Disentangling Bradykinesia and Rigidity in Parkinson's Disease: Evidence from Short- and Long-Term Subthalamic Nucleus Deep Brain Stimulation.

OBJECTIVE: Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct pathophysiological mechanisms. This study aims to examine and compare longitudinal changes in bradykinesia and rigidity in PD patients treated with bilateral subthalamic nucleus deep brain stimulation (STN-DBS). METHODS: In this retrospective cohort study, the clinical progression of appendicular and axial bradykinesia and rigidity was assessed up to 15 years after STN-DBS in the best treatment conditions (ON medication and ON stimulation). The severity of bradykinesia and rigidity was examined using ad hoc composite scores from specific subitems of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III). Short- and long-term predictors of bradykinesia and rigidity were analyzed through linear regression analysis, considering various preoperative demographic and clinical data, including disease duration and severity, phenotype, motor and cognitive scores (eg, frontal score), and medication. RESULTS: A total of 301 patients were examined before and 1 year after surgery. Among them, 101 and 56 individuals were also evaluated at 10-year and 15-year follow-ups, respectively. Bradykinesia significantly worsened after surgery, especially in appendicular segments (p < 0.001). Conversely, rigidity showed sustained benefit, with unchanged clinical scores compared to preoperative assessment (p > 0.05). Preoperative motor disability (eg, composite scores from the UPDRS-III) predicted short- and long-term outcomes for both bradykinesia and rigidity (p < 0.01). Executive dysfunction was specifically linked to bradykinesia but not to rigidity (p < 0.05). INTERPRETATION: Bradykinesia and rigidity show long-term divergent progression in PD following STN-DBS and are associated with independent clinical factors, supporting the hypothesis of partially distinct pathophysiology. ANN NEUROL 2024;96:234-246.

Neuroplasticity in Parkinson's disease.

Parkinson's disease (PD) is the second most frequent neurodegenerative disorder, affecting millions of people and rapidly increasing over the last decades. Even though there is no intervention yet to stop the neurodegenerative pathology, many efficient treatment methods are available, including for patients with advanced PD. Neuroplasticity is a fundamental property of the human brain to adapt both to external changes and internal insults and pathological processes. In this paper we examine the current knowledge and concepts concerning changes at network level, cellular level and molecular level as parts of the neuroplastic response to protein aggregation pathology, synapse loss and neuronal loss in PD. We analyse the beneficial, compensatory effects, such as augmentation of nigral neurons efficacy, as well as negative, maladaptive effects, such as levodopa-induced dyskinesia. Effects of physical activity and different treatments on neuroplasticity are considered and the opportunity of biomarkers identification and use is discussed.

Amantadine use in the French prospective NS-Park cohort.

OBJECTIVE: To assess amantadine use and associated factors in the patients with Parkinson's disease (PD). BACKGROUND: Immediate-release amantadine is approved for the treatment of PD and is largely used in clinical practice to treat "levodopa-induced dyskinesia (LIDs). Its use varies according to countries and PD stages. The prospective NS-Park cohort collects features of PD patients followed by 26 French PD Expert Centres. METHODS: Variables used for the analyses included demographics, motor and non-motor PD symptoms and motor complications [motor fluctuations (MFs), LIDs)], antiparkinsonian pharmacological classes and levodopa equivalent daily dose (LEDD). We evaluated: (i) prevalence of amantadine use and compared clinical features of amantadine users vs. non-users (cross-sectional analysis); (ii) factors associated with amantadine initiation (longitudinal analysis); (iii) amantadine effect on LIDs, MFs, apathy, impulse control disorders and freezing of gait (Fog) (longitudinal analysis). RESULTS: Amantadine use prevalence was 12.6% (1,585/12,542, median dose = 200 mg). Amantadine users were significantly younger, with longer and more severe PD symptoms, greater LEDD and more frequent use of device-aided/surgical treatment. Factors independently associated with amantadine initiation were younger age, longer PD duration, more frequent LIDs, MFs and FoG, higher LEDD and better cognitive function. 9 of the 658 patients on amantadine had stopped it at the following visit, after 12-18 months (1.3%). New users of amantadine presented a higher improvement in LIDs and MF compared to amantadine never users. CONCLUSIONS: About 12% of PD patients within the French NS-Park cohort used amantadine, mostly those with younger age and more severe PD. Amantadine initiation was associated with a subsequent reduction in LIDs and MFs.

Headaches and facial pain attributed to SARS-CoV-2 infection and vaccination: a systematic review.

