Functional correlation between cerebellum and basal ganglia: A parkinsonism model.

INTRODUCTION: The cerebellar response has been studied for years with different models of alteration of other brain structures to understand its complex functioning and its relationship with the rest of the body. Studies in patients with Parkinson's disease (PD) showed that the cerebellar function is modified by deficit of the basal ganglia; which supports the hypothesis that both structures are related anatomically and functionally. METHODS: In our study, the ventrolateral striatum (VLS) of the basal ganglia was altered by an electrolytic lesion, in order to produce a similar jaw frequency of jaw tremor movements presented in parkinsonism, thereafter we analyzed the effect of the lesion on the expression of multiunit activity (MUA) of the cerebellum. RESULTS: We found cerebellar activation during mandibular movements and increment during oral jaw tremor movements. In addition, the amplitude of baseline MUA registered in animals with alteration of the VLS decreased with respect to the intact group. CONCLUSIONS: Accordingly, we conclude that cerebellar changes in MUA may be due to a decrease in the cerebellar inflectional or as a possible compensatory function between cerebellum and basal ganglia.

Neuroprotective Effects Exerted by a Combination of Selected Lactic Acid Bacteria in a Mouse Parkinsonism Model under Levodopa-Benserazide Treatment.

Alterations of the microbiota-gut-brain axis has been associated with intestinal and neuronal inflammation in Parkinson's disease (PD). The aim of this work was to study some mechanisms associated with the neuroprotective effect of a combination (MIX) of lactic acid bacteria (LAB) composed by Lactiplantibacillus plantarum CRL2130 (riboflavin overproducing strain), Streptococcus thermophilus CRL808 (folate producer strain), and CRL807 (immunomodulatory strain) in cell cultures and in a chronic model of parkinsonism induced with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in aged mice, and under levodopa-benserazide treatment. In vitro, N2a differentiated neurons were exposed to the neurotoxin 1-methyl-4-phenylpyridinium (MPP+) and treated with intracellular bacterial extracts or with conditioned media from BV-2 cells exposed to the bacterial extracts. In vivo, motor skills, tyrosine hydrolase (TH) in brain and cytokine concentrations in serum and in brain were evaluated. The study of the faecal microbiota and the histology of the small intestine was also performed. The results showed that the neuroprotective effect associated with LAB MIX administration did not interfere with levodopa-benserazide treatment. This effect could be associated with the antioxidant and immunomodulatory potential of the LAB selected in the MIX, and was associated with the significant improvement in the motor tests and a higher number of TH + cells in the brain. In addition, LAB MIX administration was associated with modulation of the immune response. LAB administration decreased intestinal damage with an increase in the villus length /crypt depth ratio. Finally, the administration of the LAB MIX in combination with levodopa-benserazide treatment was able to partially revert the intestinal dysbiosis observed in the model, showing greater similarity to the profiles of healthy controls, and highlighting the increase in the Lactobacillaceae family. Different mechanisms of action would be related to the protective effect of the selected LAB combination which has the potential to be evaluated as an adjuvant for conventional PD therapies.

Nucleus of the solitary tract neuronal degeneration and impaired hypoxia response in a model of Parkinson's disease.

