Vitamins and Infusion of Levodopa-Carbidopa Intestinal Gel.

Levodopa-carbidopa intestinal gel infusion (LCIG) is an established therapy for advanced Parkinson disease (PD), resulting in a significant improvement of quality of life. With increased LCIG adoption worldwide, potential complications due to abnormal vitamin absorption or metabolism have been reported in these patients. Neurologists are unfamiliar with vitamins physiology and pathophysiological mechanisms in case of their deficiency. Unfortunately, clinical and laboratory guidelines related to vitamin monitoring and supplementation in the context of treatment with LCIG are not available. We herein summarize the current knowledge on three vitamins that are reduced with LCIG therapy reporting on their physiology, laboratory testing, and clinical impact of their deficiency/excess. In addition, we proposed an opinion-based recommendation for clinicians treating LCIG patients. Patients and caregivers should be informed about the risk of vitamin deficiency. Vitamin B12, homocysteine, and methylmalonic acid (MMA) should be tested before starting LCIG, six months after and once/year thereafter. Vitamin B6 and folate testing is not universally available but it should be considered if homocysteine is elevated but MMA and/or total vitamin B12 are normal. Prophylaxis of vitamin deficiency should be started as soon as LCIG is implemented, possibly even before. Dietary recommendations are enough in most patients although a subgroup of patients is at higher risk and should receive Vitamin B12 regularly and cycles of B6. Finally, once diagnosed a vitamin deficiency should be readily treated and accompanied by clinical and laboratory monitoring. Resistant cases should receive non-oral routes of administration and possibly discontinue LCIG, even temporarily.

Axial Impairment Following Deep Brain Stimulation in Parkinson's Disease: A Surgicogenomic Approach.

BACKGROUND: Postoperative outcome following deep brain stimulation (DBS) of the subthalamic nucleus is variable, particularly with respect to axial motor improvement. We hypothesized a genetic underpinning to the response to surgical intervention, termed "surgicogenomics". OBJECTIVE: We aimed to identify genetic variants associated with clinical heterogeneity in DBS outcome of Parkinson's disease (PD) patients that could then be applied clinically to target selection leading to improved surgical outcome. METHODS: Retrospective clinical data was extracted from 150 patient's charts. Each individual was genotyped using the genome-wide NeuroX array tailored to study neurologic diseases. Genetic data were clustered based on surgical outcome assessed by comparing pre- and post-operative scores of levodopa equivalent daily dose and axial impairment at one and five years post-surgery. Allele frequencies were compared between patients with excellent vs. moderate/poor outcomes grouped using a priori defined cut-offs. We analyzed common variants, burden of rare coding variants, and PD polygenic risk score. RESULTS: NeuroX identified 2,917 polymorphic markers at 113 genes mapped to known PD loci. The gene-burden analyses of 202 rare nonsynonymous variants suggested a nominal association of axial impairment with 14 genes (most consistent with CRHR1, IP6K2, and PRSS3). The strongest association with surgical outcome was detected between a reduction in levodopa equivalent daily dose and common variations tagging two linkage disequilibrium blocks with SH3GL2. CONCLUSION: Once validated in independent populations, our findings may be implemented to improve patient selection for DBS in PD.

Programming Directional Deep Brain Stimulation in Parkinson's Disease: A Randomized Prospective Trial Comparing Early versus Delayed Stimulation Steering.

INTRODUCTION: Programming directional leads poses new challenges as the optimal strategy is yet to be established. We designed a randomized control study to establish an evidence-based programming algorithm for patients with Parkinson's disease undergoing subthalamic nucleus deep brain stimulation with directional leads. METHODS: Fourteen consecutive patients were randomized to programming with either early or delayed (i.e., starting with a "ring mode") steered stimulation. Motor scores, number of programming visits, calls to the clinic, battery consumption, and stimulation adjustments required were recorded and compared between groups, using the Wilcoxon signed-ranks test, after 3 months of open-label programming. RESULTS: Thirteen patients (25 electrodes) were included, of which 23 were steerable. Nine out of 14 electrodes allocated to delayed steered stimulation were changed to steered mode due to side effects during the course of the study. No patients (11 electrodes) initially allocated to early steered stimulation were converted to ring mode. The 2 study arms did not differ in any of the considered measures at 3 months. CONCLUSION: Programming with early or delayed steered stimulation is equally effective in the short term. However, delayed steering is less time consuming and is not always needed.