BACKGROUND AND PURPOSE: The aim was to provide insights to the characteristics of headache in the context of COVID-19 on behalf of the Headache Scientific Panel and the Neuro-COVID-19 Task Force of the European Academy of Neurology (EAN) and the European Headache Federation (EHF). METHODS: Following the Delphi method the Task Force identified six relevant questions and then conducted a systematic literature review to provide evidence-based answers and suggest specific diagnostic criteria. RESULTS: No data for facial pain were identified in the literature search. (1) Headache incidence during acute COVID-19 varies considerably, with higher prevalence rates in prospective compared to retrospective studies (28.9%-74.6% vs. 6.5%-34.0%). (2) Acute COVID-19 headache is usually bilateral or holocranial and often moderate to severe with throbbing pain quality lasting 2-14 days after first signs of COVID-19; photo-phonophobia, nausea, anosmia and ageusia are common associated features; persistent headache shares similar clinical characteristics. (3) Acute COVID-19 headache is presumably caused by immune-mediated mechanisms that activate the trigeminovascular system. (4) Headache occurs in 13.3%-76.9% following SARS-CoV-2 vaccination and occurs more often amongst women with a pre-existing primary headache; the risk of developing headache is higher with the adenoviral-vector-type vaccines than with other preparations. (5) Headache related to SARS-CoV-2 vaccination is mostly bilateral, and throbbing, pressing, jolting or stabbing. (6) No studies have been conducted investigating the underlying mechanism of headache attributed to SARS-CoV-2 vaccines. CONCLUSION: The results of this joint EAN/EHF initiative provide a framework for a better understanding of headache in the context of SARS-CoV-2 infection and vaccination.

Management of patients with neurological diseases considering post-pandemic coronavirus disease 2019 (COVID-19) related risks and dangers - An updated European Academy of Neurology consensus statement.

BACKGROUND AND PURPOSE: In October 2020, the European Academy of Neurology (EAN) consensus statement for management of patients with neurological diseases during the coronavirus disease 2019 (COVID-19) pandemic was published. Due to important changes and developments that have happened since then, the need has arisen to critically reassess the original recommendations and address new challenges. METHODS: In step 1, the original items were critically reviewed by the EAN COVID-19 Task Force. In addition, new recommendations were defined. In step 2, an online survey with the recommendations forged in step 1 was sent to the Managing Groups of all Scientific and Coordinating Panels of EAN. In step 3, the final set of recommendations was made. RESULTS: In step 1, out of the original 36 recommendations, 18 were judged still relevant. They were edited to reflect the advances in knowledge and practice. In addition, 21 new recommendations were formulated to address the new knowledge and challenges. In step 2, out of the 39 recommendations sent for the survey, nine were approved as they were, whilst suggestions for improvement were given for the rest. In step 3, the recommendations were further edited, and some new items were formed to accommodate the participants' suggestions, resulting in a final set of 41 recommendations. CONCLUSION: This revision of the 2020 EAN Statement provides updated comprehensive and structured guidance on good clinical practice in people with neurological disease faced with SARS-CoV-2 infection. It now covers the issues from the more recent domains of COVID-19-related care, vaccine complications and post-COVID-19 conditions.

The European Academy of Neurology NeuroCOVID-19 Task Force: A lesson for the future.

BACKGROUND: The COVID-19 pandemic has made its mark on world history forever causing millions of deaths, and straining health systems, economies, and societies worldwide. The European Academy of Neurology (EAN) reacted promptly. A special NeuroCOVID-19 Task Force was set up at the beginning of the pandemic to promote knowledge, research, international collaborations, and raise awareness about the prevention and treatment of COVID-19-related neurological issues. METHODS: Activities carried out during and after the pandemic by the EAN NeuroCOVID-19 Task Force are described. The main aim was to review all these initiatives in detail as an overarching lesson from the past to improve the present and be better prepared in case of future pandemics. RESULTS: During the pandemic, the Task Force was engaged in several initiatives: the creation of the EAN NEuro-covid ReGistrY (ENERGY); the launch of several surveys (neurological manifestations of COVID-19 infection; the pandemic's impact on patients with chronic neurological diseases; the pandemic's impact of restrictions for clinical practice, curricular training, and health economics); the publication of position papers regarding the management of patients with neurological diseases during the pandemic, and vaccination hesitancy among people with chronic neurological disorders; and the creation of a dedicated "COVID-19 Breaking News" section in EANpages. CONCLUSIONS: The EAN NeuroCOVID-19 Task Force was immediately engaged in various activities to participate in the fight against COVID-19. The Task Force's concerted strategy may serve as a foundation for upcoming global neurological emergencies.