Parkinson's disease (PD) involves the degeneration of dopaminergic neurons in the substantia nigra (SNpc) and manifests with both classic and non-classic motor symptoms, including respiratory failure. Our study aims to investigate the involvement of the commissural and intermediate nucleus of the solitary tract (cNTS and iNTS) in the attenuated respiratory response to hypoxia in PD. Using a PD rat model induced by bilateral injection of 6-hydroxydopamine (6-OHDA) into the striatum of male Wistar rats, we explored potential alterations in the population of Phox2b neurons or hypoxia-activated neurons in the NTS projecting to the retrotrapezoid nucleus (RTN). Additionally, we explored neuronal connectivity between SNpc and cNTS. Projections pathways were assessed using unilateral injection of the retrograde tracer Fluorogold (FG) in the cNTS and RTN. Neuronal activation was evaluated by analyzing fos expression in rats exposed to hypoxia. In the PD model, the ventilatory response, measured through whole-body plethysmography, was impaired at both baseline and in response to hypoxia. A reduction in Phox2b-expressing neurons or hypoxia-activated neurons projecting to the RTN was observed. Additionally, we identified an indirect pathway linking the SNpc and cNTS, which passes through the periaqueductal gray (PAG). In conclusion, our findings suggest impairment in the SNpc-PAG-cNTS pathway in the PD model, explaining the loss of Phox2b-expressing neurons or hypoxia-activated neurons in the cNTS and subsequent respiratory impairment during hypoxic stimulation. We propose that the reduced population of Phox2b-expressing neurons in the NTS may include the same neurons activated by hypoxia and projecting to the RTN.

Speech's syllabic rhythm and articulatory features produced under different auditory feedback conditions identify Parkinsonism.

Diagnostic tests for Parkinsonism based on speech samples have shown promising results. Although abnormal auditory feedback integration during speech production and impaired rhythmic organization of speech are known in Parkinsonism, these aspects have not been incorporated into diagnostic tests. This study aimed to identify Parkinsonism using a novel speech behavioral test that involved rhythmically repeating syllables under different auditory feedback conditions. The study included 30 individuals with Parkinson's disease (PD) and 30 healthy subjects. Participants were asked to rhythmically repeat the PA-TA-KA syllable sequence, both whispering and speaking aloud under various listening conditions. The results showed that individuals with PD had difficulties in whispering and articulating under altered auditory feedback conditions, exhibited delayed speech onset, and demonstrated inconsistent rhythmic structure across trials compared to controls. These parameters were then fed into a supervised machine-learning algorithm to differentiate between the two groups. The algorithm achieved an accuracy of 85.4%, a sensitivity of 86.5%, and a specificity of 84.3%. This pilot study highlights the potential of the proposed behavioral paradigm as an objective and accessible (both in cost and time) test for identifying individuals with Parkinson's disease.

Cannabidiol improves non-motor symptoms, attenuates neuroinflammation, and favours hippocampal newborn neuronal maturation in a rat model of Parkinsonism.

OBJECTIVE: To investigate the effects of cannabidiol (CBD) on emotional and cognitive symptoms in rats with intra-nigral 6-hydroxydopamine (6-OHDA) lesions. METHODS: Adult male Wistar rats received bilateral intranigral 6-OHDA infusions and were tested in a battery of behavioural paradigms to evaluate non-motor symptoms. The brains were obtained to evaluate the effects of CBD on hippocampal neurogenesis. RESULTS: 6-OHDA-lesioned rats exhibited memory impairments and despair-like behaviour in the novelty-suppressed feeding test and forced swim test, respectively. The animals also exhibited dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc), striatum, and ventral tegmental area and a reduction of hippocampal neurogenesis. CBD decreased dopaminergic neuronal loss in the SNpc, reduced the mortality rate and decreased neuroinflammation in 6-OHDA-lesioned rats. In parallel, CBD prevented memory impairments and attenuated despair-like behaviour that were induced by bilateral intranigral 6-OHDA lesions. Repeated treatment with CBD favoured the neuronal maturation of newborn neurons in the hippocampus in Parkinsonian rats. CONCLUSION: The present findings suggest a potential beneficial effect of CBD on non-motor symptoms induced by intra-nigral 6-OHDA infusion in rats.

Effects of quercetin in preclinical models of Parkinson's disease: A systematic review.

