Amantadine in unvaccinated patients with early, mild to moderate COVID-19: A randomized, placebo-controlled, double-blind trial.

BACKGROUND AND PURPOSE: Adamantanes were listed as an interesting option as an early intervention against COVID-19. We aimed to evaluate the effectiveness of amantadine in preventing the progression of COVID-19 and its neurological sequelae. METHODS: Unvaccinated patients with confirmed SARS-CoV-2 infection within 5 days were enrolled. Subjects were randomized (50:50) to amantadine (AMD; 100 mg twice daily) or placebo (PLB) for 14 days. The Ordinal Scale for Clinical Improvement of the World Health Organization (OSCI-WHO) was the primary measure. Secondary endpoints included assessment for fatigue; depression, disorders of smell and taste, and sleepiness on Days 1 and 15. RESULTS: We enrolled 99 patients (49 AMD and 50 PLB). Disease progression (OSCI-WHO = 4) was observed in 6% (AMD) and 8% (PLB) patients (p > 0.05) with further deterioration (OSCI-WHO〉4) in 0% (AMD) and 8% (PLB) patients (p > 0.05). Complete recovery on Day 15 was 60% higher in the AMD compared with the PLB group (p = 0.025). There was improvement in taste (AMD: p = 0.003; PLB: p = 0.0001) and smell (AMD: p = 0.005; PLB: p = 0.0004) but not in fatigue in both groups. Improvement was observed in the AMD (p = 0.010) but not in the PLB group (p = 0.058) when assessing depression as well as sleepiness (AMD: p = 0.0002; PLB: p = 0.341). There was one death in the PLB group (2.0%) and none in the AMD group (p > 0.05) until Day 210. Overall, the drug was well tolerated. CONCLUSION: The central effects of amantadine on the nervous system with reduction of sleepiness and depression might have had a supportive effect on faster recovery in early COVID-19 patients.

Cognitive and Motor Decline in Dementia with Lewy Bodies and Parkinson's Disease Dementia.

Background: There is a need to better understand the rate of cognitive and motor decline of Dementia with Lewy bodies (DLB) and Parkinson's disease Dementia (PDD). Objectives: To compare the rate of cognitive and motor decline in patients with DLB and PDD from the E-DLB Consortium and the Parkinson's Incidence Cohorts Collaboration (PICC) Cohorts. Methods: The annual change in MMSE and MDS-UPDRS part III was estimated using linear mixed regression models in patients with at least one follow-up (DLB n = 837 and PDD n = 157). Results: When adjusting for confounders, we found no difference in the annual change in MMSE between DLB and PDD (-1.8 [95% CI -2.3, -1.3] vs. -1.9 [95% CI -2.6, -1.2] [P = 0.74]). MDS-UPDRS part III showed nearly identical annual changes (DLB 4.8 [95% CI 2.1, 7.5]) (PDD 4.8 [95% CI 2.7, 6.9], [P = 0.98]). Conclusions: DLB and PDD showed similar rates of cognitive and motor decline. This is relevant for future clinical trial designs.

NMOSD-Diagnostic Dilemmas Leading towards Final Diagnosis.

(1) Background: The emergence of white matter lesions in the central nervous system (CNS) can lead to diagnostic dilemmas. They are a common radiological symptom and their patterns may overlap CNS or systemic diseases and provoke underdiagnosis or misdiagnosis. The aim of the study was to assess factors influencing the underdiagnosis of neuromyelitis optica spectrum disorder (NMOSD) as well as to estimate NMOSD epidemiology in Lubelskie voivodeship, Poland. (2) Methods: This retrospective study included 1112 patients, who were made a tentative or an established diagnosis of acute or subacute onset of neurological deficits. The evaluation was based on medical history, neurological examination, laboratory and radiographic results and fulfilment of diagnosis criteria. (3) Results: Up to 1.62 percent of patients diagnosed with white matter lesions and up to 2.2% of the patients previously diagnosed with MS may suffer from NMOSD. The duration of delayed diagnosis is longer for males, despite the earlier age of onset. Seropositive cases for antibodies against aquaporin-4 have worse prognosis for degree of disability. (4) Conclusions: Underdiagnosis or misdiagnosis in NMOSD still remains a problem in clinical practice and has important implications for patients. The incorrect diagnosis is caused by atypical presentation or NMOSD-mimics; however, covariates such as gender, onset and diagnosis age may also have an influence.

