Novel RAB39B variant associated intellectual disability and levodopa-responsive young-onset parkinsonism

We report a 37-year-old Caucasian male with history of developmental delay, childhood onset Intellectual Disability (ID) and attention deficit hyperactivity disorder (ADHD) who presented at the age of 34 with tremor-dominant parkinsonism. Next Generation Sequencing (NGS) revealed pathogenic hemizygous sequence variant, c.200G > T, in the RAB39B gene. This report expands the number of described individuals with young onset PD associated with RAB39B mutation.

Interactive mobile application for Parkinson's disease deep brain stimulation (MAP DBS): An open-label, multicenter, randomized, controlled clinical trial

INTRODUCTION

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease (PD), but its efficacy is tied to DBS programming, which is often time consuming and burdensome for patients, caregivers, and clinicians. Our aim is to test whether the Mobile Application for PD DBS (MAP DBS), a clinical decision support system, can improve programming.

METHODS

We conducted an open-label, 1:1 randomized, controlled, multicenter clinical trial comparing six months of SOC standard of care (SOC) to six months of MAP DBS-aided programming. We enrolled patients between 30 and 80 years old who received DBS to treat idiopathic PD at six expert centers across the United States. The primary outcome was time spent DBS programming and secondary outcomes measured changes in motor symptoms, caregiver strain and medication requirements.

RESULTS

We found a significant reduction in initial visit time (SOC: 43.8 ± 28.9 min n = 37, MAP DBS: 27.4 ± 13.0 min n = 35, p = 0.001). We did not find a significant difference in total programming time between the groups over the 6-month study duration. MAP DBS-aided patients experienced a significantly larger reduction in UPDRS III on-medication scores (-7.0 ± 7.9) compared to SOC (-2.7 ± 6.9, p = 0.01) at six months.

CONCLUSION

MAP DBS was well tolerated and improves key aspects of DBS programming time and clinical efficacy.

Surgical Management of Parkinson's Disease in the Elderly

Background

Deep Brain Stimulation (DBS) is an increasingly popular therapy for Parkinson's Disease (PD). Despite the experience gained over time with DBS of either the subthalamus or the globus pallidus pars interna, there is still no consensus regarding the age limit for DBS indication.

Objectives

This narrative review of the literature discusses the issues of age and DBS, emphasizing the critical need for good quality evidence to support the surgical management of elderly patients with PD.

Methods

We searched PubMed using the terms Parkinson's Disease; Parkinson's Disease therapy; deep brain stimulation; antiparkinsonian agents therapeutic use; age factors; aged; aged, 80 and over; middle aged; treatment outcome; and risk assessments.

Results

We identified several limitations of the available evidence, such as under-representation of older patients in DBS studies, small sample sizes in studies with older participants, heterogeneity of outcomes, and conflicting results.

Conclusions

Despite preliminary suggestions that age might affect the outcomes of DBS, the evidence to support the hypothesis of age as an independent predictor of DBS outcomes is limited and results are controversial. Ultimately, finding an age-independent biomarker predicting DBS outcome is the final goal to expand this powerful treatment to all patients age in an effective and safe manner.

Outcomes for studies assessing the efficacy of hemostatic therapies in persons with congenital bleeding disorders

INTRODUCTION

Management strategies and hemostatic treatments to achieve control of bleeding are relevant across many disease areas. Identification of primary outcomes for studies assessing hemostatic intervention was the objective of a National Heart, Lung and Blood Institute (NHLBI) sponsored multidisciplinary initiative. The aim of this report is to summarize the evidence reviewed, and the outcomes identified by the subgroup tasked to assess outcomes for inherited bleeding disorders.

METHODS

The subgroup decided to focus on haemophilia, the prototypal congenital bleeding disorder and the one with the largest available body of evidence. MEDLINE, EMBASE and PsycINFO, The Cochrane Review, CINAHL, and Web of Science were searched for systematic and narrative reviews on outcomes used in haemophilia clinical trials. Three different clinical goals were identified as typical objectives of future research.

RESULTS

Out of 1322 unique citations, 24 reviews published in the period 2002-2019 were included. We identified 113 outcome measures, categorized in 6 domains: health-related quality of life (HRQoL), comorbidities and mortality, overall physical functioning and participation, bleeding and hemostasis, joint health, and costs and resource use. Three different clinical goals were identified as typical objectives of future research: Episodic 'on demand' replacement therapy, prevention of bleeding (Prophylaxis), and long-term and overall impact of bleeding. For each of these scenarios, specific outcomes were recommended.

