[Anti-HMGCR immune-mediated necrotizing myopathy: A case report].

The patient was a 55-year-old man who was admitted to hospital with "progressive myalgia and weakness for 4 months, and exacerbated for 1 month". Four months ago, he presented with persistent shoulder girdle myalgia and elevated creatine kinase (CK) at routine physical examination, which fluctuated from 1 271 to 2 963 U/L after discontinuation of statin treatment. Progressive myalgia and weakness worsened seriously to breath-holding and profuse sweating 1 month ago. The patient was post-operative for renal cancer, had previous diabetes mellitus and coronary artery disease medical history, had a stent implanted by percutaneous coronary intervention and was on long-term medication with aspirin, atorvastatin and metoprolol. Neurological examination showed pressure pain in the scapularis and pelvic girdle muscles, and V- grade muscle strength in the proximal extremities. Strongly positive of anti-HMGCR antibody was detected. Muscle magnetic resonance imaging (MRI) T2-weighted image and short time inversion recovery sequences (STIR) showed high signals in the right vastus lateralis and semimembranosus muscles. There was a small amount of myofibrillar degeneration and necrosis, CD4 positive inflammatory cells around the vessels and among myofibrils, MHC-Ⅰ infiltration, and multifocal lamellar deposition of C5b9 in non-necrotic myofibrils of the right quadriceps muscle pathological manifestation. According to the clinical manifestation, imageological change, increased CK, blood specific anti-HMGCR antibody and biopsy pathological immune-mediated evidence, the diagnosis of anti-HMGCR immune-mediated necrotizing myopathy was unequivocal. Methylprednisolone was administrated as 48 mg daily orally, and was reduced to medication discontinuation gradually. The patient's complaint of myalgia and breathlessness completely disappeared after 2 weeks, the weakness relief with no residual clinical symptoms 2 months later. Follow-up to date, there was no myalgia or weakness with slightly increasing CK rechecked. The case was a classical anti-HMGCR-IMNM without swallowing difficulties, joint symptoms, rash, lung symptoms, gastrointestinal symptoms, heart failure and Raynaud's phenomenon. The other clinical characters of the disease included CK as mean levels >10 times of upper limit of normal, active myogenic damage in electromyography, predominant edema and steatosis of gluteus and external rotator groups in T2WI and/or STIR at advanced disease phase except axial muscles. The symptoms may occasionally improve with discontinuation of statins, but glucocorticoids are usually required, and other treatments include a variety of immunosuppressive therapies such as methotrexate, rituximab and intravenous gammaglobulin.

[Diagnostic value of F wave changes in patients with Charcot-Marie-Tooth1A and chronic inflammatory demyelinating polyneuropathy].

