This study reports a pair of sisters with generalized dystonia and 3-methylglutaconic aciduria，including clinical phenotype analysis and genetic testing. Through medical history collection，imaging and laboratory examinations，and genetic analysis，it was found that the two patients had a homozygous mutation，c.1687T>C，in the Serac1 gene on chromosome 6，which was located at exon 16. The Serac1 gene mutation with adolescent-onset generalized dystonia as the main clinical phenotype has not been reported in the literature before. This study finds for the first time that Serac1 mutation at this site can cause generalized dystonia，which can provide a reference for the diagnosis and treatment of similar cases in the future.

The problems caused by proximal contact loss(PCL)of dental implants have been a mainstream research topic in recent years,and scholars are unanimously committed to analyzing their causes and related factors,aiming to identify solutions to the problems related to PCL.The effects of the anterior component of force(ACF),the lifelong re-molding of the adult craniofacial jaw and alveolar socket,and the osseointegration characteristics of dental implants are the main causes of PCL.On the one hand,the closing movement of the mandible causes the ACF of the tooth to move through the posterior molar cusp.Moreover,drifting between the upper and lower posterior teeth and mandibular anteri-or teeth can cause the anterior teeth of the upper and lower jaws to be displaced labially.On the other hand,reconstruc-tion of the jaw,alveolar socket and tooth root,the forward horizontal force of the masticatory muscles,the dynamic com-ponent of the jaw and the forward force generated by the oblique plane of the tooth cusp can cause the natural tooth to experience near-middle drift.Additionally,natural teeth can shift horizontally and vertically and rotate to accommodate remodeling of the stomatognathic system and maintain oral function.Nevertheless,the lack of a natural periodontal mem-brane during implant osseointegration,the lack of a physiological basis for near-medium drift,the small average degree of vertical motion and the integrated silence of dental implants without the overall drift characteristics of natural teeth increases the probability of PCL.The high incidence of PCL is clearly associated with the duration of prosthesis delivery and the mesial position;but it is also affected by the magnitude of the bite force,occlusion,the adjacent teeth,restora-tion design,implant location,jaw,and patient age and sex.PCL has shown a significant correlation with food impaction,but not a one-to-one correspondence,and did not meet the necessary and sufficient conditions.PCL is also associated with peri-implant lesions as well as dental caries.PCL prevention included informed consent,regular examinations,se-lection of retention options,point of contact enhancement,occlusal splints,and the application of multipurpose digital crowns.Management of the PCL includes adjacent contact point additions,orthodontic traction,and occlusal adjust-ment.Existing methods can solve the problem of food impaction in the short term with comprehensive intervention to seek stable,long-term effects.Symmetric and balanced considerations will expand the treatment of issues caused by PCL.

Peripherally-induced movement disorders (PIMD) are a group of involuntary movements that emerge after an injury to a body part outside the central nervous system. The phenomenology of PIMD encompasses both hyperkinesia and hypokinesia involving multiple parts of the body. The diagnosis of this disease mainly relies on the temporal and spatial relationship between peripheral injuries and movement disorders. The etiology, pathogenesis and treatment of PIMD have been a matter of debate. This article will review the clinical features, classification, diagnosis, treatment and possible pathogenesis of PIMD, and discuss the limitations and controversies of PIMD-related researches, aiming to advance the understanding of PIMD and avoid clinical misdiagnosis.

Objective To identify the pathogenic variants in 110 patients with essential tremor(ET).Methods Clinical data and peripheral blood samples of ET patients were collected from the Department of Neurology of Peking Union Medical College Hospital and then the genomic DNA was extracted.Dynamic mutation detection of NOTCH2NLC was performed in patients with essential tremor by triplet repeat primed PCR(TP-PCR).Since ET is as-sociated with multiple mechanisms of neuro-degeneration,the next generation sequencing(NGS)panel targeting neu-rodegenerative associating genes were performed to check pathogenic variants in additional genes.Results A total of 110 ET patients and 187 matched control individuals were recruited.The age of onset in the current ET group was(36.30±17.64)years,and 74.8%patients had a family history.No abnormal trinucleotide repeat expansion in NOTCH2NLC was identified.The repeat number of(GGC)n lied within normal ranges between 10－47(average 18.6±5.4).Variants burden analysis showed association of ET with PLA2G6.Three rare variants in four patients in PLA2G6 were identified with unknown significance.Conclusions Dynamic mutations of NOTCH2NLC are uncom-mon in ET patients and that suggests need of more researches for further exploring the genetic mechanism of ET.

