Brain hypometabolism in non-demented microtubule-associated protein tau H1 carriers with Parkinson's disease

BACKGROUND AND PURPOSE

The microtubule-associated protein tau (MAPT) H1 homozygosity (H1/H1 haplotype) is a genetic risk factor for neurodegenerative diseases, such as Parkinson's disease (PD). MAPT H1 homozygosity has been associated with conversion to PD; however, results are conflicting since some studies did not find a strong influence. Cortical hypometabolism is associated with cognitive impairment in PD. In this study, we aimed to evaluate the metabolic pattern in nondemented PD patients MAPT H1/H1 carriers in comparison with MAPT H1/H2 haplotype. In addition, we evaluated domain-specific cognitive differences according to MAPT haplotype.

METHODS

We compared a group of 26 H1/H1 and 20 H1/H2 carriers with late-onset PD. Participants underwent a comprehensive neuropsychological cognitive evaluation and a [18F]-Fluorodeoxyglucose PET-MR scan.

RESULTS

MAPT H1/H1 carriers showed worse performance in the digit span forward test of attention compared to MAPT H1/H2 carriers. In the [18F]-Fluorodeoxyglucose PET comparisons, MAPT H1/H1 displayed hypometabolism in the frontal cortex, parahippocampal, and cingulate gyrus, as well as in the caudate and globus pallidus.

CONCLUSION

PD patients MAPT H1/H1 carriers without dementia exhibit relative hypometabolism in several cortical areas as well as in the basal ganglia, and worse performance in attention than MAPT H1/H2 carriers. Longitudinal studies should assess if lower scores in attention and dysfunction in these areas are predictors of dementia in MAPT H1/H1 homozygotes.

Prospective Long-term Follow-up of Focused Ultrasound Unilateral Subthalamotomy for Parkinson Disease

BACKGROUND AND OBJECTIVES

Unilateral Magnetic Resonance-guided Focused Ultrasound subthalamotomy (FUS-STN) has been shown to improve the cardinal motor features of Parkinson's disease (PD). Whether this effect is sustained is not known. This study aims to report the long-term outcome of PD patients treated with unilateral FUS-STN.

METHODS

We conducted a prospective, open-label study of asymmetrical PD patients who underwent unilateral FUS-STN. All patients were evaluated up to 36 months after treatment. The primary outcome was the difference from baseline to 36 months after FUS-STN in the score of the Movement Disorders Society-Unified Rating scale (MDS-UPDRS) motor part (III) for the treated hemibody in the off-medication state. The safety outcome included all adverse events occurring during follow-up. Secondary outcomes were the change in the MDS-UPDRS III score on-medication; sub-scores of rigidity, bradykinesia, tremor, and axial features; total MDS-UPDRS III; and the MDS-UPDRS part IV. Functional disability and quality of life were assessed using the MDS-UPDRS II and the PDQ39, respectively. Patient impression of change and satisfaction with the treatment were self-assessed. The Wilcoxon signed-rank test with subsequent Bonferroni's correction was used for data analysis.

RESULTS

Thirty-two PD patients were evaluated 36 months after treatment. The mean (±SD) age at baseline was 56.0±10.1 years, with a mean disease duration of 6.8±2.8 years. The MDS-UPDRS III score for the treated hemibody off-medication was improved by 52.3% from baseline to 3 years (score reduction from 19.0±3.2 to 8.9±3.3, 95% confidence interval [95CI] 8.7 to 11.6, P<0.001), and all specific motor features were improved from baseline. No disabling or delayed adverse events were reported. The total MDS-UPDRS III off-medication score was 22.9% lower at 3 years than before treatment (36.8±7.4 vs 27.4±6.2, 95CI 6.0 to 11.5, P<0.001). The MDS-UPDRS II, IV, and PDQ39 scores and levodopa dose were equivalent to those at baseline.

DISCUSSION

The benefit of unilateral FUS-STN on PD motor features is sustained in the long term. FUS-STN contributes to better clinical control over several years of evolution. NCT02912871/03454425.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence on the utility of focused ultrasound unilateral subthalamotomy in the treatment of people with Parkinson's disease.

Striatal Blood-Brain Barrier Opening in Parkinson's Disease Dementia: A Pilot Exploratory Study

BACKGROUND

Parkinson's disease (PD) exhibits a high prevalence of dementia as disease severity and duration progress. Focused ultrasound (FUS) has been applied for transient blood-brain barrier (BBB) opening of cortical regions in neurodegenerative disorders. The striatum is a primary target for delivery of putative therapeutic agents in PD.

