Primary hemifacial spasm: anatomical insights.

BACKGROUND: Primary Hemifacial Spasm (pHFS) is a disorder caused by compression of vessels on the root of the facial nerve. There has been conflicting evidence regarding the side of the face that is more frequently affected. Moreover, it has been found in several studies that women are afflicted by approximately twice as many as men. OBJECTIVES: We reviewed the literature to explain HFS tendencies from an anatomical aspect. We wanted to see whether there are anatomical variations that can increase the risk of developing HFS or underlie its tendency to a specific gender and side of the face. METHODS AND MATERIAL: A PubMed search was done for the articles on "Hemifacial Spasm" published in English literature, and we selected the articles regarding the significant anatomical differences in HFS patients. RESULTS: AICA proximal branching pattern, highly originated PICA, VA dominancy, and VA deviation are among the predisposing anatomical variances. Overall, both sides of the face are equally affected in HFS. However, there are side preferences based on the causative vessels, which may be due to differences in the anatomical features of the left and right side vessels. CONCLUSIONS: Various anatomical variations regarding posterior circulation can increase the risk of HFS. Recent evidence suggests whether there is no side dominance or a tendency exists toward the left side. There is no comprehensive explanation for precise reasons underlying the tendency of HFS to affect women. Evidence regarding anatomical variations of the posterior circulation comparing men and women with HFS is scarce, and further studies are required.

Relapse-Independent disease activity in neuromyelitis optica spectrum disorder: A systematic review.

INTRODUCTION: Neuromyelitis Optica Spectrum Disorders (NMOSD) is a neuroinflammatory condition characterized by optic neuritis and transverse myelitis. While the current approach to NMOSD focuses on relapse-associated worsening (RAW), recent evidence indicates Relapse-Independent Disease Activity (RIDA) in patients. METHOD: Databases including Embase, PubMed, Scopus, and Web of Sciences were systematically searched up to December 2023. No restrictions were applied. Inclusion criteria focused on studies reporting evidence of RIDA in NMOSD patients. Data extraction involved details such as study title, author, participant characteristics, treatment, evaluation methods, positive findings according to RIDA, and prevalence of findings in NMOSD patients. This study is conducted following the PRISMA guidelines with a registered protocol on PROSPERO (ID = CRD42023492352). RESULT: Of 802 studies, 38 were included in the systematic review, covering 1881 NMOSD patients. AQP4-IGg status was positive in 90.6 % of the patients. Ocular findings indicative of RIDA were reported in 23 studies, including thinning of GCIPL, RNFL, GCC, and GCL layers, foveal and macular shape and volume abnormalities, vessel loss, and visual evoked potentials (VEPs) abnormalities. MRI findings supporting the RIDA were reported in 13 studies, including new lesion incidence and brain and spinal cord atrophy. Serum and CSF RIDA-supporting findings were reported in five studies, including elevation in sGFAP and sNFL. Biopsies and autopsies suggested inflammatory processes in relapse-free patients in 2 studies. The predominant manifestation of RIDA in NMOSD was identified in the visual system, suggesting the impaired retinal glial cells like Müller cells during the relapse-free period in NMOSD. INTERPRETATION: Our systematic review provides valuable insights into RIDA in NMOSD. Establishing guidelines for the diagnosis and treatment of RIDA is crucial. Further studies are needed to provide robust evidence on RIDA in NMOSD patients.

Pure spinal multiple sclerosis: A case series of a possible new entity.

