[Towards a positive physiological definition of the deep brain nuclei in humans]

INTRODUCTION

Using microelectrodes for recording purposes in deep brain stimulation (DBS) has proven to be very useful. Their efficiency can be improved by characterising the properties of extracellular action potentials (EAPs).

PATIENTS AND METHODS

We analysed the records of nine patients who underwent surgery for epilepsy or aggressiveness under general anaesthesia. The properties of the EAPs of the centromedian, ventral intermediate, ventrocaudal and posteromedial hypothalamic nuclei of the thalamus have been determined.

RESULTS

We have analysed 706 thalamic and 142 hypothalamic cells. The proportion of cell types was found to be specific to each cell nucleus. The most frequent cell type was P1P2N1 (59.5%), followed by N1P1N2 (23.1%). The first phase of the EAP is highly variable. The properties of the EAP phases of the same morphology differ greatly from one nucleus to another.

CONCLUSIONS

We have shown that several deep brain nuclei have properties that are specific to the morphology of the EAPs. This will allow for improved localisation of these nuclei during DBS.

Trial of Prasinezumab in Early-Stage Parkinson's Disease

BACKGROUND

Aggregated α-synuclein plays an important role in the pathogenesis of Parkinson's disease. The monoclonal antibody prasinezumab, directed at aggregated α-synuclein, is being studied for its effect on Parkinson's disease.

METHODS

In this phase 2 trial, we randomly assigned participants with early-stage Parkinson's disease in a 1:1:1 ratio to receive intravenous placebo or prasinezumab at a dose of 1500 mg or 4500 mg every 4 weeks for 52 weeks. The primary end point was the change from baseline to week 52 in the sum of scores on parts I, II, and III of the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS; range, 0 to 236, with higher scores indicating greater impairment). Secondary end points included the dopamine transporter levels in the putamen of the hemisphere ipsilateral to the clinically more affected side of the body, as measured by ¹²³I-ioflupane single-photon-emission computed tomography (SPECT).

RESULTS

A total of 316 participants were enrolled; 105 were assigned to receive placebo, 105 to receive 1500 mg of prasinezumab, and 106 to receive 4500 mg of prasinezumab. The baseline mean MDS-UPDRS scores were 32.0 in the placebo group, 31.5 in the 1500-mg group, and 30.8 in the 4500-mg group, and mean (±SE) changes from baseline to 52 weeks were 9.4±1.2 in the placebo group, 7.4±1.2 in the 1500-mg group (difference vs. placebo, -2.0; 80% confidence interval [CI], -4.2 to 0.2; P = 0.24), and 8.8±1.2 in the 4500-mg group (difference vs. placebo, -0.6; 80% CI, -2.8 to 1.6; P = 0.72). There was no substantial difference between the active-treatment groups and the placebo group in dopamine transporter levels on SPECT. The results for most clinical secondary end points were similar in the active-treatment groups and the placebo group. Serious adverse events occurred in 6.7% of the participants in the 1500-mg group and in 7.5% of those in the 4500-mg group; infusion reactions occurred in 19.0% and 34.0%, respectively.

CONCLUSIONS

Prasinezumab therapy had no meaningful effect on global or imaging measures of Parkinson's disease progression as compared with placebo and was associated with infusion reactions. (Funded by F. Hoffmann-La Roche and Prothena Biosciences; PASADENA ClinicalTrials.gov number, NCT03100149.).

Comparison of the Results of a Parkinson's Holter Monitor With Patient Diaries, in Real Conditions of Use: A Sub-analysis of the MoMoPa-EC Clinical Trial

Background

For specialists in charge of Parkinson's disease (PD), one of the most time-consuming tasks of the consultations is the assessment of symptoms and motor fluctuations. This task is complex and is usually based on the information provided by the patients themselves, which in most cases is complex and biased. In recent times, different tools have appeared on the market that allow automatic ambulatory monitoring. The MoMoPa-EC clinical trial (NCT04176302) investigates the effect of one of these tools—Sense4Care's STAT-ON—can have on routine clinical practice. In this sub-analysis the agreement between the Hauser diaries and the STAT-ON sensor is analyzed.

Methods

Eighty four patients from MoMoPa-EC cohort were included in this sub-analysis. The intraclass correlation coefficient was calculated between the patient diary entries and the sensor data.

