Peng Guo

Nonmotor symptoms in patients with Parkinson disease: A cross-sectional observational study.

AbstractParkinson disease (PD) is usually accompanied by numerous nonmotor symptoms (NMS), such as neuropsychiatric symptoms, sleep disorders, autonomic dysfunctions, and sensory disturbances. However, it is not clear that the factors influencing the occurrence of NMS and its sequence with motor symptoms (MS).We conducted comprehensive assessments of NMS by using 13 scales in 1119 PD patients.A total of 70.8% PD patients present NMS. Olfactory dysfunction tends to occur in PD patients with older age, more severe depression, sleep problems, and autonomic dysfunctions. Older patients are more likely to have olfactory dysfunction before MS than younger patients. Rapid eye movement behavior disorder is more prone to happen in patients with older age, older onset age, more severe depression, sleep problems, and autonomic dysfunctions. Patients with rapid eye movement behavior disorder before MS are older in onset age than after group.Olfactory dysfunction, constipation, rapid eye movement behavior disorder, and depression, as early warning NMSs of PD, connected to each other. There is a clinical heterogeneity that older patients are more likely to have NMS before MS, while younger patients are opposite.

Serotonergic dysfunctions and abnormal iron metabolism: Relevant to mental fatigue of Parkinson disease

Fatigue is a very common non-motor symptom in Parkinson disease (PD) patients. It included physical fatigue and mental fatigue. The potential mechanisms of mental fatigue involving serotonergic dysfunction and abnormal iron metabolism are still unknown. Therefore, we evaluated the fatigue symptoms, classified PD patients into fatigue group and non-fatigue group, and detected the levels of serotonin, iron and related proteins in CSF and serum. In CSF, 5-HT level is significantly decreased and the levels of iron and transferrin are dramatically increased in fatigue group. In fatigue group, mental fatigue score is negatively correlated with 5-HT level in CSF, and positively correlated with the scores of depression and excessive daytime sleepiness, and disease duration, also, mental fatigue is positively correlated with the levels of iron and transferrin in CSF. Transferrin level is negatively correlated with 5-HT level in CSF. In serum, the levels of 5-HT and transferrin are markedly decreased in fatigue group; mental fatigue score exhibits a negative correlation with 5-HT level. Thus serotonin dysfunction in both central and peripheral systems may be correlated with mental fatigue through abnormal iron metabolism. Depression, excessive daytime sleepiness and disease duration were the risk factors for mental fatigue of PD.

Restless legs syndrome in Parkinson disease: Clinical characteristics, abnormal iron metabolism and altered neurotransmitters

Relationships among clinical characteristics, iron metabolism and neurotransmitters in Parkinson disease (PD) patients with restless legs syndrome (RLS) remains unclear. We divided 218 patients into PD with and with no RLS (PD-RLS and PD-NRLS) groups by RLS-rating scale (RLS-RS) score. Motor and non-motor symptoms were rated by related scales. Iron and related proteins, and neurotransmitters in cerebrospinal fluid (CSF) and serum were measured. PD-RLS frequency was 40.37%. PD-RLS group had longer duration, higher stage and scores of motor symptoms, depression, anxiety, sleep disorders, fatigue and apathy, and increased transferrin and decreased iron, ferritin, dopamine (DA) and 5-hydroxytryptamine (5-HT) in CSF. In CSF of PD-RLS group, RLS-RS score was positively correlated with transferrin level and negatively correlated with iron and ferritin levels; RLS-RS score was negatively correlated with DA and 5-HT levels; transferrin level was negatively correlated with DA and 5-HT levels, and ferritin level was positively correlated with DA level. In serum, PD-RLS group had decreased iron and transferrin levels, which were negatively correlated with RLS-RS score. PD-RLS was common and severer in motor and some non-motor symptoms. Iron deficiency induced by its metabolism dysfunctions in peripheral and central systems might cause PD-RLS through decreasing brain DA and 5-HT.