OBJECTIVE

Here, we report a prospective, single-arm, nonrandomized, proof-of-concept, phase I clinical trial (NCT03608553 amended) in PD with dementia to test the safety and feasibility of striatal BBB opening in PD patients.

METHODS

Seven PD patients with cognitive impairment were treated for BBB opening in the posterior putamen. This was performed in two sessions separated by 2 to 4 weeks, where the second session included bilateral putamina opening in 3 patients. Primary outcome measures included safety and feasibility of focal striatal BBB opening. Changes in motor and cognitive functions, magnetic resonance imaging (MRI), ¹⁸ F-fluorodopa (FDOPA), and β-amyloid PET (positron emission tomography) images were determined.

RESULTS

The procedure was feasible and well tolerated, with no serious adverse events. No neurologically relevant change in motor and cognitive (battery of neuropsychological tests) functions was recognized at follow-up. MRI revealed putamen BBB closing shortly after treatment (24 hours to 14 days) and ruled out hemorrhagic and ischemic lesions. There was a discrete but significant reduction in β-amyloid uptake in the targeted region and no change in FDOPA PET.

CONCLUSIONS

These initial results indicate that FUS-mediated striatal BBB opening is feasible and safe and therefore could become an effective tool to facilitate the delivery of putative neurorestorative molecules in PD. © 2022 International Parkinson and Movement Disorder Society.

Bilateral staged magnetic resonance-guided focused ultrasound thalamotomy for the treatment of essential tremor: a case series study

BACKGROUND

Unilateral magnetic resonance-guided focused ultrasound (FUS) thalamotomy is efficacious for the treatment of medically refractory essential tremor (ET). Viability of bilateral FUS ablation is unexplored.

METHODS

Patients diagnosed with medically refractory ET and previously treated with unilateral FUS thalamotomy at least 5 months before underwent bilateral treatment. The timepoints were baseline (before first thalamotomy) and FUS1 and FUS2 (4 weeks before and 6 months after second thalamotomy, respectively). The primary endpoint was safety. Efficacy was assessed through the Clinical Rating Scale for Tremor (CRST), which includes subscales for tremor examination (part A), task performance (part B) and tremor-related disability (part C).

RESULTS

Nine patients were treated. No permanent adverse events were registered. Six patients presented mild gait instability and one dysarthria, all resolving within the first few weeks. Three patients reported perioral hypoesthesia, resolving in one case. Total CRST score improved by 71% from baseline to FUS2 (from 52.3±12 to 15.5±9.4, p<0.001), conveying a 67% reduction in bilateral upper limb A+B (from 32.3±7.8 to 10.8±7.3, p=0.001). Part C decreased by 81% (from 16.4±3.6 to 3.1±2.9, p<0.001). Reduction in head and voice tremor was 66% (from 1.2±0.44 to 0.4±0.54, p=0.01) and 45% (from 1.8±1.1 to 1±0.8, p=0.02), respectively.

CONCLUSION

Bilateral staged FUS thalamotomy for ET is feasible and might be safe and effective. Voice and head tremor might also improve. A controlled study is warranted.

Cortical disinhibition in Parkinson's disease

In Parkinson's disease, striatal dopamine depletion produces profound alterations in the neural activity of the cortico-basal ganglia motor loop, leading to dysfunctional motor output and parkinsonism. A key regulator of motor output is the balance between excitation and inhibition in the primary motor cortex, which can be assessed in humans with transcranial magnetic stimulation techniques. Despite decades of research, the functional state of cortical inhibition in Parkinson's disease remains uncertain. Towards resolving this issue, we applied paired-pulse transcranial magnetic stimulation protocols in 166 patients with Parkinson's disease (57 levodopa-naïve, 50 non-dyskinetic, 59 dyskinetic) and 40 healthy controls (age-matched with the levodopa-naïve group). All patients were studied OFF medication. All analyses were performed with fully automatic procedures to avoid confirmation bias, and we systematically considered and excluded several potential confounding factors such as age, gender, resting motor threshold, EMG background activity and amplitude of the motor evoked potential elicited by the single-pulse test stimuli. Our results show that short-interval intracortical inhibition is decreased in Parkinson's disease compared to controls. This reduction of intracortical inhibition was obtained with relatively low-intensity conditioning stimuli (80% of the resting motor threshold) and was not associated with any significant increase in short-interval intracortical facilitation or intracortical facilitation with the same low-intensity conditioning stimuli, supporting the involvement of cortical inhibitory circuits. Short-interval intracortical inhibition was similarly reduced in levodopa-naïve, non-dyskinetic and dyskinetic patients. Importantly, intracortical inhibition was reduced compared to control subjects also on the less affected side (n = 145), even in de novo drug-naïve patients in whom the less affected side was minimally symptomatic (lateralized Unified Parkinson's Disease Rating Scale part III = 0 or 1, n = 23). These results suggest that cortical disinhibition is a very early, possibly prodromal feature of Parkinson's disease.