The use of amantadine in the prevention of progression and treatment of COVID-19 symptoms in patients infected with the SARS-CoV-2 virus (COV-PREVENT): Study rationale and design.

BACKGROUND: COVID-19, a disease caused by infection with the SARS-CoV-2 virus, is asymptomatic or mildly symptomatic in most cases. Some patients, usually burdened with risk factors develop acute respiratory failure and other organ dysfunction. In such cases, the mortality rate is very high despite the use of intensive therapy. Amantadine has complex activity including antiviral, antiinflammatory and dopaminergic effects. This clinical trial will assess the efficacy and safety of amantadine in the prevention of COVID-19 progression toward acute respiratory failure and neurological complications. METHODS AND RESULTS: The trial will enroll 200 patients who are positive for SARS-CoV-2 infection and have one or more risk factors for worsening the disease. These patients will be included as hospitalized or ambulatory subjects for early treatment of illness. The recruitment will take place in 8 centers covering different regions of Poland. For 14 days they will be given either 200 mg of amantadine a day or placebo. Our hypothesis is a considerable reduction in the number of patients with progression toward respiratory insufficiency or neurological complications thanks to the treatment of amantadine. CONCLUSIONS: Demonstrating the efficacy and safety of amantadine treatment in improving the clinical condition of patients diagnosed with COVID-19 is of great importance in combating the effects of the pandemic. It has potential to influence on the severity and course of neurological complications, which are very common and persist long after the infection as long-COVID syndrome. CLINICAL TRIAL REGISTRATION: www. CLINICALTRIALS: gov identification no. NCT04854759; Eudra CT number: 2021-001144-98 (dated 27 February 2021).

Targeting pain in the long-term treatment of cervical dystonia with botulinum toxin A.

AIMS: Cervical pain is one of the most common non-motor symptoms of cervical dystonia (CD) and affects from 54.6% to 88.9% of patients. To date, minority of studies investigated the relevance of pain in a long-term botulinum toxin (BoNT) therapy of CD. The aim of the study was to define an impact of cervical pain on the disease severity and disability, as well as to assess antinociceptive BoNT efficacy in a long-term treatment of CD. MATERIALS AND METHODS: In this case-control study, CD patients who received stable doses of BoNT for at least 3 years were assessed with the use of validated scales. Participants were divided into two groups depending on the occurrence of CD-related pain. RESULTS: We examined 50 participants who received a mean of 24 injection cycles (6-51) of BoNT during a mean treatment period of 10.3 years (3.0-23.5). Participants with cervical pain (68.0%) were characterized by higher scores in all scales used in this study: TWSTRS severity (p = 0.030), disability (p < 0.001), total (p < 0.001) and TSUI score (p = 0.046). Pain reduction following BoNT injection lasted longer than muscle relaxation in 85.3% of patients. Pain improvement between first and last BoNT injection cycle was reported by 76.5% of patients with CD-related pain. CONCLUSIONS: The presence of cervical pain in CD may increase the severity of muscular symptoms and disease-related disability. BoNT has a noticeable antinociceptive effect in the long-term treatment of CD.

The Usefulness of Optical Coherence Tomography in Disease Progression Monitoring in Younger Patients with Relapsing-Remitting Multiple Sclerosis: A Single-Centre Study.

The purpose of the study was to assess the usefulness of optical coherence tomography (OCT) in the detection of the neurodegenerative process in younger patients with multiple sclerosis (MS). The study group consisted of 61 patients with a relapsing remitting course of MS (mean age 36.4 ± 6.7 years) divided into two groups: short (≤5 years) and long (>10 years) disease duration. OCT, P300 evoked potential, Montreal Cognitive Assessment, and performance subtests (Picture Completion and Digit Symbol) of the Wechsler Adult Intelligence Scale were performed in all patients. Mean values of most parameters assessed in OCT (pRNFL Total, pRNFL Inferior, pRNFL Superior, pRNFL Temporalis, mRNFL, GCIPL, mRNFL+GCIPL) were significantly lower in MS patients in comparison to controls. And in patients with longer disease duration in comparison to those with shorter. Most OCT parameters negatively correlated with the EDSS score (p < 0.05). No significant correlation was found between OCT results and both P300 latency and the results of psychometric tests. OCT, as a simple, non-invasive, quick, and inexpensive method, could be useful for monitoring the progression of disease in MS patients.

