Reduction In Levodopa Research Articles

Teaching Video NeuroImage: Improvement in Motor Development After Start of Levodopa in Tyrosine Hydroxylase Deficiency

A 7-month-old boy was referred with developmental delay and axial hypotonia (video 1). Screening for inborn errors of metabolism was negative and single nucleotide polymorphism array was normal (46,XY). Myotonic dystrophy (type 1) and spinal muscular atrophy were excluded. Whole exome sequencing yielded biallelic mutations in the tyrosine hydroxylase gene (c.698 G>A, p.Arg233His and c.1211C>T, p.Thr404Met). Subsequent CSF analysis revealed a significantly lowered homovanillic acid/5-hydroxyindoleacetic acid ratio, confirming tyrosine hydroxylase deficiency.1 Treatment with monotherapy levodopa resulted in profoundly improved motor development (video 1). After several weeks of treatment, the patient developed levodopa-induced dyskinesias (video 1),2 insomnia, and hyperactive behavior. All symptoms ameliorated with levodopa reduction.

The Role of Focused Ultrasound in the Management of Movement Disorders: Insights after 5 Years of Experience.

The Role of Focused Ultrasound in the Management of Movement Disorders: Insights after 5 Years of Experience.

New pharmacological and neuromodulation approaches for impulsive-compulsive behaviors in Parkinson's disease.

A significant proportion of patients with Parkinson's disease (PD) display a set of impulsive-compulsive behaviors at some point during the course of illness. These behaviors range from the so-called behavioral addictions to dopamine dysregulation syndrome, punding and hoarding disorders. These behaviors have been consistently linked to the use of dopaminergic medications used to treat PD motor symptoms (dopamine agonists, levodopa, and other agents) and less consistently to neuromodulation techniques such as deep brain stimulation (DBS). Since there are still no approved treatments for these conditions, their pharmacological management is still a big challenge for clinicians. We conducted an extensive review of current pharmacological and neuromodulation literature for the management of impulsive-compulsive disorders in PD patients. Pharmacological treatment approaches for impulsive-compulsive behaviors and DDS in PD patients include reduction of levodopa (LD), reduction/cessation of dopamine agonist (DA), and initiation of infusion therapies (apomorphine infusion and duodopa). Also, atomoxetine, a noradrenergic agent approved for the treatment of attention deficit hyperactivity disorder, showed some interesting preliminary results but there is still a lack of controlled longitudinal studies. Finally, while DBS effects on impulsive-compulsive disorders are still controversial, non-invasive techniques (such as transcranial magnetic stimulation and transcranial direct current stimulation) could have a potential positive effect but, again, there is still a lack of controlled trials. Managing impulsivity and compulsivity in PD patients is still a non-evidence-based challenge for clinicians. Controlled trials on promising approaches such as atomoxetine and non-invasive neuromodulation techniques are needed.

Medical management after subthalamic stimulation in Parkinson's disease: a phenotype perspective.

Subthalamic nucleus deep brain stimulation (STN DBS) is an established treatment that improves motor fluctuations, dyskinesia, and tremor in Parkinson's disease (PD). After the surgery, a careful electrode programming strategy and medical management are crucial, because an imbalance between them can compromise the quality of life over time. Clinical management is not straightforward and depends on several perioperative motor and non-motor symptoms. In this study, we review the literature data on acute medical management after STN DBS in PD and propose a clinical algorithm on medical management focused on the patient's phenotypic profile at the perioperative period. Overall, across the trials, the levodopa equivalent daily dose is reduced by 30 to 50% one year after surgery. In patients taking high doses of dopaminergic drugs or with high risk of impulse control disorders, an initial reduction in dopamine agonists after STN DBS is recommended to avoid the hyperdopaminergic syndrome, particularly hypomania. On the other hand, a rapid reduction of dopaminergic agonists of more than 70% during the first months can lead to dopaminergic agonist withdrawal syndrome, characterized by apathy, pain, and autonomic features. In a subset of patients with severe dyskinesia before surgery, an initial reduction in levodopa seems to be a more reasonable approach. Finally, when the patient's phenotype before the surgery is the severe parkinsonism (wearing-off) with or without tremor, reduction of the medication after surgery can be more conservative. Individualized medical management following DBS contributes to the ultimate therapy success.