OBJECTIVE: To analyze and compare the characteristics and causes of F wave changes in patients with Charcot-Marie-Tooth1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Thirty patients with CMT1A and 30 patients with CIDP were enrolled in Peking University Third Hospital from January 2012 to December 2018. Their clinical data, electrophysiological data(nerve conduction velocity, F wave and H reflex) and neurological function scores were recorded. Some patients underwent magnetic resonance imaging of brachial plexus and lumbar plexus, and the results were analyzed and compared. RESULTS: The average motor conduction velocity (MCV) of median nerve was (21.10±10.60) m/s in CMT1A and (31.52±12.46) m/s in CIDP. There was a significant difference between the two groups (t=-6.75, P < 0.001). About 43.3% (13/30) of the patients with CMT1A did not elicit F wave in ulnar nerve, which was significantly higher than that of the patients with CIDP (4/30, 13.3%), χ2=6.65, P=0.010. Among the patients who could elicit F wave, the latency of F wave in CMT1A group was (52.40±17.56) ms and that in CIDP group was (42.20±12.73) ms. There was a significant difference between the two groups (t=2.96, P=0.006). The occurrence rate of F wave in CMT1A group was 34.6%±39%, and that in CIDP group was 70.7%±15.2%. There was a significant difference between the two groups (t=-5.13, P < 0.001). The MCV of median nerve in a patient with anti neurofascin 155 (NF155) was 23.22 m/s, the latency of F wave was 62.9-70.7 ms, and the occurrence rate was 85%-95%. The proportion of brachial plexus and lumbar plexus thickening in CMT1A was 83.3% (5/6) and 85.7% (6/7), respectively. The proportion of brachial plexus and lumbar plexus thickening in the CIDP patients was only 25.0% (1/4, 2/8). The nerve roots of brachial plexus and lumbar plexus were significantly thickened in a patient with anti NF155 antibody. CONCLUSION: The prolonged latency of F wave in patients with CMT1A reflects the homogenous changes in both proximal and distal peripheral nerves, which can be used as a method to differentiate the CIDP patients characterized by focal demyelinating pathology. Moreover, attention should be paid to differentiate it from the peripheral neuropathy caused by anti NF155 CIDP. Although F wave is often used as an indicator of proximal nerve injury, motor neuron excitability, anterior horn cells, and motor nerve myelin sheath lesions can affect its latency and occurrence rate. F wave abnormalities need to be comprehensively analyzed in combination with the etiology, other electrophysiological results, and MRI imaging.

[Cortical thickness and cognitive impairment in patients with amyotrophic lateral sclerosis].

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with high morbidity and mortality. There are about 5%-15% of ALS patients combining with frontotemporal lobe degeneration (FTLD) at the same time and 50% of patients combing with cognitive function changes. The analysis of cortical thickness based on MRI is an important imaging method to evaluate brain structure. The aim of the study was to explore the changes of brain structure in ALS patients by cortical thickness analysis, and to explore the correlation between the brain structure and cognitive function. METHODS: In the study, 18 ALS patients treated in Department of Neurology, Peking University Third Hospital and 18 normal controls (age, gender and education level matched) were included. 3D magnetization prepared rapid gradient echo imaging (MPRAGE) sequence MRI was performed and the cortical thickness was analyzed. At the same time, all the ALS patients took neuropsychology assessments, including: mini-mental state examination (MMSE), verbal fluency test (VFT), Stroop color word test (SCWT), prospective memory (PM), emotional picture perception and recognition, and faux pas story test. RESULTS: After cognitive assessment, two ALS patients had cognitive impairment. One was in accordance with ALS-frontotemporal dementia (FTD) diagnosis and the other one was in accordance with ALS cognitive impairment (ALSci) diagnosis. In all the 18 ALS patients and 18 normal controls, the cortical thickness of the left medial orbitofrontal lobe and the medial temporal lobe were significantly reduced (P < 0.05) in ALS group by the vertex-wise comparison. Cortical thickness of the left entorhinal cortex, the left inferior temporal gyrus, the left medial orbitofrontal lobe and the left insular lobe was significantly reduced (P < 0.05) by the region-wise comparison. However, when only concluded the 16 ALS non-cognitive impairment patients, there was no significant difference between the two groups (P>0.05). There were correlations between the scores of prospective memory, emotional picture perception and recognition, faux pas story test and the cortical thickness of their corresponding regions (P < 0.05). CONCLUSION: The cortical thickness of ALS patients are correlated with neuropsychological scores which may reflect the changes of cortical structure corresponding to the cognitive assessment, and may provide help for the early diagnosis of cognitive changes in ALS patients.

[Genetic distribution in Chinese patients with hereditary peripheral neuropathy].

