Focused ultrasound therapy in movement disorders: management roadmap toward optimal pathway organization.

MRI-guided focused ultrasound (MRgFUS) lesioning is an innovative, safe and effective treatment which provides an innovative development in the field of minimally invasive stereotactic neurosurgery. Based on the application of focused ultrasound energy under full MR planning and thermal imaging control, unilateral lesioning of the thalamus, subthalamic nucleus, and globus pallidus is indicated for the treatment of movement disorders, including essential tremor, Parkinson's disease, and dystonia. We started to apply this technique in February 2019 for the treatment of patients with movement disorders. The authors developed a diagnostic therapeutic care pathway, which is herewith proposed and applied as an explication of standard clinical practice in use. The project was the result of the application of different methods such as Health Technology Assessment (HTA), Strengths, Weaknesses, Opportunities and Threats analysis (SWOT) and Demin -Plan, Do, Check, Act (PDCA) cycle. The aim of this project was to standardize the MRgFUS diagnostic-therapeutic pathway (DTP), describe its application and the appropriateness of different phases (patient selection, intervention phase and follow-up). Here, we described in detail our experience in the DTP application from 2019 up to now in 610 patients with movement disorders.

The Optimal Targeting for Focused Ultrasound Thalamotomy Differs between Dystonic and Essential Tremor: A 12-Month Prospective Pilot Study.

BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is increasingly used to treat drug-resistant essential tremor (ET). Data on MRgFUS thalamotomy in dystonic tremor (DT) are anecdotal. OBJECTIVES: To investigate efficacy, safety, and differences in target coordinates of MRgFUS thalamotomy in DT versus ET. METHODS: Ten patients with DT and 35 with ET who consecutively underwent MRgFUS thalamotomy were followed for 12 months. Although in both groups the initial surgical planning coordinates corresponded to the ventralis intermediate (Vim), the final target could be modified intraoperatively based on clinical response. RESULTS: Tremor significantly improved in both groups. The thalamic lesion was significantly more anterior in DT than ET. Considering both ET and DT groups, the more anterior the lesion, the lower the odds ratio for adverse events. CONCLUSIONS: MRgFUS thalamotomy is safe and effective in DT and ET. Compared to classical Vim coordinates used for ET, more anterior targeting should be considered for DT.

Unraveling Autonomic Dysfunction in GBA-Related Parkinson's Disease.

Background: Patients with Parkinson's disease (PD) and GBA gene mutations (GBA-PD) develop nonmotor complications more frequently than noncarriers. However, an objective characterization of both cardiovascular and sudomotor autonomic dysfunction using extensive clinical and instrumental measures has never been provided so far. Survival is reduced in GBA-PD regardless of age and dementia, suggesting that other hitherto unrecognized factors are involved. Objectives: To provide instrumental measures of pattern and severity of autonomic dysfunction in GBA-PD and explore their correlation with other non-motor symptoms and implications for clinical practice. Methods: In this cross-sectional study, 21 GBA-PD and 24 matched PD noncarriers underwent extensive assessment of motor and non-motor features, including neuropsychological testing. Cardiovascular autonomic function was explored through a comprehensive battery of indexes, including power spectral analysis of the R-R intervals and blood pressure short-term variability during resting state and active maneuvers. Dynamic Sweat Test was used to assess post-ganglionic sudomotor dysfunction. Results: Despite minimal or absent clinical correlates, cardiovagal and sympathetic indexes, heart rate variability parameters and sudomotor postganglionic function were more severely impaired in GBA-PD than noncarriers (overcoming relatively preserved compensatory peripheral sympathetic function), suggesting more prominent cardiac sympatho-vagal demodulation, efferent baroreflex failure and peripheral sympathetic dysfunction in GBA-PD. Cardiovascular dysautonomia showed marginal correlations with cognitive impairment. Conclusions: Compared to PD noncarriers, GBA-PD display more severe instrumental autonomic abnormalities, which may be underestimated by purely clinical measures, despite their relevance on morbidity and mortality. This supports the necessity of implementing instrumental autonomic assessment in all GBA-PD, regardless of clinically overt symptoms.