Parkinson's disease (PD) is a neurodegenerative disease that affects dopaminergic neurons, thus impairing dopaminergic signalling. Quercetin (QUE) has antioxidant and neuroprotective properties that are promising for the treatment of PD. This systematic review aimed to investigate the therapeutic effects of QUE against PD in preclinical models. The systematic search was performed in PubMed, Scopus and Web of Science. At the final screening stage, 26 articles were selected according to pre-established criteria. Selected studies used different methods for PD induction, as well as animal models. Most studies used rats (73.08%) and mice (23.08%), with 6-OHDA as the main strategy for PD induction (38.6%), followed by rotenone (30.8%). QUE was tested immersed in oil, nanosystems or in free formulations, in varied routes of administration and doses, ranging from 10 to 400 mg/kg and from 5 to 200 mg/kg in oral and intraperitoneal administrations, respectively. Overall, evidence from published data suggests a potential use of QUE as a treatment for PD, mainly through the inhibition of oxidative stress, neuroinflammatory response and apoptotic pathways.

Sleep deprivation induces late deleterious effects in a pharmacological model of Parkinsonism.

Parkinson's disease is a degenerative, chronic and progressive disease, characterized by motor dysfunctions. Patients also exhibit non-motor symptoms, such as affective and sleep disorders. Sleep disorders can potentiate clinical and neuropathological features and lead to worse prognosis. The goal of this study was to evaluate the effects of sleep deprivation (SD) in mice submitted to a progressive pharmacological model of Parkinsonism (chronic administration with a low dose of reserpine). Male Swiss mice received 20 injections of reserpine (0.1 mg/kg) or vehicle, on alternate days. SD was applied before or during reserpine treatment and was performed by gentle handling for 6 h per day for 10 consecutive days. Animals were submitted to motor and non-motor behavioral assessments and neurochemical evaluations. Locomotion was increased by SD and decreased by reserpine treatment. SD during treatment delayed the onset of catalepsy, but SD prior to treatment potentiated reserpine-induced catalepsy. Thus, although SD induced an apparent beneficial effect on motor parameters, a delayed deleterious effect on alterations induced by reserpine was found. In the object recognition test, both SD and reserpine treatment produced cognitive deficits. In addition, the association between SD and reserpine induced anhedonic-like behavior. Finally, an increase in oxidative stress was found in hippocampus of mice subjected to SD, and tyrosine hydroxylase immunoreactivity was reduced in substantia nigra of reserpine-treated animals. Results point to a possible late effect of SD, aggravating the deficits in mice submitted to the reserpine progressive model of PD.

X-Linked Levodopa-Responsive Parkinsonism-Epilepsy Syndrome: A Novel PGK1 Mutation and Literature Review.

BACKGROUND: Genetic underpinnings in Parkinson's disease (PD) and parkinsonian syndromes are challenging, and recent discoveries regarding their genetic pathways have led to potential gene-specific treatment trials. CASES: We report 3 X-linked levodopa (l-dopa)-responsive parkinsonism-epilepsy syndrome cases due to a hemizygous variant in the phosphoglycerate kinase 1 (PGK1) gene. The likely pathogenic variant NM_000291.4 (PGK1):c.950G > A;p.(Gly317Asp) was identified in a hemizygous state. LITERATURE REVIEW: Only 8 previous cases have linked this phenotype to PGK1, a gene more commonly associated with hemolytic anemia and myopathy. The unusual association of epilepsy, psychiatric symptoms, action tremor, limb dystonia, cognitive symptoms, and l-dopa-responsive parkinsonism must draw attention to PGK1 mutations, especially because this gene is absent from most commercial hereditary parkinsonism panels. CONCLUSIONS: This report aims to shed light on an overlooked gene that causes hereditary parkinsonian syndromes. Further research regarding genetic pathways in PD may provide a better understanding of its pathophysiology and open possibilities for new disease-modifying trials, such as SNCA, LRRK2, PRKN, PINK1, and DJ-1 genes.

Identification of metabolic pathways and key genes associated with atypical parkinsonism using a systems biology approach.