OBJECTIVE: To analyze the distribution characteristics of hereditary peripheral neuropathy (HPN) pathogenic genes in Chinese Han population, and to explore the potential pathogenesis and treatment prospects of HPN and related diseases. METHODS: Six hundred and fifty-six index patients with HPN were enrolled in Peking University Third Hospital and China-Japan Friendship Hospital from January 2007 to May 2022. The PMP22 duplication and deletion mutations were screened and validated by multiplex ligation probe amplification technique. The next-generation sequencing gene panel or whole exome sequencing was used, and the suspected genes were validated by Sanger sequencing. RESULTS: Charcot-Marie-Tooth (CMT) accounted for 74.3% (495/666) of the patients with HPN, of whom 69.1% (342/495) were genetically confirmed. The most common genes of CMT were PMP22 duplication, MFN2 and GJB1 mutations, which accounted for 71.3% (244/342) of the patients with genetically confirmed CMT. Hereditary motor neuropathy (HMN) accounted for 16.1% (107/666) of HPN, and 43% (46/107) of HPN was genetically confirmed. The most common genes of HMN were HSPB1, aminoacyl tRNA synthetases and SORD mutations, which accounted for 56.5% (26/46) of the patients with genetically confirmed HMN. Most genes associated with HMN could cause different phenotypes. HMN and CMT shared many genes (e.g. HSPB1, GARS, IGHMBP2). Some genes associated with dHMN-plus shared genes associated with amyotrophic lateral sclerosis (KIF5A, FIG4, DCTN1, SETX, VRK1), hereditary spastic paraplegia (KIF5A, ZFYVE26, BSCL2) and spinal muscular atrophy (MORC2, IGHMBP, DNAJB2), suggesting that HMN was a continuum rather than a distinct entity. Hereditary sensor and autosomal neuropathy (HSAN) accounted for a small proportion of 2.6% (17/666) in HPN. The most common pathogenic gene was SPTLC1 mutation. TTR was the main gene causing hereditary amyloid peripheral neuropathy. The most common types of gene mutations were p.A117S and p.V50M. The symptoms were characterized by late-onset and prominent autonomic nerve involvement. CONCLUSION: CMT and HMN are the most common diseases of HPN. There is a large overlap between HMN and motor-CMT2 pathogenic genes, and some HMN pathogenic genes overlap with amyotrophic lateral sclerosis, hereditary spastic hemiplegia and spinal muscular atrophy, suggesting that there may be a potential common pathogenic pathway between different diseases.

[Corneal confocal microscopy detects small-fiber neuropathy in patients with amyotrophic lateral sclerosis].

Objective: To investigate small fiber neuropathy in patients with amyotrophic lateral sclerosis (ALS) by corneal confocal microscopy. Methods: A total of 57 ALS patients were consecutively enrolled in Department of Neurology between June 2015 and February 2016, including 37 men and 20 women with mean age 24-80 (52±11) years. There were 30 controls including 21 men and 9 women with mean age 23-76 (55±13) years. All subjects underwent corneal confocal microscopy (CCM), contact heat evoked potential (CHEP) and skin sympathetic reflection (SSR) to quantify small nerve fiber pathology. Four parameters, such as nerve fiber length (NFL), nerve branch density (NBD), nerve fiber density (NFD) and nerve fiber tortuosity (NFT) were assessed by corneal confocal microscopy. All statistical calculations were conducted using SPSS version 12.0. Results: Compared with control group, corneal nerve fiber length (NFL),nerve fiber density (NFD) were significantly decreased [(12.2±4.4)mm/mm2 vs.(15.1±4.5) mm/mm2,P=0.028;(50.8±24.0)/mm2 vs. (68.3±16.4)/mm2,P=0.002],and nerve fiber tortuosity (NFT) were significantly increased [(2.6±1.0)level vs.(1.0±0.5)level, P<0.01)] in SFN group, while nerve branch density (NBD) were comparable (P=0.700).The course of disease is correlated with NFT (r=0.25,P=0.030). Conclusions: CCM is a new sensitive noninvasive clinical technique that detects early small fiber nerve damage in patients with ALS.

[Evaluation of vestibular-evoked myogenic potential for functional integrity of the brain stem in Kennedy's disease].