Minimally Toxic Dose of Lipopolysaccharide and α-Synuclein Oligomer Elicit Synergistic Dopaminergic Neurodegeneration: Role and Mechanism of Microglial NOX2 Activation

The aim of this study is to investigate the role and mechanism of microglial NOX2 activation in minimally toxic dose of LPS and Syn-elicited synergistic dopaminergic neurodegeneration. NOX2+/+ and NOX2−/− mice and multiple primary cultures were treated with LPS and/or Syn in vivo and in vitro. Neuronal function and morphology were evaluated by uptake of related neurotransmitter and immunostaining with specific antibody. Levels of superoxide, intracellular reactive oxygen species, mRNA and protein of relevant molecules, and dopamine were detected. LPS and Syn synergistically induce selective and progressive dopaminergic neurodegeneration. Microglia are functionally and morphologically activated, contributing to synergistic dopaminergic neurotoxicity elicited by LPS and Syn. NOX2−/− mice are more resistant to synergistic neurotoxicity than NOX2+/+mice in vivo and in vitro, and NOX2 inhibitor protects against synergistic neurotoxicity through decreasing microglial superoxide production, illustrating a critical role of microglial NOX2. Microglial NOX2 is activated by LPS and Syn as mRNA and protein levels of NOX2 subunits P47and gp91 are enhanced. Molecules relevant to microglial NOX2 activation include PKC-σ, P38, ERK1/2, JNK, and NF-КBP50 as their mRNA and protein levels are elevated after treatment with LPS and Syn. Combination of exogenous and endogenous environmental factors with minimally toxic dose synergistically propagates dopaminergic neurodegeneration through activating microglial NOX2 and relevant signaling molecules, casting a new light for PD pathogenesis.

Phenotype of postural instability/gait difficulty in Parkinson disease: relevance to cognitive impairment and mechanism relating pathological proteins and neurotransmitters

Parkinson disease (PD) is identified as tremor-dominant (TD) and postural instability and gait difficulty (PIGD) phenotypes. The relationships between motor phenotypes and cognitive impairment and the underlying mechanisms relating pathological proteins and neurotransmitters in cerebrospinal fluid (CSF) are unknown. We evaluated the motor symptoms and cognitive function by scales, and detected the levels of pathological proteins and neurotransmitters in CSF. TD group and PIGD group had significantly higher levels of total tau, tau phosphorylated at the position of threonine 181(P-tau181t), threonine 231, serine 396, serine 199 and lower β amyloid (Aβ)1–42 level in CSF than those in control group; PIGD group had significantly higher P-tau181t level and lower Aβ1–42 level than those in TD group. In PD group, PIGD severity was negatively correlated with MoCA score and Aβ1–42 level in CSF, and positively correlated with Hoehn-Yahr stage and P-tau181t level in CSF. In PIGD group, PIGD severity was negatively correlated with homovanillic acid (HVA) level in CSF, and HVA level was positively correlated with Aβ1–42 level in CSF. PIGD was significantly correlated with cognitive impairment, which underlying mechanism might be involved in Aβ1–42 aggregation in brain and relevant neurochemical disturbance featured by the depletion of HVA in CSF.

Iron deposition in substantia nigra: abnormal iron metabolism, neuroinflammatory mechanism and clinical relevance

Parkinson disease (PD) is associated with multiple factors, including iron, which is demonstrated to deposit excessively in PD brains. We detected iron deposition by susceptibility weighted image (SWI) and measured the levels of iron metabolism-related proteins and inflammatory factors in cerebrospinal fluid (CSF) and serum of PD patients and control subjects. Clinical symptoms of PD were evaluated by series of rating scales. Relationships among above factors were analyzed. Results showed that corrected phase (CP) value of substantia nigra (SN) was significantly decreased in PD group compared to control group, hence, SN was the main region with excessive iron deposition. In PD group, ferritin was significantly elevated in CSF and reduced in serum compared to control group, and levels of ferritin in CSF and serum were both significantly and positively correlated with CP value of SN, thus, abnormal iron metabolism in central and peripheral systems was associated with iron deposition. CP value of SN in PD group was significantly and negatively correlated with interleukin-1β level in CSF, so interleukin-1β might be a neuroinflammatory factor produced by excessive iron in SN. Iron deposition in SN was significantly correlated with motor symptoms and part of non-motor symptoms of PD.

Parkinson disease with constipation: clinical features and relevant factors

Constipation is one of the most frequent non-motor symptoms of Parkinson disease (PD) and it may be ignored by PD patients, leading to this problem not to be reported in time. The relationships between constipation and demographic variables, motor symptoms and other non-motor symptoms of PD are still unknown. PD patients were evaluated by diagnostic criteria of functional constipation in Rome III and divided into PD with constipation (PD-C) and PD with no constipation (PD-NC) groups. PD patients were assessed by rating scales of motor symptoms and other non-motor symptoms, activity of daily living and quality of life. The frequency of constipation in PD patients was 61.4%, and 24.5% of PD patients had constipation before the onset of motor symptoms. PD-C group had older age and age of onset, longer disease duration, more advanced disease stage, and more severe motor symptoms and non-motor symptoms, including worse cognition and emotion, poorer sleep quality, severer autonomic symptoms, fatigue and apathy. Binary Logistic regression analysis showed that the age, H-Y stage, depression, anxiety and autonomic dysfunction increased the risk of constipation in PD patients. Constipation exerted serious impact on the activity of daily living and quality of life in PD patients.

