Development and validation of a nomogram for freezing of gait in patients with Parkinson's Disease.

OBJECTIVES: Freezing of gait (FOG) is a common and complex disabling episodic gait disturbance in patients with Parkinson's disease (PD). Currently, the treatment of FOG remains a challenge for clinicians. The aim of our study was to develop a nomogram for FOG risk based on data collected from Chinese patients with PD. MATERIALS & METHODS: A total of 379 PD patients (197 with FOG) from Kunming Medical University were recruited as a training cohort. Additionally, 339 PD patients (166 with FOG) were recruited from West China Hospital of Sichuan University, to serve as the validation cohort. The least absolute shrinkage and selection operator regression model was used to select clinical and demographic characteristics as well as blood markers, which were incorporated into a predictive model using multivariate logistic regression to predict the risk of developing FOG. The model was validated using the validation dataset, and model performance was evaluated using the C-index, calibration plot, and decision curve analyses. RESULTS: The final predictive model included the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) score, Parkinson's Disease Questionnaire (PDQ39), H-Y stage, and visuospatial function. The model showed good calibration and good discrimination, with a C-index value of 0.772 against the training cohort and 0.766 against the validation cohort. Decision curve analysis demonstrated the clinical utility of the nomogram. CONCLUSION: A nomogram incorporating RBDSQ, PDQ39, H-Y stage, and visuospatial function may reliably predict the risk of FOG in PD patients.

Prevalence and associated factors of frailty and sarcopenia in multiple system atrophy and progressive supranuclear palsy: a cross-sectional study.

OBJECTIVE: To investigate the prevalence of, and clinicodemographic factors associated with, frailty and sarcopenia in patients with multiple system atrophy or progressive supranuclear palsy. METHODS: A total of 264 participants were recruited in this study. Demographic and clinical data were collected through structured interviews. Frailty was assessed with the clinical frailty scale (CFS), and sarcopenia was assessed with the simple five-item scoring questionnaire (SARC-F). RESULTS: The prevalence of frailty and sarcopenia was 48.57% and 35.71% in multiple system atrophy, and 51.09% and 39.13% in progressive supranuclear palsy. Multiple system atrophy patients with frailty or sarcopenia were more likely to be female and have longer disease duration, greater motor impairment, greater non-motor burden, and lower life quality. In multiple system atrophy, frailty was associated with reduced motor function and sarcopenia was associated with female sex, reduced motor function, and orthostatic hypotension. Progressive supranuclear palsy patients with frailty or sarcopenia had more severe motor impairment and non-motor burden, longer disease duration, and lower life quality. In progressive supranuclear palsy, frailty was associated with mentation and gait/midline symptoms, while sarcopenia was associated with reduced daily activity and severe gait/midline symptoms. CONCLUSION: Frailty and sarcopenia may be more common among patients with multiple system atrophy or progressive supranuclear palsy than among the general population, and they are associated with more severe forms of the two diseases. Prospective studies are necessary to clarify causal relationships between frailty/sarcopenia and clinical manifestations of multiple system atrophy and progressive supranuclear palsy.

Fatigue prevalence and associated factors in patients with multiple system atrophy.

OBJECTIVE: Fatigue was reported a determinant of poor quality of life in multiple system atrophy (MSA) patients. This study aimed to determine fatigue prevalence and associated demographic, motor, and non-motor symptoms in MSA patients. MATERIALS AND METHODS: A total of 174 MSA patients met "Probable" diagnostic criteria were included in this cross-sectional study. Fatigue Severity Scale (FSS) was used to measure fatigue prevalence. Unified MSA Rating Scale (UMSARS), Non-Motor Symptoms Scale (NMSS), Hamilton Depression Rating Scale-17 (HDRS-17), Hamilton Anxiety Scale (HAMA), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), and Mini-Mental State Exam (MMSE) were used for comprehensive clinical assessments. Nonparametric Mann-Whitney or Pearson's chi-square test was used to compare the patient score with or without fatigue (defined as a mean FSS score≥4). Binary logistic regression analysis was performed to determine features independently associated with the presence of fatigue. RESULTS: Fifty (28.7%) patients enrolled reported fatigue. Results of multivariate analysis revealed that anxiety (OR = 3.01, 95% CI = 1.43-6.31), excessive daytime sleepiness (OR = 2.70, 95% CI = 1.23-5.90), and use of sleep medicine (OR = 3.58, 95% CI = 1.39-9.24) were significantly associated with fatigue in MSA patients. CONCLUSIONS: Fatigue is common in our MSA patients. Anxiety, excessive daytime sleepiness, and current sleep medicine use may be associated with an increased risk of fatigue. However, the severity of motor symptoms may not be associated with fatigue. Our findings highlight the need to identify, investigate, and treat fatigue in MSA.