Advanced Therapies for the Management of Dopamine Dysregulation Syndrome in Parkinson's Disease.

BACKGROUND: Dopamine Dysregulation Syndrome (DDS) is an adverse non-motor complication of dopamine replacement therapy in Parkinson's disease. The current literature on this syndrome is limited, and it remains underdiagnosed and challenging to manage. OBJECTIVE: To assess the role of advanced therapies in the management of DDS. METHODS: We performed a retrospective chart review and identified patients who fit the inclusion criteria for DDS. They were classified according to risk factors that have been identified in the literature, motor and complication scores, intervention (medical or surgical) and outcome. Multivariate analyses were performed to analyze these characteristics. RESULTS: Twenty-seven patients were identified (23 males, mean age of onset: 49 ± 8.8 years). Average levodopa equivalent daily dose was 1916.7 ± 804 mg and a history of impulse control disorders, psychiatric illness, and substance abuse was present in 89%, 70% and 3.7% of the patients, respectively. Overall 81.5% of patients had symptom resolution at follow up, on average 4.8 ± 3.5 years after management, with medication only (7/9), levodopa-carbidopa intestinal gel (1/3), deep brain stimulation of subthalamic nucleus (10/13), or globus pallidus pars interna (2/2). Reduction of medications occurred with deep brain stimulation of subthalamic nucleus (P = 0.01) but was associated with a relapse in two patients. CONCLUSION: Although the small sample size of some subgroups limits our ability to draw meaningful conclusions, our results did not suggest superiority of a single treatment option. Advanced therapies including deep brain stimulation can be considered in patients with DDS refractory to conservative measures, but outcome is variable and relapse is possible.

Non-Motor Fluctuations in Parkinson's Disease: Validation of the Non-Motor Fluctuation Assessment Questionnaire.

BACKGROUND: In patients with Parkinson's disease (PD), sleep, mood, cognitive, autonomic, and other non-motor symptoms may fluctuate in a manner similar to motor symptoms. OBJECTIVES: To validate a final version of a patient-rated questionnaire that captures the presence and severity of non-motor fluctuations in levodopa-treated PD patients (NoMoFA). METHODS: We recruited PD subjects from five movement disorders centers across the US and Canada. We assessed the internal consistency, floor and ceiling effects, test-retest reliability, and concurrent validity of NoMoFA. Classical test theory and item response theory methods informed item reduction and Delphi process yielded a final questionnaire. RESULTS: Two hundred subjects and their care-partners participated in the study (age: 66.4 ± 9.6 years; disease duration: 9 ± 5.5 years; median Hoehn and Yahr [H&Y] OFF: 3 [range 1-5]; mean Unified Parkinson's Disease Rating Scale (UPDRS) III ON score: 27.4 ± 14.9). Acceptability of the scale was adequate. There were floor effects in 8/28 items. Cronbach's alpha was 0.894. While eight items had "item-to-total" correlations below the cutoff of 0.4, removing these items did not improve Cronbach's alpha. Test-retest reliability was acceptable (intraclass correlation coefficient [ICC] 0.73; 95% confidence interval, 0.64-0.80). Concurrent validity was adequate with all Spearman's rho values comparing NoMoFA score to other measures of parkinsonian severity showing significance and in the expected direction. A final Delphi panel eliminated one item to avoid redundancy. CONCLUSIONS: The final 27-item self-administered NoMoFA is a valid and reliable questionnaire, capturing both static and fluctuating non-motor symptoms in PD. © 2021 International Parkinson and Movement Disorder Society.

Levodopa Versus Dopamine Agonist after Subthalamic Stimulation in Parkinson's Disease.