Cladribine suppresses disease activity in neuromyelitis optica spectrum disorder: a 2-year follow-up study.

BACKGROUND AND PURPOSE: Neuromyelitis optica spectrum disorder (NMOSD) is a difficult condition to treat. Cladribine selectively and transiently depletes B and T lymphocytes, leading to long-lasting immune reconstitution. This report describes observations from 24 months of follow-up after cladribine in NMOSD patients. METHODS: This is a retrospective analysis of a case series including 12 seropositive patients with NMOSD. Patients were given cladribine by subcutaneous injections in a series of several 2-day cycles of 20 mg administered at intervals of 4-6 weeks. Thus, the full treatment course delivered a cumulative bioavailable dose similar to that approved for treatment of multiple sclerosis. Annualized relapse rate (ARR), disability (Expanded Disability Status Scale [EDSS] score) and safety in the 24 months preceding and the 24 months following the initiation of cladribine treatment were assessed. RESULTS: The mean ARR in the 24 months preceding cladribine treatment was 1.04 (95% confidence interval [CI] 0.67-1.62). The mean ARR in the 24 months following initiation of cladribine treatment was 0.21 (95% CI 0.08-0.56). The ratio in the rate of events post versus prior cladribine initiation was 0.20 (95% CI 0.07-0.59) and highly significant (p = 0.0073). The EDSS score did not change over the follow-up period (2.5 ± 1.7; mean ± SD) compared to baseline (2.5 ± 1.5; mean ± SD). No serious adverse events considered to be linked to cladribine were observed during follow-up. CONCLUSIONS: Cladribine was safe in NMOSD patients over a 2-year observation period. Cladribine treatment was associated with clinical stabilization, as evidenced by significantly decreased ARR and no progression of EDSS score.

Decreased Cerebrospinal Fluid Orexin-A (Hypocretin-1) Concentrations in Patients after Generalized Convulsive Status Epilepticus.

The effects of status epilepticus on the orexin/hypocretin system have yet to be investigated. The present study aimed to assay orexin-A/hypocretin-1 in the cerebrospinal fluid (CSF) of patients after generalized convulsive status epilepticus (GCSE). The study groups included 20 GCSE patients, 24 patients diagnosed with epilepsy but remaining in remission (ER), and 25 normal controls (CTR). Diagnostic lumbar puncture was performed in GCSE patients within 3-10 days of seizure cessation, as well as in the ER and to CTR subjects. Among all GCSE patients, the outcome was graded according to the modified Rankin Scale (mRS) at 1-month follow-up. Orexin-A levels were measured in unextracted CSF samples, using a commercial radioimmunoassay. There was a significant overall difference in median CSF orexin-A concentrations between GCSE, RE, and CTR patients (p < 0.001). The lowest concentrations were noted in the GCSE group compared to ER (p < 0.001) or CTR (p < 0.001). CSF orexin-A levels in GCSE patients inversely correlated with clinical outcome as assessed on the mRS at 1-month follow-up (r = -0.55; p = 0.1). In conclusion, CSF orexin-A levels may serve as a biomarker of increased turn-over of the peptide or post-SE neuronal damage, and implicates the orexin system in the pathogenesis of SE.

Increased Cerebrospinal Fluid S100B and NSE Reflect Neuronal and Glial Damage in Parkinson's Disease.