Clinical value of C-reactive protein/albumin ratio in Guillain-Barré syndrome.

BACKGROUND: Respiratory failure in patients with Guillain-Barré syndrome (GBS) can lead to serious complications and dysfunctions, emphasizing the importance of early detection. The C-reactive protein-to-albumin ratio (CAR) is emerging as a novel inflammatory marker for predicting neurological outcome. We aimed to identify the association of CAR with respiratory failure and short-term outcome in GBS patients. METHODS: A total of 200 patients diagnosed with GBS were retrospectively analyzed. Data were collected from an electronic database. The associations of C-reactive protein (CRP), albumin, and CAR at admission with outcomes were evaluated by logistic regression analysis. Using receiver operating characteristic curves, we calculated the cutoff value for the CAR and compared its discriminatory power with that of C-reactive protein alone. RESULTS: Fifty-two (26%) patients showed poor short-term outcome, and 50 (25%) developed respiratory failure. CAR > 0.21 was an independent predictor of respiratory failure, and CAR > 0.19 was an independent predictor of poor short-term outcome. CAR showed a better predictive value than CRP alone. In addition, the c-index of the predictive nomogram for respiratory failure was higher when it included CAR (0.962) than when it did not (0.958). A similar result was observed for the predictive nomogram for poor short-term outcome (0.953 vs 0.947). CONCLUSION: CAR > 0.21, a novel inflammatory biomarker, is independently associated with the occurrence of respiratory failure in GBS patients, while CAR > 0.19 is independently associated with poor short-term outcome. CAR may help identify GBS patients at high risk of poor prognosis.

Clinical characteristics of patients with essential tremor or essential tremor plus.

BACKGROUND: The International Parkinson and Movement Disorder Society introduced the category of essential tremor (ET)-plus in its new ET classification scheme, but how the clinical correlates of ET-plus differ from those of "pure" ET is unclear. By comparing the clinical characteristics of ET and ET-plus patients, we expect to better understand the impact and invoked questions of the new classification on clinical practice. METHODS: We reviewed the medical records of 280 ET syndrome patients in an ongoing cross-sectional study in a Chinese population and reclassified them according to the new criteria. Clinico-demographic characteristics were compared between ET and ET-plus patients. Risk factors of diagnosis of ET-plus were explored using logistic regression. RESULTS: A total of 121 patients (50.8%) were reclassified as having ET and 117 as having ET-plus. ET-plus group was significantly older at tremor onset, less educated, and more likely to have cranial tremor, depression symptom, anxiety symptom, and probable REM sleep behavior disorder. ET-plus group also showed more severe upper limb tremor and cognition impairment. Regression analysis identified four independent risk factors associated with ET-plus: late tremor onset (OR 3.04, 95%CI 1.60-5.79), less educated (OR 0.91, 95%CI 0.85-0.97), severe upper limb tremor (OR 2.46, 95%CI 1.30-4.62), and presence of cranial tremor (OR 2.30, 95%CI 1.20-4.41). CONCLUSIONS: The new classification scheme emphasized that ET syndrome is heterogeneous. ET-plus cannot be seen as a subtype or a diagnosis of ET syndrome, but rather as a placeholder, representing an area of current scientific uncertainty.

A nomogram to predict mechanical ventilation in Guillain-Barré syndrome patients.