Ambroxol as a disease-modifying treatment to reduce the risk of cognitive impairment in GBA-associated Parkinson's disease: a multicentre, randomised, double-blind, placebo-controlled, phase II trial. The AMBITIOUS study protocol.

Background: Heterozygous mutations in the GBA gene, encoding the lysosomal enzyme ß-glucocerebrosidase (GCase), are the most frequent genetic risk factor for Parkinson's disease (PD). GBA-related PD (GBA-PD) patients have higher risk of dementia and reduced survival than non-carriers. Preclinical studies and one open-label trial in humans demonstrated that the chaperone ambroxol (ABX) increases GCase levels and modulates α-synuclein levels in the blood and cerebrospinal fluid (CSF). Methods and analysis: In this multicentre, double-blind, placebo-controlled, phase II clinical trial, we randomise patients with GBA-PD in a 1:1 ratio to either oral ABX 1.2 g/day or placebo. The duration of treatment is 52 weeks. Each participant is assessed at baseline and weeks 12, 26, 38, 52 and 78. Changes in the Montreal Cognitive Assessment score and the frequency of mild cognitive impairment and dementia between baseline and weeks 52 are the primary outcome measures. Secondary outcome measures include changes in validated scales/questionnaires assessing motor and non-motor symptoms. Neuroimaging features and CSF neurodegeneration markers are used as surrogate markers of disease progression. GCase activity, ABX and α-synuclein levels are also analysed in blood and CSF. A repeated-measures analysis of variance will be used for elaborating results. The primary analysis will be by intention to treat. Ethics and dissemination: The study and protocols have been approved by the ethics committee of centres. The study is conducted according to good clinical practice and the Declaration of Helsinki. The trial findings will be published in peer-reviewed journals and presented at conferences. Trial registration numbers: NCT05287503, EudraCT 2021-004565-13.

Corrigendum: PMCA-based detection of prions in the olfactory mucosa of patients with sporadic Creutzfeldt-Jakob disease.

[This corrects the article DOI: 10.3389/fnagi.2022.848991.].

Magnetic Resonance-Guided Focused Ultrasound Thalamotomy May Spare Dopaminergic Therapy in Early-Stage Tremor-Dominant Parkinson's Disease: A Pilot Study.

BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy is a safe and effective procedure for drug-resistant tremor in Parkinson's disease (PD). OBJECTIVE: The aim of this study was to demonstrate that MRgFUS ventralis intermedius thalamotomy in early-stage tremor-dominant PD may prevent an increase in dopaminergic medication 6 months after treatment compared with matched PD control subjects on standard medical therapy. METHODS: We prospectively enrolled patients with early-stage PD who underwent MRgFUS ventralis intermedius thalamotomy (PD-FUS) and patients treated with oral dopaminergic therapy (PD-ODT) with a 1:2 ratio. We collected demographic and clinical data at baseline and 6 and 12 months after thalamotomy. RESULTS: We included 10 patients in the PD-FUS group and 20 patients in the PD-ODT group. We found a significant increase in total levodopa equivalent daily dose and levodopa plus monoamine oxidase B inhibitors dose in the PD-ODT group 6 months after thalamotomy. CONCLUSIONS: In early-stage tremor-dominant PD, MRgFUS thalamotomy may be useful to reduce tremor and avoid the need to increase dopaminergic medications. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