Subthalamic nucleus deep brain stimulation improves dyskinesias in Parkinson's disease beyond levodopa reduction.

Bilateral subthalamic nucleus deep brain stimulation (STN DBS) improves motor fluctuations and dyskinesias in patients with Parkinson's disease (PD). Dyskinesia improvement with STN DBS is believed to result entirely from levodopa reduction. However, some studies suggest that STN DBS may also directly suppress dyskinesias. To determine whether bilateral STN DBS improves dyskinesias beyond what would be expected from levodopa reduction alone,weanalyzed pre-operative and post-operative dyskinesia scores (sum of MDS-UPDRS items 4.1 and 4.2) from 61 PD patients with bilateral STN DBS. A multiple regression model (adjusted for disease severity, disease duration, active contacts above the STN, use of amantadine, high pre-operative levodopa-equivalent dose (LED), sex, and interaction between active contacts above the STN and amantadine use) was created to describe the relationship between dyskinesia scores and LED prior to DBS. Using this model, a post-operative dyskinesia score was estimated from post-operative LED and compared to the actual post-operative dyskinesia score. The regression model was statistically significant overall (p = 0.003, R2 = 0.34, adjusted R2 = 0.24). The actual post-operative dyskinesia score (1.0 ± 1.4) was significantly lower than the score predicted by the model (3.0 ± 1.1, p < 0.0001). Dyskinesias after STN DBS improved more than predicted by levodopa reduction alone. Our data support the idea that STN stimulation may directly improve dyskinesias.

Rasagiline and safinamide as a dopamine-sparing therapy for Parkinson's disease.

To evaluate whether the prescription of monoamine oxidase B inhibitors (MAOB-I), rasagiline and safinamide, contributes to the reduction of levodopa and/or dopamine agonists (DA) dose in order to minimize adverse effects. A total of 724 patients with Parkinson's disease (PD) have been prospectively included in our database since the year 2000, representing a total of 5124 visits. For each patient and visit, antiparkinsonian treatment was recorded. In the presence of rasagiline and safinamide, we analysed the evolution of levodopa equivalent dose (LED) and LED for DA (LED-DA). The data obtained from the 1664 visits between 2006 and 2010 (321 patients) and the 1709 visits between 2014 and 2018 (403 patients) were analysed in order to assess the impact of the introduction of rasagiline and safinamide, respectively. The annual mean LED remained stable without statistically significant differences. In the first period (impact of rasagiline), the annual mean LED-DA in 2010 was significantly higher than in 2006 (P=0.001). In the second period (impact of safinamide), the annual mean LED-DA in 2018 was significantly lower than in 2014 (P=0.002). A repeated-measure analyses of LED-DA including only patients who had taken safinamide showed a statistically significant decrease in LED-DA (P=0.027). The introduction of MAOB-I in the overall treatment of PD as part of routine clinical practice has not helped to reduce annual mean LED. However, safinamide reduces annual mean LED-DA and may be linked to a reduction in dose-dependent adverse effects in the long term.

The Outcome of Dopamine Dysregulation Syndrome in Parkinson's Disease: A Retrospective Postmortem Study.

We have performed a retrospective analysis of the frequency and relation to treatment of dopamine dysregulation syndrome (DDS) using the Queen Square Brain Bank (QSBB) database. A search of the QSBB database for consecutive cases donated between 2005 and 2016 with a pathological diagnosis of Parkinson's disease was performed. DDS was present in 8.8% of cases, was more prevalent in males, and was associated with younger age of onset, longer disease duration, and more dopa-induced dyskinesias. Treatment approaches for DDS included: reduction of levodopa, reduction/cessation of dopamine agonist (DA), and initiation of infusion therapies. DDS had completely resolved in just over half the patients. DA peak l-dopa equivalent daily dose (LEDD) was higher in patients who failed to achieve remission. This is the first study to provide data on the course of DDS until death. Treatment strategies consisted mainly of reduction of dopaminergic treatment, and, despite the majority of patients showing some improvement, half remained symptomatic. Successful treatment was associated with a lower l-dopa dosage at death.