Results

The intraclass correlation coefficient of both methods was 0.57 (95% CI: 0.3–0.73) for the OFF time (%), 0.48 (95% CI: 0.17–0.68) for the time in ON (%), and 0.65 (95% CI%: 0.44–0.78) for the time with dyskinesias (%). Furthermore, the Spearman correlations with the UPDRS scale have been analyzed for different parameters of the two methods. The maximum correlation found was −0.63 (p < 0.001) between Mean Fluidity (one of the variables offered by the STAT-dON) and factor 1 of the UPDRS.

Conclusion

This sub-analysis shows a moderate concordance between the two tools, it is clearly appreciated that the correlation between the different UPDRS indices is better with the STAT-ON than with the Hauser diary.

Trial Registration

https://clinicaltrials.gov/show/NCT04176302 (NCT04176302).

Deep brain stimulation in Parkinson's disease: analysis of brain fractional anisotropy differences in operated patients

INTRODUCTION

Deep brain stimulation (DBS) of the subthalamic nucleus is currently an evidence-based therapeutic option for motor symptoms in patients with Parkinson's disease (PD), although other non-motor symptoms can be affected by stimulation.

AIM

Our objective is to evaluate the global changes in the connectivity of the large-scale structural network in PD patients that have obtained a benefit from subthalamic DBS.

SUBJECTS AND METHODS

Retrospective study of 31 subjects: 7 PD patients with subthalamic DBS (group A), 12 age and gender-matched non-operated PD (B) and 12 healthy controls (C). All subjects had undergone a 1.5 T brain MRI with DTI. DICOM images were processed with the FSL5.0 software and TBSS tool.

RESULTS

The study group comprised 23 men and 8 women. No statistically significant differences in age, gender, scores on the HandY scale and mean follow-up between group A and B were found, and in age and gender between groups A and C. Statistical analysis revealed differences in the fractional anisotropy of the different groups in certain areas: bilateral corticospinal tract, anterior thalamic radiations, bilateral fronto-occipital fascicle, both superior longitudinal fascicles, and left inferior longitudinal fascicle.

CONCLUSIONS

In our series, PD patients treated with bilateral subthalamic DBS showed a significantly higher fractional anisotropy in widespread areas of the cerebral white matter; suggesting that neuromodulation produces connectivity changes in different neural networks.

Identifying comorbidities and lifestyle factors contributing to the cognitive profile of early Parkinson's disease

BACKGROUND

Identifying modifiable risk factors for cognitive impairment in the early stages of Parkinson's disease (PD) and estimating their impact on cognitive status may help prevent dementia (PDD) and the design of cognitive trials.

METHODS

Using a standard approach for the assessment of global cognition in PD and controlling for the effects of age, education and disease duration, we explored the associations between cognitive status, comorbidities, metabolic variables and lifestyle variables in 533 PD participants from the COPPADIS study.

RESULTS

Among the overall sample, 21% of participants were classified as PD-MCI (n = 114) and 4% as PDD (n = 26). The prevalence of hypertension, diabetes and dyslipidemia was significantly higher in cognitively impaired patients while no between-group differences were found for smoking, alcohol intake or use of supplementary vitamins. Better cognitive scores were significantly associated with regular physical exercise (p < 0.05) and cognitive stimulation (< 0.01). Cognitive performance was negatively associated with interleukin 2 (Il2) (p < 0.05), Il6 (p < 0.05), iron (p < 0.05), and homocysteine (p < 0.005) levels, and positively associated with vitamin B12 levels (p < 0.005).

CONCLUSIONS

We extend previous findings regarding the positive and negative influence of various comorbidities and lifestyle factors on cognitive status in early PD patients, and reinforce the need to identify and treat potentially modifiable variables with the intention of exploring the possible improvement of the global cognitive status of patients with PD.

Present and Future of Parkinson's Disease in Spain: PARKINSON-2030 Delphi Project

Parkinson's disease (PD) is a chronic progressive and irreversible disease and the second most common neurodegenerative disease worldwide. In Spain, it affects around 120.000-150.000 individuals, and its prevalence is estimated to increase in the future. PD has a great impact on patients' and caregivers' lives and also entails a substantial socioeconomic burden. The aim of the present study was to examine the current situation and the 10-year PD forecast for Spain in order to optimize and design future management strategies. This study was performed using the modified Delphi method to try to obtain a consensus among a panel of movement disorders experts. According to the panel, future PD management will improve diagnostic capacity and follow-up, it will include multidisciplinary teams, and innovative treatments will be developed. The expansion of new technologies and studies on biomarkers will have an impact on future PD management, leading to more accurate diagnoses, prognoses, and individualized therapies. However, the socio-economic impact of the disease will continue to be significant by 2030, especially for patients in advanced stages. This study highlighted the unmet needs in diagnosis and treatment and how crucial it is to establish recommendations for future diagnostic and therapeutic management of PD.