INTRODUCTION: Guillain-Barré syndrome (GBS) is one of the most common causes of acute flaccid paralysis, with up to 20%-30% of patients requiring mechanical ventilation. The aim of our study was to develop and validate a mechanical ventilation risk nomogram in a Chinese population of patients with GBS. METHODS: A total of 312 GBS patients were recruited from January 1, 2015, to June 31, 2018, of whom 17% received mechanical ventilation. The least absolute shrinkage and selection operator (LASSO) regression model was used to select clinicodemographic characteristics and blood markers that were then incorporated, using multivariate logistic regression, into a risk model to predict the need for mechanical ventilation. The model was characterized and assessed using the C-index, calibration plot, and decision curve analysis. The model was validated using bootstrap resampling in a prospective study of 114 patients recruited from July 1, 2018, to July 10, 2019. RESULTS: The predictive model included hospital stay, glossopharyngeal and vagal nerve deficits, Hughes functional grading scale scores at admission, and neutrophil/lymphocyte ratio (NLR). The model showed good discrimination with a C-index value of 0.938 and good calibration. A high C-index value of 0.856 was reached in the validation group. Decision curve analysis demonstrated the clinical utility of the mechanical ventilation nomogram. CONCLUSIONS: A nomogram incorporating hospital stay, glossopharyngeal and vagal nerve deficits, Hughes functional grading scale scores at admission, and NLR may reliably predict the probability of requiring mechanical ventilation in GBS patients.

Non-motor symptoms are associated with midline tremor in essential tremor.

OBJECTIVES: Essential tremor (ET) patients presenting tremor in the midline structures may be a distinct subtype of the syndrome. Therefore, we sought to explore the clinical manifestations, especially non-motor symptoms (NMS) of Chinese ET patients with midline tremor (MT). METHODS: In the cross-sectional study, we grouped 290 definite or probable ET patients based on their MT conditions. The NMS in ET patients were evaluated using the NMS scale (NMSS). NMS and other clinical correlates were then compared among subgroups with, and without MT. RESULTS: We revealed that 39.0%, 27.6%, and 6.9% of the patients respectively had neck, voice, and facial tremors. With the accumulation of tremor in midline structures, NMS became more severe and prevalent. Logistic regression analyses revealed that factors such as: female gender (OR = 2.164, 95% CI: 1.307-3.583), having least or highest action arm tremor (OR = 2.512, 95% CI: 1.520-4.151), having higher score of sleep/fatigue domain (OR = 1.692, 95% CI: 1.004-2.850) and mood/apathy (OR = 1.926, 95% CI: 1.143-3.246) domain, to be independently associated with MT manifestation. CONCLUSIONS: Our study demonstrates the heterogeneity of symptoms in ET patients with MT, especially in prominent NMS. In addition, the discrepancy of NMS between patients with, and without MT provides novel insight into the underlying pathophysiology and therapeutic of ET.

Clinical features of multiple system atrophy with or without rapid eye movement behavior disorder: a cross-sectional study in southwest China.

OBJECTIVE: The aim of this study was to investigate the prevalence of rapid eye movement behavior disorder (RBD) in Chinese patients with multiple system atrophy (MSA) and to compare motor and non-motor symptoms and sleep disturbance of MSA patients with and without RBD. METHODS: A total of 55 patients who were consecutively admitted to West China Hospital of Sichuan University from 2016 to 2019 and subsequently diagnosed with probable MSA were enrolled in this cross-sectional study. The diagnosis of RBD was based on the results of video polysomnography (PSG) and a history of abnormal sleep-related behaviors. The patients were divided into two groups: those with RBD and those without. These two groups were then compared in terms of severity of motor symptoms (Unified Multiple System Arophy Rating Scale) and non-motor symptoms (Non-Motor Symptoms Scale, Mini-Mental State Examination score, Epworth Sleepiness Scale, Fatigue Severity Scale, Pittsburgh Sleep Quality Index, REM Sleep Behavior Disorder Screening Questionnaire, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale) and sleep parameters as recorded on PSG. RESULTS: Of the 55 patients (35 males), 18 (33%, 13 males) were diagnosed with RBD. Patients with or without RBD did not differ in demographic characteristics, clinical features, or sleep parameters based on PSG. CONCLUSION: There was no difference in motor and non-motor symptoms between MSA patients with or without RBD, indicating that the presence of RBD may not be significantly associated with the severity of motor or non-motor dysfunction in MSA.

Frequency and factors related to drooling in Chinese patients with multiple system atrophy: a cross-sectional study.

