s disease (AD). Recent neuropsychological studies have shown an association between visual cognitive impairments and VHs in LBD-D, and radionuclear studies have demonstrated decreased blood flow in the posterior lobe in those disorders. Based on these findings together, it is possible to speculate that visual information processing functions are selectively impaired in LBD-D, contributing, in part, to the pathophysiology of VHs. To clarify this issue and to examine whether neurophysiological evaluation of visual cognitive functions can differentiate LBD-D from AD, we compared DLB, PDD and AD patients with event-related potentials (ERPs). Methods: We compared visual and auditory ERP latencies among patients with PDD (17), DLB (24), and AD (21). Twenty healthy volunteers served as control subjects. The mean ages and MMS scores of the 3 patient groups were comparable. To elicit visual and auditory ERPs, a facial discrimination paradigm and a conventional auditory odd-ball paradigm, respectively, were used. Results: The mean visual P3 latencies in the DLB and PDD groups were significantly or tended to be longer than that in the AD group, while the mean auditory P3 latencies in all three patient groups were comparable. When VP3/AP3 ratios were calculated to compare visual and auditory cognitive states, the PDD and DLB groups had larger ratios than other groups, and a significant difference was present between each of the two groups and the control group. With regard to the remaining parameters of the ERPs, the mean visual P2 latencies in the PDD and DLB groups were significantly longer than that in the control group. Conclusions: Our findings suggest that compared with AD patients, visual cognitive functions are selectively impaired in hallucinatory LBD-D patients. VHs may be associated in part with predominant visual cognitive impairments attributable to LBD pathologies. Our findings also suggest the clinical utility of visual and auditory ERP analyses in the differential diagnosis of LBD-D and AD. P1-028
PROTECTIVE EFFECTS OF HYDROGEN SULFIDE ON NEURODEGENERATION IN UNILATERAL 6-OHDA-LESIONED RATS
Ming Lu, Li-Fang Hu, Chi Xin Tiong, Jin-Song Bian, National University of Singapore, Singapore, Singapore. Contact e-mail: [email protected]
P1-025
ALTERED EXPRESSION OF SYNAPTIC PROTEINS IN THE NEOCORTEX OF PARKINSON’S DISEASE WITH DEMENTIA (PDD) AND DEMENTIA WITH LEWY BODIES (DLB)
Nur-Ezan Mohamed1, Jasinda Lee1, Paul Francis2, Mitchell Lai3,1, Christopher Chen1, 1National University of Singapore, Singapore, Singapore; 2Wolfson Centre for Age-Related Disease, King’s College London, London, United Kingdom; 3Singapore General hospital, Singapore, Singapore. Contact e-mail: [email protected] Background: Neurodegenerative diseases are often characterized by synaptic dysfunction. In Alzheimer’s Disease, significant down regulation of presynaptic proteins such as synaptotagmin, synaptophysin and GAP43 have been observed in frontal and entorhinal cortex whereas postsynaptic protein PSD95, is significantly increase in the frontal cortex. Here we aim to characterize synaptic changes in PDD and DLB patients and age-matched controls. Methods: Neocortical tissues from subjects (14 PDD, 13 DLB and 7 agematched controls) were obtained from established longitudinal studies. Immunoblotting was performed on post-mortem brain tissue homogenates from the parahippocampus gyrus (Brodmann area 36) to measure pre and post synatic markers (synaptophysin, synaptotagmin, synapsin, Rabphilin 3A, syntaxin, SV2A, GAP 43 and PSD 95). Immunoblot densities were analyzed using one-way ANOVA with post-hoc Bonferroni correction. Results were considered statistically significant if p < 0.05. Results: We found a significant reduction of synapsin, Rabphilin3A and synaptophysin in PDD (p ¼ 0.030, 0.003 and 0.003 respectively) compared to control. Rabphilin 3A, synaptophysin and synaptotagmin were significantly reduced in DLB (p ¼ 0.003, 0.035 and 0.004 respectively) compared to controls. No significant changes observed between PDD and DLB. Conclusions: SNARE complex, which is formed prior to neurotransmitter release, involved the specific docking of V-SNARE (Vesicle) and its respective targeted T-SNARE (Target). Interestingly, presynaptic proteins, that formed the V-SNARE (synaptotagmin, synapsin, synaptophysin) but not those involved in the T-SNARE (syntaxin) are significantly reduced in PDD and DLB. Significant down regulation of Rabphilin 3A, a GTPase which assists and regulates the efficiency of docking and matching of V-SNARE and T-SNARE is also observed in both PDD and DLB. These findings confirm a distinctive pattern of presynaptic changes which are likely linked to impairment of neurotransmitter release and points to further investigation of synaptic changes in various brain regions of PDD and DLB.