Objective:To explore the related factors affecting the prognosis of patients with tardive dyskinesia, in order to find the risk factors of poor prognosis.Methods:A retrospective cohort study was implemented to collect the data of 113 patients with tardive dyskinesia from the movement disorders clinic of the Department of Neurology, Peking Union Medical College Hospital by telephone follow-up. The main variables studied included gender, age, educational level, living environment, job, cigarette smoking, alcohol drinking, hypertension, diabetes, medication type, interval from taking medicine to dyskinesia, course of dyskinesia and intervention measures. The data were analyzed by the statistical software SPSS 25.0. The quantitative data analysis was done by normality test and descriptive statistics, and the qualitative data analysis was done by χ 2 test or Fisher exact probability test. The variables with P≤0.01 in univariate analysis were included in multivariate Logistic regression analysis. Results:Among the 113 patients, 16 patients (14.16%) were cured, 27 patients (23.89%) had obvious improvement, 25 patients (22.12%) had slight improvement, 26 patients (23.01%) had no obvious change, 15 patients (13.27%) had slight deterioration, and 4 patients (3.54%) had obvious deterioration. The good prognosis rate was 60.18%, and the poor prognosis rate was 39.82%. In single factor analysis, the related factors for poor prognosis included age>52 years (χ 2=15.07, P<0.001), educational level in secondary schools and below (χ 2=8.58, P=0.003), physical labor (χ 2=4.66, P=0.031), hypertension (χ 2 = 16.38, P<0.001), diabetes mellitus (χ 2=6.06, P=0.011), dyskinesia caused by first-generation antipsychotics, calcium channel blocker or flupentixol/melitracen tablets ( P<0.001), and the duration of dyskinesia more than 2 years (χ 2 =7.05, P=0.008). Multivariate Logistic regression analysis showed that the independent risk factors for poor prognosis of tardive dyskinesia included hypertension ( OR=3.60, 95% CI 1.17-11.05, P=0.025) and dyskinesia caused by first-generation antipsychotics, calcium channel blocker or flupentixol/melitracen tablets ( OR=3.14, 95% CI 1.21-8.16, P=0.019). Conclusions:Most patients with tardive dyskinesia have a good prognosis. Hypertension and dyskinesia caused by first-generation antipsychotics, calcium channel blocker or flupentixol/melitracen tablets are independent risk factors for poor prognosis.

Objective:To improve the evaluation method of hospital beds efficiency based on diagnosis-related groups (DRG), and to provide a basis for hospitals to allocate beds reasonably and improve bed efficiency.Methods:Taking a tertiary hospital in Beijing as the research object, the types of beds were evaluated by the beds utilization matrix with the time consumption index as the X-axis and the bed utilization rate as the Y-axis. The types of beds in the department were divided into efficiency type, pressure type, turnover type, and idle type. The efficiency of medical services and the level of diagnosis and treatment were evaluated by the weight of DRG per bed. The calculation method of theoretical number of beds was improved by incorporating hospital case mix index as a risk adjustment factor into the formula to evaluate the status of beds allocation. Combining the bed type, DRG weight per bed, and bed allocation status, the improvement emphasis and management strategy of bed utilization could be comprehensively analyzed.Results:Among the 24 departments in the hospital, there were 5, 9, 1 and 9 departments being efficiency type, pressure type, turnover type and idle type, respectively. The weight per bed of 11 departments was higher than the average level of the hospital. There were 16, 5, and 3 departments with appropriate, fewer, and excessive beds, respectively.Conclusions:The comprehensive analysis of beds utilization type, allocation status and weight of each bed based on DRG is an effective method to evaluate the efficiency of hospital beds, and can provide decision-making basis for hospital bed resource allocation, hospital operation focus adjustment, and subject development planning.