Introduction: The diagnosis of Parkinson's disease (PD) mainly relies on clinical manifestation, but may be difficult to make in very early stages of the disease, especially in pre-motor PD. Thus, there is great interest in finding a biomarker for PD. Among diagnostic biomarkers, the most promising molecules are those which reflect the pathophysiological mechanisms of the disease. Until now, only α-synuclein, a classical CSF Alzheimer's disease biomarker, and neurofilament light (NFL) chains have turned out to be helpful in differential diagnosis between PD and healthy control subjects. Aim: To assess whether CSF molecules related to some pathological processes present in PD might be of interest in the diagnosis of PD and whether they correlate with disease severity. Methods: CSF levels of S100B and neuron-specific enolase (NSE) were measured in 58 PD patients and in 28 healthy control subjects. Correlations were determined between the levels of these CSF molecules and measures of disease severity (Hoehn-Yahr scale and UPDRS part III), as well as disease duration and levodopa dose. Results: CSF S100B and CSF NSE were both significantly increased in PD subjects vs. healthy controls (p = 0.007 and p = 0.00035, respectively). CSF S100B was significantly positively correlated with measures of disease severity (H-Y score and UPDRS part III), as well as disease duration (p < 0.05). No correlation was found between CSF NSE levels and disease severity or disease duration (p > 0.05). CSF S100B levels alone provided a relatively high discrimination (AUC 0.77) between PD and healthy controls, with 60.7% sensitivity and 88.5% specificity (p < 0.001) at a cut-off value of 123.22 pg/ml. Similarly, CSF NSE levels alone provided a relatively high discrimination (AUC 0.775) between PD and healthy controls, with 78.6% sensitivity and 74.1% specificity at a cut-off value of 51.56 ng/ml (p < 0.001). Conclusions: Our results show that both CSF S100B and CSF NSE seem to be promising markers of the axonal and glial degeneration present in PD. Additionally CSF S100B may be a promising marker of PD progression.

[Orbital pseudotumor - current state of knowledge].

The orbital pseudo-tumor is an orbital inflammatory disease of unknown origin that can affect all the anatomical structures that make up the orbit. The diagnosis is based on the assessment of clinical symptoms, imaging tests and the exclusion of other possible causes. Glucocorticosteroids are used for treatment, but other immunosuppressants as well as biological treatments can be used. The aim of the study is to present, based on the literature review, the current state of knowledge about pathogenesis, symptoms, differential diagnosis, and treatment of the orbital pseudotumor.

Increased CSF NFL in Non-demented Parkinson's Disease Subjects Reflects Early White Matter Damage.

Parkinson's disease (PD) is a chronic neurodegenerative disorder with various underlying pathological processes. Until now, no fluid biomarkers have been established for PD. Given recent biochemical and neuroimaging evidence for the presence of white matter damage in PD, which may even precede neuronal loss, we investigated whether neurofilament light (NFL) was increased in the cerebrospinal fluid (CSF) of PD patients in comparison to controls. NFL is located mainly in large myelinated axons, and increased CSF levels of this protein reflect axonal injury. CSF levels of NFL in 58 early PD patients and 28 controls were quantified by ELISA (Uman Diagnostics). Measures of PD severity included disease duration, UPDRS-III, and Hoehn-Yahr stage. Statistically significant differences in CSF NFL levels were found between PD patients and controls [median with interquartile range 524.82 (393.28-678.34) vs. 271.84 (198.09-335.24) ng/l; p < 0.05)]. In PD patients, there were no correlations between CSF NFL level and the measures of disease severity. The CSF NFL turned out to have a high discriminatory value (AUC 0.850) for differentiating between PD subjects and healthy controls, with 84% sensitivity and 85.2% specificity. The study indirectly demonstrates that axonal damage is present in early PD in addition to neuronal loss. Interestingly, white matter damage was observed in non-demented PD patients. In the light of the results of recent MRI studies which confirm early white matter damage in PD, our data may turn out to be potentially useful in the diagnosis of early, or even preclinical, stages of the disease.

The role of myelin damage in Alzheimer's disease pathology.

Although Alois Alzheimer described myelin disruption in Alzheimer's disease (AD) as early as in 1911, his observation has escaped the attention of researchers since that time. Alzheimer's disease has been mainly considered as a grey matter disorder; nevertheless, recent evidence suggests that myelin impairment may play an important role in AD pathology. Classical neuropathological changes in AD, e.g. the accumulation of aggregated Aß 42 and the presence of neurofibrillary tangles, are responsible for neuronal loss, but they may also induce death of oligodendrocytes and myelin damage. There is also evidence that myelin pathology may even precede Aß and tau pathologies in AD. The state of the art does not allow us to determine whether myelin damage is a primary or a secondary injury in AD subjects. The article presents an overview of current knowledge on the role of myelin in AD pathology and its interactions with Aß and tau pathologies.

Continuous subcutaneous apomorphine monotherapy in Parkinson's disease.