Blood-brain barrier opening with focused ultrasound in Parkinson's disease dementia

MR-guided focused ultrasound (MRgFUS), in combination with intravenous microbubble administration, has been applied for focal temporary BBB opening in patients with neurodegenerative disorders and brain tumors. MRgFUS could become a therapeutic tool for drug delivery of putative neurorestorative therapies. Treatment for Parkinson’s disease with dementia (PDD) is an important unmet need. We initiated a prospective, single-arm, non-randomized, proof-of-concept, safety and feasibility phase I clinical trial (NCT03608553), which is still in progress. The primary outcomes of the study were to demonstrate the safety, feasibility and reversibility of BBB disruption in PDD, targeting the right parieto-occipito-temporal cortex where cortical pathology is foremost in this clinical state. Changes in β-amyloid burden, brain metabolism after treatments and neuropsychological assessments, were analyzed as exploratory measurements. Five patients were recruited from October 2018 until May 2019, and received two treatment sessions separated by 2–3 weeks. The results are set out in a descriptive manner. Overall, this procedure was feasible and reversible with no serious clinical or radiological side effects. We report BBB opening in the parieto-occipito-temporal junction in 8/10 treatments in 5 patients as demonstrated by gadolinium enhancement. In all cases the procedures were uneventful and no side effects were encountered associated with BBB opening. From pre- to post-treatment, mild cognitive improvement was observed, and no major changes were detected in amyloid or fluorodeoxyglucose PET. MRgFUS-BBB opening in PDD is thus safe, reversible, and can be performed repeatedly. This study provides encouragement for the concept of BBB opening for drug delivery to treat dementia in PD and other neurodegenerative disorders.

Blood brain barrier (BBB) opening is being investigated as a therapeutic approach for neurodegenerative diseases. Here, the authors report the results of a phase I trial to evaluate the feasibility and safety of BBB opening of the right parieto-occipito-temporal cortex in Parkinson´s disease with dementia.

[Mortality in patients with intracerebral haemorrhage associated with oral anticoagulation. Efficacy of a reversal protocol and clinical follow-up (ICH-OAC project)]

INTRODUCTION

Spontaneous intracerebral haemorrhage associated with oral anticoagulants (ICH-OAC) has a high mortality rate. The emergence of new anticoagulant drugs and reversal protocols increases interest in this entity.

OBJECTIVES

The main objective is to determine the mortality rate in patients with ICH-OAC (early, in-hospital, global) in our health area and to analyse the main variables related to it. The secondary objective is to determine the efficacy of anticoagulation reversal therapies (ART) as reflected by radiological expansion of the haematoma and the functional prognosis.

PATIENTS AND METHODS

A prospective observational study that introduced a protocol aimed at the management of patients with ICH-OAC. It included general measures and neuromonitoring, individualised administration of ART, cranial tomography and a six-month follow-up. Data on the drugs prescribed in the area during this period, mortality and functional prognosis were collected. A bivariate and logistic regression study was designed to investigate mortality-related variables.

RESULTS

Forty-nine patients were included over three years; of these, 71.4% received ART. Mortality was 16.3% (first 24 hours), 53.1% (admission) and 61.2% (180 days). Lower survival was observed among patients with higher baseline scores on the National Institutes of Health Stroke Scale (NIHSS) (p < 0.0001), creatinine value (p = 0.02), International Normalised Index (p = 0.048), bleeding volume (p = 0.008), hydrocephalus (p = 0.015) and acenocoumarol intake (p = 0.030). Patients who did not receive ART had a greater rate of early mortality (p = 0.003). The only variable independently related to overall mortality was the baseline NIHSS score (odds ratio = 1.282; 95% confidence interval: 1.023-1.608; p = 0.031).

CONCLUSIONS

ICH-OAC has a high mortality rate, related to the use of acenocoumarol and regardless of the initial clinical situation. A lower rate of early mortality was found among patients who received ART.