PURPOSE: Drooling is a common symptom of neurodegenerative diseases. We aimed to explore the frequency of drooling and its relationship to clinical features in a relatively large cohort of Chinese patients with multiple system atrophy (MSA). METHODS: We conducted a cross-sectional survey of 143 patients with MSA. Patients with drooling were identified as those with a score ≥ 1 on item 6 of the Unified Parkinson's Disease Rating Scale. Additional scales were used to rate daily functionality, neurologic and cognitive capabilities, levels of anxiety and depression, and sleep quality. These results were compared between patients with and without drooling. RESULTS: The frequency of drooling in this cohort was 59.4% (85/143). Drooling was associated with significantly poorer scores on the Unified MSA Rating Scale (subscore I, subscore II, subscore IV, total score), Pittsburgh Sleep Quality Index, Hamilton Depression Scale, Hamilton Anxiety Scale, and Mini-Mental State Examination. After adjusting for confounders, regression analysis identified two independent risk factors for drooling: parkinsonism-associated MSA (OR 2.54, 95% CI 1.15-5.65) and hypomimia (OR 3.18, 95% CI 1.32-7.68). CONCLUSIONS: Drooling is relatively common among Chinese MSA patients, and parkinsonism-associated MSA and hypomimia appear to be independent risk factors for drooling. The severity of this symptom correlates with the presence of severe motor symptoms, anxiety, depression, and sleep disorders.

Meta-analysis of the association between ZNF512B polymorphism rs2275294 and risk of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS), the most common motor neuron disease, appears to result from the combination of genetic and environmental factors. Whether the rs2275294 polymorphism in the ZNF512B gene influences ALS risk is controversial. We meta-analysed the association between rs2275294 and ALS risk based on evidence published in the PubMed database. Five case-control studies involving 2559 patients with sporadic ALS and 5740 controls were analysed. Based on random-effects meta-analysis, the polymorphism rs2275294 was associated with increased risk of ALS disease in an allele model (C vs. T: OR 1.222, 95%CI 1.057 to 1.414, p = 0.007). The available evidence suggests that the ZNF512B polymorphism rs2275294 is associated with ALS risk. These results should be validated in large, well-designed studies, especially in non-Asian populations.

Smooth bridge between guided waves and spoof surface plasmon polaritons.

In this work, we build a smooth bridge between a coaxial waveguide and a plasmonic waveguide with subwavelength periodically cylindrical radial grooves, to realize high-efficiency mode conversion between conventional guided waves and spoof surface plasmon polaritons in broadband. This bridge consists of a flaring coaxial waveguide connected with a metal cylindrical wire corrugated with subwavelength gradient radial grooves. Experimental results of the transmission and reflection coefficients show excellent agreement with the numerical simulations. The proposed scheme can be extended readily to other bands and the bridge structure can find potential applications in the integration of conventional microwave or terahertz devices with plasmonic circuits.

Tunable band-notched coplanar waveguide based on localized spoof surface plasmons.

This Letter proposes a simple band-notched coplanar waveguide (BNCPW), which consists of a coplanar waveguide (CPW) and an ultra-thin periodic corrugated metallic strip that supports spoof surface plasmon polaritons (SSPPs) with defect units on the back of the substrate. By introducing a defect unit or multiple defect units into the strip, a narrow stopband or multiple narrow stopbands would be generated flexibly and conveniently. The band-notch function is based on the idea that a defect mode, which exists in the bandgap between the fundamental and the first higher mode of the SSPPs, can be introduced to form a stopband. Thus, the SSPPs field is localized around the defect units, which is another form of localized spoof surface plasmons (LSSPs). By properly tuning the dimensions of each defect unit, the absorption level and center frequency of the stopband could be adjusted independently. We offer theoretical analysis and experimental results to validate our idea and design. In this framework, a variety of band-notched devices and antennas in the microwave and terahertz (THz) frequencies can be easily designed without additional band-stop filters.

A corrugated perfect magnetic conductor surface supporting spoof surface magnon polaritons.

In this paper, we demonstrate that spoof surface magnon polaritons (SSMPs) can propagate along a corrugated perfect magnetic conductor (PMC) surface. From duality theorem, the existence of surface electromagnetic modes on corrugated PMC surfaces are manifest to be transverse electric (TE) mode compared with the transverse magnetic (TM) mode of spoof surface plasmon plaritons (SSPPs) excited on corrugated perfect electric conductor surfaces. Theoretical deduction through modal expansion method and simulation results clearly verify that SSMPs share the same dispersion relationship with the SSPPs. It is worth noting that this metamaterial will have more similar properties and potential applications as the SSPPs in large number of areas.