PMCA-Based Detection of Prions in the Olfactory Mucosa of Patients With Sporadic Creutzfeldt-Jakob Disease.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rare neurodegenerative disorder caused by the conformational conversion of the prion protein (PrPC) into an abnormally folded form, named prion (or PrPSc). The combination of the polymorphism at codon 129 of the PrP gene (coding either methionine or valine) with the biochemical feature of the proteinase-K resistant PrP (generating either PrPSc type 1 or 2) gives rise to different PrPSc strains, which cause variable phenotypes of sCJD. The definitive diagnosis of sCJD and its classification can be achieved only post-mortem after PrPSc identification and characterization in the brain. By exploiting the Real-Time Quaking-Induced Conversion (RT-QuIC) assay, traces of PrPSc were found in the olfactory mucosa (OM) of sCJD patients, thus demonstrating that PrPSc is not confined to the brain. Here, we have optimized another technique, named protein misfolding cyclic amplification (PMCA) for detecting PrPSc in OM samples of sCJD patients. OM samples were collected from 27 sCJD and 2 genetic CJD patients (E200K). Samples from 34 patients with other neurodegenerative disorders were included as controls. Brains were collected from 26 sCJD patients and 16 of them underwent OM collection. Brain and OM samples were subjected to PMCA using the brains of transgenic mice expressing human PrPC with methionine at codon 129 as reaction substrates. The amplified products were analyzed by Western blot after proteinase K digestion. Quantitative PMCA was performed to estimate PrPSc concentration in OM. PMCA enabled the detection of prions in OM samples with 79.3% sensitivity and 100% specificity. Except for a few cases, a predominant type 1 PrPSc was generated, regardless of the tissues analyzed. Notably, all amplified PrPSc were less resistant to PK compared to the original strain. In conclusion, although the optimized PMCA did not consent to recognize sCJD subtypes from the analysis of OM collected from living patients, it enabled us to estimate for the first time the amount of prions accumulating in this biological tissue. Further assay optimizations are needed to faithfully amplify peripheral prions whose recognition could lead to a better diagnosis and selection of patients for future clinical trials.

Short- and long-term motor outcome of STN-DBS in Parkinson's Disease: focus on sex differences.

INTRODUCTION: Subthalamic nucleus deep brain stimulation (STN-DBS) is an established treatment for patients with Parkinson's disease (PD) with motor complications; the contribution of sex in determining the outcome is still not understood. METHODS: We included 107 patients (71 males) with PD consecutively implanted with STN-DBS at our center. We reviewed patient charts from our database and retrospectively collected demographical and clinical data at baseline and at three follow-up visits (1, 5 and 10 years). RESULTS: We found a long-lasting effect of DBS on motor complications, despite a progressive worsening of motor performances in the ON medication condition. Bradykinesia and non-dopaminergic features seem to be the major determinant of this progression. Conversely to males, females showed a trend towards worsening in bradykinesia already at 1-year follow-up and poorer scores in non-dopaminergic features at 10-year follow-up. Levodopa Equivalent Daily Dose (LEDD) was significantly reduced after surgery compared to baseline values; however, while in males LEDD remained significantly lower than baseline even 10 years after surgery, in females LEDD returned at baseline values. Males showed a sustained effect on dyskinesias, but this benefit was less clear in females; the total electrical energy delivered was consistently lower in females compared to males. The profile of adverse events did not appear to be influenced by sex. CONCLUSION: Our data suggest that there are no major differences on the motor effect of STN-DBS between males and females. However, there may be some slight differences that should be specifically investigated in the future and that may influence therapeutic decisions in the chronic follow-up.

Discrimination of MSA-P and MSA-C by RT-QuIC analysis of olfactory mucosa: the first assessment of assay reproducibility between two specialized laboratories.

BACKGROUND: Detection of the pathological and disease-associated alpha-synuclein (αSynD) in the brain is required to formulate the definitive diagnosis of multiple system atrophy (MSA) and Parkinson's disease (PD). We recently showed that αSynD can be detected in the olfactory mucosa (OM) of MSA and PD patients. For this reason, we have performed the first interlaboratory study based on α-synuclein Real-Time Quaking-Induced Conversion (αSyn_RT-QuIC) analysis of OM samples collected from PD and MSA patients with the parkinsonian (MSA-P) and cerebellar (MSA-C) phenotypes. METHODS: OM samples were prospectively collected from patients with a probable diagnosis of MSA-P (n = 20, mean disease duration 4.4 years), MSA-C (n = 10, mean disease duration 4 years), PD (n = 13, mean disease duration 8 years), and healthy control subjects (HS) (n = 11). Each sample was analyzed by αSyn_RT-QuIC in two independent specialized laboratories, one located in Italy (ITA-lab) and one located in the USA (USA-lab). Both laboratories have developed and used harmonized αSyn_RT-QuIC analytical procedures. Results were correlated with demographic and clinical data. RESULTS: The αSyn_RT-QuIC analysis reached a 96% interrater agreement of results (IAR) between laboratories (Kappa = 0.93, 95% CI 0.83-1.00). In particular, αSyn_RT-QuIC seeding activity was found in the OM of 9/13 patients with PD (sensitivity 69%, IAR 100%) and 18/20 patients with MSA-P (sensitivity 90%, IAR 100%). Interestingly, samples collected from patients with MSA-C did not induce αSyn_RT-QuIC seeding activity, except for one subject in USA-lab. Therefore, we found that MSA-P and MSA-C induced opposite effects. Regardless of disease diagnosis, the αSyn_RT-QuIC seeding activity correlated with some clinical parameters, including the rigidity and postural instability. CONCLUSIONS: Our study provides evidence that OM-αSynD may serve as a novel biomarker for accurate clinical diagnoses of PD, MSA-P, and MSA-C. Moreover, αSyn_RT-QuIC represents a reliable assay that can distinguish patients with MSA-P from those with MSA-C, and may lead to significant advancements in patients stratification and selection for emerging pharmacological treatments and clinical trials.