Randomized Trial of Focused Ultrasound Subthalamotomy for Parkinson's Disease

BACKGROUND

The subthalamic nucleus is the preferred neurosurgical target for deep-brain stimulation to treat cardinal motor features of Parkinson's disease. Focused ultrasound is an imaging-guided method for creating therapeutic lesions in deep-brain structures, including the subthalamic nucleus.

METHODS

We randomly assigned, in a 2:1 ratio, patients with markedly asymmetric Parkinson's disease who had motor signs not fully controlled by medication or who were ineligible for deep-brain stimulation surgery to undergo focused ultrasound subthalamotomy on the side opposite their main motor signs or a sham procedure. The primary efficacy outcome was the between-group difference in the change from baseline to 4 months in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (i.e., part III) for the more affected body side (range, 0 to 44, with higher scores indicating worse parkinsonism) in the off-medication state. The primary safety outcome (procedure-related complications) was assessed at 4 months.

RESULTS

Among 40 enrolled patients, 27 were assigned to focused ultrasound subthalamotomy (active treatment) and 13 to the sham procedure (control). The mean MDS-UPDRS III score for the more affected side decreased from 19.9 at baseline to 9.9 at 4 months in the active-treatment group (least-squares mean difference, 9.8 points; 95% confidence interval [CI], 8.6 to 11.1) and from 18.7 to 17.1 in the control group (least-squares mean difference, 1.7 points; 95% CI, 0.0 to 3.5); the between-group difference was 8.1 points (95% CI, 6.0 to 10.3; P<0.001). Adverse events in the active-treatment group were dyskinesia in the off-medication state in 6 patients and in the on-medication state in 6, which persisted in 3 and 1, respectively, at 4 months; weakness on the treated side in 5 patients, which persisted in 2 at 4 months; speech disturbance in 15 patients, which persisted in 3 at 4 months; facial weakness in 3 patients, which persisted in 1 at 4 months; and gait disturbance in 13 patients, which persisted in 2 at 4 months. In 6 patients in the active-treatment group, some of these deficits were present at 12 months.

CONCLUSIONS

Focused ultrasound subthalamotomy in one hemisphere improved motor features of Parkinson's disease in selected patients with asymmetric signs. Adverse events included speech and gait disturbances, weakness on the treated side, and dyskinesia. (Funded by Insightec and others; ClinicalTrials.gov number, NCT03454425.).

Transcranial Magnetic Resonance-Guided Focused Ultrasound Thalamotomy in Essential Tremor: A Comprehensive Lesion Characterization

BACKGROUND

Transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) thalamotomy is a novel and effective treatment for controlling tremor in essential tremor patients.

OBJECTIVE

To provide a comprehensive characterization of the radiological, topographical, and volumetric aspects of the tcMRgFUS thalamic lesion, and to quantify how they relate to the clinical outcomes.

METHODS

In this study, clinical and radiological data from forty patients with medically-refractory essential tremor treated with unilateral tcMRgFUS thalamotomy were retrospectively analyzed. Treatment efficacy was assessed with Clinical Rating Scale for Tremor (CRST). Lesions were manually segmented on T1, T2, and susceptibility-weighted images, and 3-dimensional topographical analysis was then carried out. Statistical comparisons were performed using nonparametric statistics.

RESULTS

The greatest clinical improvement was correlated with a more inferior and posterior lesion, a bigger lesion volume, and percentage of the ventral intermediate nucleus covered by the lesion; whereas, the largest lesions accounted for the occurrence of gait imbalance. Furthermore, the volume of the lesion was significantly predicted by the number of sonications surpassing 52°C.

CONCLUSION

Here we provide a comprehensive characterization of the thalamic tcMRgFUS lesion including radiological and topographical analysis. Our results indicate that the location and volume of the lesion were significantly associated with the clinical outcome and that mid-temperatures may be responsible for the lesion size. This could serve ultimately to improve targeting and judgment and to optimize clinical outcome of tcMRgFUS thalamotomy.

Has the aetiology of ischaemic stroke changed in the past decades? Analysis and comparison of data from current and historical stroke databases

OBJECTIVES

We aimed to determine whether the aetiology of ischaemic stroke has changed in recent years and, if so, to ascertain the possible reasons for these changes.

PATIENTS AND METHODS

We analysed the epidemiological history and vascular risk factors of all patients diagnosed with ischaemic stroke at Complejo Hospitalario Universitario de Albacete (CHUA) from 2009 to 2014. Ischaemic stroke subtypes were established using the TOAST criteria. Our results were compared to data from the classic Stroke Data Bank (SDB); in addition, both series were compared to those of other hospital databases covering the period between the two.