BACKGROUND: Recent literature describes a condition similar to multiple sclerosis (MS) but with demyelinating lesions limited to the spinal cord. This condition, referred to as "pure spinal" MS, might benefit from disease-modifying treatment (DMT). METHODS: We screened the medical records of approximately 8000 patients with demyelinating diseases at the Isfahan MS clinic in Iran. Criteria for inclusion in the case series were adults with a demyelinating disease limited to the spinal cord, positive oligoclonal IgG bands in cerebrospinal fluid (CSF), and negative results for other potential diagnoses. RESULTS: Seven people with pure spinal MS were identified (all women, mean age [SD]: 40.14 [6.17] years at the first visit, mean follow-up duration [SD]: 98 [39.41] months). Two had a family history of conventional MS in their siblings. All patients exhibited lower limb weakness and tested negative for anti-MOG and anti-AQP4 antibodies. They experienced relapsing-remitting partial myelitis, with new spinal cord lesions on MRI but no extraspinal CNS lesions. DMT significantly reduced relapse rates in all patients, and two showed no increase in EDSS scores. CONCLUSION: Pure spinal MS might be an atypical form of MS. Those affected may benefit from DMT; therefore, further investigation and consideration in the upcoming revisions of the McDonald criteria are recommended.

Anti-CD20 therapies for pediatric-onset multiple sclerosis: A systematic review.

BACKGROUND: Pediatric-onset multiple sclerosis (POMS) cases, defined as multiple sclerosis (MS) with onset before the age of 18, represent between 3 and 5 % of all MS patients. Anti-CD20 drugs mainly rituximab, ocrelizumab, and ofatumumab are being widely used in adult-onset MS. Their use in POMS is also being increasingly considered by experts. OBJECTIVE: to review the latest evidence on safety and efficacy of the use of anti-CD20 therapies in POMS. METHODS: An extensive search was performed in PubMed, Scopus, and Web of Science databases until the end of July 1st, 2024. Two independent reviewers screened the articles, and collected data. 832 studies were screened using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS: 12 studies on rituximab (328 patients) and 6 studies on ocrelizumab (106 patients) were synthesized. Using monoclonal antibodies in POMS patients has a noteworthy effect on reducing relapses and lesions and achieving no evidence of disease activity especially in highly active POMS patients. However, anti-CD20 therapies in MS are associated with potential adverse events (AEs). Additional data is required on the effect of anti-CD20 therapy on disability accrual. CONCLUSION: Although anti-CD20 therapy is associated with some AEs, it can be provided in several circumstances, especially to patients with highly active disease, or ones resistant to platform therapies.

Atraumatic hip fracture due to stiff person syndrome: Case report and literature review.

INTRODUCTION AND IMPORTANCE: Stiff person syndrome (SPS) is a rare autoimmune disorder that affects the central nervous system. Patients with this condition may experience sudden muscle spasms, leading to falls and subsequent fractures. Diagnosis is based on clinical presentation, the presence of anti-GAD antibodies, and electromyography (EMG) findings that show continuous motor unit activity. However, there have been few reports of atraumatic fractures in these patients. CASE PRESENTATION: In this article, we present a case of a patient with stiff person syndrome who sustained an intertrochanteric fracture without any prior history of trauma. Additionally, we review and discuss previous literature on this subject. CLINICAL DISCUSSION: SPS is a rare autoimmune neurological disease with muscle rigidity and spasms predominantly in the trunk and lower limbs. The authors mentioned that SPS diagnosis and managing related fractures could be challenging. They recommended optimizing the patient's status with proper medical treatments before surgical interventions to reduce further complications. CONCLUSION: In conclusion, it appears that stiff person syndrome can lead to recurrent and even atraumatic fractures, and should be considered as an underlying cause. Additionally, uncontrolled spasms in these patients can result in the failure of previous surgical fixations and complicated surgical management. To prevent surgical complications, it is crucial to initiate and maintain appropriate medical treatment to control spasms as soon as the underlying disease is diagnosed.

Span of spleen is associated with disability status in multiple sclerosis: a cross-sectional abdominopelvic ultrasonography study.