[Deep brain stimulation in drug-resistant epilepsy]

INTRODUCTION

Deep brain stimulation (DBS) in drug-resistant epilepsy has been applied to several brain targets. However, its exact mechanism of action is not known, and the diversity of targets makes it difficult to know the degree of evidence that supports its use.

DEVELOPMENT

A review of the literature on DBS for drug-resistant epilepsy was conducted. The efficacy of DBS in drug-resistant epilepsy seems to be mediated by a desynchronisation of neuronal activity at the epileptogenic focus or a modulation of the «circuitopathies» that exist in epilepsy, depending on the target. In DBS multiple cortical and subcortical structures have been used, but class I evidence exists only for DBS of the anterior nucleus of the thalamus.

CONCLUSIONS

DBS in epilepsy is still under investigation, with class I evidence for DBS of the anterior nucleus of the thalamus. The rest of the targets have yielded variable results that must be confirmed with randomised designs in larger series.

[Clinical experience in the treatment of motor fluctuations in Parkinson's disease. Delphi consensus of a group of experts in movement disorders]

INTRODUCTION

Motor fluctuations are one of the most common complications of Parkinson's disease and their treatment is still a complex matter. Therefore, from the Neurology Movement Disorders Group we present our clinical experience in the treatment of these complications, with the intention of it being useful in decision-making in daily clinical practice.

DEVELOPMENT

Nineteen questions were developed based on a literature review and an open survey answered by members of this group. These issues were discussed in two phases, using the Delphi methodology. Considering the results of the survey, levodopa dose adjustment and dopamine agonists are the option with the best efficacy/tolerability ratio in the treatment of motor fluctuations. Rotigotine is useful in the motor fluctuations associated with gastroparesis, and intermittent subcutaneous apomorphine has positive effects in patients with unpredictable off periods. The most relevant adverse effect associated with dopamine agonists is impulse control disorder. Catechol-O-methyltransferase inhibitors are useful in the initial stages of motor fluctuations, especially in wearing off. Monoamine oxidase inhibitors are generally drugs that are well-tolerated and useful in motor fluctuations. If these measures are not effective, second-line treatments should be indicated on a case-by-case basis.

CONCLUSION

The clinical profile of patients with Parkinson's disease is paramount in deciding the most appropriate therapy for the treatment of motor fluctuations.

[Bases of deep brain stimulation]

INTRODUCTION

Deep brain stimulation is an effective therapy that is being used in an increasing number of indications. The mechanisms by which it exerts its therapeutic effect are still largely unknown, although there is increasing evidence of its influence at various levels.

AIM

To review the existing literature on the mechanism of action of deep brain stimulation.

DEVELOPMENT

Deep brain stimulation acts on brain tissue that is stimulated at various levels: molecular, cellular and neural networks. Spatial, temporal and electrical factors are involved in its effectiveness, but it mainly seems to perform its function by replacing anomalous firing patterns, which are present in certain neurological and psychiatric diseases. Other mechanisms, such as neuroprotection or neurogenesis, remain under study.

CONCLUSIONS

Although many of the effects by which deep brain stimulation acts on the brain are still unknown, it seems to be a complex treatment, with large-scale effects, in which the correction of circuitopathies seems to prevail as the main mechanism.

Remote Monitoring of Treatment Response in Parkinson's Disease: The Habit of Typing on a Computer

OBJECTIVE

The recent advances in technology are opening a new opportunity to remotely evaluate motor features in people with Parkinson's disease (PD). We hypothesized that typing on an electronic device, a habitual behavior facilitated by the nigrostriatal dopaminergic pathway, could allow for objectively and nonobtrusively monitoring parkinsonian features and response to medication in an at-home setting.

METHODS

We enrolled 31 participants recently diagnosed with PD who were due to start dopaminergic treatment and 30 age-matched controls. We remotely monitored their typing pattern during a 6-month (24 weeks) follow-up period before and while dopaminergic medications were being titrated. The typing data were used to develop a novel algorithm based on recursive neural networks and detect participants' responses to medication. The latter were defined by the Unified Parkinson's Disease Rating Scale-III (UPDRS-III) minimal clinically important difference. Furthermore, we tested the accuracy of the algorithm to predict the final response to medication as early as 21 weeks prior to the final 6-month clinical outcome.

