Background::In the clinic, practitioners encounter many patients with an abnormal pattern of dense punctate magnetic resonance imaging (MRI) signal in the basal ganglia, a phenomenon known as "cheese sign". This sign is reported as common in cerebrovascular diseases, dementia, and old age. Recently, cheese sign has been speculated to consist of dense perivascular space (PVS). This study aimed to assess the lesion types of cheese sign and analyze the correlation between this sign and vascular disease risk factors.Methods::A total of 812 patients from Peking Union Medical College Hospital (PUMCH) dementia cohort were enrolled. We analyzed the relationship between cheese sign and vascular risk. For assessing cheese sign and defining its degree, the abnormal punctate signals were classified into basal ganglia hyperintensity (BGH), PVS, lacunae/infarctions and microbleeds, and counted separately. Each type of lesion was rated on a four-level scale, and then the sum was calculated; this total was defined as the cheese sign score. Fazekas and Age-Related White Matter Changes (ARWMC) scores were used to evaluate the paraventricular, deep, and subcortical gray/white matter hyperintensities.Results::A total of 118 patients (14.5%) in this dementia cohort were found to have cheese sign. Age (odds ratio [OR]: 1.090, 95% confidence interval [CI]: 1.064-1.120, P <0.001), hypertension (OR: 1.828, 95% CI: 1.123-2.983, P = 0.014), and stroke (OR: 1.901, 95% CI: 1.092-3.259, P = 0.025) were risk factors for cheese sign. There was no significant relationship between diabetes, hyperlipidemia, and cheese sign. The main components of cheese sign were BGH, PVS, and lacunae/infarction. The proportion of PVS increased with cheese sign severity. Conclusions::The risk factors for cheese sign were hypertension, age, and stroke. Cheese sign consists of BGH, PVS, and lacunae/infarction.

The ApoE gene is a genetic risk determinant for sporadic Alzheimer′s disease (AD). The ApoEε4 allele increases the risk of developing AD relative to the common ApoEε3 allele, whereas the ApoEε2 allele decreases the risk of developing the disease. The 3 alleles encode ApoE2, ApoE3, and ApoE4 protein isoforms, respectively. ApoE4 contributes to the pathogenesis of AD by regulating β-amyloid protein, tau protein, transactive response DNA-binding protein-43, neuroinflammation, and cerebral vascular function. The pathways associated with ApoE also offer new opportunities for the treatment of AD. In addition, studies have shown that ApoE4 also plays a toxic role in other neurological disorders. This article described the biological characteristics of ApoE, as well as the impact of ApoE4 on AD and related dementias, aiming to enhance clinical doctors′ understanding of the involvement of ApoE4 in the pathogenesis of AD and related dementia.

Objective:To analyze the clinical and imaging features of patients with COVID-19-related osmotic demyelination syndrome (ODS).Methods:COVID-19-related ODS cases diagnosed in the Department of Neurology, Peking Union Medical College Hospital from January 2020 to September 2023 were retrospectively reviewed. And their past medical history, possible triggers, clinical manifestations, imaging manifestations, treatment and prognosis were summarized.Results:A total of 5 patients with COVID-19-related ODS were included. Electrolyte disturbances acted as an inducement of ODS in all patients (5/5),4 of whom with hyponatremia. Four of 5 patients first presented with disturbance of consciousness, followed by predominant dystonia. Imaging of all patients (5/5) showed isolated extrapontine myelinolysis (EPM). With the prolongation of the course of disease, such signal intensity could return to normal, and lesions showed atrophic changes in some patients. The patients′ clinical symptoms were partly relieved within a few days to a few months after treatment.Conclusions:COVID-19-related ODS is mostly associated with hyponatremia, and EPM is more common. COVID-19 should be considered as a risk factor for ODS.

Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.

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.

Paraneoplastic neurological syndromes (PNS) are heterogeneous disorders caused by autoimmune responses of cancer, which can affect any part of the nervous system. Anti-amphiphysin antibody is one of the high-risk PNS antibodies, which is usually associated with small cell lung cancer and breast cancer. However, extrapulmonary neuroendocrine carcinoma is rare in patients with anti-amphiphysin antibody. A case of anti-amphiphysin-associated paraneoplastic brainstem encephalitis with esophageal neuroendocrine carcinoma is reported. The tumor was detected by fluorine 18 fluorodeoxyglucose positron emission tomography and pathologically confirmed by gastroscopic biopsy. The patient′s neurological symptoms were partially improved after treatment of intravenous immunoglobulin and glucocorticoids. However, the disease prognosis is closely related to the accompanying tumor.

