Objective To investigate the characteristics of tremor in Parkinson disease （PD）， essential tremor （ET）， and neuronal intranuclear inclusion disease （NIID）. Methods The surface electromyography （sEMG） data of both upper limbs were collected from 73 patients with tremor （30 patients in PD group， 23 in ET group， and 20 in NIID group）， and the a power spectral analysis was used to investigate frequency characteristics. A one-way analysis of variance and the chi-square test were used for comparison of electrophysiological parameters on sEMG between the three groups. Results The ET group had a higher tremor frequency than the PD group （F=41.86， P<0.01）， while the PD group had a higher tremor frequency than the NIID group in resting state （F=41.86， P=0.002） and in postural state （F=41.86， P=0.011）. The PD group had a higher proportion of patients with alternating contractions than the NIID group in resting state （χ2=5.70， P=0.017） and in postural state （χ2=7.24， P=0.007）， as well as a higher proportion of such patients than the ET group （χ2=9.67， P=0.002）. The PD group also had a higher proportion of patients with harmonic resonances than the NIID group in resting state （χ2=4.64， P=0.031） and in postural state （χ2=7.73， P=0.005）， as well as a higher proportion of such patients than the ET group （χ2=6.52， P=0.011）. Conclusion The highest tremor frequency is observed in ET， while the lowest tremor frequency is observed in NIID； patients with PD have a higher proportion of individuals with alternating contractions or harmonic resonances than patients with NIID and ET.
Parkinson Disease ; Tremor

Objective:To compare the surface electromyography characteristics of essential tremor (ET), Parkinson′s disease (PD) and essential tremor-Parkinson′s disease syndrome (ET-PD).Methods:A total of 74 patients [ET group ( n=23), PD group ( n=30), and ET-PD group ( n=21)] admitted to the Parkinson′s and Movement Disorders Center of the Department of Neurology of Xuanwu Hospital from August 2020 to December 2023 were enrolled, and results of their bilateral upper limbs surface electromyography (sEMG) were collected. sEMG activities were analyzed offline. Power spectral analysis was performed to explore the sEMG activities. One-way analysis of variance and chi-square test were used to compare the differences of electrophysiological parameters. Results:For the ET group characterized by postural tremor, the frequency was (6.06±0.68) Hz, the amplitude was (1 200.91±360.69) μV, the proportion of alternating contractions was 30.4% (7/23), and the proportion of harmonic resonances was 34.8% (8/23). For the PD group characterized by rest tremor, the frequency was (4.81±0.61) Hz, the amplitude was (1 057.40±354.52) μV, the proportion of alternating contractions was 73.3% (22/30), and the proportion of harmonic resonances was 70.0% (21/30). For the ET-PD group in rest and postural state respectively, the frequencies were (5.04±0.44) Hz and (5.80±0.47) Hz, the amplitudes were (1 026.05±191.90) μV and (1 196.67±212.12) μV, the proportions of alternating contractions were 52.4% (11/21) and 38.1% (8/21), and the proportions of harmonic resonances were 52.4% (11/21) and 33.3% (7/21). Analysis of variance revealed that tremor frequencies for the PD group and the ET-PD group in rest state were lower than the ET group and the ET-PD group in postural state ( F=27.439, P<0.001). The proportion of alternating contractions for the PD group was higher than the ET group ( χ 2=9.669, P=0.002) and the ET-PD group in postural state ( χ 2=6.333, P=0.012). The proportion of harmonic resonances for the PD group was higher than the ET group ( χ 2=6.517, P=0.011) and the ET-PD group in postural state ( χ 2=6.708, P=0.010). No statistically significant differences were found for tremor amplitudes among all the groups ( F=2.143, P=0.100). Conclusions:ET is characterized by postural tremors, with a higher frequency and a lower alternating contractions and harmonic resonances. PD is characterized by rest tremors, with a lower frequency and a higher alternating contractions and harmonic resonances. The parameters of ET-PD are between ET and PD, which provide objective evidences for differential diagnosis of tremors.