Chronic Inflammatory Demyelinating Polyneuropathy after ChAdOx1 nCoV-19 Vaccination.

Recently several patients, who developed Guillain-Barré syndrome characterized by prominent bifacial weakness after ChAdOx1 nCoV-19 vaccination, were described from different centers. We recently observed a patient who developed a similar syndrome, later in the follow up he showed worsening of the neuropathy two months after the initial presentation. Repeat EMG showed reduced nerve sensory and motor conduction velocities of both upper and lower limbs, and a diagnosis of chronic inflammatory demyelinating polyneuropathy (typical CIDP) was made according to established criteria. Our report expands on the possible outcomes in patients who develop Guillain-Barrè syndrome after COVID-19 vaccinations and suggest that close monitoring after the acute phase is needed in these patients to exclude a chronic evolution of the disease, which has important implications for long-term treatment.

Overall Efficacy and Safety of Safinamide in Parkinson's Disease: A Systematic Review and a Meta-analysis.

BACKGROUND AND OBJECTIVE: Safinamide is a novel anti-parkinsonian drug with possible anti-dyskinetic properties. Parkinson's disease (PD) is a complex disease. The objective of this systematic review and meta-analysis is to evaluate the efficacy and safety of safinamide administration compared to placebo in PD patients on multiple outcomes. METHODS: PubMed, EMBASE, Cochrane CENTRAL, LILACS, and trial databases were searched up to 23 December 2020 for randomized controlled studies (RCTs) comparing safinamide to placebo, alone or as add-on therapy in PD. Data were extracted from literature and regulatory agencies. Primary outcomes were ON-time without troublesome dyskinesia, OFF-time, and Unified Parkinson's Disease Rating Scale (UPDRS) section III (UPDRS-III). Secondary outcomes included any dyskinesia rating scale (DRS), ON-time with troublesome dyskinesia, UPDRS-II, and Parkinson's Disease Questionnaire 39 (PDQ-39). In order to estimate mean difference (MD) and odds ratios with 95% confidence intervals (CI), generic inverse variance and Mantel-Haenszel methods were used for continuous and dichotomous variables, respectively. Analyses were performed grouping by PD with (PDwMF) or without (PDwoMF) motor fluctuations, safinamide dose, and concomitant dopaminergic treatment. Summary of findings with GRADE were performed. RESULTS: Six studies with a total of 2792 participants were identified. In PDwMF patients, safinamide 100 mg as add-on to levodopa (L-dopa) significantly increased ON-time without troublesome dyskinesia (MD = 0.95 h; 95% CI from 0.41 to 1.49), reduced OFF-time (MD = - 1.06 h; 95% CI from - 1.60 to - 0.51), and improved UPDRS-III (MD = - 2.77; 95% CI from - 4.27 to - 1.28) with moderate quality of evidence. Similar results were observed for the 50 mg dose. However, the quality of evidence was moderate only for ON-time without troublesome dyskinesia, whereas for OFF-time and UPDRS-III was low. In PDwoMF patients taking a single dopamine agonist, safinamide 100 mg resulted in little to no clinically significant improvement in UPDRS-III (MD = - 1.84; 95% CI from - 3.19 to - 0.49), with moderate quality of evidence. Conversely, in PDwoMF patients, the 200 mg and 50 mg doses showed nonsignificant improvement in UPDRS-III, with very low and moderate quality of evidence, respectively. In PDwMF patients taking safinamide 100 mg or 50 mg, nonsignificant differences were observed for ON-time with troublesome dyskinesia and DRS, with high and low quality of evidence, respectively. In the same patients, UPDRS-II was significantly improved at the 100 mg and 50 mg dose, with high and moderate quality of evidence. In PDwoMF, UPDRS-II showed a little yet significant difference only at 100 mg, with low quality of evidence. PDQ-39 resulted significantly improved only with the 100 mg dose in PDwMF, with low quality of evidence. CONCLUSION: Overall, safinamide is effective in PDwMF patients taking L-dopa both at 100 and 50 mg daily. Evidence for efficacy in early PD is limited. Further trials are needed to better evaluate the anti-dyskinetic properties of safinamide.