Deep Brain Stimulation in Patients with Parkinson's Disease: Effect on Psychiatric Symptoms and Quality of Life.

To determine the effect on psychiatric symptoms and quality of life in 30 patients with Parkinson's disease (PD) treated with deep brain stimulation (DBS) of both subthalamic nuclei (STN) after 1 year of follow-up. We conducted a prospective 1-year follow-up study with a baseline assessment before and 6 and 12 months after surgery. The following were used as assessment instruments: the Bech-Rafaelsen Melancholia Scale (MES), the Bech-Rafaelsen Mania Scale (MAS), the Beck Scale for Suicidal Ideation (SSI), the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Oviedo Sleep Questionnaire (OSQ), the 36-Item Short Form Health Survey (SF-36), the Unified Parkinson's Disease Rating Scale (UPDRS), the dose of levodopa, and the active contact stereotactic coordinates. We recorded a clinical improvement between baseline with medication use (ON medication) and the results obtained at 6 and 12 months with medication use and stimulation (ON stimulation, ON medication) in MES and OSQ (p < 0.0001) and in SF-36 (p < 0.005). No changes were observed in MAS and SSI. There was a clinical improvement between baseline with ON medication and the results obtained at 12 months with ON stimulation, ON medication in Y-BOCS (p < 0.04). Also, there was a 53.3% reduction in levodopa at 6 months and a 54.7% reduction at 12 months after surgery (p < 0.0001). There was an improvement between baseline with OFF medication and the results obtained at 6 and 12 months OFF medication, ON stimulation (p < 0.0001) in UPDRS-III. There were no statistically significant differences between the initial and final active contact coordinates, or between stimulation parameters. DBS of the STN in patients with PD is associated with an improvement in psychiatric (affective and sleep-wake cycle) symptoms, clinical motor symptoms, and quality of life at 1 year after surgery.

Efficacies of globus pallidus stimulation and subthalamic nucleus stimulation for advanced Parkinson's disease: a meta-analysis of randomized controlled trials.

ObjectivesDeep brain stimulation (DBS) is the surgical procedure for patients with advanced Parkinson’s disease. Globus pallidus internus (GPi) and subthalamic nucleus (STN) are the most targeted locations for the procedure. To investigate the variable efficiencies for the two different locations, we conducted a meta-analysis to compare both stimulation sites.Materials and methodsA systematic search was performed in PubMed, Embase, and the Cochrane Library databases. Randomized controlled trials comparing the efficacies of GPi and STN DBS were included. Clinical outcomes of motor function, nonmotor function, and quality of life (QOL) were collected for the meta-analysis.ResultsTen eligible trials with 1,034 patients were included in the analysis. Unified Parkinson’s disease rating scale III (UPDRS-III) scores were collected at 6, 12, and 24 months postsurgery separately to assess the motor function of the patients. A statistically significant effect in favor of the GPi DBS was obtained in the off-medication/on-stimulation phase of UPDRS-III at 12 months (mean difference [MD] =6.87, 95% confidence interval [95% CI]: 3.00–10.74, P=0.57, I2=0%). However, GPi DBS showed an opposite result at 24 months (MD =−2.46, 95% CI: −4.91 to −0.02, P=0.05, I2=0%). In the on-medication/on-stimulation phase, GPi DBS obtained a worse outcome compared with STN DBS (MD =−2.90, 95% CI: −5.71 to −0.09, P=0.05, I2=0%). Compared with STN DBS, increased dosage of levodopa equivalent doses was needed in GPi DBS (standardized MD =0.60, 95% CI: 0.46–0.74, P<0.00001, I2=24%). Meanwhile, Beck Depression Inventory II scores demonstrated that STN has a better performance (standardized MD =−0.31, 95% CI: −0.51 to −0.12, P=0.002, I2=0%). As for neurocognitive phase postsurgery, GPi DBS showed better performance in three of the nine tests, especially in verbal fluency. Use of GPi DBS was associated with a greater effect in eight of the nine subscales of QOL.ConclusionGPi and STN DBS significantly improve advanced Parkinson’s patients’ symptoms, functionality, and QOL. Variable therapeutic efficiencies were observed in both procedures, GPi and STN DBS. GPi DBS allowed greater recovery of verbal fluency and provided greater relief of depression symptoms. Better QOL was also obtained using GPi DBS. Meanwhile, GPi DBS was also associated with increased dosage of levodopa equivalent doses. The question regarding which target is superior remained open for discussion. An understanding of the target selection still depends on individual symptoms, neurocognitive/mood status, therapeutic goals of DBS (eg, levodopa reduction), and surgical expertise.