Objective To investigate the association between excessive daytime sleepiness （EDS） and other non-motor symptoms （NMS） in patients with Parkinson disease （PD） using a graphical LASSO （GLASSO） network analysis， as well as the potential role of the sleepiness-olfaction-emotion axis in the onset of EDS. Methods A total of 500 PD patients who attended Xuanwu Hospital， Capital Medical University， from February 2023 to February 2024 were enrolled， and according to the Epworth Sleepiness Scale （ESS） score， they were divided into EDS group （ESS score ≥10） and non-EDS group （ESS score<10）. General clinical data were collected from all patients， and NMSS， HAMA， HAMD， PDSS， RBDQ-HK， MoCA， MMSE， and QOD-F scales were used to assess NMS. A graphical LASSO analysis was used to construct the NMS network in PD， and centrality indices were calculated to investigate the core role of EDS in the NMS network. Results The incidence rate of EDS was 7.12% in this study population. Compared with the non-EDS group， the EDS group had significantly higher HAMA， HAMD， NMSS， PDSS， and RBDQ-HK scores （P<0.05）. The network analysis showed that NMSS had the highest centrality （strength=0.906） in the non-EDS group， serving as the core node of the NMS network. However， in the EDS group， there was a significant increase in the centrality of olfactory function （strength=0.930）， replacing NMSS as the core of the network， and there was also an increase in the influence of RBDQ-HK （strength=0.318）. Conclusion EDS is closely associated with multiple NMS in PD patients， and the state of somnolence may alter the structure of the NMS network. Further studies can be conducted to investigate the role of the sleepiness-olfaction-emotion axis in the development of EDS.
Parkinson Disease

Objective:To compare the surface electromyography characteristics of essential tremor (ET), Parkinson′s disease (PD) and essential tremor-Parkinson′s disease syndrome (ET-PD).Methods:A total of 74 patients [ET group ( n=23), PD group ( n=30), and ET-PD group ( n=21)] admitted to the Parkinson′s and Movement Disorders Center of the Department of Neurology of Xuanwu Hospital from August 2020 to December 2023 were enrolled, and results of their bilateral upper limbs surface electromyography (sEMG) were collected. sEMG activities were analyzed offline. Power spectral analysis was performed to explore the sEMG activities. One-way analysis of variance and chi-square test were used to compare the differences of electrophysiological parameters. Results:For the ET group characterized by postural tremor, the frequency was (6.06±0.68) Hz, the amplitude was (1 200.91±360.69) μV, the proportion of alternating contractions was 30.4% (7/23), and the proportion of harmonic resonances was 34.8% (8/23). For the PD group characterized by rest tremor, the frequency was (4.81±0.61) Hz, the amplitude was (1 057.40±354.52) μV, the proportion of alternating contractions was 73.3% (22/30), and the proportion of harmonic resonances was 70.0% (21/30). For the ET-PD group in rest and postural state respectively, the frequencies were (5.04±0.44) Hz and (5.80±0.47) Hz, the amplitudes were (1 026.05±191.90) μV and (1 196.67±212.12) μV, the proportions of alternating contractions were 52.4% (11/21) and 38.1% (8/21), and the proportions of harmonic resonances were 52.4% (11/21) and 33.3% (7/21). Analysis of variance revealed that tremor frequencies for the PD group and the ET-PD group in rest state were lower than the ET group and the ET-PD group in postural state ( F=27.439, P<0.001). The proportion of alternating contractions for the PD group was higher than the ET group ( χ 2=9.669, P=0.002) and the ET-PD group in postural state ( χ 2=6.333, P=0.012). The proportion of harmonic resonances for the PD group was higher than the ET group ( χ 2=6.517, P=0.011) and the ET-PD group in postural state ( χ 2=6.708, P=0.010). No statistically significant differences were found for tremor amplitudes among all the groups ( F=2.143, P=0.100). Conclusions:ET is characterized by postural tremors, with a higher frequency and a lower alternating contractions and harmonic resonances. PD is characterized by rest tremors, with a lower frequency and a higher alternating contractions and harmonic resonances. The parameters of ET-PD are between ET and PD, which provide objective evidences for differential diagnosis of tremors.