Objective: To investigate whether vestibular-evoked myogenic potentials(VEMPs) can be used to assess brainstem involvement in patients with Kennedy's disease (KD). Method: This was a case-control study.Twenty consecutive patients with genetically confirmed KD and 20 age-and sex-matched healthy subjects were enrolled from November 2018 to September 2020.All subjects were tested for three types of VEMPs, including cervical VEMP (c-VEMP) recorded by the sternocleidomastoid muscle (parameter:p13, n23), masseter VEMP (m-VEMP) recorded by the masseter muscle(parameter: p11), and ocular VEMP (o-VEMP) recorded by the inferior oblique muscle (parameter n10, p15).The latency of each wave, interside peak latency and interpeak latency of c-VEMP, the corrected amplitude and amplitude asymmetry ratio were recorded. Bilateral sternocleidomastoid muscle (SCMM) electromyography (EMG) was performed. The spinal cord and bulbous muscular atrophy functional rating scale (SBMAFRS) was used for assessment. Results: The mean p13 latency of c-VEMP was (15.5±1.4)ms, which was longer than that of the control group[(13.3±0.9)ms](P<0.05); the mean n23 latency was(25.5±1.4)ms, which was also longer than that of the control group[(22.5±1.0)ms] (P<0.05); the difference of bilateral p13[(2.3±0.6)ms] was significantly higher than that of the control group(P<0.05). The abnormal rates of c-, m-, o-VEMP in KD patients were 75%(15/20), 30%(6/20) and 20%(4/20), respectively. There was a significant positive correlation between c-VEMP latency and course of disease in KD patients(left: r=0.715, 0.695, right: r= 0.708, 0.715, both P<0.05). However, c-VEMP latency was negatively correlated with SBMAFRS score (left: r=-0.701, -0.694, right: r=-0.644, -0.685, both P<0.05). Abnormal rates of SCMM EMG in KD group were as follows: 15%(3/20)of patients showed spontaneous potential in resting state and 45% (9/20) of patients exhibited simple recruitment. Conclusions: The c-VEMP latency is a sensitive tool for detecting lower brainstem involvement in patients with KD, and the degree of damage increases with prolongation of disease course. The o-and m-VEMP abnormalities indicate that some KD patients develop upper brainstem damage.

[Association between rare UBQLN2 variants and amyotrophic lateral sclerosis in Chinese population].

Objective: To explore the association between rare UBQLN2 variants and amyotrophic lateral sclerosis (ALS) in Chinese population, and the characteristic of phenotypes of their carriers. Methods: A total of 166 ALS patients who visited Department of Neurology of Peking University Third Hospital between January 2018 and July 2020 were recruited. The next-generation sequencing was performed to screen possible pathogenic rare variants of UBQLN2. Meanwhile, control individuals were obtained from 1000 Genome Project (2 504 samples) and an in-house whole-exome sequencing database (1 812 samples), separately. The sequence kernel association test (SKAT) and the SKAT-optimal test (SKAT-O) were used to identify the association between UBQLN2 rare variants and ALS. The clinical characteristics of rare variant carriers were analyzed. Results: A total of 33 familiar ALS and 133 sporadic ALS of Chinese ancestry were enrolled. Of the 166 ALS patients, 12.7% had bulbar-onset, 85.5% had limb-onset, and 5 cases were ALS with frontotemporal dementia (3.0%). The male-to-female ratio was 1.68∶1, with a mean age at symptom onset of (43.8±12.2) years. Three possible pathogenic rare variants of UBQLN2 were detected, including c.128A>G (p.Lys43Arg), c.142G>T (p.Val48Leu) and c.1451T>G (p.Val484Gly), and all of them were novel missense mutations. Compared with 1000 Genome Project, SKAT and SKAT-O showed a P value of 2.49×10-6 and 9.22×10-7, respectively. While compared with the in-house database, SKAT and SKAT-O revealed a P value of 1.42×10-3 and 1.10×10-3, respectively. Patients who carried rare UBQLN2 variants were with a higher rate of bulbar-onset (2/3 vs 19/163, P=0.042). Conclusion: Rare variants of UBQLN2 are associated with ALS in Chinese population, and mutation of UBQLN2 may be relevant to bulbar-onset.