BACKGROUND: No clinical trials have been specifically designed to compare medical treatments after surgery in Parkinson's disease (PD). OBJECTIVE: Study's objective was to compare the efficacy and safety of levodopa versus dopamine agonist monotherapy after deep brain stimulation (DBS) in PD. METHODS: Thirty-five surgical candidates were randomly assigned to receive postoperative monotherapy with either levodopa or dopamine agonist in a randomized, single-blind study. All patients were reevaluated in short- (3 months), mid- (6 months), and long-term (2.5 years) follow-up after surgery. The primary outcome measure was the change in the Non-Motor Symptoms Scale (NMSS) 3 months after surgery. Secondary outcome measures were the percentage of patients maintaining monotherapy, change in motor symptoms, and specific non-motor symptoms (NMS). Analysis was performed primarily in the intention-to-treat population. RESULTS: Randomization did not significantly affect the primary outcome (difference in NMSS between treatment groups was 4.88 [95% confidence interval: -11.78-21.53, P = 0.566]). In short- and mid-term follow-up, monotherapy was safe and feasible in more than half of patients (60% in short- and 51.5% in mid-term follow-up), but it was more often possible for patients on levodopa. The ability to maintain dopamine agonist monotherapy was related to optimal contact location. In the long term, levodopa monotherapy was feasible only in a minority of patients (34.2%), whereas dopamine agonist monotherapy was not tolerated due to worsening of motor conditions or occurrence of impulse control disorders. CONCLUSIONS: This trial provides evidence for simplifying pharmacological treatment after functional neurosurgery for PD. The reduction in dopamine receptor agonists should be attempted while monitoring for occurrence of NMSs, such as apathy and sleep disturbances. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Dyspnea after subthalamic deep brain stimulation in Parkinson's disease: a case-control study.

OBJECTIVE: Dyspnea can be present as non-motor symptom in patients with Parkinson's disease (PD). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor and non-motor symptoms in PD. However, new-onset dyspnea has been reported after DBS surgery. We have studied respiratory characteristics of PD patients with bilateral STN-DBS to assess the impact of DBS on pulmonary function. METHODS: STN-DBS PD patients with dyspnea after surgery (cases) were matched with STN-DBS PD patients without dyspnea (controls). Motor and pulmonary function were assessed with stimulation and without medication (on stim/off med), and without stimulation and medication (off stim/off med). Pulmonary function was investigated with spirometry and dyspnea with the Medical Research Council Dyspnea Scale (MRCDS) and the Borg Scale (BS). RESULTS: Seven cases (five men, 58.30 ± 6.70 years of age) and seven controls (six men, 61.10 ± 6.30 years of age) were enrolled. MRCDS and BS revealed the presence of dyspnea in both groups. No significant changes in pulmonary function were found in both cases and controls in on stim/off med vs. off stim/off med condition (p < 0.05), and in cases vs. controls in on stim/ off med condition (p < 0.05). CONCLUSIONS: No impact of STN-DBS on pulmonary function was found in cases. Impaired perception of dyspnea and spread of stimulation surrounding the STN might account for new-onset dyspnea after DBS surgery. Dyspnea was detected also in controls using ad hoc questionnaires. Our findings suggest further investigation of this non-motor symptom in PD patients.

Complex dyskinesias in Parkinson patients on levodopa/carbidopa intestinal gel.

BACKGROUND: Levodopa-carbidopa intestinal infusion is an effective treatment for motor fluctuations in Parkinson's disease. However, it has been recently associated with emergent complex/atypical dyskinesias. We sought to characterize patients who developed these dyskinesias after levodopa infusion initiation, and to compare these patients to a control population with conventional motor fluctuations. METHODS: 208 Parkinson's disease patients, treated with levodopa intestinal infusion due to motor fluctuations, were screened for onset and/or worsening of dyskinesias after initiation of levodopa infusion, resistant to the routine titration, and presenting with atypical or unexpected patterns. Patients with extensive follow-up data were enrolled for a longitudinal analysis. Cases were compared to a control sample with conventional motor fluctuations in order to investigate predisposing factors, difference in dyskinesia phenotype, management strategies and dropouts. RESULTS: Thirty patients out of 208 (14.4%) reported atypical (i.e. long-lasting) biphasic, biphasic-like (i.e. continuous) or mixed (peak-dose and continuous biphasic) dyskinesias after levodopa infusion. They were compared at baseline and follow-up to a sample of 49 patients with conventional motor fluctuations on levodopa infusion. Both groups had similar demographic and clinical features, except the former having higher prevalence of biphasic dyskinesias while on oral therapy. Biphasic-like dyskinesias in nearly half the number of cases improved with increasing the dopaminergic load, while mixed dyskinesias had the worst outcome and highest dropout rate (58%). CONCLUSIONS: Atypical biphasic, biphasic-like and complex dyskinesias could hinder the course of patients treated with levodopa infusion. This study further informs the selection process of advanced therapies, particularly in dyskinetic patients.