INTRODUCTION AND OBJECTIVE: Continuous subcutaneous apomorphine (APO) treatment is one of the 3 therapeutic options for advanced Parkinson's disease (PD), in addition to deep brain stimulation (DBS) and intrajejunal levodopa. Data from previously performed studies show that few PD patients can achieve APO infusion as monotherapy. The current pilot study presents the authors' experience in achieving APO monotherapy. MATERIAL AND METHODS: During the last 2 years, 9 patients with APO were treated in the Department of Neurology of the Medical University of Lublin; each patient was offered a 5-day duration APO treatment as monotherapy. The main indication for the APO therapy was advanced PD with motor fluctuations and the patient's non-agreement for DBS therapy. Mean age of treated patients - 65.11 years, mean disease duration - 7.67 years, mean Hoehn-Yahr - 2.67, mean L-dopa equivalent before APO treatment - 1751.11 mg, mean daily dose of apomorphine as monotherapy - 106.11 ± 14.09 mg. RESULTS: All treated patients managed to achieve APO monotherapy. A statistically significant reduction was found in the duration of the 'off' states in the observed PD patients on APO monotherapy (p<0.05). No significant improvement was observed in the III motor score of the UPDRS on APO treatment, compared to optimized oral therapy used before APO treatment. CONCLUSIONS: APO monotherapy can be achieved in advanced PD, and seems to be a good therapeutic option for this group of patients, especially in that it allows a significant reduction in the off-time which significantly simplifies the drug regime. Nevertheless, hospital admission with experienced neurologist supervision is recommended when establishing a PD patient's APO monotherapy.

[Review of diagnostic criteria for multiple sclerosis].

Multiple sclerosis (MS) is a chronic, autoimmune disease of the central nervous system, leading to inflammatory demyelination and damage to neurons and their axons. The essence of MS is the occurrence of neurological symptoms associated with the occurance of demyelinating lesions disseminated in time (DIT) and space (DIS) (i.e. occurring within various CNS structures, in particular: pyramidal and cerebellar pathways). The aim of the article was to present the evolution of diagnostic criteria of multiple sclerosis in the years 1965-2017. Analysis of the changing criteria reveal that over the last several years, the time necessary to diagnose the disease, previously associated with the anticipation of subsequent symptoms of MS, now is definitely shorter, and the diagnosis can be made before the next relapse of MS, including cerebrospinal fluid examination.

[Dementia - diagnostic and therapeutic problems].

Deterioration of higher cortical functions in the course of dementia affects population of about 50 million people around the world. This clinical syndrome may be accompanied by diagnostic and therapeutic problems. Among them is the delayed diagnosis of dementia resulting from lack of knowledge of the disease, as well as the lack of good diagnostic tools used by general practitioners. Inadequate training of medical personnel may also be the problem, making it difficult to diagnose dementia at its early stage. The phenomenon of social stigmatization of people struggling with dementia is also very important. It affects both the patients themselves, making them look for help later, but also to the attitude of doctors, significantly hindering early diagnostics. Dementia is often accompanied by communication difficulties of the patient, resulting from cognitive impairment. In this study we discuss the main limitations of making early diagnostisc of dementia.

[Stigmatisation of people with dementi].

The history of the concept of stigmatization dates back to ancient times, but the meaning of this term has changed over the years. Presently it is defined as the attitude of disapproval, negative perception, discrimination by a group due to certain features presented by it. This problem is also valid in medicine, affecting, among many others disorders, patients with dementia. Stigmatization carries a lot of negative consequences, causing feelings of shame that may lead to the exclusion from society. It also affects families and close relatives. The intensification of stigmatization depends on many factors, such as age, gender, education and ethnic structure of community. In this review paper we try to highlight the problem of stigmatization among people affected by dementia.

[Paroxysmal dyskinesias - disorder categories, their causes and treatment].

Paroxysmal dyskinesias refer to category of abnormal involuntary movements, such as chorea, dystonia, athetosis, ballism or their various configurations. Depending on the type of seizure, sudden movement, stress, emotions, coffee or alcohol may be the trigger factors. Acute seizures are characterized by short duration and are self-limitated. Patients present correct portray of movements between seizures. Intact consciousness during seizure is the invariable characteristic of all paroxysmal dyskinesias. The intent of this work is to systematize knowledge about paroxysmal dyskinesias. This research includes synthetic information developed based on specialistic literature cencerned with paroxysmal movement disorders. The authors focused primarily on characteristics of the most important issues in this area, into which types of disorders, their causes and treament as well as psychopathology aspect having crucial influence on patients' life comfort were included. The essence of three categories of seizures were put across more extesively: paroxysmal kinesigenic dyskinesia, proxysmal non-kinesigenic dyskinesia and paroxysmal exercise-induced dyskinesia. Primary dyskinesias with genetic basis and secondary to other diseases, such as multiple sclerosis were distinguished. Modes of pharmacological treatment with antiepileptic drug and benzodiazepines were described. Special concern was put on holistic approach to problem of diagnosis and treatment of analyzed movement disorders.