Objective:To summarize genotype-phenotype features and explore the long-term outcome of bilateral globus pallidus interna deep brain stimulation (DBS) in chorea-acanthocytosis (ChAc) patients.Methods:Seven patients who diagnosed with ChAc were included in this study from April 2016 to April 2018 at Peking Union Medical College Hospital. Whole-exome sequencing was used for gene analysis of the patients, and the genotype-phenotype features of these patients were recorded. All patients underwent the DBS surgery, and long term follow-up was conducted before surgery, 3 months, 6 months, 1 year, 3 years, and 5 years after surgery. Patients were scored using the Unified Huntington Disease Rating Scale (UHDRS) to evaluate the long-term efficacy of DBS surgery.Results:The main clinical manifestations in all 7 patients were oro-faciol-ingual dyskinesia, limb chorea, dystonia, and dysarthria. Genetic testing found that all patients had VPS13A gene pathogenic variation, but the type of variation was different. The UHDRS motor score before bilateral pallidal DBS surgery was 37.00±16.68, which significantly improved to 19.67±5.99 at 1 year post-surgery, with average improvement of 46.8% ( t=5.20, P=0.003), to 23.86±8.99 at 3 years post-surgery, with average improvement of 35.5% ( t=3.08, P=0.022), and to 29.00±14.97 at 5 years post-surgery, with average improvement of 21.6% ( t=1.41, P=0.217). The symptoms of patients were most significantly improved in limb chorea and oro-facio-lingual dyskinesia. However, at the 5-year follow-up, severe dystonia and gait difficulties reoccurred in 3/7 and 4/7 of the patients, respectively. The patient′s dysarthria had not been effectively improved. Conclusions:The clinical manifestations of patients with ChAc are relatively consistent, but there is significant genetic heterogeneity. Bilateral pallidal DBS therapy is effective for patients with ChAc, but the long-term efficacy decreases with disease progression.

Objective:To elucidate the clinical and genetic characteristics of PLA2G6-related parkinsonism. Methods:The clinical, imaging and genetic data of 6 patients with PLA2G6-related parkinsonism admitted to Peking Union Medical College Hospital from January 2015 to December 2022 were retrospectively collected and analyzed. The prognosis was followed up through phone call. Results:There were 3 male and 3 female patients, and the age of disease onset was (24.3±5.4) years. Phenotypically, 5 of them had dystonia-parkinsonism (DP) with obvious atrophy of cerebellum and 1 presented as early-onset Parkinson′s disease (EOPD) with no brain structural abnormality. Only 1 patient presented with abnormal brain iron deposition. All of the patients were partially responsive to levodopa. Three cases underwent levodopa challenge test with the objective levodopa responsiveness varied from 10.3% and 10.6% in 2 DP patients, to 77.0% in 1 EOPD patient. Levodopa-induced dyskinesias were present in 4 of them, and all appeared within the first year since the initiation of dopaminergic treatment. Two patients underwent bilateral deep brain stimulation (DBS) of subthalamic nucleus and globus pallidus internus respectively, albeit revealed poor outcome. Genetically, 8 PLA2G6 variants were identified. Two of them were found to be novel (c.1973A>G and exon2 heterozygous deletion), and the most frequent variant was the c.991G>T mutation which was detected in 4 patients. Conclusions:The phenotype of PLA2G6-related parkinsonism is complex. Cerebellar atrophy is a frequent magnetic resonance imaging feature. Levodopa responsiveness tends to depend on the clinical phenotype, and EOPD is better than DP. DBS might not be promising in DP patients with obvious cerebral atrophy. The c.991G>T mutation is the most frequent mutation, suggesting a common founder effect.