RESULTS

We analysed 1664 patients (58% were men) with a mean age of 74 years. Stroke aetiology in both series (CHUA, SDB) was as follows: atherosclerosis (12%, 9%), small-vessel occlusion (13%, 25%), cardioembolism (32%, 19%), stroke of other determined aetiology (3%, 4%), and stroke of undetermined aetiology (40%, 44%). Sixty-three percent of the patients from the CHUA and 42% of the patients from the SDB were older than 70 years. Cardioembolic strokes were more prevalent in patients older than 70 years in both series. Untreated hypertension was more frequent in the SDB (SDB = 31% vs CHUA = 10%). The analysis of other databases shows that the prevalence of cardioembolic stroke is increasing worldwide.

CONCLUSIONS

Our data show that the prevalence of lacunar strokes is decreasing worldwide whereas cardioembolic strokes are increasingly more frequent in both our hospital and other series compared to the SDB. These differences may be explained by population ageing and the improvements in management of hypertension and detection of cardioembolic arrhythmias in stroke units.

Effect of metallation, substituents and inter/intra-molecular polarization on electronic couplings for hole transport in stacked porphyrin dyads

Hole transport properties for stacked porphyrins are analyzed with density functional theory.

[IMSIII, SYNTHESIS, and MR-RESCUE studies: the end of endovascular treatment for stroke?]

Last March, in a single issue New England Journal of Medicine published 3 studies that evaluated the efficacy of endovascular treatment for ischemic stroke, leading to a heated controversy between neurologists and interventional neuroradiologists. The negative results have resulted in numerous reviews pointing out serious methodological defects. In this article, we analyze the outcomes of thrombolytic treatment for stroke and discuss the strengths and weaknesses of the three above-mentioned studies. Despite the negative results, these studies can point the way for new trials that will justify this treatment modality that is backed up by scientific evidence.

Hemorrhage/contrast staining areas after mechanical intra-arterial thrombectomy in acute ischemic stroke: imaging findings and clinical significance

BACKGROUND AND PURPOSE

The aim of this study was to report the CT evolution and clinical significance of HCA after intra-arterial mechanical thrombectomy (revascularization by using retrievers and/or other mechanical devices without concomitant delivery of intra-arterial thrombolytics) in our patients. These lesions are common after intra-arterial thrombolysis, being considered a negative prognostic sign. Their significance after pure mechanical thrombectomy remains unknown.

MATERIALS AND METHODS

Forty-eight patients were treated with mechanical thrombectomy by using retrievable stents between April 2010 and February 2011. All patients underwent initial (first 24 hours) and follow-up (48-72 hours) nonenhanced CT. We retrospectively analyzed the clinical and radiologic data of the patients with HCA and compared them with controls.

RESULTS

Fifteen of 48 patients presented with HCA. The site of occlusion was the MCA in 7 patients, both the extra- and intracranial segments of the ICA in 6, and the intracranial ICA in 2. In 7 patients, previous intravenous thrombolysis was administered. Complete recanalization (TICI 3) was achieved in 12 patients, and incomplete recanalization (TICI 2b), in 3. The location of HCA was the subarachnoid space in 6 patients, the brain parenchyma in 4 patients, and both in 5 patients. The HCA were asymptomatic in all patients. There was no statistical difference in final NIHSS score reduction (NIHSS pretreatment-NIHSS at discharge) between patients and controls.

CONCLUSIONS

In our series, HCA are common after mechanical thrombectomy but do not carry an increased risk of symptomatic hemorrhage or negative prognosis. These data might be related to the high rate of recanalization and the absence of intra-arterial thrombolytics.

[Non-motor disorders in Parkinson's disease: introduction and general features]

INTRODUCTION

Two hundred years ago James Parkinson accurately described the disease that bears his name today, focusing not only on motor aspects but also on non-motor symptoms suffered by these patients.

DEVELOPMENT

Non-motor symptoms are prevalent and decrease the quality of life of the patients with Parkinson's disease. In recent years, some non-motor scales have been developed to avoid the problem of underdiagnosis. Moreover, some of them have been proposed as clinical predictors for Parkinson's disease and it is has been suggested that individuals with any of these non-motor symptoms and without motor manifestations of the disease could be the aim for neuroprotective therapies when they become available.

CONCLUSIONS

Non-motor symptoms are prevalent and have a great impact in the quality of life of patients. Therefore, it is important to detect and treat them. Their role as predictors of the disease is unclear yet.