Objective: To evaluate the value of cerebrospinal fluid markers expecially total-tau protein (T-tau), phosphorylated-tau protein (P-tau) in diagnosis and differentiation of sporadic Creutzfeldt-Jakob disease (sCJD). Methods: sCJD (according to 2009 Brain criteria, 2018 Neurology amended criteria), Alzheimer's disease (AD; the National Institute on Aging at National Institutes of Health and the Alzheimer's Association revised guidelines 2011 criteria) and other patients without cognitive impairment, matched for sex and age, in the Department of Neurology, Peking Union Medical College Hospital from 2018 to 2019 were enrolled. Twelve sCJD patients, 49 AD patients and 14 normal controls were enrolled. Cerebrospinal fluid (CSF) specimens were collected through gravity dropping directly, and further stored in -80 ℃ and disposed according to widely used standards. The levels of T-tau and P-tau were measured by ELISA. The data on electroencephalogram and neuroimaging findings of sCJD patients were recorded. Moreover, specimens of sCJD patients were sent to the Chinese Center for Disease Control and Prevention to test 14-3-3 protein and PRNP genotype. Results: Using Mann-Whitney U test, T-tau concentrations were found higher in patients with sCJD (1 211(448, 2 227) pg/ml) than in AD patients (549(314, 1 078) pg/ml; U=178, P=0.034 9), and both groups had higher T-tau than the control group (127(79, 192) pg/ml; U=20, 73, P<0.01). The level of P-tau was significantly increased in AD patients (72(58,109) pg/ml) compared to the control group (27(15, 42) pg/ml; U=82, P<0.01), but not in sCJD patients (32(24, 47) pg/ml). The T-tau/P-tau ratio was higher in sCJD patients (29.77(20.01, 54.53)) than in AD patients (7.45(4.79, 10.43); U=87, P<0.01). Twelve sCJD patients had cotical hyperintensity on diffusion weighted imaging and five had periodic three-phase waves on electroencephalogram. Nine sCJD patients, whose CSF samples were tested in the Chinese Center for Disease Control and Prevention, carried an M/M genotype at codon 129 and E/E at codon 219. Conclusion The CSF tau level and T-tau/P-tau ratio are significantly increased in sCJD, which may promote the diagnosis and differentiation of sCJD in routine clinical setting.

The National Institute on Aging-Alzheimer's Association (NIA-AA) research framework of biological definition of Alzheimer's disease 2018 is introduced to Chinese counterparts to share a common "language" with dementia researchers.The abnormal definitions of Alzheimer's disease (AD),βamyloid deposition (Aβ) and tau,were proposed to be detected by biological methods,and a series of changes before dementia and dementia were proposed to be studied under a unified biological framework.The characteristic biomarkers were defined as AT(N):A is [β amyloid deposition,T is pathological tau protein,and (N) is neurodegeneration.The diversity of the pathological nature of dementia was emphasized,and AD combined with dementia was proposed not to be directly attributable to dementia due to AD.The definition of biomarkers requires more standardization and confirmation of autopsy pathology.

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disease characterized by localized neuronal loss,and the presence of eosinophilic intranuclear inclusions in neurons and glial cells.Biopsy samples of skin,rectal and sural nerve showed hyaline intranuclear inclusions.Reported NIID cases showed familial type according to family history,and three clinical subgroups (infantile,juvenile and adult form) according to onset and disease duration.NIID has been considered as a heterogeneous disease because of the highly variable clinical manifestations including cognitive dysfunction,parkinsonism,cerebellar ataxia,peripheral neuropathy and autonomic dysfunction.Additionally,some NIID cases presented episodes of conscious disturbance,cognitive decline,movement disorder or even fever.Head magnetic resonance imaging of some patients revealed symmetrical leukoencephalopathy in T2 image and fluid attenuated inversion recovery image and high intensity signal in corticomedullary junction in diffusion weighted image.But it is not the only abnormal finding of imaging,and other diseases may also present the similar changing.Other diseases including fragile X-associated tremor-ataxia syndrome,Huntington's disease and spinocerebellar ataxia should be considered in differential diagnosis.

Objective To analyze the clinical and histology characteristics of a patient with frontal lobe epilepsy diagnosed with mild malformation of cortical development with oligodendroglial hyperplasia, and to recognize the new neuropathological entity. Methods Clinical history, seizure types, neuroimaging, electroencephalography as well as macroscope, histology and immunohistochemistry characteristics were collected from a frontal lobe epilepsy patient and were compared with cases from literature. Results It was a female patient aged 16 years with 12 years history of epilepsy. The seizures manifested as episodes of conscious loss with automatism including grope and voice lasting for seconds. About 10 episodes a day were found and sometimes with secondary generalized tonic-clonic seizures. MRI showed blurring of grey-white matter interface in left orbital frontal cortex. Video-encephalography revealed left frontal lobe origin of seizures. So left prefrontal lobe was removed. Histology showed almost normal cortex neuropil and neurons. Blurring of grey-white interface in some area with patches of proliferation of oligodendrocytes in the corresponding sub-cortical white matter was found. The density of oligodendrocytes was significantly higher in sub-cortical than in deep white matter both shown in HE and Oligo-2 staining. Obvious oligodendrocytes increase and satellite phenomenon in deep cortical layer as well as increased ectopic neurons in sub-cortical white matter were found in the lesion. In proliferation area, there were some nuclei stained with Ki-67, but not as high as tumor. Subsequent follow up for two years proved the operation efficacy and benign prognosis. Conclusions There are special and undiscovered histopathological entities in epilepsy etiology. Although known as grey matter disease, white matter pathology plays an important role in epilepsy pathophysiology which needs further research.