Characteristics of livers and spleens of people with multiple sclerosis (pwMS) could constitute good biomarkers of MS-related characteristics such as the disability status. To test the hypothesis "the gross anatomical features of livers and spleens, are not similar between pwMS with different disease characteristics" a cross-sectional study was conducted on pwMS seen at the Isfahan MS clinic, Iran, from February until December 2023. Definitive, otherwise-healthy, pwMS were enrolled after an initial laboratory evaluation. Presence/absence and grading of non-alcoholic fatty liver disease (NAFLD) and the span of spleen were determined by a radiologist using high-resolution abdominopelvic ultrasonography. 193 pwMS (160 women) were enrolled. Of whom, 143 (74.1%) were receiving first-line disease-modifying therapies (DMTs), 24 (12.4%) fingolimod, and 26 (13.5%) rituximab. The span of spleen was negatively associated with EDSS (adjusted ß [SE] - 4.08 [1.52], p < 0.01), as well as 6 m-CDW (adjusted ß [SE] - 6.94 [3.56], p = 0.05), unlike age, DMTs, and MS duration (all with p > 0.05). Receiver operating characteristic analysis showed, spleen span performs significant but poor in discrimination of EDSS > 1 from EDSS = 1 (area under curve [AUC] 0.62, SE 0.05, p < 0.01), yet, significant and fair in discrimination of presence from absence of 6 m-CDW (AUC 0.72, SE 0.06, p < 0.01). Other findings were unremarkable. Further longitudinal, prospective studies are warranted to confirm whether smaller spleens are predictive of higher disability accrual rate in pwMS. Particularly, findings require further validation in untreated/treatment-naïve pwMS, and ones with higher EDSS scores.

Risk of depression after Parkinson's disease, stroke, multiple sclerosis, and migraine in an Iranian population and assess psychometric characteristics of three prevalent depression questionnaires.

Objective: We aim to evaluate the prevalence of depression in disorders including multiple sclerosis (MS), Parkinson's disease (PD), migraine, and stroke. Also, we detect risk factors for depression occurrence within each disorder. Moreover, we compare the risk factors in these four common neurologic disorders. In advance, we assess the three surveys in order to better comprehend their distinctions. Background: Depression is a globally prevalent Psychologic disorder and common co-morbidity in neurological diseases. However, it is mostly underdiagnosed in chronic patients and causes numerous adverse effects. Methods: We used the database of neurology specialty clinics in a hospital in Tehran, the largest city of Iran. Five hundred nineteen patients, including 105 PD patients, 101 patients with stroke, 213 cases with MS, and 100 Migraine patients, were assessed. They were asked about their chief characteristics and disease-specific variables that may cause depression. Moreover, depression criteria were measured with three internationally used scales to study their variances. Results: Overall, the prevalence of depression in PD, stroke, MS, and migraine, according to the BDI-II scale, were 43.8%, 38.6%, 45.1%, 37.6%, and according to HDRS scale, were 56.2%, 51.5%, 39.4%, and 43.6% respectively. Finally, according to DSM-XC the depression prevalence were 64.8%, 34.7%, 36.2%, and 67.3% respectively. Possible risk factors of depression were lower educational level, disease severity, socioeconomic level, marital or employment status, female gender, higher age, and consumption of some specific drugs. Conclusion: Depression is a widespread disorder in chronic neurologic conditions. Our data suggests the odds of depression in neurologic disorders depend on the characteristics of the patient and the features of the disease.

The effects of laser cane cues on the freezing of gait of Parkinson's disease patients: can increasing the laser light beam width play a role?