General neurology: Current challenges and future implications.

BACKGROUND AND PURPOSE: In the coming decades, the world will face an increasing burden of neurological disorders (ND) and an urgent need to promote brain health. These challenges contrast with an insufficient neurological workforce in most countries, as well as decreasing numbers of general neurologists and neurologists attracted to work in general neurology (GN). This white paper aims to review the current situation of GN and reflect on its future. METHODS: The European Academy of Neurology (EAN) task force (TF) met nine times between November 2021 and June 2023. During the 2023 EAN annual meeting, attendees were asked to answer five questions concerning the future of GN. The document was sent for suggestions and eventually approval to the board and the presidents of the 47 national societies of the EAN. RESULTS: The TF first identified four relevant current and future challenges related to GN: (i) definition, (ii) practice, (iii) education, and (iv) research. The TF then identified seven initiatives to further develop GN at both the academic and community level. Finally, the TF formulated 16 recommendations to promote GN in the future. CONCLUSIONS: GN will remain essential in the coming decades to provide rapid, accessible, and comprehensive management of patients with ND that is affordable and cost-effective. There is also a need for research, education, and other initiatives aiming to facilitate improved working conditions, recognition, and prestige for those pursuing a career in GN.

COVID-19 and stroke in women: impact on clinical, psychosocial and research aspects.

Despite the growing interest in gender medicine, the influence of sex and gender on human diseases, including stroke, continues to be underestimated and understudied. The COVID-19 pandemic has overall impacted not only the occurrence and management of stroke but has also exacerbated sex and gender disparities among both patients and healthcare providers. This paper aims to provide an updated overview on the influence of sex and gender in stroke pathophysiology and care during COVID-19 pandemic, through biological, clinical, psychosocial and research perspectives. Gender equity and awareness of the importance of sexual differences are sorely needed, especially in times of health crisis but have not yet been achieved to date. To this purpose, the sudden yet worldwide diffusion of COVID-19 represents a unique learning experience that highlights critical unmet needs also in gender medicine. The failures of this recent past should be kept as food for thought to inspire proper strategies reducing inequalities and to address women's health and wellbeing issues, particularly in case of future pandemics.

[Langerhans histiocytosis and panhypopituitarism in adults. Case report]. / Histiocitosis de Langerhans y panhipopituitarismo en adulto. Reporte de caso.

Langerhans-cells Histiocytosis (LCH) is a rare disease characterized by the clonal proliferation of immature dendritic cells that locally or diffusely infiltrate different systems, mainly affecting children. We present the case of a 38-year-old man with a long-standing history of multiple tooth loss without association with trauma, smoking, or poor dental hygiene. Skull computed tomography (CT) showed multiple lytic jaw lesions. Jaw biopsy and immunohistochemical results were compatible with the finding of LCH. The patient evolved with polyuria, polydipsia, and nocturia, confirming the presence of diabetes insipidus and panhypopituitarism through hormonal studies. Magnetic resonance imaging (MRI) of the brain shows a hypothalamic neoplasm with infundibular involvement and an image suggestive of a pituitary granuloma. The treatment consisted of maxillobuccofacial defocusing, hormonal supplementation, chemotherapy, and radiotherapy with favorable evolution.

The impact of COVID-19 pandemic on patients with Huntington's disease and care-givers: A French survey.

Although the impact of the first wave of the COVID-19 pandemic on people with several neurological diseases has been largely investigated, little is available concerning people with Huntington's disease (HD). The main objective of the study was to interview people with HD and their caregivers in the Auvergne-Rhone Alpes region, France. The interview consisted of 16 items concerning general and medical information, and the impact of the first wave of COVID-19 pandemic on the medical care of people with HD and on their caregivers. The questionnaire was made available as online survey from October 1st, 2020 until November 15th, 2020. Fifty-two subjects participated (13 men, 39 women, mean age of 47.3 ± 15.5 years). Almost half participants (48%) experienced a worsening of pre-existing symptoms, with new-onset symptoms in the 44% of cases. The most frequent worsening was reported in gait and balance issues (67%), fatigue (58%), anxiety (50%), and depression (50%). The 70.8% of participants reported an inappropriate overall care of HD due to long delays to access medical care (30%) and other health care teams (60%). More than half of the participants (54.2%) reported that the COVID-19 pandemic had a negative impact on their caregiver/family. Our findings emphasize the negative impact of the first wave of COVID-19 pandemic on the healthcare of HD population and their caregivers. Not only some symptoms were aggravated, but new symptoms appeared during the pandemic. In the future, health policies should be considered to improve the care of patients with rare diseases such as HD.