Atypical parkinsonism (AP) is a group of complex neurodegenerative disorders with marked clinical and pathophysiological heterogeneity. The use of systems biology tools may contribute to the characterization of hub-bottleneck genes, and the identification of its biological pathways to broaden the understanding of the bases of these disorders. A systematic search was performed on the DisGeNET database, which integrates data from expert curated repositories, GWAS catalogues, animal models and the scientific literature. The tools STRING 11.0 and Cytoscape 3.8.2 were used for analysis of protein-protein interaction (PPI) network. The PPI network topography analyses were performed using the CytoHubba 0.1 plugin for Cytoscape. The hub and bottleneck genes were inserted into 4 different sets on the InteractiveVenn. Additional functional enrichment analyses were performed to identify Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and gene ontology for a described set of genes. The systematic search in the DisGeNET database identified 485 genes involved with Atypical Parkinsonism. Superimposing these genes, we detected a total of 31 hub-bottleneck genes. Moreover, our functional enrichment analyses demonstrated the involvement of these hub-bottleneck genes in 3 major KEGG pathways. We identified 31 highly interconnected hub-bottleneck genes through a systems biology approach, which may play a key role in the pathogenesis of atypical parkinsonism. The functional enrichment analyses showed that these genes are involved in several biological processes and pathways, such as the glial cell development, glial cell activation and cognition, pathways were related to Alzheimer disease and Parkinson disease. As a hypothesis, we highlight as possible key genes for AP the MAPT (microtubule associated protein tau), APOE (apolipoprotein E), SNCA (synuclein alpha) and APP (amyloid beta precursor protein) genes.

Frequency of Hereditary and GBA1-Related Parkinsonism in Latin America: A Systematic Review and Meta-Analysis.

BACKGROUND: Identifying hereditary parkinsonism is valuable for diagnosis, genetic counseling, patient prioritization in trials, and studying the disease for personalized therapies. However, most studies were conducted in Europeans, and limited data exist on admixed populations like those from Latin America. OBJECTIVES: This study aims to assess the frequency and distribution of genetic parkinsonism in Latin America. METHODS: We conducted a systematic review and meta-analysis of the frequency of parkinsonian syndromes associated with genetic pathogenic variants in Latin America. We defined hereditary parkinsonism as those caused by the genes outlined by the MDS Nomenclature of Genetic Movement Disorders and heterozygous carriers of GBA1 pathogenic variants. A systematic search was conducted in PubMed, Web of Science, Embase, and LILACS in August 2022. Researchers reviewed titles and abstracts, and disagreements were resolved by a third researcher. After this screening, five researchers reanalyzed the selection criteria and extracted information based on the full paper. The frequency for each parkinsonism-related gene was determined by the presence of pathogenic/likely pathogenic variants among screened patients. Cochran's Q and I2 tests were used to quantify heterogeneity. Meta-regression, publication bias tests, and sensitivity analysis regarding study quality were also used for LRRK2-, PRKN-, and GBA1-related papers. RESULTS: We included 73 studies involving 3014 screened studies from 16 countries. Among 7668 Latin American patients, pathogenic variants were found in 19 different genes. The frequency of the pathogenic variants in LRRK2 was 1.38% (95% confidence interval [CI]: 0.52-2.57), PRKN was 1.16% (95% CI: 0.08-3.05), and GBA1 was 4.17% (95% CI: 2.57-6.08). For all meta-analysis, heterogeneity was high and publication bias tests were negative, except for PRKN, which was contradictory. Information on the number of pathogenic variants in the other genes is further presented in the text. CONCLUSIONS: This study provides insights into hereditary and GBA1-related parkinsonism in Latin America. Lower GBA1 frequencies compared to European/North American cohorts may result from limited access to gene sequencing. Further research is vital for regional prevalence understanding, enabling personalized care and therapies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Neurological gait assessment.