[Calculation of the prevalence of progressive muscular atrophy among adults in China based on urban medical insurance data from 15 provinces].

OBJECTIVE: To analyze the characteristics of patients with progressive muscular atrophy (PMA) and calculate the prevalence of PMA in China in 2016. METHODS: A retrospective analysis based on China's urban employee basic medical insurance data and the urban residence basic medical insu-rance data from January 1, 2016 to December 31, 2016 was carried out. Children under 18 years old were excluded. Patients with progressive muscular atrophy were identified by disease names and codes. Subgroup analyses by gender, region and age were carried out to calculate the gender-specific, region-specific and age-specific prevalences. Age-adjusted national prevalence was estimated based on 2010 Chinese census data. Sensitivity analyses were done by only considering the observed cases and by excluding the top 10% provinces regarding the missing rate of diagnostic information, respectively. RESULTS: A total of 996.09 million person-years were included in this study, with 518.41 million person-years in males and 477.67 million person-years in females. The age and gender distribution of the study population was similar to that of the 2010 Chinese census data, therefore the study population was nationally representative. The prevalence of PMA in China in 2016 was 0.28 per 100 000 person-years (95%CI: 0.24-0.33), with 0.21 per 100 000 person-years (95%CI: 0.16-0.26) and 0.35 per 100 000 person-years (95%CI: 0.28-0.42) for females and males, respectively. Regional disparity existed in the Chinese PMA prevalence, with the lowest prevalence in Southwest region (0.11 per 100 000 person-years, 95%CI: 0.07-0.15) and the highest prevalence in Northwest region (3.47 per 100 000 person-years, 95%CI: 0.80-7.99). Age trend in the PMA prevalence was not obvious, but the prevalence among those aged 70 years and older was relatively higher. The age-adjusted prevalence based on 2010 Chinese census data was 0.29 per 100 000 person-years (95%CI: 0.27-0.31). The national prevalences calculated by only considering the observed cases and by excluding the top 10% provinces regar-ding the missing rate of diagnostic information were 0.17 per 100 000 person-years (95%CI: 0.14-0.20) and 0.24 per 100 000 person-years (95%CI: 0.20-0.28), respectively. CONCLUSION: This study is to calculate the prevalence of PMA among adults in urban China, which can provide basic statistics for the enactment of PMA related medical policies, and clues for the studies on the mechanisms of PMA.

[The diagnostic value of tremor analysis for defining the Parkinson's disease subtype].

Objective: To find more objective evidence and support for clinical classification of Parkinson's disease by means of tremor analysis in patients with early confirmed Parkinson's disease. Methods: A cross-sectional study was conducted to collect 65 patients with early Parkinson's disease treated in the Third Hospital of Peking University from January 2015 to December 2016. Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn-Yahr scale (H-Y scale), Mini-mental state examination (MMSE), Hamilton depression scale (HAMD) were recorded in all patients. According to the ratio of UPDRS rigidity score to tremor score, the patients were divided into tremor dominant (TD), postural instability/gait difficulty (PIGD) and mixed types. All patients were examined by tremor analysis and the results were analyzed and compared. Results: Among the 65 patients, the mean age of onset was (63±10) years, the course of disease was (14±8) months. Twenty-one patients were classified to TD group, 28 patients were classified to PIGD type, and 16 patients with mixed type. There was no significant difference in frequency and amplitude of tremor between the three groups (P>0.05), but the proportion of alternating contraction and harmonic resonance of active and antagonistic muscles in TD group was significantly higher (P<0.05). Twenty patients (71.4%) in TD group showed typical Parkinson's disease manifestations in tremor analysis. Only four patients (14.3%) in PIGD group showed the typical manifestations. More patients in PIGD group showed no clear main peak of tremor at rest. Some patients showed 6-8 Hz/sec peak frequency in posture position and simultaneous contraction of the active and antagonist muscles. These two manifestations occured simultaneously in mixed type patients, including 10 cases (62.5%) with typical Parkinson's disease manifestations. Conclusion: As an objective electrophysiological method to evaluate tremor type, tremor analysis can be used as an important assistant method for clinical classification of Parkinson's disease. It can provide information of the pathway of pathological loss in different types and give important hints in prognosis and treatment.