Previous studies mainly used β-amyloid and α-synuclein as the biomarkers for the diagnosis of neurodegenerative diseases. In recent years，studies have shown that telomeres at the end of chromosome can be used as an index to measure the degree of biological aging，and telomere length and telomerase activity may also be used as the blood markers to evaluate the risk，progression，and poor prognosis of neurodegenerative diseases in the elderly；however，there is still a lack of consistency between the research findings in China and globally. Understanding the role of telomere-related biomarkers in age-related diseases can help clinicians learn more about the mechanism of disease development and progression. This article reviews the latest research advances in the telomere-telomerase system in neurodegenerative diseases，in order to introduce the influence of telomere length and telomerase activity on neurodegenerative diseases and their potential mechanisms of action.
Telomere ; Telomerase ; Neurodegenerative Diseases ; Alzheimer Disease ; Parkinson Disease

Cerebral blood flow directly affects substance metabolism and neural activity in the brain,and it is closely associated with the development and progression of neurodegenerative diseases.The ability for cerebral blood flow regulation directly affects the stability of cerebral blood perfusion,which is an important indicator for evaluating brain function.At present,studies have shown that the reduction in cortical perfusion is closely associated with cognitive decline in patients with Parkinson disease,and orthostatic hypotension often occurs in the late stage of the disease,thereby further increasing the risk of hypoperfusion,which reflects the importance of the ability for cerebral blood flow regulation in Parkinson disease.By reviewing related articles,this article summarizes the mechanism of cerebral blood flow regulation in patients with Parkinson disease,such as cerebral blood flow autoregulation,cerebral vasomotor reactivity,neurovascular coupling,and endothelium-dependent response,so as to provide new ideas and directions for exploring the effect of cerebral blood flow on Parkinson disease.

Objective:To examine the clinical subtypes of patients with multisystem atrophy(MSA)that may indicate the prognosis of patients.Additionally, we aim to compare the ability to perform daily activities among patients of each subtype using cluster analysis.Methods:The retrospective analysis included demographic data, clinical symptoms and signs, scale scores, and ancillary examinations of 94 patients diagnosed with multisystem atrophy at Xuanwu Hospital of Capital Medical University.The study aimed to analyze the clinical characteristics of each subtype obtained through clustering.Additionally, a comparison was made between patients with traditional motor subtypes and those with new subtypes in terms of activities of daily living.The study consisted of 94 MSA patients, with an average age of 61 years and a female representation of 51.1%.Using the data collected on the continuum, a full linkage hierarchical cluster analysis was performed to classify MSA patients into four clinical subtypes: gait disorder(17 cases, 18.1%), malignant tonic hyperkinetic with premature haircut(25 cases, 26.6%), intermediate(43 cases, 45.7%), and autonomic benign type(9 cases, 9.6%).Each subtype exhibited various clinical motor and non-motor symptoms, including UPDRS-Ⅲ( χ2=27.90, P<0.001), gait disturbance( χ2=33.23, P<0.001), MoCA( χ2=10.98, P=0.012), HAMA( χ2=12.14, P=0.007), HAMD( χ2=13.62, P=0.003), smell score( χ2=10.16, P=0.017), postural hypotension( χ2=14.59, P=0.028), and a statistically significant difference in the ability to perform daily living score( χ2=25.35, P<0.001).No statistically significant differences in non-motor symptoms and activities of daily living abilities were observed between the cerebellar and Parkinsonian types of traditional motor typing( P>0.05). Conclusions:The hierarchical clustering analysis conducted in this study reveals that the clinical phenotype of MSA provides a more accurate reflection of patients' clinical characteristics and their impact on quality of life compared to the traditional motor phenotype.Additionally, it may help predict variations in the underlying pathological impairment and the rate of disease progression.These findings offer a foundation for precise diagnostic interventions in patients with MSA.