CONCLUSIONS

Primary outcomes for clinical trials assessing the efficacy of hemostatic treatment in achieving control, prevention and limiting long-term consequences of bleeding in inherited bleeding disorders are suggested, and their strength and limitations discussed.

Interleaved deep brain stimulation for dyskinesia management in Parkinson's disease

BACKGROUND

In patients with Parkinson's disease, stimulation above the subthalamic nucleus (STN) may engage the pallidofugal fibers and directly suppress dyskinesia.

OBJECTIVES

The objective of this study was to evaluate the effect of interleaving stimulation through a dorsal deep brain stimulation contact above the STN in a cohort of PD patients and to define the volume of tissue activated with antidyskinesia effects.

METHODS

We analyzed the Core Assessment Program for Surgical Interventional Therapies dyskinesia scale, Unified Parkinson's Disease Rating Scale parts III and IV, and other endpoints in 20 patients with interleaving stimulation for management of dyskinesia. Individual models of volume of tissue activated and heat maps were used to identify stimulation sites with antidyskinesia effects.

RESULTS

The Core Assessment Program for Surgical Interventional Therapies dyskinesia score in the on medication phase improved 70.9 ± 20.6% from baseline with noninterleaved settings (P < 0.003). With interleaved settings, dyskinesia improved 82.0 ± 27.3% from baseline (P < 0.001) and 61.6 ± 39.3% from the noninterleaved phase (P = 0.006). The heat map showed a concentration of volume of tissue activated dorsally to the STN during the interleaved setting with an antidyskinesia effect.

CONCLUSION

Interleaved deep brain stimulation using the dorsal contacts can directly suppress dyskinesia, probably because of the involvement of the pallidofugal tract, allowing more conservative medication reduction. © 2019 International Parkinson and Movement Disorder Society.

The Relationship Between Serotonin-2A Receptor and Cognitive Functions in Nondemented Parkinson's Disease Patients with Visual Hallucinations

Background

There is growing evidence that the serotonergic system, in particular serotonin 2A receptors, is involved in neuropsychiatric symptoms in Parkinson's disease (PD), including cognitive processing and visual hallucinations. However, the relationship between serotonin 2A receptor availability, visual hallucinations, and cognitive profile is unknown. The objective of this study was to investigate the level of serotonin 2A receptor availability in brain regions affected by visual hallucinations and to test the association with cognitive/behavioral changes in patients who have PD with visual hallucinations.

Methods

Nondemented patients who had PD with (n = 11) and without (n = 8) visual hallucinations and age-matched controls (n = 10) were recruited. All participants completed neuropsychological testing, which consisted of visuoperceptual, executive, memory, language, and frontal-behavioral function. Positron emission tomography scans using [¹⁸F]setoperone, a serotonin 2A antagonist radioligand, were acquired in patients with PD, and a parametric binding potential map of [¹⁸F]setoperone was calculated with the simplified reference tissue model using the cerebellum as a reference.

Results

Patients who had PD with visual hallucinations exhibited significantly lower scores on measures of executive and visuoperceptual functions compared with age-matched controls. These changes were paralleled by decreased [¹⁸F]setoperone binding in the right insula, bilateral dorsolateral prefrontal cortex, right orbitofrontal cortex, right middle temporal gyrus, and right fusiform gyrus. The psychometric correlation analysis revealed significant relationships among tests associated with visuoperceptual function, memory and learning, and serotonin 2A binding in different prefrontal and ventral visual stream regions. There was also reduced serotonin 2A receptor binding in patients who had PD with depression.

Conclusions

These findings support a complex interaction between serotonin 2A receptor function and cognitive processing in patients who have PD with visual hallucinations.

Deep Brain Stimulation in Rare Inherited Dystonias

BACKGROUND

Rare causes of inherited movement disorders often present with a debilitating phenotype of dystonia, sometimes combined with parkinsonism and other neurological signs. Since these disorders are often resistant to medications, DBS may be considered as a possible treatment.

METHODS

Patients with identified genetic diseases (ataxia-telangiectasia, chorea-achantocytosis, dopa-responsive dystonia, congenital nemaline myopathy, methylmalonic aciduria, neuronal ceroid lipofuscinosis, spinocerebellar ataxia types 2 and 3, Wilson's disease, Woodhouse-Sakati syndrome, methylmalonic aciduria, and X trisomy) and disabling dystonia underwent bilateral GPi DBS (bilateral thalamic Vim nucleus in 1 case). The primary outcome was the difference in the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) between baseline, 1 year and last available follow-up. Preoperative factors such as age at surgery, disease duration at surgery, proportion of life lived with dystonia and severity of dystonia were correlated to the primary outcome.