Predictors of deep brain stimulation outcome in tremor patients.

BACKGROUND: Deep brain stimulation of the ventro-intermedius nucleus of the thalamus is an established treatment for tremor of differing etiologies but factors that may predict the short- and especially long-term outcome of surgery are still largely unknown. METHODS: We retrospectively investigated the clinical, pharmacological, electrophysiological and anatomical features that might predict the initial response and preservation of benefit in all patients who underwent deep brain stimulation for tremor. Data were collected at the following time points: baseline (preoperative), one-year post-surgery, and most recent visit. Tremor severity was recorded using the Fahn-Tolosa-Marin Tremor Rating Scale and/or the Unified Parkinson's Disease Rating Scale. RESULTS: A total of 52 patients were included in the final analysis: 31 with essential tremor, 15 with cerebellar tremor of different etiologies, and 6 with Parkinson's disease. Long-term success (mean follow-up duration 34.7 months, range 1.7-121.1 months) was reported in 63.5%. Predictors of long-term benefit were: underlying tremor etiology (best outcome in Parkinson's disease, worst outcome in cerebellar tremor); age at surgery (the older the better); baseline tremor severity (the greater the better); lack of response to benzodiazepines; a more anterior electrode placement and single-unit beta power (the greater the better). CONCLUSIONS: Specific patients' features (including single unit beta activity) and electrode locations may predict the short- and long-term benefit of thalamic stimulation for tremor. Future prospective studies enrolling a much larger sample of patients are needed to substantiate the associations detected by this retrospective study.

Establishing a Standard of Care for Deep Brain Stimulation Centers in Canada.

During the "DBS Canada Day" symposium held in Toronto July 4-5, 2014, the scientific committee invited experts to share their knowledge regarding deep brain stimulation (DBS) management of movement disorders in three domains: (1) the programming algorithms, (2) the necessary team to run a neurosurgery program, and (3) the appropriate scales to better define in a more comprehensive fashion the effect of the brain surgery. Each presentation was followed by an open discussion, and this article reports on the conclusions of this meeting on these three questions. Concerning programming, the role of the pulse width and the switching off of the stimulation at night for thalamic stimulation for the control of tremor have been discussed. The algorithms proposed in the literature for programming in Parkinson's disease (PD) need validation. In dystonia, the use of monopolar vs bipolar parameters, the use of low vs high frequencies and the use of smaller versus larger pulse widths all need to be examined properly. Concerning the necessary team to run a neurosurgical program, recommendations will follow the suggestions for standardized outcome measures. Regarding the outcome measures for DBS in PD, investigations need to focus on the non-motor aspects of PD. Identifying which nonmotor symptoms respond to DBS would allow a better screening before and satisfaction postoperatively. There is an important need for more data to determine the optimal programming protocol and the standard measures that should be performed routinely by all centers.

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.

Long-term double-blinded unilateral pedunculopontine area stimulation in Parkinson's disease.