Multiband localized spoof plasmons in closed textured cavities.

In this work, we explore the existence of multiband localized spoof plasmons (LSPs) in closed textured cavities with multiple groove depths. It is interesting to note that the spoof LSPs in each band resemble those generated by the textured 2D cavities of the same periodicity with the corresponding single groove depth, and the field distributions and confinement characteristics of the plasmon-like modes in such a corrugated cavity are different from the conventional cavity. Hence, these multiple resonance band structures can find potential applications in the microwave and terahertz frequencies.

Hearing loss is not associated with risk of Parkinson's disease: A Mendelian randomization study.

Purpose: A few observational studies have indicated that Parkinson's disease (PD) risk may be higher in those with hearing loss, but the two's causal relationship is yet unknown. Using Mendelian randomization (MR) methods, this study sought to explore the causal link between hearing loss and the risk of PD. Methods: We identified single nucleotide polymorphisms (SNPs) linked to hearing loss (P-value<5E-08) in a genome-wide association study (GWAS) included 323,978 people from the UK Biobank. The summary data for PD in the discovery group came from a GWAS meta-analysis of 33,647 cases and 449,056 healthy participants of European descent. Using summary data from the aforementioned GWAS of PD (N = 33,647) and hearing loss (N = 323,978), we carried out a two-sample MR study. As validation groups, two separate PD GWAS studies were used. Inverse variance weighting (IVW) was utilized in the principal MR analysis. For our findings to be reliable, further analyses were carried out with the Cochran's Q test, MR-Egger intercept, and leave-one-out analysis. In addition, we assessed the causal link between various forms of hearing loss and PD using the IVW approach. Results: Twenty-two SNPs with genome-wide significance linked to hearing loss were used as instrumental factors. In the discovery dataset, we failed to detect a causal relationship between hearing loss and PD (OR = 1.297; 95 % CI = 0.420-4.007; P-value = 0.651). The findings of other methods agreed with the IVW method. The results were robust under sensitivity analyses. Furthermore, the above findings were confirmed in two validation PD datasets. Additionally, no causal correlation was found between genetic prediction of four different types of hearing loss and PD (conductive hearing loss, IVW: OR = 1.058, 95%CI = 0.988-1.133, P-value = 0.108; sudden idiopathic hearing loss, IVW: OR = 0.936, 95%CI = 0.863-1.016, P-value = 0.113; mixed conductive and sensorineural hearing loss, IVW: OR = 0.963, 95%CI = 0.878-1.058, P-value = 0.436; sensorineural hearing loss, IVW: OR = 1.050, 95%CI = 0.948-1.161, P-value = 0.354). Conclusion: In those of European heritage, our investigation revealed no causal link between hearing loss and PD risk.

Exploring the association between air pollution and Parkinson's disease or Alzheimer's disease: a Mendelian randomization study.

The correlation between air pollution and neurodegenerative diseases has garnered growing attention. Although observational studies have indicated a potential link between air pollution and neurodegenerative disease, establishing a causal relationship remains uncertain. To address this gap, we performed a two-sample Mendelian randomization analysis utilizing genetic instruments. This analysis aimed to investigate the causal connections between PM2.5, PM10, NO2, and NOX exposure and the occurrence of Parkinson's disease (PD) and Alzheimer's disease (AD). We implemented a series of filtering steps to identify suitable genetic instruments that demonstrated significant associations (P < 5 × 10-8) with PM2.5, PM10, NO2, and NOX. These instruments were derived from a comprehensive genome-wide association study (GWAS) encompassing up to 456,380 participants in the UK Biobank. To obtain summary statistics for PD (N = 482,730) and AD risk (N = 63,926), we utilized the most recent GWAS datasets available. For our primary analysis, we employed the inverse-variance weighted approach for two-sample MR. A multivariable MR (MVMR) was also performed to verify the impact of air pollution exposure on the risk of PD and AD. To ensure the robustness of our findings, sensitivity analyses and heterogeneity assessments were performed. In two-sample MR, by employing the inverse-variance weighted method, our result suggested that genetically NO2 exposure showed a significant association with an elevated risk of PD (OR = 4.07, 95% CI: 1.13 to 19.62, P = 0.034) and genetically PM10 exposure exhibited a significant association with a heightened risk of AD (OR = 1.93, 95% CI: 1.03-3.59, P = 0.040). Further MVMR analysis demonstrated that the causal effect between NO2 and PD disappeared (OR = 3.489, 95% CI: 0.01 to 2.1e + 03, P = 0.703), and only PM10 was associated with an increased risk of AD (OR = 6.500, 95% CI: 1.10 to 38.51, P = 0.039). Sensitivity analysis showed no detectable heterogeneity and pleiotropy (P > 0.05). Our findings demonstrate that NO2 and PM10 exposure may contribute to a risk of PD and AD, respectively. Future research is necessary to elucidate potential physiopathological mechanisms.