RESULTS

Eleven patients were operated between February 2003 and December 2013. Age and duration of disease at time of surgery were 30 ± 19 and 12.5 ± 15.7 years, respectively. DBS effects on dystonia severity were variable but overall marginally effective, with a mean improvement of 7.9% (p = 0.39) at 1-year follow-up and 16.7% (p = 0.46) at last follow-up (mean 47.3 ± 19.9 months after surgery). No preoperative factors were identified to predict the surgical outcome.

CONCLUSION

Our findings support the current knowledge that DBS is modestly effective in treating rare inherited dystonias with a combined phenotype. However, the BFMDRS might not be the best tool to measure outcome in these severely affected patients.

What is a clinically important change in the Unified Dyskinesia Rating Scale in Parkinson's disease?

INTRODUCTION

Dyskinesia remain a significant problem in Parkinson Disease (PD). The translation process of novel drug targets for dyskinesia has proven difficult with several failures at phase III level. Determining the 'clinically important change' (CIC) for dyskinesia rating scales in phase II clinical trials may assist in optimizing drug development of new anti-dyskinetic treatments. We used a standard phase IIa acute levodopa infusion paradigm to determine for the first time the CIC for dyskinesia using the new UDysRS.

METHODS

We performed a randomized, double-blind, placebo-controlled crossover study with eleven PD patients with stable bothersome dyskinesia. We used the following patient-reported clinically important events as CIC anchors: onset, maximum intensity, remission of dyskinesia. Objective dyskinesia scores using the UDysRS part III Impairment were determined at these same events by blinded video-rating. The CIC was determined using the 'within-patient' score change and a sensitivity- and specificity-based approach.

RESULTS

Patients were most aware of 'onset of dyskinesia', followed by 'remission of dyskinesia'. An 11.1-point median change (UDysRS Part III Impairment, p < 0.0001) was the CIC for patient-reported remission of dyskinesia from a practically defined-OFF state. A 2.32-point change (UDysRS Part III Impairment) had the best specificity and sensitivity to distinguish between patient-reported remission and perception of dyskinesia.

CONCLUSIONS

In this study, we provide the first report of a CIC for the UDysRS Part III Impairment. Early knowledge of a CIC may help inform the decision to advance into phase III trials and contribute for a higher yield of success in finding new anti-dyskinetic treatments.

Dystonic Pseudo Foot Drop

The most common presentation of foot dystonia in patients with Parkinson's disease (PD) or dystonia is inversion of the foot accompanied by flexion of the toes, with or without extension of the hallux. Less commonly, foot dystonia may mimic foot drop, as occurs with weakness of the dorsiflexors muscles, resulting in a pseudo foot drop. This has rarely been reported in the literature and has been poorly recognized, often leading to misdiagnosis and unnecessary investigations and treatment. We report 5 patients with dystonic pseudo foot drop, one of them diagnosed with early-onset PD, 2 with sporadic PD, and 2 with dystonia. Despite the steppage gait, their physical exam revealed normal strength, and no other explanation for a "foot drop" was found. It is important to recognize this phenomenology, which can be a clue to the diagnosis of early-onset PD, and may be responsive to levodopa in selected patients.

Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/-) and wild-type (APOE+/+) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/- -challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

Axial disability and deep brain stimulation in patients with Parkinson disease

Axial motor signs-including gait impairment, postural instability and postural abnormalities-are common and debilitating symptoms in patients with advanced Parkinson disease. Dopamine replacement therapy and physiotherapy provide, at best, partial relief from axial motor symptoms. In carefully selected candidates, deep brain stimulation (DBS) of the subthalamic nucleus or globus pallidus internus is an established treatment for 'appendicular' motor signs (limb tremor, bradykinesia and rigidity). However, the effects of DBS on axial signs are much less clear, presumably because motor control of axial and appendicular functions is mediated by different anatomical-functional pathways. Here, we discuss the successes and failures of DBS in managing axial motor signs. We systematically address a series of common clinical questions associated with the preoperative phase, during which patients presenting with prominent axial signs are considered for DBS implantation surgery, and the postoperative phase, in particular, the management of axial motor signs that newly develop as postoperative complications, either acutely or with a delay. We also address the possible merits of new targets-including the pedunculopontine nucleus area, zona incerta and substantia nigra pars reticulata-to specifically alleviate axial symptoms. Supported by a rapidly growing body of evidence, this practically oriented Review aims to support decision-making in the management of axial symptoms.