[ROLA I WARTOSC ROKOWNICZA MIKROKRWAWIEN MÓZGOWYCH W SCHORZENIACH NEUROLOGICZNYCH THE ROLE AND PROGNOSTIC VALUE OF CEREBRAL MICROBLEEDS IN NEUROLOGICAL DISORDERS 907].

Cerebral microbleeds (CMB) are small foci of low signal which are detected in neuroimaging. They correspond to hemosiderin and other blood breakdown products from brain vessels whose structure was affected by pathological processes. Their pathogenesis is closely related to angiopathy associated with hypertension and cerebral amyloid angiopathy. Microbleeds occur in a completely healthy population as well as in numerous neurological disorders. They are often present in people afflicted with dementia, in the course of neurodegenerative diseases and due to vascular causes. Their prevalence is also higher in people with ischemic stroke and in non-traumatic intracerebral bleeding. The presence of microbleeds is reflected in the prognosis of the patients, the presence of complications of treatment, and the occurrence of the disease entities in previously healthy people. They also affect the emotional state and quality of life of patients. We will try to summarize the current state of knowledge regarding the relationship between microbleeds and neurological disorders and present their potential predictive value.

[Brain microbleeds - definition, pathophysiology and the consequences].

Brain microbleeds are defined as small, circular hypointense changes in T2-sequensec of brain MRI, well demarcated from the surrounding tissue. They represent the phagocytized products of blood distribution extravasated from pathologically altered vessels. The echo-T2-dependent gradient (GRE) and magnetic susceptibility testing (SWI) sequences are usually used to visualize them. The pathogenesis of microbleeds very complex but angiopathy associated with arterial hypertension and cerebral amyloid angiopathy play a special role. Atherosclerotic lesions and inflammatory processes are also important. Microbleeds can be found in healthy people as well as in many disorders such as hypertension, Alzheimer's disease or other types of dementia. Their prevalence increases with age. Microbleeds may have a multidimensional effect on the surrounding brain tissue. It is suggested that they disrupt both the brain structure and the electrical function of neurons. In this review article we present current knowledge on the cerebral microbleeds.

Anti-MAG autoantibodies are increased in Parkinson's disease but not in atypical parkinsonism.

There is emerging evidence that glial cells are involved in the neuropathological process in Parkinson's disease (PD) in addition to degeneration of neuronal structures. Recently, we confirmed the presence of an adaptive immune response against different glial-derived antigens in PD, with a possible role of anti-MAG, anti-MBP and anti-PLP antibodies in the disease progression. The aim of the present study was to assess humoral response against myelin-associated glycoprotein (MAG) in patients with parkinsonism (both idiopathic and atypical) to check whether these antibodies could serve as biomarkers of PD, its severity and progression. Anti-MAG autoantibodies were measured by an ELISA system in 99 PD patients, 33 atypical parkinsonism patients, and 36 control subjects. In PD patients, anti-MAG IgM autoantibodies were significantly higher in comparison to healthy control subjects (p = 0.038). IgM anti-MAG autoantibodies titers were also significantly higher in the whole group of patients with parkinsonism (either idiopathic or atypical) in comparison to healthy control subjects (1.88 ± 0.84 vs 1.70 ± 1.19, p = 0.017). This difference was mainly driven by the PD group, as the atypical parkinsonism group did not differ significantly from the control group in anti-MAG antibody levels (p = 0.51). A negative correlation between anti-MAG levels and disease duration was found in PD patients. Our study provides evidence for an increased production of autoantibodies against a protein of glial origin in PD. The negative correlation between anti-MAG antibodies and disease duration may suggest possible involvement of the immune system in disease progression. Increasing evidence that glia are involved in the neurodegenerative process to a greater extent than previously thought may turn out be useful in the search for biomarkers of the neurodegenerative process in PD.