Clinical features and dysfunctions of iron metabolism in Parkinson disease patients with hyper echogenicity in substantia nigra: a cross-sectional study

BackgroundTranscranial ultrasound is a useful tool for providing the evidences for the early diagnosis and differential diagnosis of Parkinson disease (PD). However, the relationship between hyper echogenicity in substantia nigra (SN) and clinical symptoms of PD patients remains unknown, and the role of dysfunction of iron metabolism on the pathogenesis of SN hyper echogenicity is unclear.MethodsPD patients was detected by transcranial sonography and divided into with no hyper echogenicity (PDSN-) group and with hyper echogenicity (PDSN+) group. Motor symptoms (MS) and non-motor symptoms (NMS) were evaluated, and the levels of iron and related proteins in serum and cerebrospinal fluid (CSF) were detected for PD patients. Data comparison between the two groups and correlation analyses were performed.ResultsPDSN+ group was significantly older, and had significantly older age of onset, more advanced Hohen-Yahr stage, higher SCOPA-AUT score and lower MoCA score than PDSN- group (P < 0.05). Compared with PDSN- group, the levels of transferrin and light-ferritin in serum and iron level in CSF were significantly elevated (P < 0.05), but ferroportin level in CSF was significantly decreased in PDSN+ group (P < 0.05).ConclusionsPD patients with hyper echogenicity in SN are older, at more advanced disease stage, have severer motor symptoms, and non-motor symptoms of cognitive impairment and autonomic dysfunction. Hyper echogenicity of SN in PD patients is related to dysfunction of iron metabolism, involving increased iron transport from peripheral system to central nervous system, reduction of intracellular iron release and excessive iron deposition in brain.

THE CLINICAL FEATURES AND OLFACTORY DYSFUNCTION OF ALZHEIMER DISEASE WITH APATHY

patients’ neuropsychological data in relationship to amyloid status. Methods: Patients with atypical mild cognitive impairment (MCI) or dementia diagnosis completed neuropsychological evaluation and amyloid-PET imaging, either through IDEAS (n1⁄444) or independently of this trial (n1⁄44). Demographic variables, cognitive screening results, neuropsychological data, and preand post-PET diagnoses were manually extracted from the electronic medical record (EMR). Neuropsychological data was characterized by two neuropsychologists with subspecialty training in neurodegenerative disease. Amyloid status was determined by consensus between a radiologist and behavioral neurologist. Results: A total of 48 patients (mean age 71.168.2, 53.3% female) completed amyloid PET imaging with an average MOCA score of 19.66 6.3. Neuropsychological testing yielded an amnestic memory profile in 39.6% of subjects. However, 58.3% of individuals enrolled in the study were found to be amyloid positive. Notably, non-amnestic memory profiles were observed in 33.3% of amyloid positive subjects ultimately diagnosed with AD and in 71.4% of amyloid positive individuals who received a diagnosis of MCI due to AD. Amyloid positive subjects diagnosed with an atypical presentation of AD (posterior cortical atrophy, progressive primary aphasia, or corticobasal degeneration), displayed non-amnestic memory profiles in 33.3% of cases. Conclusions: Findings suggest a significant percentage of amyloid positive patients do not show the hallmark signs of an amnestic memory disturbance traditionally associated with AD. Amyloid imaging has the potential to contribute to the differential diagnosis of neurodegenerative disease.

ANALYSES OF CLINICAL FEATURES AND INVESTIGATIONS ON POTENTIAL MECHANISMS IN PATIENTS WITH ALZHEIMER’S DISEASE AND OLFACTORY DYSFUNCTION

Ang elica Zuno Reyes, Mellissa Withers, Esmeralda Matute, Lourdes Ram ırez Due~nas, Lucy Montoya, John M. Ringman, Instituto de Neurociencias, Centro Universitario de Ciencias Biol ogicas y Agropecuarias, Universidad de Guadalajara, Guadalajara, Mexico; University of Southern California, Keck School of Medicine, Institute for Global Health, Los Angeles, CA, USA; Keck School of Medicine of USC, Los Angeles, CA, USA. Contact e-mail: angelicazunor@gmail.com