Behavioral effects of levodopa

In recent years, levodopa-induced behavioral changes have received increased attention in the medical literature and in clinical practice. The spectrum of these symptoms includes non-motor fluctuations with neuropsychiatric symptoms, compulsive behaviors such as punding, dopamine dysregulation syndrome, and impulse control disorders, psychosis and hallucinations, as well as hypomania and mania. Despite knowledge of the clinical features associated with these behaviors, many of them are probably underdiagnosed. Although the mechanisms underlying behavioral symptoms are still incompletely understood, recent data from imaging and pathological studies have increased our understanding and guided new treatment strategies. Appropriate management remains challenging, because reduction of levodopa (l-dopa) and dopaminergic treatment is often recommended; however, doses required for control of motor symptoms may still induce behavioral changes. Newer modes of delivery of dopaminergic treatment, deep brain stimulation, and nondopaminergic agents may either provide alternatives for treatment of these behavioral problems or permit treatment of parkinsonism with less risk of these behavioral disorders.

Zonisamide: a review of the clinical and experimental evidence for its use in Parkinson's disease.

The limitations of currently available therapies in addressing the non motor symptoms of Parkinson's disease (PD) have egged on the search for newer options. Zonisamide has been in use for epilepsy and it was serendipitously found to improve the symptoms of PD in a patient who had both epilepsy and PD. Thereafter, various trials were designed to assess the use of zonisamide in PD. The present article investigates the evidence for use of zonisamide in PD from the various clinical trials that were designed to address this issue. Furthermore, the article also summarizes the various mechanisms of its use in PD as described in various animal experiments. A search protocol was designed with predefined inclusion and exclusion criteria. The databases searched were Pubmed, Ovid medline, Cochrane and clinicaltrials.gov. The data thus generated, was fed into a predesigned format. Most of the clinical trials on zonisamide in PD have come from Japan. Most of these trials used the changes in the Unified Parkinson's Disease Rating Scale (UPDRS) score as the endpoints and the most conclusive evidence is for a dose of 25-50 mg, which caused a change in UPDRS part III (motor symptoms). These patients were on levodopa and other drugs used for PD during the trials. One of the clinical trials conducted in Spain investigates the use of zonisamide in impulse control disorders among 15 patients of PD. Among the many mechanisms postulated, a reduction in levodopa induced quinone formation, protection against mitochondrial impairment and an increase in astroglial cysteine transport, an inhibition of microglial activation, monoamine oxidase-B (MAO-B) inhibition, an increased dopamine release and blockade of calcium channels are the most cited. There is evidence for use of zonisamide in PD in addition to levodopa and other therapies for control of motor symptoms. For now, the evidence for its use in control of non motor symptoms in PD is not enough and needs to be investigated further.

Potentiation of response to low doses of levodopa in MPTP-injected monkeys by chemical unilateral subthalamotomy

Subthalamotomy is a stereotactic surgery performed in patients with disabling dyskinesias due to Parkinson disease. The authors set out to model this human condition in MPTP monkeys and determine if subthalamotomy allowed a reduction of levodopa for similar benefit. The authors performed unilateral subthalamotomy in 4 parkinsonian dyskinetic monkeys by stereotactic injection of ibotenic acid. An optimal dose, defined as the highest dose of levodopa improving parkinsonian motor symptoms while inducing low or no dyskinesias, was established in these animals. Each monkey was scored for the antiparkinsonian and dyskinetic effects of the optimal dose of levodopa, as well as suboptimal and dyskinesia-inducing doses (60% and 140% of the optimal dose, respectively), and these scores were compared with those obtained at baseline before and after subthalamotomy. Bradykinesia was assessed by a prehension task. Unilateral subthalamotomy had a positive effect on the antiparkinsonian response for all doses of levodopa as well as the baseline. There were no differences in the antiparkinsonian response between the suboptimal dose postsurgery and the optimal dose presurgery. Dyskinesias were increased at the suboptimal and the optimal doses. After surgery, the duration of response to levodopa increased between 20% and 25% in the suboptimal dose, whereas it remained unchanged with higher doses. Bradykinesia was significantly reduced after surgery only at the suboptimal dose. Subthalamotomy potentiated the response to suboptimal doses of levodopa. Thus, levodopa can be reduced by 40% after surgery for similar beneficial antiparkinsonian response and less dyskinesia than with an optimal dose before surgery.