P1-026
TRANSIENT GLOBAL AMNESIA: IS CRANIAL ATHEROSCLEROSIS THE RISK FACTOR TO TRANSIENT GLOBAL AMNESIA ?
Hee-Jeong Jeong, Heeyoung Kang, Kyusik Kang, Ki-Jong Park, NackCheon Choi, Oh-Young Kwon, Byeong Hoon Lim, Department of Neurology, Gyeongsang National University School of Medicine, Jinju, Korea. Contact e-mail: [email protected]
S181
Background: The pathomechanism of transient global amnesia (TGA) was uncertain. The carotid atherosclerosis is more in TGA group than normal healthy adults in one study. In other previous studies, TGA had no correlation to risk factor of cerebral ischemia. However, there are no report between TGA and cranial atherosclerosis. Methods: 49 patients with TGA, 61 agematched lacune infarct and 62 normal controls were enrolled. We examined brain MR images and angiography and vascular risk factors including diabetes, hypertension, hyperlipidemia, systolic blood pressure, and smoking. The cranial atherosclerosis divided into six parts (anterior, middle, posterior cerebral, vertebral, basilar, and internal carotid artery). We examined the difference of risk factors and atherosclerosis among three groups. Results: 15 TGA patients (30%) shown hippocampal hyperintensity on diffusion weighted MRI. The atherosclerosis on middle cerebral artery and internal carotid artery were more prevalent in lacune group than TGA and normal group. However, there was no difference of cranial atherosclerosis and vascular risk factors between TGA and normal group. Conclusions: TGA seems to have no correlation with cranial atherosclerosis and it reject the cerebral ischemia as cause of TGA. P1-027
VISUAL INFORMATION PROCESSING FUNCTIONS ARE SELECTIVELY IMPAIRED IN LEWY BODY DISEASE WITH DEMENTIA, BUT NOT IN ALZHEIMER’S DISEASE
Akira Kurita1, Masahiko Suzuki2, Maiko Murakami2, Satoshi Takagi3, Kazutaka Matsui3, 1Kashiwa Hospital, Jikei University School of Medicine, Kashiwa, Chiba, Japan; 2Aoto Hospital, Jikei University School of Medicine, Katsushika, Tokyo, Japan; 3Jikei University School of Medicine, Minato-ku, Tokyo, Japan. Contact e-mail: [email protected] Background: Visual hallucinations (VHs) are common in Lewy body disease with dementia (LBD-D) including dementia with Lewy bodies (DLB) and Parkinson’s disease (PD) with dementia (PDD), while those are not so frequently observed in Alzheimer’s disease (AD). Recent neuropsychological studies have shown an association between visual cognitive impairments and VHs in LBD-D, and radionuclear studies have demonstrated decreased blood flow in the posterior lobe in those disorders. Based on these findings together, it is possible to speculate that visual information processing functions are selectively impaired in LBD-D, contributing, in part, to the pathophysiology of VHs. To clarify this issue and to examine whether neurophysiological evaluation of visual cognitive functions can differentiate LBD-D from AD, we compared DLB, PDD and AD patients with event-related potentials (ERPs). Methods: We compared visual and auditory ERP latencies among patients with PDD (17), DLB (24), and AD (21). Twenty healthy volunteers served as control subjects. The mean ages and MMS scores of the 3 patient groups were comparable. To elicit visual and auditory ERPs, a facial discrimination paradigm and a conventional auditory odd-ball paradigm, respectively, were used. Results: The mean visual P3 latencies in the DLB and PDD groups were significantly or tended to be longer than that in the AD group, while the mean auditory P3 latencies in all three patient groups were comparable. When VP3/AP3 ratios were calculated to compare visual and auditory cognitive states, the PDD and DLB groups had larger ratios than other groups, and a significant difference was present between each of the two groups and the control group. With regard to the remaining parameters of the ERPs, the mean visual P2 latencies in the PDD and DLB groups were significantly longer than that in the control group. Conclusions: Our findings suggest that compared with AD patients, visual cognitive functions are selectively impaired in hallucinatory LBD-D patients. VHs may be associated in part with predominant visual cognitive impairments attributable to LBD pathologies. Our findings also suggest the clinical utility of visual and auditory ERP analyses in the differential diagnosis of LBD-D and AD. P1-028
PROTECTIVE EFFECTS OF HYDROGEN SULFIDE ON NEURODEGENERATION IN UNILATERAL 6-OHDA-LESIONED RATS
Ming Lu, Li-Fang Hu, Chi Xin Tiong, Jin-Song Bian, National University of Singapore, Singapore, Singapore. Contact e-mail: [email protected]