Prevalence of restless legs syndrome in people with diabetes mellitus: A pooling analysis of observational studies.

Background: Diabetes mellitus (DM) is associated with different clinical complications. The aim of this study was to explore the prevalence of RLS in people with diabetes mellitus and compare the risk of restless leg syndrome (RLS) between diabetic and non-diabetic population. Methods: We searched for studies of RLS prevalence in DM through PubMed, Embase, and Web of Science. Two authors independently completed the literature screening, data extraction, and bias risk assessment of eligible studies. All observational studies that assessed the prevalence or risk of RLS in DM were included, where the diagnosis of RLS was based on the International Restless Legs Syndrome Study Group (IRLSSG). Percentages, odds ratio (OR) with 95% confidence intervals (CI) were used to assess pooled estimates of RLS prevalence and risk based on random-effects models. Newcastle-Ottawa-scale (NOS) or a modified NOS were used to evaluate the quality of studies. Findings: A total of 42 studies, including 835,986 participants, met the eligibility criteria for the meta-analysis. Among them, 30 studies were included in meta-analysis to analyze the prevalence of RLS. A second meta-analysis was conducted using 31 studies to determine RLS risk between diabetes and non-diabetes. The results indicate that between 25% (95% confidence interval 21%-29%) of people with diabetes showed signs of RLS, and people with diabetes had an increased risk of developing RLS compare to people without diabetes (OR 1.98, 95%CI 1.66- 2.34, p < 0.001). However, the available evidence was limited due to potential risk of bias and variability between studies (I2 >75%), all of observational design. Interpretation: Our study suggests that the prevalence and risk of RLS might be higher in DM patients than in non-diabetes population. However, given limitations in the analysis and study design, the findings need to be corroborated in future studies. Funding: This work was supported by the Basic Conditions Platform Construction Project of Sichuan Science and Technology Department (2019JDPT0015), and the "1・3・5 project for disciplines of excellence, West China Hospital, Sichuan University" (ZYJC18003).

Exploring the dual character of metformin in Alzheimer's disease.

Alzheimer's disease (AD) is the most common neurodegenerative disease, which results in dementia typically in the elderly. The disease is mainly characterized by the deposition of amyloid beta (Aß) plaques and neurofibrillary tangles (NFTs) in the brain. However, only few drugs are available for AD because of its unknown pathological mechanism which limits the development of new drugs. Therefore, it is urgent to identify potential therapeutic strategies for AD. Moreover, research have showed that there is a significant association between Type 2 diabetes mellites (T2DM) and AD, suggesting that the two diseases may share common pathophysiological mechanisms. Such mechanisms include impaired insulin signaling, altered glucose metabolism, inflammation, oxidative stress, and premature aging, which strongly affect cognitive function and increased risk of dementia. Consequently, as a widely used drug for T2DM, metformin also has therapeutic potential for AD in vivo. It has been confirmed that metformin is beneficial on the brain of AD animal models. The mechanisms underlying the effects of metformin in Alzheimer's disease are complex and multifaceted. Metformin may work through mechanisms involving homeostasis of glucose metabolism, decrease of amyloid plaque deposition, normalization of tau protein phosphorylation and enhancement of autophagy. However, in clinical trials, metformin had little effects on patients with mild cognitive impairment or mild AD. Pathological effects and negative clinical results of metformin on AD make the current topic quite controversial. By reviewing the latest progress of related research, this paper summarizes the possible role of metformin in AD. The purpose of this study is not only to determine the potential treatment of AD, but also other related neurodegenerative diseases.