Gait disorders are a common feature of neurological disease. The gait examination is an essential part of the neurological clinical assessment, providing valuable clues to a myriad of causes. Understanding how to examine gait is not only essential for neurological diagnosis but also for treatment and prognosis. Here, we review aspects of the clinical history and examination of neurological gait to help guide gait disorder assessment. We focus particularly on how to differentiate between common gait abnormalities and highlight the characteristic features of the more prevalent neurological gait patterns such as ataxia, waddling, steppage, spastic gait, Parkinson's disease and functional gait disorders. We also offer diagnostic clues for some unusual gait presentations, such as dystonic, stiff-person and choreiform gait, along with red flags that help differentiate atypical parkinsonism from Parkinson's disease.

Oral Administration of Lactobacillus Inhibits the Permeability of Blood-Brain and Gut Barriers in a Parkinsonism Model.

It has recently been shown that the administration of probiotics can modulate the microbiota-gut-brain axis and may have favorable effects in models of Parkinson's disease. In this study, we used a hemiparkinsonism model induced by the neurotoxin 6-OHDA to evaluate the efficacy of the administration of a four-week administration of a mixture containing the microorganisms Lactobacillus fermentum LH01, Lactobacillus reuteri LH03, and Lactobacillus plantarum LH05. The hemiparkinsonism model induced an increase in rotations in the apomorphine test, along with a decrease in the latency time to fall in the rotarod test on days 14 and 21 after surgery, respectively. The administration of probiotics was sufficient to improve this condition. The model also showed a decrease in tyrosine hydroxylase immunoreactivity in the striatum and the number of labeled cells in the substantia nigra, both of which were counteracted by the administration of probiotics. The permeability of the blood-brain barrier was increased in the model, but this effect was reversed by the probiotics for both brain regions. The gut barrier was permeated with the model, and this effect was reversed and dropped to lower levels than the control group after the administration of probiotics. Finally, lipid peroxidation showed a pattern of differences similar to that of permeabilities. The inhibition of the permeability of the blood-brain and gut barriers mediated by the administration of probiotics will likely provide protection by downregulating oxidative stress, thus affecting the rotarod test performance.

Movement disorders in hereditary spastic paraplegias.

BACKGROUND: Hereditary or familial spastic paraplegias (SPG) comprise a group of genetically and phenotypically heterogeneous diseases characterized by progressive degeneration of the corticospinal tracts. The complicated forms evolve with other various neurological signs and symptoms, including movement disorders and ataxia. OBJECTIVE: To summarize the clinical descriptions of SPG that manifest with movement disorders or ataxias to assist the clinician in the task of diagnosing these diseases. METHODS: We conducted a narrative review of the literature, including case reports, case series, review articles and observational studies published in English until December 2022. RESULTS: Juvenile or early-onset parkinsonism with variable levodopa-responsiveness have been reported, mainly in SPG7 and SPG11. Dystonia can be observed in patients with SPG7, SPG11, SPG22, SPG26, SPG35, SPG48, SPG49, SPG58, SPG64 and SPG76. Tremor is not a frequent finding in patients with SPG, but it is described in different types of SPG, including SPG7, SPG9, SPG11, SPG15, and SPG76. Myoclonus is rarely described in SPG, affecting patients with SPG4, SPG7, SPG35, SPG48, and SPOAN (spastic paraplegia, optic atrophy, and neuropathy). SPG4, SPG6, SPG10, SPG27, SPG30 and SPG31 may rarely present with ataxia with cerebellar atrophy. And autosomal recessive SPG such as SPG7 and SPG11 can also present with ataxia. CONCLUSION: Patients with SPG may present with different forms of movement disorders such as parkinsonism, dystonia, tremor, myoclonus and ataxia. The specific movement disorder in the clinical manifestation of a patient with SPG may be a clinical clue for the diagnosis.