The history of deep brain stimulation.

Deep brain stimulation (DBS) surgery is an established and effective treatment for several movement disorders (tremor, Parkinson's disease, and dystonia), and is under investigation in numerous other neurological and psychiatric disorders. However, the origins and development of this neurofunctional technique are not always well understood and recognized. In this mini-review, we review the history of DBS, highlighting important milestones and the most remarkable protagonists (neurosurgeons, neurologists, and neurophysiologists) who pioneered and fostered this therapy throughout the 20th and early 21st century. Alongside DBS historical markers, we also briefly discuss newer developments in the field, and the future challenges which accompany such progress.

How to Use the New European Academy of Neurology/Movement Disorder Society European Section Guideline for Invasive Therapies in Parkinson's Disease.

BACKGROUND: The decision to choose invasive treatments for Parkinson's disease (PD) is complex and needs careful consideration. OBJECTIVES: Although the recommendations of the European Academy of Neurology/Movement Disorder Society European Section guideline for invasive therapies of PD are useful, the different clinical profiles of people with PD who seek advice for possible invasive therapy need further attention. METHODS AND RESULTS: Here we describe 8 clinical standard situations of people with PD unsatisfied with their current oral treatment where invasive therapies may be considered. These are PD patients presenting with the following symptoms: (1) severe motor fluctuations, (2) beginning of levodopa-responsive fluctuations, severe tremor at (3) young or (4) advanced age, (5) impulse control disorders and related behavioral disorders, (6) hallucinations and psychosis, (7) minimal cognitive impairment or mild dementia, and (8) patients in need of palliative care. For some of these conditions, evidence at lower level or simple clinical considerations exist. CONCLUSIONS: There are no one-fits-all answers, but physician and patient should discuss each option carefully considering symptom profile, psychosocial context, availability of therapy alternatives, and many other factors. The current paper outlines our proposed approach to these circumstances.

Spatiotemporal Gait Differences before and after Botulinum Toxin in People with Focal Dystonia: A Pilot Study.

BACKGROUND: The impact of focal dystonia on gait has attracted little attention and remains elusive. Considering the importance of both visual and head control in gait, blepharospasm and cervical dystonia should affect gait. Improvement of cervical/eyelid control following botulinum toxin (BTX) injections would translate into gait changes. OBJECTIVES: To assess gait differences in people with focal dystonia before and after BTX treatment. METHODS: Ten patients with blepharospasm, 10 patients with cervical dystonia, and 20 healthy age- and gender-matched controls were included. Gait was assessed before and 1-month after BTX injections using Biodex Gait Trainer™ 3. Gait velocity, cadence, step length, step asymmetry, and variability of step length were compared between patients and controls, and between the two time-points using non-parametric statistics. RESULTS: At baseline, compared to controls, cervical dystonia patients showed reduced gait velocity, step length, and cadence. After BTX injections, while gait velocity and step length were significantly increased and step length variability reduced, gait parameters still differed between patients and controls. In blepharospasm patients, baseline gait velocity and step length were significantly smaller than in controls. After BTX injections, these gait parameters were significantly increased and variability decreased, so that patients no longer differed from controls. CONCLUSION: Gait differences exist between patients with focal dystonia not directly affecting the lower limbs and healthy controls. These gait abnormalities were improved differently by BTX treatment according to the type of dystonia. These disparities suggest different pathophysiological mechanisms and support the need for changes in rehabilitation routines in cervical dystonia.

A Pragmatic Review on Spinal Cord Stimulation Therapy for Parkinson's Disease Gait Related Disorders: Gaps and Controversies.

BACKGROUND: Parkinson's Disease (PD) is a progressive neurological disorder that results in potentially debilitating mobility deficits. Recently, spinal cord stimulation (SCS) has been proposed as a novel therapy for PD gait disorders. The highest levels of evidence remain limited for SCS. OBJECTIVES: In this systematic review and narrative synthesis, the literature was searched using combinations of key phrases indicating spinal cord stimulation and PD. METHODS: We included pre-clinical studies and all published clinical trials, case reports, conference abstracts as well as protocols for ongoing clinical trials. Additionally, we included trials of SCS applied to atypical parkinsonism. RESULTS: A total of 45 human studies and trials met the inclusion criteria. Based on the narrative synthesis, a number of knowledge gaps and future avenues of potential research were identified. This review demonstrated that evidence for SCS is currently not sufficient to recommend it as an evidence-based therapy for PD related gait disorders. There remain challenges and significant barriers to widespread implementation, including issues regarding patient selection, effective outcome selection, stimulation location and mode, and in programming parameter optimization. Results of early randomized controlled trials are currently pending. SCS is prone to placebo, lessebo and nocebo as well as blinding effects which may impact interpretation of outcomes, particularly when studies are underpowered. CONCLUSION: Therapies such as SCS may build on current evidence and be shown to improve specific gait features in PD. Early negative trials should be interpreted with caution, as more evidence will be required to develop effective methodologies in order to drive clinical outcomes.