Efficient RT-QuIC seeding activity for α-synuclein in olfactory mucosa samples of patients with Parkinson's disease and multiple system atrophy.

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder whose diagnosis is often challenging because symptoms may overlap with neurodegenerative parkinsonisms. PD is characterized by intraneuronal accumulation of abnormal α-synuclein in brainstem while neurodegenerative parkinsonisms might be associated with accumulation of either α-synuclein, as in the case of Multiple System Atrophy (MSA) or tau, as in the case of Corticobasal Degeneration (CBD) and Progressive Supranuclear Palsy (PSP), in other disease-specific brain regions. Definite diagnosis of all these diseases can be formulated only neuropathologically by detection and localization of α-synuclein or tau aggregates in the brain. Compelling evidence suggests that trace-amount of these proteins can appear in peripheral tissues, including receptor neurons of the olfactory mucosa (OM). METHODS: We have set and standardized the experimental conditions to extend the ultrasensitive Real Time Quaking Induced Conversion (RT-QuIC) assay for OM analysis. In particular, by using human recombinant α-synuclein as substrate of reaction, we have assessed the ability of OM collected from patients with clinical diagnoses of PD and MSA to induce α-synuclein aggregation, and compared their seeding ability to that of OM samples collected from patients with clinical diagnoses of CBD and PSP. RESULTS: Our results showed that a significant percentage of MSA and PD samples induced α-synuclein aggregation with high efficiency, but also few samples of patients with the clinical diagnosis of CBD and PSP caused the same effect. Notably, the final RT-QuIC aggregates obtained from MSA and PD samples owned peculiar biochemical and morphological features potentially enabling their discrimination. CONCLUSIONS: Our study provide the proof-of-concept that olfactory mucosa samples collected from patients with PD and MSA possess important seeding activities for α-synuclein. Additional studies are required for (i) estimating sensitivity and specificity of the technique and for (ii) evaluating its application for the diagnosis of PD and neurodegenerative parkinsonisms. RT-QuIC analyses of OM and cerebrospinal fluid (CSF) can be combined with the aim of increasing the overall diagnostic accuracy of these diseases, especially in the early stages.

Substantia nigra in Parkinson's disease: a multimodal MRI comparison between early and advanced stages of the disease.

This study focused on the substantia nigra (SN) in Parkinson's disease (PD). We measured its area and volume, mean diffusivity (MD), fractional anisotropy (FA) and iron concentration in early and late PD and correlated the values with clinical scores. Twenty-two early PD (EPD), 20 late PD (LPD) and 20 healthy subjects (age 64.7 ± 4.9, 60.5 ± 6.1, and 61 ± 7.2 years, respectively) underwent 1.5 T MR imaging with double-TI-IR T1-weighted, T2*-weighted and diffusion tensor imaging scans. Relative SN area, MD, FA and R2* were measured in ROIs traced on SN. Correlation with Unified Parkinson Disease Rating Scale (UPDRS) scores was assessed. In LPD, the SN area was significantly reduced with respect to EPD (p = 0.04) and control subjects (p < 0.001). In EPD, the SN area was also significantly smaller than in controls (p = 0.006). Similarly, the SN volume significantly differed between LPD and controls (p = 0.001) and between EPD and LPD (p = 0.049), while no significant differences were found between controls and EPD. Both SN area (r = 0.47, p = 0.004) and volume (r = 0.46, p = 0.005) correlated with UPDRS scores. At 1.5 T, SN morphological measurements were sensitive to early PD changes and able to track the disease progression, while MD and FA measures and relaxometry did not provide significant results.