Rehabilitation improves dyskinesias in Parkinsonian patients: A pilot study comparing two different rehabilitative treatments

The present study was devised: (a) to test whether an intensive (60 hours in 4 weeks) multidisciplinary rehabilitation treatment (involving physiotherapy, exercises to improve gait and balance using treadmill and stabilometric platform, occupational therapy) for Parkinsonian patients is effective in improving dyskinesia and motor performance compared to a control group undergoing a non-intensive non multidisciplinary rehabilitation treatment (30 hours in 4 weeks involving physiotherapy only); and (b) to verify whether rehabilitation may lead to a reduction in levodopa dosage. Forty Parkinsonian patients suffering from dyskinesias were admitted to study: 20 for an intensive multidisciplinary (Group1) and 20 for a non-intensive non multidisciplinary rehabilitation treatment (Group2). The rating scales used for the clinical evaluation were: Unified Parkinson's Disease Rating Scales (UPDRS) II, III, IV, Parkinson's disease disability scale (PDDS), Abnormal Involuntary Movement Scale (AIMS). All outcome measurements improved in both groups of patients, but patients Group1 presented better results: UPDRS II was reduced by 33% in Group1 and by 22% in Group2, UPDRS III 29% vs. 22%, UPDRS IV 74% vs. 10%, PDDS 18% vs. 12%, and AIMS 71% vs. 8%. A different behaviour was observed for levodopa dosage at baseline and after treatment: dosage decreased by an average value of 210 mg (p< 0.0001) in Group1 and was virtually unchanged (30 mg reduction, p=0.08) in Group2. Our findings suggest that a rehabilitation protocol should be considered as a valid non-invasive therapeutic support for patients who show dyskinesias and that there are better results when the treatment is intensive.

Subthalamic stimulation in Parkinson’s disease: restoring the balance of motivated behaviours

Addictions to dopaminergic drugs or to pleasant behaviours are frequent and potentially devastating neuropsychiatric disorders observed in Parkinson's disease. They encompass impulse control disorders, punding and dopamine dysregulation syndrome. A relationship with dopaminergic treatment is strongly suggested. Subthalamic stimulation improves motor complications and allows for drastic reductions in medication. This treatment might, therefore, be considered for patients with behavioural addictions, when attempts to reduce dopaminergic medication have failed. However, conflicting data have reported suppression, alleviation, worsening or new onset of behavioural addictions after subthalamic stimulation. Non-motor fluctuations are also a disabling feature of the disease. We prospectively investigated behaviour in a cohort of 63 patients with Parkinson's disease, before and 1 year after subthalamic stimulation using the Ardouin scale, with systematic evaluation of functioning in overall appetitive or apathetic modes, non-motor fluctuations, dopaminergic dysregulation syndrome, as well as behavioural addictions (including impulse control disorders and punding) and compulsive use of dopaminergic medication. Defined drug management included immediate postoperative discontinuation of dopamine agonists and reduction in levodopa. Motor and cognitive statuses were controlled (Unified Parkinson's Disease Rating Scale, Mattis Dementia Rating Scale, frontal score). After surgery, the OFF medication motor score improved (-45.2%), allowing for a 73% reduction in dopaminergic treatment, while overall cognitive evaluation was unchanged. Preoperative dopamine dysregulation syndrome had disappeared in 4/4, behavioural addictions in 17/17 and compulsive dopaminergic medication use in 9/9 patients. New onset of levodopa abuse occurred in one patient with surgical failure. Non-motor fluctuations were significantly reduced with improvements in off-dysphoria (P ≤ 0.001) and reduction in on-euphoria (P ≤ 0.001). There was an inversion in the number of patients functioning in an overall appetitive mode (29 before versus 2 after surgery, P ≤ 0.0001) to an overall apathetic mode (3 before versus 13 after surgery, P < 0.05). Two patients attempted suicide. Improvement in motor fluctuations is linked to the direct effect of stimulation on the sensory-motor subthalamic territory, while improvement in dyskinesias is mainly explained by an indirect effect related to the decrease in dopaminergic drugs. Our data suggest that non-motor fluctuations could similarly be directly alleviated through stimulation of the non-motor subthalamic territories, and hyperdopaminergic side effects might improve mainly due to the decrease in dopaminergic medication. We show an overall improvement in neuropsychiatric symptomatology and propose that disabling non-motor fluctuations, dopaminergic treatment abuse and drug-induced behavioural addictions in Parkinson's disease may be considered as new indications for subthalamic stimulation.