Clinical neurophysiology in the treatment of movement disorders: IFCN handbook chapter.

In this review, different aspects of the use of clinical neurophysiology techniques for the treatment of movement disorders are addressed. First of all, these techniques can be used to guide neuromodulation techniques or to perform therapeutic neuromodulation as such. Neuromodulation includes invasive techniques based on the surgical implantation of electrodes and a pulse generator, such as deep brain stimulation (DBS) or spinal cord stimulation (SCS) on the one hand, and non-invasive techniques aimed at modulating or even lesioning neural structures by transcranial application. Movement disorders are one of the main areas of indication for the various neuromodulation techniques. This review focuses on the following techniques: DBS, repetitive transcranial magnetic stimulation (rTMS), low-intensity transcranial electrical stimulation, including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), and focused ultrasound (FUS), including high-intensity magnetic resonance-guided FUS (MRgFUS), and pulsed mode low-intensity transcranial FUS stimulation (TUS). The main clinical conditions in which neuromodulation has proven its efficacy are Parkinson's disease, dystonia, and essential tremor, mainly using DBS or MRgFUS. There is also some evidence for Tourette syndrome (DBS), Huntington's disease (DBS), cerebellar ataxia (tDCS), and axial signs (SCS) and depression (rTMS) in PD. The development of non-invasive transcranial neuromodulation techniques is limited by the short-term clinical impact of these techniques, especially rTMS, in the context of very chronic diseases. However, at-home use (tDCS) or current advances in the design of closed-loop stimulation (tACS) may open new perspectives for the application of these techniques in patients, favored by their easier use and lower rate of adverse effects compared to invasive or lesioning methods. Finally, this review summarizes the evidence for keeping the use of electromyography to optimize the identification of muscles to be treated with botulinum toxin injection, which is indicated and widely performed for the treatment of various movement disorders.

Unmet Need in Early-Onset Parkinson's Disease: Deep Brain Stimulation and Pregnancy.

Pregnancy in women with early-onset Parkinson's disease (PD) is likely to have a higher frequency given the trend toward increasing maternal age, thus resulting in a greater overlap time between childbearing age and PD risk. Deep brain stimulation (DBS) therapy is nowadays offered to PD patients at earlier stage of the disease, when women can still be pre-menopausal. However, few data are available about DBS safety during pregnancy. From a review of the available literature, only one article was published on this topic so far. Therefore, we have developed a clinical consensus on the safety of DBS during pregnancy in PD patients.

Outcome predictors of post-COVID conditions in the European Academy of Neurology COVID-19 registry.

Several neurological manifestations are part of the post-COVID condition. We aimed to: (1) evaluate the 6-month outcome in the cohort of patients with neurological manifestations during the COVID-19 acute phase and surviving the infection, and find outcome predictors; (2) define the prevalence and type of neurological symptoms persistent at six months after the infection. Data source was an international registry of patients with COVID-19 infection and neurological symptoms, signs or diagnoses established by the European Academy of Neurology. Functional status at six-month follow-up was measured with the modified Rankin scale (mRS), and defined as: "stable/improved" if the mRS at six months was equal as or lower than the baseline score; "worse" if it was higher than the baseline score. By October 30, 2022, 1,003 lab-confirmed COVID-19 patients were followed up for a median of 6.5 months. Compared to their pre-morbid status, 522 patients (52%) were stable/improved, whereas 465 (46%) were worse (functional status missing for 16). Age, hospitalization, several pre-COVID-19 comorbidities, and COVID-19 general complications were predictors of a worse status. Amongst neurological manifestations, stroke carried the highest risk for worse outcome (OR 5.96), followed by hyperactive delirium (2.8), and peripheral neuropathies (2.37). On the other hand, hyposmia/hypogeusia (0.38), headache (0.40), myalgia (0.45), and COVID-19 vaccination (0.52) were predictors of a favourable prognosis. Persisting neurological symptoms or signs were reported by 316/1003 patients (31.5%), the commonest being fatigue (n = 133), and impaired memory or concentration (n = 103). Our study identified significant long-term prognostic predictors in patients with COVID-19 and neurological manifestations.