Different mutations at V363 MAPT codon are associated with atypical clinical phenotypes and show unusual structural and functional features.

Microtubule-associated protein tau gene (MAPT) is one of the major genes linked to frontotemporal lobar degeneration, a group of neurodegenerative diseases clinically, pathologically, and genetically heterogeneous. In particular, MAPT mutations give rise to the subgroup of tauopathies. The pathogenetic mechanisms underlying the MAPT mutations so far described are the decreased ability of tau protein to promote microtubule polymerization (missense mutations) or the altered ratio of tau isoforms (splicing mutations), both leading to accumulation of hyperphosphorylated filamentous tau protein. Following a genetic screening of patients affected by frontotemporal lobar degeneration, we identified 2 MAPT mutations, V363I and V363A, leading to atypical clinical phenotypes, such as posterior cortical atrophy. We investigated in vitro features of the recombinant mutated tau isoforms and revealed unusual functional and structural characteristics such as an increased ability to promote microtubule polymerization and a tendency to form oligomeric instead of filamentous aggregates. Thus, we disclosed a greater than expected complexity of abnormal features of mutated tau isoforms. Overall our findings suggest a high probability that these mutations are pathogenic.

Botulinum neurotoxins for post-stroke spasticity in adults: a systematic review.

The aim of this systematic review was to determine whether botulinum neurotoxin (BoNT) reduce spasticity or improve function in adult patients after stroke. Eleven double-blind randomized placebo-controlled trials met inclusion criteria. They encompassed 782 patients, 767 (98%) of whom received BoNT/A, and 15 (2%) BoNT/B. Most studies used the Ashworth scale as primary outcome measure. Differences between treated and control groups were assessed as categorical or continuous comparisons. The overall effect on upper limb spasticity was in favor of BoNT/A. A significantly higher number of patients had a reduction of upper limb spasticity at 4-week and 8-week evaluations in the treatment group compared with placebo. Mean changes in joint spasticity revealed improvement 3 to 6 weeks and 9 to 12 weeks after treatment. There were insufficient data to establish BoNT/A efficacy on lower limb spasticity or the effect of BoNT/B on the upper and lower limbs. Because of inconsistency and heterogeneity of the available data, it was not possible to perform a meta-analysis on disability and patients' reported outcomes. There was an overlapping safety profile between the treatment and the placebo groups. BoNT/A reduces upper limb spasticity in patients post-stroke, but the improvement in functional ability remains to be established. This gap needs to be filled by new studies to assess the effect of BoNT in the context of multidisciplinary patient management.

Non-DYT1 early-onset primary torsion dystonia: comparison with DYT1 phenotype and review of the literature.

To investigate the clinical features of early-onset primary torsion dystonia (EO-PTD), 57 consecutive genetically characterized patients with onset before 21 years were studied. Sex, ethnic origin, family history of dystonia, age at onset, disease duration, site of dystonia onset and distribution at latest examination, dystonia progression, time to generalization, and motor disability were noted. The 14 patients (25%) with GAG deletion (904_906/907_909delGAG) in the DYT1 gene were compared with the remaining non-DYT1 patients. Cranial involvement was present in 49% of non-DYT1 cases, but only 14% of DYT1 cases; non-DYT1 patients were younger at time of generalization. DYT1 cases had features similar to sporadic non-DYT1 cases but differed markedly from familial non-DYT1 cases, the latter having later age at onset, less common limb onset, more frequent cervical involvement, and slower progression than DYT1 PTD. These findings indicate that non-DYT1 forms of EO-PTD differ clinically from those of DYT1 forms. Cranial involvement before 21 years of age is the strongest predictor of non-DYT1 status. Positive family history and cervical involvement are associated with less severe progression in non-DYT1 forms.