Combined pallidal and subthalamic nucleus stimulation in sporadic dystonia-parkinsonism

Multifocal deep brain stimulation (DBS) is a new technique that has been introduced recently. A 39-year-old man with dystonia-parkinsonism underwent the simultaneous implantation of subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS electrodes. While bilateral STN DBS controlled the parkinsonian symptoms well and allowed for a reduction in levodopa, the improvement of dystonia was only temporary. Additional GPi DBS also alleviated dystonic symptoms. Formal assessment at the 1-year follow-up showed that both the parkinsonian symptoms and the dystonia were markedly improved via continuous bilateral combined STN and GPi stimulation. Sustained benefit was achieved at 3 years postoperatively.

General anaesthesia for deep brain stimulator electrode insertion in Parkinson’s disease

This paper compares the use of general and local anaesthetic in patients having deep brain stimulator (DBS) surgery. It is a retrospective case note study of 46 patients treated consecutively with subthalamic nucleus stimulation for Parkinson's disease as practise changed in a Neurosurgical unit. The first 20 patients (LA group) had permanent electrodes placed under local anaesthesia. The remaining 26 patients (GA group) had the entire procedure under general anaesthesia. The groups were similar for age, sex, duration of Parkinson's disease and preoperative levodopa requirement. The clinical results were similar in that within each group, the reduction in levodopa was not only clinically but also statistically significant (p < 0.001 for both, paired t test): for the LA group, the 6-month requirement was 39.4% (29.5-52.6%) of the preoperative requirement and for the GA group, the 6-month requirement was 32.3% (25.2-41.5%) of the preoperative requirement. The reduction in levodopa was maintained at 1year. Of note, duration of surgery and length of stay were reduced. The mean duration of surgery was 8.2h (7.8-8.6) for the LA group and 7.5h (7.2-7.8) for the GA group (p = 0.003). The geometric mean of length of hospital stay was 5.4days(4.6-6.3) for the LA group and 3.8days (3.4-4.4) for the GA group (p = 0.001) There was no difference in electrophysiological recording. This study describes benefits in the GA group for the entire procedure of STN DBS. In these samples, there was no difference in the adverse effects seen in patients undergoing deep brain stimulator insertion with general anaesthetic compared with local anaesthetic. The use of general anaesthetic did not detract from the known benefits of surgery.

Reply: Dopamine agonist withdrawal syndrome and non-motor symptoms after Parkinson's disease surgery

We would like to thank Dr Nirenberg for her thoughtful comments on our prospective study reporting the occurrence of a delayed withdrawal syndrome in patients with Parkinson’s disease treated with bilateral subthalamic stimulation. This syndrome, which includes depression, apathy and anxiety, is the consequence of a marked decrease in dopaminergic treatment rendered possible by a major improvement in motor symptoms (Thobois et al ., 2010). This study identified preoperative non-motor fluctuations as predictors of post-operative apathy and demonstrated that non-motor psychic symptoms of Parkinson’s disease can be explained by mesolimbic dopaminergic denervation. In order to examine and discuss the points raised by Dr Nirenberg (2010), several aspects of our study need to be highlighted and clarified. The fact that Parkinson’s disease surgery that preferentially targets the sensorimotor rather than the limbic subthalamic nucleus deep brain stimulation produces better motor than non-motor effects provides an almost experimental model with which to study non-motor psychic symptoms of Parkinson’s disease. This study was designed to obtain a better understanding of post-operative non-motor withdrawal symptoms, their time course and mechanisms. In accordance with our study protocol, dopaminergic treatment was reduced drastically, with complete arrest of dopamine agonists at time of surgery and marked reduction of levodopa depending on patients’ motor state in the two weeks following surgery, when stimulation parameters were increased. Reduction of dopaminergic treatment after surgery is a normal procedure, which is necessary for the adjustment of subthalamic stimulation parameters and the establishment of satisfactory control of motor fluctuations and dyskinesias (Krack et al ., 2002; Thobois et al ., 2003). It is important to note that the management of medication in our study differs from routine practice, where medication is adapted more individually and where low-dosage dopamine agonists are often maintained in order to prevent the delayed appearance of …