[Diagnostic value of tremor analysis in identifying the early Parkinson's syndrome].

OBJECTIVE: To investigate the diagnostic value of tremor analysis in early stages of Parkinson's syndrome, when the clinical symptoms of tremor onset are not unilaterally often able for a definite diagnosis to be made. METHODS: We included 70 patients with unilateral tremor, under 45 years old and disease duration within 3 years enrolled in Peking University Third Hospital from January, 2014 to December 2015. We recorded clinical features, unified Parkinson's disease rating scale (UPDRS)-III, non-motor symptom (NMS) scores. Tremor analysis and transcranial sonography were performed for all the patients. Based on the results of tremor analysis, we arbitrarily divided the patients into 3 groups: (1) The patients with classical Parkinson's syndrome manifestations on one side (25 cases); (2) The patients with classical Parkinson's syndrome manifestations on both sides (15 cases); (3) The patients with no classical Parkinson's syndrome manifestations (30 cases). The patients were monitored every 6 months to 3 years, until the final diagnosis was made. RESULTS: There was no significant difference in age, gender distribution, Hamilton depression scale (HAMD) scores and H-Y scores among the three groups (P>0.05). The average UPDRS-III motor scores of the three groups were significantly different (P=0.001), with 18.23, 18.79 and 14.67, respectively. The average scores of NMS were significantly different, with 15.81, 17.07 and 9.90, respectively (P<0.001). The positive rates of transcranial sonography (TCS) in the three groups were 48.0%, 60.0% and 26.67%, with no significant difference (P=0.702). After three years of follow-up, 35 patients (50%) met the diagnostic criteria of Parkinson's disease of International Parkinson and Movement Disorder Society (MDS) in 2015, 19 patients (27.1%) met the criteria of idiopathic tremor, and 7 patients (10%) met the criteria of Parkinson's plus syndrome. The sensitivity and specificity of tremor analysis for early diagnosis of Parkinson's disease were 82.8% and 68.6%, respectively. Compared with TCS, the sensitivity and specificity of TCS were 65.7% and 62.9%. There were consistency (Kappa=0.568) and significant difference (P=0.031) between the two methods. CONCLUSION: Tremor analysis is sensitive and a superior way in identifying early Parkinson's syndrome patients with tremor dominant manifestation. The combination of non-motor symptoms and transcranial sonography are also needed at diagnosis.

[Clinical and neuroimaging features in 6 patients with corticobasal syndrome].

The clinical and imaging data in 6 patients with corticobasal syndrome were retrospectively analyzed. Six patients presented asymmetric clinical symptoms, including 5 with cognitive impairment, 6 with emotional disorders, 2 with cortical sensory deficit, 5 with lalopathy, and 4 with apraxia. All patients developed limb dystonia and limb or trunk stiffness, 4 with tumble, 4 with bradykinesia, and 2 with tremor. Brain magnetic resonance imaging (MRI) showed that 4 patients had unilateral cerebral atrophy and 2 had mild atrophy of bilateral hippocampus. Localized low glucose metabolism in the unilateral cerebral lobe was seen in four patients by positron emission computed tomography (PET) examination, suggesting that PET is helpful for the diagnosis of corticobasal syndrome.