INTRODUCTION: Freezing of gait can be seen in a significant number of people with Parkinson's disease. Disappointingly, the classic standard treatment of Parkinson's disease with dopamine replacement has not shown promising results in improving the freezing of gait. Hence the approach have shifted towards using non-invasive methods to address this problem. OBJECTIVES: To assess the effect of laser cane as a visual cue on the freezing of gait of people with Parkinson's disease and further determine the effect of laser light beam width and color on the freezing of gait. METHODS: 7 known Parkinson's Disease patients were enrolled in this study, all of whom had at least one episode of freezing at at least one clinical visit. These patients underwent gait analysis in 4 stages: walking without a cane, walking with a thin red light laser cane, a thick red light laser cane, and a green light laser cane. RESULTS: Using laser canes effectively improved nearly all parameters of walking, including right and left stride length, step length, the velocity of movement, and rotation time, compared to walking without a stick. Using different colors of laser cane didn't make any significant difference in improving the freezing of gait of our patients. Nevertheless, increasing the laser light beam width significantly improved almost all walking parameters. CONCLUSION: This is the first study assessing the effect of laser light beam width on freezing of gait in Parkinson's disease patients and shows promising results in regards to increasing the thickness of laser lights in order to improve walking parameters in Parkinson's disease patients more effectively. Furthermore, this is the second study to evaluate the effect of laser light color, contradicting the previous results by showing no significant correlation between the color of laser light and improvements in walking parameters.

Translational Approach Using Advanced Therapy Medicinal Products for Huntington's Disease.

Current therapeutic approaches for Huntington's disease (HD) focus on symptomatic treatment. Therefore, the unavailability of efficient disease-modifying medicines is a significant challenge. Regarding the molecular etiology, targeting the mutant gene or advanced translational steps could be considered promising strategies. The evidence in gene therapy suggests various molecular techniques, including knocking down mHTT expression using antisense oligonucleotides and small interfering RNAs and gene editing with zinc finger proteins and CRISPR-Cas9-based techniques. Several post-transcriptional and post-translational modifications have also been proposed. However, the efficacy and long-term side effects of these modalities have yet to be verified. Currently, cell therapy can be employed in combination with conventional treatment and could be used for HD in which the structural and functional restoration of degenerated neurons can occur. Several animal models have been established recently to develop cell-based therapies using renewable cell sources such as embryonic stem cells, induced pluripotent stem cells, mesenchymal stromal cells, and neural stem cells. These models face numerous challenges in translation into clinics. Nevertheless, investigations in Advanced Therapy Medicinal Products (ATMPs) open a promising window for HD research and their clinical application. In this study, the ATMPs entry pathway in HD management was highlighted, and their advantages and disadvantages were discussed.

Whole spinal transverse myelitis in neuromyelitis optica spectrum disorder.

BACKGROUND: Spinal cord is one of the prominent targets of autoimmune mechanisms in Neuromyelitis Optica Spectrum Disorder (NMOSD). Rarely, NMOSD causes damage to the entire length of the spinal cord, from cervical segments to conus medullaris, which has not been characterized in the existing literature. MATERIAL AND METHOD: We reviewed medical records, demographic information, and magnetic resonance imaging (MRI) sequences of 174 NMOSD patients from January 2011 to January 2023 who were admitted to Isfahan Multiple Sclerosis center to find patients with whole spinal transverse myelitis (TM). RESULTS: Whole spinal TM was present in five patients (2.9 %). Three patients were seropositive for Aquaporin-4 (AQP4) antibody; Myelin Oligodendrocyte Glycoprotein antibody (MOG IgG) tested negative for all of them. Lower limb weakness was the most frequent clinical complaint. Two patients presented with optic neuritis; One patient reported having episodes of nausea and vomiting. These patients, overall, yielded a higher expanded disability status scale (EDSS) score than the other NMOSD patients. CONCLUSION: Whole spinal TM is a rare finding in NMOSD, which is strongly associated with a higher severity and a worse outcome of the disease. The role of anti-AQP4 antibodies in the extent of myelitis in NMOSD has yet to be investigated.

The diagnostic performance of AI-based algorithms to discriminate between NMOSD and MS using MRI features: A systematic review and meta-analysis.