BACKGROUND: Gait-related symptoms are often refractory to current available treatment options with a significant reduction in quality of life in Parkinson's disease. OBJECTIVES: The objective of this study was to determine the long-term efficacy and safety of unilateral pedunculopontine area stimulation for refractory gait and balance impairment in Parkinson's disease. METHODS: This study used periodic randomized double-blinded assessments until 4 years postoperatively. The primary outcomes were gait-related items of the UPDRS part II and the MDS-UPDRS part III. RESULTS: At baseline, the median age and disease duration was 63 years (interquartile range: 62, 65) and 15 years (interquartile range: 11, 20). At 2 years, patient-reported freezing (UPDRS part II, off-time) was significantly better when compared with baseline (P =.028), with 62.5% of responders. At 4 years, there was no significant change in the used outcomes, but 66.7 % (n = 4 of 6) were responders for off-time patient-reported freezing and falling. CONCLUSIONS: Pedunculopontine area stimulation has an initial but not sustained benefit for gait-related symptoms. © 2016 International Parkinson and Movement Disorder Society.

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.

Long-term neuropsychiatric outcomes after pallidal stimulation in primary and secondary dystonia.

OBJECTIVE: To evaluate changes in the diagnosis of Axis I psychiatric disorders in patients with primary and secondary dystonia after deep brain stimulation (DBS) of the globus pallidus internus (GPi). METHODS: Structured Clinical Interviews for the DSM-IV, Axis I psychiatric disorders, were prospectively performed before and after surgery. Diagnoses were made based on DSM-IV criteria. Psychiatric disorders were grouped into 5 categories: mood, anxiety, addiction, obsessive-compulsive disorders, and psychosis. Patients could be stratified to more than one category. Rates for unchanged diagnoses, diagnoses in remission, and new-onset diagnoses after surgery for each category were calculated. RESULTS: Fifty-seven patients with primary and secondary dystonia were included. Mean ± SD age at surgery and dystonia duration at time of surgery was 50.6 ± 13.8 and 19.0 ± 13.2 years, respectively. Preoperatively, 37 Axis I diagnoses were made in 25 patients, 43.8% of those presenting with at least 1 Axis I diagnosis (mostly mood and anxiety disorders). Mean ± SD duration of psychiatric follow-up was 24.4 ± 19.6 months. Overall, after surgery no significant changes (p = 0.16) were found in Axis I diagnoses (23 patients, 40.3%): 27 (73%) unchanged, 10 (27%) in complete remission, and 4 (12.9%) new-onset diagnoses. CONCLUSIONS: Our results support the overall psychiatric stability of patients with primary and secondary dystonia treated with GPi DBS. However, considering the high psychiatric morbidity in the dystonia population, psychiatric assessments before and after surgery are strongly recommended. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that GPi DBS does not change Axis I psychiatric diagnoses in patients with primary and secondary dystonia.

Short- and long-term outcome of chronic pallidal neurostimulation in monogenic isolated dystonia.

OBJECTIVES: Deep brain stimulation of the internal pallidum (GPi-DBS) is an established therapeutic option in treatment-refractory dystonia, and the identification of factors predicting surgical outcome is needed to optimize patient selection. METHODS: In this retrospective multicenter study, GPi-DBS outcome of 8 patients with DYT6, 9 with DYT1, and 38 with isolated dystonia without known monogenic cause (non-DYT) was assessed at early (1-16 months) and late (22-92 months) follow-up using Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores. RESULTS: At early follow-up, mean reduction of dystonia severity was greater in patients with DYT1 (BFMDRS score: -60%) and non-DYT dystonia (-52%) than in patients with DYT6 dystonia (-32%; p = 0.046). Accordingly, the rate of responders was considerably lower in the latter group (57% vs >90%; p = 0.017). At late follow-up, however, GPi-DBS resulted in comparable improvement in all 3 groups (DYT6, -42%; DYT1, -44; non-DYT, -61%). Additional DBS of the same or another brain target was performed in 3 of 8 patients with DYT6 dystonia with varying results. Regardless of the genotype, patients with a shorter duration from onset of dystonia to surgery had better control of dystonia postoperatively. CONCLUSIONS: Long-term GPi-DBS is effective in patients with DYT6, DYT1, and non-DYT dystonia. However, the effect of DBS appears to be less predictable in patients with DYT6, suggesting that pre-DBS genetic testing and counseling for known dystonia gene mutations may be indicated. GPi-DBS should probably be considered earlier in the disease course. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that long-term GPi-DBS improves dystonia in patients with DYT1, DYT6, and non-DYT dystonia.