RESULTS

The score on the novel algorithm based on recursive neural networks had an overall moderate kappa agreement and fair area under the receiver operating characteristic (ROC) curve with the time-coincident UPDRS-III minimal clinically important difference. The participants classified as responders at the final visit (based on the UPDRS-III minimal clinically important difference) had higher scores on the novel algorithm based on recursive neural networks when compared with the participants with stable UPDRS-III, from the third week of the study onward.

CONCLUSIONS

This preliminary study suggests that remotely gathered unsupervised typing data allows for the accurate detection and prediction of drug response in PD. © 2019 International Parkinson and Movement Disorder Society.

Antidepressants in Parkinson's disease. Recommendations by the movement disorder study group of the Neurological Association of Madrid

INTRODUCTION

Although antidepressants are widely used in Parkinson's disease (PD), few well-designed studies to support their efficacy have been conducted.

DEVELOPMENT

These clinical guidelines are based on a review of the literature and the results of an AMN movement disorder study group survey.

CONCLUSIONS

Evidence suggests that nortriptyline, venlafaxine, paroxetine, and citalopram may be useful in treating depression in PD, although studies on paroxetine and citalopram yield conflicting results. In clinical practice, however, selective serotonin reuptake inhibitors are usually considered the treatment of choice. Duloxetine may be an alternative to venlafaxine, although the evidence for this is less, and venlafaxine plus mirtazapine may be useful in drug-resistant cases. Furthermore, citalopram may be indicated for the treatment of anxiety, atomoxetine for hypersomnia, trazodone and mirtazapine for insomnia and psychosis, and bupropion for apathy. In general, antidepressants are well tolerated in PD. However, clinicians should consider the anticholinergic effect of tricyclic antidepressants, the impact of serotonin-norepinephrine reuptake inhibitors on blood pressure, the extrapyramidal effects of antidepressants, and any potential interactions between monoamine oxidase B inhibitors and other antidepressants.

In vivo gastric detection of α-synuclein inclusions in Parkinson's disease

α-Synuclein inclusions have been identified in the brain and some parts of the enteric nervous system in Parkinson's disease cases. We aimed to assess these inclusions in gastric mucosa samples from patients with symptomatic Parkinson's disease. Random biopsies were performed by gastroscopy in 28 patients with Parkinson's disease and in 29 age- and sex-matched controls. Gastroscopy was performed to start enteral levodopa (L-dopa) therapy in cases and for diagnostic purposes in controls (gastroesophageal reflux, anemia, and abdominal pain were the main indications). The clinical definition of cases and controls was made a priori. Six controls had data suggestive of "mild presymptomatic parkinsonism". Biopsy specimens were immunostained for α-synuclein. The neuropathological diagnosis was established post hoc. No differences were found in the baseline characteristics of the groups. Positive fibers for the α-synuclein protein were observed in 17 of 28 (60.7%) Parkinson's disease patients, 1 of 23 controls (4.3%), and 1 of 6 (16.7%) cases of incident "mild presymptomatic parkinsonism." Neuropathological diagnosis based on α-synuclein immunostaining showed a sensitivity of 85% (95% confidence interval [CI] 62.1-96.8), specificity of 95% (95% CI 76.2-99.9) and area under the receiver operating characteristics curve (AUC) of 0.90 (95% CI 0.80-1.00). No adverse events occurred. Detection of α-synuclein inclusions in the gastric mucosa is a useful and safe tool providing in vivo evidence of the underlying neurodegenerative peripheral involvement linked to Parkinson's disease. Further studies are warranted to determine its pathophysiological implications.

[Accidental finding of a cri du chat syndrome in an adult patient by means of array-CGH]

INTRODUCTION

The cri du chat syndrome (CDCS) come from a partial or total deletion of the short arm of chromosome 5, being one of the most common deletion syndromes in human beings. The great majority of patients are diagnosed between the first month and first year of life, but herein we report a finding of a CDCS in a woman with a suspect of spinocerebellar ataxia, and a family medical record of ataxia and bipolar disorder. We pay special attention to the clinical features as well as the diagnostics tests, used to identify the CDCS.