BACKGROUND: Magnetic resonance imaging [MRI] findings in Neuromyelitis optica spectrum disorder [NMOSD] and Multiple Sclerosis [MS] patients could lead us to discriminate toward them. For instance, U-fiber and Dawson's finger-type lesions are suggestive of MS, however linear ependymal lesions raise the possibility of NMOSD. Recently, artificial intelligence [AI] models have been used to discriminate between NMOSD and MS based on MRI features. In this study, we aim to systematically review the capability of AI algorithms in NMOSD and MS discrimination based on MRI features. METHOD: We searched PubMed, Scopus, Web of Sciences, Embase, and IEEE databases up to August 2023. All studies that used AI-based algorithms to discriminate between NMOSD and MS using MRI features were included, without any restriction in time, region, race, and age. Data on NMOSD and MS patients, Aquaporin-4 antibodies [AQP4-Ab] status, diagnosis criteria, performance metrics (accuracy, sensitivity, specificity, and AUC), artificial intelligence paradigm, MR imaging, and used features were extracted. This study is registered with PROSPERO, CRD42023465265. RESULTS: Fifteen studies were included in this systematic review, with sample sizes ranging between 53 and 351. 1,362 MS patients and 1,118 NMOSD patients were included in our systematic review. AQP4-Ab was positive in 94.9% of NMOSD patients in 9 studies. Eight studies used machine learning [ML] as a classifier, while 7 used deep learning [DL]. AI models based on only MRI or MRI and clinical features yielded a pooled accuracy of 82% (95% CI: 78-86%), sensitivity of 83% (95% CI: 79-88%), and specificity of 80% (95% CI: 75-86%). In subgroup analysis, using only MRI features yielded an accuracy, sensitivity, and specificity of 83% (95% CI: 78-88%), 81% (95% CI: 76-87%), and 84% (95% CI: 79-89%), respectively. CONCLUSION: AI models based on MRI features showed a high potential to discriminate between NMOSD and MS. However, heterogeneity in MR imaging, model evaluation, and reporting performance metrics, among other confounders, affected the reliability of our results. Well-designed studies on multicentric datasets, standardized imaging and evaluation protocols, and detailed transparent reporting of results are needed to reach optimal performance.

Co-administration of probiotics and vitamin D reduced disease severity and complications in patients with Parkinson's disease: a randomized controlled clinical trial.

RATIONALE: Probiotics have beneficial effects on the nervous system by modulating the gut-brain axis. Additionally, vitamin D supplementation presents a potential way for ameliorating neuropsychological disorders, particularly in regions with a high prevalence of vitamin D deficiency. OBJECTIVES: The current clinical trial aimed to investigate the role of co-administered supplementation of probiotics and Vitamin D on the different inflammatory aspects of patients with Parkinson's disease. METHODS: Forty-six patients with PD were recruited From the Functional Neurosurgery Research Center, Tehran, Iran. These patients were randomly allocated to one of the two treatment groups: Group A, who received probiotic/vitamin D supplements (n = 23), and Group B who received placebo capsules (n = 23) for 12 weeks. As primary outcomes, Interferon-Gamma (IFN-γ), interleukin 1 beta (IL-1ß), IL-6, IL-10, Tumor Necrosis Factor-Alpha (TNF-α), total antioxidant capacity (TAC), and malondialdehyde (MDA) in serum were evaluated at the baseline and the end of the trial. Moreover, Additional questionnaire-based factors including gastrointestinal symptom rating scale (GSRS), Beck Anxiety Inventory (BAI), and Unified Parkinson's Disease Rating Scale (UPDRS) were evaluated. RESULTS: Our findings demonstrated that the consumption of probiotic/vitamin D supplements leads to a significant decrease in IL-1ß, INF-γ, IL-6, and MDA levels, while showing a significant increase in IL-10 and TAC levels compared to the placebo group (P < 0.05). Additionally, it leads to a significant decrease in the disease severity, anxiety, and gastrointestinal problems in PD patients in comparison to the placebo group (P < 0.05). CONCLUSIONS: Given the acknowledged role of inflammation in the pathogenesis of Parkinson's disease on one hand, and the recognized anti-inflammatory and antioxidant effects associated with probiotics and vitamin D on the other hand, the concurrent administration of probiotics and vitamin D supplements emerges as a promising and potentially effective treatment option for individuals with PD.