ANTECEDENTES: As paraplegias espásticas hereditárias ou familiares (SPG) compreendem um grupo de doenças geneticamente e fenotipicamente heterogêneas caracterizadas por degeneração progressiva dos tratos corticospinais. As formas complicadas evoluem com vários outros sinais e sintomas neurológicos, incluindo distúrbios do movimento e ataxia. OBJETIVO: Resumir as descrições clínicas de SPG que se manifestam com distúrbios do movimento ou ataxias para auxiliar o clínico na tarefa de diagnosticar essas doenças. MéTODOS: Realizamos uma revisão da literatura, incluindo relatos de casos, séries de casos, artigos de revisão e estudos observacionais publicados em inglês até dezembro de 2022. RESULTADOS: O parkinsonismo juvenil ou de início precoce com resposta variável à levodopa foi relatado principalmente em SPG7 e SPG11. A distonia pode ser observada em pacientes com SPG7, SPG11, SPG22, SPG26, SPG35, SPG48, SPG49, SPG58, SPG64 e SPG76. O tremor não é um achado frequente em pacientes com SPG, mas é descrito em diferentes tipos de SPG, incluindo SPG7, SPG9, SPG11, SPG15 e SPG76. A mioclonia é raramente descrita em SPG, afetando pacientes com SPG4, SPG7, SPG35, SPG48 e SPOAN (paraplegia espástica, atrofia óptica e neuropatia). SPG4, SPG6, SPG10, SPG27, SPG30 e SPG31 podem raramente apresentar ataxia com atrofia cerebelar. E SPG autossômico recessivo, como SPG7 e SPG11, também pode apresentar ataxia. CONCLUSãO: Indivíduos com SPG podem apresentar diferentes formas de distúrbios do movimento, como parkinsonismo, distonia, tremor, mioclonia e ataxia. O distúrbio específico do movimento na manifestação clínica de um paciente com SPG pode ser uma pista clínica para o diagnóstico.

[Parkinson-dementia and amyotrophic lateral sclerosis association (complex of Guam). Diagnostic challenge, Mexican patient]. / Asociación Parkinson-demencia y esclerosis lateral amiotrófica (complejo Guam). Reto diagnóstico, paciente mexicano.

Background: The Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia Complex (ALS-PDC) was first described in the islands of Guam. This pathology presented its peak incidence in the 1950s. Due to the rarity of the association, we report a clinical case with this complex. The objective was to describe the nosological and pathogenic implications of these neurodegenerative disorder, since they are not frequent to find in our population. Clinical case: We present a case of Latinoamerican origin who initially manifested systemic symptoms of more than 6 years of evolution, with subsequent cognitive alterations. Later, patient began with gait disturbances and motor symptoms suggestive of parkinsonism with atypical data and data of motor neurone disease (MND). More studies were carried out and confirmed findings compatible with upper and lower motor neuron involvement. A mutation in the POLG gene was observed, related to mitochondrial depletion syndrome. Conclusion: Despite the knowledge of this association, it is an entity whose clinical diagnosis could be very difficult to achieve. In addition, molecular mechanisms have not been fully identified, the most common genes related to Parkinsonism and ALS have been excluded, and even attempts to locate the locus were made, without achieving accurate results. Unfortunately, being a neurodegenerative disease, the prognosis is fatal, with no disease-modifying treatment.