An Interaction Between Levodopa and Enteral Nutrition Resulting in Neuroleptic Malignant-Like Syndrome and Prolonged ICU Stay

To describe a probable interaction between enteral feeds and levodopa leading to neuroleptic malignant-like syndrome (NMLS) in a polytrauma patient with Parkinson's disease (PD). A 63-year-old morbidly obese male polytrauma patient with PD and type 2 diabetes mellitus was admitted to our intensive care unit postoperatively. Enteral feeds were administered per nasogastric tube and provided 0.88 g /kg/day of protein based on ideal body weight (IBW). His PD medications (pramipexole, entacapone, and immediate-release levodopa/carbidopa 100 mg/25 mg, 1.5 tablets 4 times daily) were administered via nasogastric tube. To achieve better glycemic control, his enteral feeds were changed to a formula that provided 1.8 g/kg/day of protein based on IBW. In the following 24 hours, the patient's mental status deteriorated and he was reintubated. He developed a high fever (40.5 degrees C), leukocytosis, elevated serum creatine kinase (CK) (480-1801 units/L), and acute renal impairment. His enteral nutrition was changed to decrease protein intake to 1.0 g/kg/day based on IBW and he was given bromocriptine 5 mg 3 times daily via nasogastric tube. Within 24 hours, the patient's mental status improved, his temperature and CK decreased, and his renal function began to improve; the values returned to baseline levels on the 18th day of admission. Withdrawal or dose reduction of levodopa in patients with PD has been reported to precipitate NMLS, which is potentially fatal. Because dietary protein can decrease the absorp0tion of levodopa, a potential for an interaction between levodopa and enteral feedings exists, although published reports of such an interaction are limited. In this patient, the likelihood that a drug-nutrient interaction occurred between levodopa and enteral feedings is considered to be probable based on the Naranjo probability scale and the Horn Drug Interaction Probability Scale. Health-care professionals should be aware of the interaction between levodopa and protein content of enteral nutrition to avoid the occurrence of NMLS in patients with PD.

Revisión crítica de la estimulación subtalámica en la enfermedad de Parkinson

The authors critically review subthalamic nucleus (STN) stimulation for Parkinson's disease (PD) at long follow-up (3-5 years). Subthalamic stimulation induce a significant improvement during the "off" medication in the assessment motor score UPDRS (Unified Parkinson Disease Rating Scale) 3-5 years after surgery. Results show that the benefits obtained in tremor, rigidity, bradykinesia, dyskinesias induced by medication and levodopa reduction are significantly maintained during long term. The improvement in other clinical signs as gait and postural stability at long follow-up are not maintained comparing with the benefits obtained one year after surgery. A high percentage of patients show a cognitive disturbance during the follow-up period that may be correlated with the disease progression. The conclusion is that bilateral STN stimulation is an effective treatment for PD patients at long term but it should be considered earlier in the course of PD.

Apraxia of eyelid opening after subthalamic deep brain stimulation may be caused by reduction of levodopa

Apraxia of eyelid opening (ALO) is an infrequent side effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease (PD). However, the pathogenesis of ALO after STN DBS is not well understood. We report on two patients who suffered from disabling ALO after bilateral STN DBS. Their ALO improved by resuming the levodopa medication that had been discontinued after the surgery. Although ALO after STN DBS is considered as an adverse effect of STN stimulation, postoperative modification of dopaminergic medication may be a cause of ALO after STN DBS.