A decision support system based on recurrent neural networks to predict medication dosage for patients with Parkinson's disease.

Using deep learning has demonstrated significant potential in making informed decisions based on clinical evidence. In this study, we deal with optimizing medication and quantitatively present the role of deep learning in predicting the medication dosage for patients with Parkinson's disease (PD). The proposed method is based on recurrent neural networks (RNNs) and tries to predict the dosage of five critical medication types for PD, including levodopa, dopamine agonists, monoamine oxidase-B inhibitors, catechol-O-methyltransferase inhibitors, and amantadine. Recurrent neural networks have memory blocks that retain crucial information from previous patient visits. This feature is helpful for patients with PD, as the neurologist can refer to the patient's previous state and the prescribed medication to make informed decisions. We employed data from the Parkinson's Progression Markers Initiative. The dataset included information on the Unified Parkinson's Disease Rating Scale, Activities of Daily Living, Hoehn and Yahr scale, demographic details, and medication use logs for each patient. We evaluated several models, such as multi-layer perceptron (MLP), Simple-RNN, long short-term memory (LSTM), and gated recurrent units (GRU). Our analysis found that recurrent neural networks (LSTM and GRU) performed the best. More specifically, when using LSTM, we were able to predict levodopa and dopamine agonist dosage with a mean squared error of 0.009 and 0.003, mean absolute error of 0.062 and 0.030, root mean square error of 0.099 and 0.053, and R-squared of 0.514 and 0.711, respectively.

Abnormal multisensory temporal discrimination in Parkinson's disease.

Cognitive deficits are prevalent in Parkinson's disease (PD), ranging from mild deficits in perception and executive function to severe dementia. Multisensory integration (MSI), the ability to pool information from different sensory modalities to form a combined, coherent perception of the environment, is known to be impaired in PD. This study investigated the disruption of audiovisual MSI in PD patients by evaluating temporal discrimination ability between auditory and visual stimuli with different stimulus onset asynchronies (SOAs). The experiment was conducted with Fifteen PD patients and fifteen age-matched healthy controls where participants were requested to report whether the audiovisual stimuli pairs were temporal simultaneous. The temporal binding window (TBW), the time during which sensory modalities are perceived as synchronous, was adapted as the comparison index between PD patients and healthy individuals. Our results showed that PD patients had a significantly wider TBW than healthy controls, indicating abnormal audiovisual temporal discrimination. Furthermore, PD patients had more difficulty in discriminating temporal asynchrony in visual-first, but not in auditory-first stimuli, compared to healthy controls. In contrast, no significant difference was observed for auditory-first stimuli. PD patients also had shorter reaction times than healthy controls regardless of stimulus priority. Together, our findings point to abnormal audiovisual temporal discrimination, a major component of MSI irregularity, in PD patients. These results have important implications for future models of MSI experiments and models that aim to uncover the underlying mechanism of MSI in patients afflicted with PD.

Sex hormone therapy in Multiple Sclerosis: A systematic review of randomized clinical trials.

Background: In spite of the observed immunomodulatory properties of different sex hormones on Multiple Sclerosis (MS) in different investigations, to date, there has been no study to systematically review the documents to add more powerful data to the field. Objectives: Therefore, in this paper we aim to systematically review clinical and randomized controlled trials (RCT) assessing the effect of sex hormone therapies on individuals with MS. Design: A comprehensive search of electronic databases including PubMed, EMBASE, and Scopus was conducted. Clinical trials and RCTs that assessed the impact of sex hormones on individuals with MS were selected and included in the systematic review. Data sources and methods: In the final phase of the search strategy, 9 papers reached the criteria for entering in the systematic review. Two independent reviewers extracted the relevant data from each article according to the standardized data extraction form. Two reviewers also assessed the quality of each study independently using PEDro scale. Results: We categorized three different classifications of outcomes including clinical, MRI, and immune system findings and put each measured outcome in the category which matched best. Conclusion: In conclusion, the existed investigations on the effect of sex hormones on inflammatory and neurodegenerative components of MS are promising particularly in relapsing-remitting MS (RRMS).