Introducción: el complejo parkinsonismo-demencia-esclerosis lateral amiotrófica fue descrito por primera vez en las islas de Guam. Esta patología presentó su pico de incidencia en los años 50. Debido a la rareza de la asociación, informamos sobre un caso clínico que la presenta. El objetivo fue describir las implicaciones nosológicas y patogénicas de este trastorno neurodegenerativo, ya que no es frecuente encontrar esta asociación en nuestra población. Caso clínico: presentamos un caso de origen latinoamericano que inicialmente se manifestó con síntomas sistémicos de más de 6 años de evolución, con posteriores alteraciones cognitivas. Después presentó alteraciones de la marcha y síntomas motores sugestivos de parkinsonismo con datos atípicos y datos de enfermedad de motoneurona. Se hicieron estudios de extensión que confirmaron hallazgos compatibles con afectación en motoneurona superior e inferior. Observamos mutación en gen POLG, relacionada con síndrome de depleción mitocondrial. Conclusión: a pesar del conocimiento de esta asociación, es una entidad cuyo diagnóstico clínico puede ser muy difícil de obtener. Además, no se han identificado del todo los mecanismos moleculares, se han excluido los genes más comunes relacionados con parkinsonismos y esclerosis lateral amiotrófica e incluso se intentó localizar el locus, sin lograr resultados certeros. Desafortunadamente al ser una enfermedad neurodegenerativa el pronóstico es fatal, sin que haya tratamiento modificador de la enfermedad.

Endemic parkinsonism: clusters, biology and clinical features.

The term 'endemic parkinsonism' refers to diseases that manifest with a dominant parkinsonian syndrome, which can be typical or atypical, and are present only in a particular geographically defined location or population. Ten phenotypes of endemic parkinsonism are currently known: three in the Western Pacific region; two in the Asian-Oceanic region; one in the Caribbean islands of Guadeloupe and Martinique; and four in Europe. Some of these disease entities seem to be disappearing over time and therefore are probably triggered by unique environmental factors. By contrast, other types persist because they are exclusively genetically determined. Given the geographical clustering and potential overlap in biological and clinical features of these exceptionally interesting diseases, this Review provides a historical reference text and offers current perspectives on each of the 10 phenotypes of endemic parkinsonism. Knowledge obtained from the study of these disease entities supports the hypothesis that both genetic and environmental factors contribute to the development of neurodegenerative diseases, not only in endemic parkinsonism but also in general. At the same time, this understanding suggests useful directions for further research in this area.

Brainstem Modulates Parkinsonism-Induced Orofacial Sensorimotor Dysfunctions.

Parkinson's Disease (PD), treated with the dopamine precursor l-3,4-dihydroxyphenylalanine (L-DOPA), displays motor and non-motor orofacial manifestations. We investigated the pathophysiologic mechanisms of the lateral pterygoid muscles (LPMs) and the trigeminal system related to PD-induced orofacial manifestations. A PD rat model was produced by unilateral injection of 6-hydroxydopamine into the medial forebrain bundle. Abnormal involuntary movements (dyskinesia) and nociceptive responses were determined. We analyzed the immunodetection of Fos-B and microglia/astrocytes in trigeminal and facial nuclei and morphological markers in the LPMs. Hyperalgesia response was increased in hemiparkinsonian and dyskinetic rats. Hemiparkinsonism increased slow skeletal myosin fibers in the LPMs, while in the dyskinetic ones, these fibers decreased in the contralateral side of the lesion. Bilateral increased glycolytic metabolism and an inflammatory muscle profile were detected in dyskinetic rats. There was increased Fos-B expression in the spinal nucleus of lesioned rats and in the motor and facial nucleus in L-DOPA-induced dyskinetic rats in the contralateral side of the lesion. Glial cells were increased in the facial nucleus on the contralateral side of the lesion. Overall, spinal trigeminal nucleus activation may be associated with orofacial sensorial impairment in Parkinsonian rats, while a fatigue profile on LPMs is suggested in L-DOPA-induced dyskinesia when the motor and facial nucleus are activated.

Clinical and functional correlates of parkinsonism in a population-based sample of individuals aged 75 + : the Pietà study.