CASE REPORT

We report a case of a 46 years-old woman showing a borderline intelligence and bilateral cataract surgery at the age of 43. Beginning of symptoms in childhood included hypoacusia, ataxia, dysarthria, dysphagia, depression, cognitive impairment and bipolar disorder. Physical examination showed microcephaly, micrognathia, talipes equinovarus and ataxia. Karyotype and array-CGH were carried out on peripheral blood. The patient showed a rearrangement involving chromosomes 5 and 15, as well as an inversion of chromosome 9: 45,XX,inv9(p11q13);t(5,15)(p15.33;q11.2). Array comparative genomic hybridization was performed showing a 2.91 Mb deletion at 5p15.33, genomic formula arr 5p15.33 (151537-3057771)x1. The deletion involved 20 genes, including TERT gene.

CONCLUSIONS

The multiple gene deletions confirmed the CDCS diagnosis, being responsible for the patient phenotype. It has been showed up the importance of using the correct diagnosis techniques (array-CGH, peripheral blood karyotype) as well as their appropriate choice.

[Vagus nerve stimulation in patients with migraine]

INTRODUCTION

Vagus nerve stimulation (VNS) has been approved for the treatment of refractory epilepsy when resective surgery is not possible, and has proved to be highly effective. Series published in the literature suggest a beneficial effect of VNS in the treatment of migraine.

AIMS

To determine the degree to which headaches improve in patients with migraine after the placement of VNS to treat refractory epilepsy, and to evaluate what variables are associated with an increased chance of success with this measure.

PATIENTS AND METHODS

An observation-based retrospective study was conducted from 1st January 1999 until 31st December 2010. Patients with VNS for refractory epilepsy were contacted by telephone, after selecting those who fulfilled International Headache Society criteria for migraine. Data collected included age, gender, year of placement, age at onset of epilepsy and migraine, improvement of seizures and migraine, presence of migraine with aura and coexistence of anxious-depressive syndrome. Ninety-four patients with VNS were contacted and 13 patients with migraine were selected.

RESULTS

Following placement of the VNS, the number of episodes of migraine was seen to decrease by at least 50% in nine patients (69%) (p = 0.004) and there was a drop in the number of episodes of migraine in those patients who had also reduced their epileptic seizures (p = 0.012). No statistically significant associations were observed as regards sex, age, length of disease history, existence of migraine with aura or coexistence of anxious-depressive syndrome.

CONCLUSIONS

VNS could have beneficial effects for patients with migraine, especially in cases that are difficult to control. Due to the type of study, these conclusions must be taken with caution. Prospective clinical studies are needed before introducing the technique into daily clinical practice.

Body temperature and response to thrombolytic therapy in acute ischaemic stroke

OBJECTIVE

To determine the relationship between body temperature (BT), arterial recanalization, functional outcome, and hemorrhagic transformation (HT) of cerebral infarction in patients treated with i.v. tissue plasminogen activator (tPA).

METHODS

We studied 254 patients treated with tPA within 3 h from stroke onset. National Institute of Health Stroke Scale score, BT, and transcranial Doppler ultrasound (n = 99) on admission and at 24 h were recorded. Hypodensity volume and HT were evaluated on CT at 24-36 h. Poor outcome (Rankin Scale > 2) was evaluated at 3 months.

RESULTS

Arterial recanalization at 24 h was found in 70.7% of patients, HT in 24.8% (symptomatic in 4.7%) and poor outcome in 44.1%. Baseline BT was not associated with greater stroke severity at admission or at 24 h, HT or poor outcome. However, BT at 24 h correlated to stroke severity (P < 0.001) and hypodensity volume (P < 0.001) at 24 h, and was higher in patients who did not recanalize (P = 0.001), had symptomatic HT (P = 0.063) and poor outcome (P < 0.001). The adjusted odds ratio of poor outcome for patients with BT at 24 h > or = 37 degrees C was 2.56 (1.19-5.50, P = 0.016).

CONCLUSION

Body temperature > or =37 degrees C at 24 h, but not at baseline, is associated with a lack of recanalization, greater hypodensity volume and worse outcome in stroke patients treated with tPA.

Transient blepharospasm secondary to unilateral striatal infarction

We report on a patient who presented a transient eyelid motor disorder characterized by bilateral reflex blepharospasm as the main clinical manifestation of a right-sided striatal infarction. This case emphasizes the role of the nondominant striatum in the pathophysiology of eyelid motor abnormalities.