Immunomodulatory properties of different sex hormones on Multiple Sclerosis (MS) have been proposed. Therefore, in this paper we aim to systematically review clinical and randomized controlled trials (RCT) assessing the effect of sex hormone therapies on individuals with MS. A comprehensive search of electronic databases was conducted. Clinical trials and RCTs that assessed the impact of sex hormones on individuals with MS were selected and included in the systematic review. In the final phase of the search strategy, 9 papers reached the criteria for entering in the systematic review. Two independent reviewers extracted the relevant data from each article according to the standardized data extraction form. We categorized three different classifications of outcomes including clinical, MRI, and immune system findings and put each measured outcome in the category which matched best. The existed investigations on the effect of sex hormones on inflammatory and neurodegenerative components of MS are promising particularly in relapsing-remitting MS (RRMS).

A Review of Ocular Movement Abnormalities in Hereditary Cerebellar Ataxias.

Cerebellar ataxias are a wide heterogeneous group of disorders that may present with fine motor deficits as well as gait and balance disturbances that have a significant influence on everyday activities. To review the ocular movements in cerebellar ataxias in order to improve the clinical knowledge of cerebellar ataxias and related subtypes. English papers published from January 1990 to May 2022 were selected by searching PubMed services. The main search keywords were ocular motor, oculomotor, eye movement, eye motility, and ocular motility, along with each ataxia subtype. The eligible papers were analyzed for clinical presentation, involved mutations, the underlying pathology, and ocular movement alterations. Forty-three subtypes of spinocerebellar ataxias and a number of autosomal dominant and autosomal recessive ataxias were discussed in terms of pathology, clinical manifestations, involved mutations, and with a focus on the ocular abnormalities. A flowchart has been made using ocular movement manifestations to differentiate different ataxia subtypes. And underlying pathology of each subtype is reviewed in form of illustrated models to reach a better understanding of each disorder.

Predictors and Pathophysiology of Axial Postural Abnormalities in Parkinsonism: A Scoping Review.

Background: Postural abnormalities involving the trunk are referred to as axial postural abnormalities and can be observed in over 20% of patients with Parkinson's disease (PD) and in atypical parkinsonism. These symptoms are highly disabling and frequently associated with back pain and a worse quality of life in PD. Despite their frequency, little is known about the pathophysiology of these symptoms and scant data are reported about their clinical predictors, making it difficult to prompt prevention strategies. Objectives: We conducted a scoping literature review of clinical predictors and pathophysiology of axial postural abnormalities in patients with parkinsonism to identify key concepts, theories and evidence on this topic. Methods: We applied a systematic approach to identify studies, appraise quality of evidence, summarize main findings, and highlight knowledge gaps. Results: Ninety-two articles were reviewed: 25% reported on clinical predictors and 75% on pathophysiology. Most studies identified advanced disease stage and greater motor symptoms severity as independent clinical predictors in both PD and multiple system atrophy. Discrepant pathophysiology data suggested different potential central and peripheral pathogenic mechanisms. Conclusions: The recognition of clinical predictors and pathophysiology of axial postural abnormalities in parkinsonism is far from being elucidated due to literature bias, encompassing different inclusion criteria and measurement tools and heterogeneity of patient samples. Most studies identified advanced disease stage and higher burden of motor symptoms as possible clinical predictors. Pathophysiology data point toward many different (possibly non-mutually exclusive) mechanisms, including dystonia, rigidity, proprioceptive and vestibular impairment, and higher cognitive deficits.