BACKGROUND: Parkinsonism is strongly associated with ageing, and many studies have suggested that parkinsonian signs may affect up to half of older adults and is associated with a wide range of adverse health outcomes. We compared clinical and functional characteristics of oldest-old community-dwelling individuals with parkinsonism (parkinsonian group [PG]) to individuals without parkinsonism (non-parkinsonian group [NPG]. METHODS: The Pietà study is a population-based study conducted in Caeté, southeast Brazil, involving 607 individuals aged 75 + years submitted to an extensive clinical evaluation. A subset of 65 PG individuals (61.5% women, median age of 82 years) was compared to 542 NPG individuals (64.8% women, median age of 80 years). RESULTS: PG individuals had significantly more functional impairment, clinical comorbidities (including number of falls, loss of bladder control and dysphagia) and major depression. Multivariate analysis revealed that older age, higher UPDRSm scores, lower category fluency test (animals/minute) and delayed recall memory scores were associated with PG. This group was also more cognitively impaired, with lower performance than NPG individuals in the Mini-Mental State Examination, category fluency test (animals/minute), clock drawing and in delayed recall (p < 0.001 for all tests). UPDRSm scores were the most contributing factor to cognition that independently explained variability in functionality of the entire sample. CONCLUSION: Individuals aged 75 + years with parkinsonism were significantly more clinically and functionally impaired in this population-based sample. Cognitive dysfunction explained most of the loss of functionality in these patients. UPDRS-m scores contributed independently to explain variability in functionality in the whole sample.

Metabolic Disturbances in the Gut-brain Axis of a Mouse Model of MPTP-induced Parkinsonism Evaluated by Nuclear Magnetic Resonance.

Parkinson's Disease is a synucleinopathy that primarily affects the dopaminergic cells of the central nervous system, leading to motor and gastrointestinal disturbances. However, intestinal peripheral neurons undergo a similar neurodegeneration process, marked by α-synuclein (αSyn) accumulation and loss of mitochondrial homeostasis. We investigated the metabolic alterations in different biometrics that compose the gut-brain axis (blood, brain, large intestine, and feces) in an MPTP-induced mouse model of sporadic Parkinson's Disease. Animals received escalating administration of MPTP. Tissues and fecal pellets were collected, and the metabolites were identified through the untargeted Nuclear Magnetic Resonance spectroscopic (1H NMR) technique. We found differences in many metabolites from all the tissues evaluated. The differential expression of metabolites in these samples mainly reflects inflammatory aspects, cytotoxicity, and mitochondrial impairment (oxidative stress and energy metabolism) in the animal model used. The direct evaluation of fecal metabolites revealed changes in several classes of metabolites. This data reinforces previous studies showing that Parkinson's disease is associated with metabolic perturbation not only in brain-related tissues, but also in periphery structures such as the gut. In addition, the evaluation of the microbiome and metabolites from gut and feces emerge as promising sources of information for understanding the evolution and progression of sporadic Parkinson's Disease.

Clinical correlates of fear of falling in progressive supranuclear palsy and multiple system atrophy.

BACKGROUND AND PURPOSE: Clinical correlates of fear of falling (FoF) are scarcely studied in patients with progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). This study was undertaken to evaluate the clinical correlates of FoF in PSP and MSA. METHODS: This cross-sectional study features motor, cognitive, and psychiatric assessment and longitudinal evaluation of falls and FoF at 6-month follow-up. RESULTS: Twenty-one patients with PSP-parkinsonism, 22 patients with MSA (13 parkinsonian type and nine cerebellar type), and 22 healthy controls were evaluated; 76.2% of patients with PSP and 86.4% of patients with MSA had FoF regardless of falls. Berg Balance Scale (p < 0.001), Tinetti Mobility Test (p < 0.01), Beck Anxiety Inventory (p = 0.001), and Beck Depression Inventory-II (p = 0.01) correlated with FoF in patients with PSP and MSA, whereas Timed Up and Go test (p = 0.01) and Starkstein Apathy Scale correlated only in MSA (p = 0.04). CONCLUSIONS: Mobility, balance, and gait performance as well as anxiety and depression in PSP and MSA, and apathy in MSA, were determinants of FoF. These findings underline the importance of a multidisciplinary approach to FoF in neurodegenerative atypical parkinsonism.