Objective:To summarize and compare the characteristics of orthostatic hypotension (OH)　in　patients　with　Parkinson′s disease and multiple system atrophy (MSA).Methods:The active standing test data of 210 Parkinson′s disease patients (Parkinson′s disease group) and 85 MSA patients (MSA group) admitted to the Department of Neurology, Xuanwu Hospital, Capital Medical University from January 2021 to March 2022 were retrospectively analyzed. Demographic information, clinical data, Hoehn-Yahr staging, and Unified Parkinson′s Disease Rating Scale (UPDRS), Non-Motor Symptoms Questionnaire (NMSQ), Montreal Cognitive Assessment Scale and Mini-Mental State Examination scores were collected. The comparative analysis of OH was conducted according to the changes of heart rate and blood pressure during the active standing test.Results:Among the 85 patients with MSA, 52 were found with MSA parkinsonism variant (MSA-P) and 33 with MSA cerebellar variant (MSA-C). The 210 Parkinson′s disease patients were aged (61.5±11.0) years, with 116 males (55.2%). The 85　MSA　patients　were aged (60.1±6.8) years, with 44 males (51.8%). Compared with the Parkinson′s disease group, the Hoehn-Yahr staging [2.0(2.0, 3.0) vs 3.0(2.0, 3.0), Z=-5.278, P<0.001], NMSQ[ 25.0(11.0,46.5) vs 45.0(24.0,70.0), Z=-3.632, P<0.001] and UPDRS scores [50.0(32.0,68.0) vs 65.5(44.5,78.5), Z=-3.073, P=0.003] in the MSA group were higher. The incidence of OH in the MSA group was higher than that in the Parkinson′s disease group [63.5% (54/85) vs 25.7%(54/210), χ 2= 37.284, P<0.001], but there was no statistically significant difference between the MSA-P and MSA-C groups . Compared with the Parkinson′s disease group, the MSA group had a higher incidence of classical OH [54.1%(46/85) vs 12.9%(27/210), χ 2=55.316, P<0.001] and neurogenic OH [36.5%(31/85) vs 9.0%(19/210), χ 2=32.326, P<0.001],but there was no statistically significant difference in the incidence of initial OH and delayed OH between the two groups. The incidence of severe OH in the MSA group was also higher than that in the Parkinson′s disease group [57.6%(49/85) vs 16.7%(35/210), χ 2=49.894, P<0.001], but there was no statistically significant difference in the incidence of pre-clinical OH and mild OH between the two groups. Conclusions:The incidence, time change, severity and pathophysiological basis of OH in Parkinson′s disease and MSA patients are different. Different types of OH may help to distinguish MSA from Parkinson′s disease.

In the clinic postgraduate cultivation,the student-centralized teaching philosophy claims to elevate students’ activeness,develop their leading function sufficiently,carry out students-centralized and teachers-assisted case discussion,and meanwhile proceed phase tests. In this way,it is profitable for improving students’ ability of thinking and teaching effectiveness.

AIM: To investigate the relationship between Alzheimer disease(AD) and alpha 2-macroglobulin(α2M) initially so as to provide evidence for the pathogenesis of late-onset AD.METHODS: The significance of α2M in the late-onset AD was revealed through pathology of α2M in AD and the polymorphism of α2M in AD patients.RESULTS: The association between AD and α2M region on the twelfth chromatosome was analyzed with the genic linkage, and pathological symptom of α2M in AD patients was supported by many evidences. Two polymorphism sites of α2M were located on the 12P12-13, which could increase more risks to AD patients.CONCLUSION: It is significant to investigate the frequency, mutation,polymorphism and expression of gene α2M for the pathogenesis of late-onset AD and its genic diagnosis.