Objective To investigate the clinical features of facial myokymia (FM),assess the therapeutic effect of botulinum toxin A for this condition,and offer clinical guidance for the treatment of this rare disease. Methods A retrospective analysis was performed on the clinical data of 17 patients who visited the Dyskinesia Outpatient Clinic of the Department of Neurology in Peking Union Medical College Hospital and were diagnosed with FM or facial peristalsis from March 2018 to March 2023,and the patients were followed up for the therapeutic effect of botulinum toxin A. Results Among the 17 patients with FM,12 were female and 5 were male;the mean age of onset was (31.4±9.3) years,and the duration of disease ranged from 1.5 months to 22 years. Unilateral onset was seen in all the cases;the onset in 3 cases was associated with trauma or extreme fatigue,while the cause was unclear in the remaining cases. The initial symptoms affected the lower eyelid,temporal muscle,and masseter muscle;symptoms progressed to the muscles on the same side of the face in 6 cases and involved the lower eyelid on the opposite side in 1 case;6 cases had concomitant pain;9 cases experienced functional impairment;12 cases had worsening symptoms due to coldness,tension,excitement,or strong light stimulation;1 case had head MRI results which revealed abnormal signals in the right insula,possibly due to abnormal congenital development (gray matter heterotopia);1 case had MRI results which revealed multiple intracranial ischemic foci. Seven cases showed improved symptoms after the use of carbamazepine,oxcarbazepine,phenytoin sodium,baclofen,and nicergoline during the course of disease;4 cases showed no response;6 cases did not receive any medication. Ten cases received treatment with BTX-A injection,with a mean onset of action of (5.0±2.7) days,a mean time to best effect of (8.5±4.9) days,a mean improvement rate of (78.5±15.8)%,and a mean maintenance time of (7.1±2.9) months. Following BTX-A injection,all patients experienced alleviation of anxiety and pain. Five cases who received regular BTX-A injections had a mean maintenance time of (6.3±3.4) months and a mean improvement rate of (85±13.7)%. Conclusion FM is a rare disease,lacking effective treatment consensus. Botulinum toxin A injection is a safe and effective treatment and is considered a first-line treatment for various types of focal dystonia. Based on limited case reports in the literature and our clinical research experience,botulinum toxin A injection can be recommended for the symptomatic treatment of FM.

Objective:To summarize the clinical manifestation and imaging of superficial siderosis of the central nervous system and explore the potential etiology.Methods:The clinical and imaging data of 7 patients diagnosed as superficial siderosis of the central nervous system in Peking Union Medical College Hospital from May 2013 to November 2019 were retrospectively reviewed. The etiology and follow-up prognosis through phone call were analyzed.Results:There were 7 patients included (3 male and 4 female) with an average age of 53 years (41-58 years). The cardinal manifestations were sensorineural deafness (all 7 cases), cerebellar ataxia (all 7 cases) and pyramidal signs (all 7 cases). Dizziness (6 cases), bladder disturbance (5 cases), headache (3 cases), double vision (2 cases) and congnitive impairment (1 case) could also happen. Magnetic resonance imaging showed symmetrical well-defined curvilinear homogeneous low signal on T 2 or blood-sensitive sequences (T 2* gradient echo or susceptibility-weighted imaging) over the superficial surface of cerebellar, brain stem, and spinal cord or cranio-cervical junction. All the 7 patients showed cerebellar atrophy especially the upper vermis. The potential causes included trauma history in 3 cases, intraspinal fluid-filled collection which indicated dural defect or duropathologies in 3 cases, intraspinal mass in 1 case and vertebral and disc degeneration in all 7 patients. The 5 patients who successsfully got follow-up showed exacerbation of variable degree. Conclusions:Classical superficial siderosis of the central nervous system is a rare disease with cardinal manifestation of progressive ataxia, sensorineural deafness and pyramidal signs. T 2WI of magnetic resonance imaging showing low signal over the superficial surface of cerebellar, brain stem, and spinal cord could indicate the diagnosis, and blood-sensitive sequences such as T 2* gradient echo or susceptibility-weighted imaging were more sensitive. Duropathologies or dural defect may be the most probable causes of the disease and should be examined and treated carefully.