Restless legs syndrome: diagnostic assessment and the advantages and risks of dopaminergic treatment

Pramipexole Increases Go Timeouts but Not No-go Errors in Healthy Volunteers

Parkinson's disease (PD) is characterized by motor symptoms, such as resting tremor, bradykinesia and rigidity, but also features non-motor complications. PD patients taking dopaminergic therapy, such as levodopa but especially dopamine agonists (DAs), evidence an increase in impulse control disorders (ICDs), suggesting a link between dopaminergic therapy and impulsive pursuit of pleasurable activities. However, impulsivity is a multifaceted construct. Motor impulsivity refers to the inability to overcome automatic responses or cancel pre-potent responses. Previous research has suggested that PD patients, on dopaminergic medications, have decreased motor impulsivity. Whether effects on impulsivity are main effects of dopaminergic therapies or are specific to PD is unclear. Using a Go No-go task, we investigated the effect of a single dose of the DA pramipexole on motor impulsivity in healthy participants. The Go No-go task consisted of Go trials, for which keystroke responses were made as quickly as possible, and lesser frequency No-go trials, on which motor responses were to be inhibited. We hypothesized that pramipexole would decrease motor impulsivity. This would manifest as: (a) fewer No-go errors (i.e., fewer responses on trials in which a response ought to have been inhibited); and (b) more timed-out Go trials (i.e., more trials on which the deadline elapsed before a decision to make a keystroke occurred). Healthy volunteers were treated with either 0.5 mg of pramipexole or a standard placebo (randomly determined). During the 2-h wait period, they completed demographic, cognitive, physiological and affective measures. The pramipexole group had significantly more Go timeouts (p < 0.05) compared to the placebo group though they did not differ in percent of No-go errors. In contrast to its effect on pursuit of pleasurable activities, pramipexole did not increase motor impulsivity. In fact, in line with findings in PD and addiction, dopaminergic therapy might increase motor impulse control. In these patient groups, by enhancing function of the dorsal striatum (DS) of the basal ganglia in contrast to its effect on impulsive pursuit of pleasurable activities. These findings have implications for use and effects of pramipexole in PD as well as in other conditions (e.g., restless leg, dystonia, depression, addiction-related problems).

The Effect of Stretching Exercises on Severity of Restless Legs Syndrome in Patients on Hemodialysis

BACKGROUND

The restless legs syndrome is a sensorimotor disorder that is very common in patients on hemodialysis. Due to pharmacological treatments which have their own side effects, nowadays, studies have turned to non-pharmacological treatments.

OBJECTIVES

The present study aims to assess the effect of stretching exercises on the severity of restless legs syndrome in patients on hemodialysis.

PATIENTS AND METHODS

This clinical trial study was conducted on 33 patients who had been identified using diagnostic criteria from the hemodialysis ward of Hasheminejad Hospital in Tehran. Participants were randomly divided into the intervention group (n = 17) and control group (n = 16). Stretching exercises were performed on legs during the dialysis for half an hour, three times a week for 8 weeks in intervention group. Data were collected by using the international restless legs syndrome study group scale.

RESULTS

The results showed that the majority of participants were suffering from moderate restless legs syndrome. The symptom severity of this syndrome meaningfully changed eight weeks after intervention in the intervention group compared to the control group (P < 0.001).

CONCLUSIONS

The results highlighted the significance of training and performing the stretching exercises during dialysis for the purpose of improving restless legs syndrome symptoms and the quality of care of hemodialysis patients.

Augmentation in restless legs syndrome patients in Korea

PURPOSE

Augmentation has been known as the major complication of long-term dopaminergic treatment of restless legs syndrome (RLS). However, there have been no reports on the prevalence of augmentation in Korea. Thus, we aimed to assess the rate of augmentation and evaluate related factors in Korean RLS patients.

METHODS

Ninety-four idiopathic RLS patients who have been treated over a period of at least 6 months were enrolled. Thirty subjects were treated with a dopamine agonist only, and 64 were treated with a dopamine agonist and alpha two delta ligands. We assessed the clinical characteristics of those RLS subjects and evaluated the rate of augmentation. Augmentation was assessed using the NIH criteria for augmentation by two RLS experts independently.

RESULTS

Eleven subjects (11.7%) were classified as having definitive or highly suggestive clinical indication of augmentation. In comparing the augmentation group with the non-augmentation group, there were no significant differences of baseline clinical characteristics. Four (13.3%) of the dopamine agonists monotherapy group and seven (10.9%) of the combination therapy group were categorized as augmentation. There was no significant difference in the augmentation rate between these two groups.

CONCLUSIONS

We found an 11.7% augmentation rate in Korean RLS subjects. There was no difference in the rate of RLS augmentation between the dopaminergic monotherapy group and the combined treatment group. It may be related with using a similar dosage of dopaminergic drugs.

Review: management of Parkinson's disease

Parkinson's disease (PD) is one of the most frequent neurological diseases. Despite the modern imaging and nuclear techniques which help to diagnose it in a very early stage and lead to a better discrimination of similar diseases, PD has remained a clinical diagnosis. The increasing number of available treatment options makes the disease management often complicated even when the presence of PD seems undoubted. In addition, nonmotor symptoms and side effects of some therapies constitute some pitfalls already in the preclinical state or at the beginnings of the disease, especially with the progressive effect on patients. Therefore, this review aimed to summarize study results and depict recommended medical treatments for the most common motor and nonmotor symptoms in PD. Additionally, emerging new therapeutic options such as continuous pump therapies, eg, with apomorphine or parenteral levodopa, or the implantation of electrodes for deep brain stimulation were also considered.

The effect of selenium administration on restless leg syndrome treatment

BACKGROUND

Restless leg syndrome (RLS) is defined as an uncomfortable feeling in the limbs which is prominently sensed in legs. Dopamine system involvement is considered as the base of RLS's etiology. Because of safety, anti-oxidant and dopaminergic promoting action of selenium, this study aims to investigate the effect of selenium on restless leg syndrome treatment.

METHODS

Sixty patients with primary RLS were enrolled in this clinical trial (Irct2011103015943n1). It was based on 3 periods of drug prescription with one month wash out period. As placebo, 50 and 200 μg of selenium were administered in each separated month. The diagnosis was based on criteria published by IRLSG (International RLS Study Group). The questionnaire included 10 questions while each question's rating was between 0 and 4. Points between 1 and 10 were considered mild, 11 to 20 as moderate, 21 to 30 as severe and 31 to 40 as very severe. After end of each month of drug consumption, questionnaires were completed and each subject was asked to report the severity of disease and side effects of the drugs. At least 10 declines in scale were considered as appropriate responses.

RESULTS

Improvement (decline IRLS score >10) was significantly higher in selenium (50 and 200 μg) than placebo group.

CONCLUSION

Selenium prescription in daily recommended dose of 50 μg instead of a dopamine agonist would be an alternative treatment in improvement of RLS symptoms.

Update on the management of restless legs syndrome: existing and emerging treatment options

Restless legs syndrome (RLS) is a sensorimotor disorder, characterized by a circadian variation of symptoms involving an urge to move the limbs (usually the legs) as well as paresthesias. There is a primary (familial) and a secondary (acquired) form, which affects a wide variety of individuals, such as pregnant women, patients with end-stage renal disease, iron deficiency, rheumatic disease, and persons taking medications. The symptoms reflect a circadian fluctuation of dopamine in the substantia nigra. RLS patients have lower dopamine and iron levels in the substantia nigra and respond to both dopaminergic therapy and iron administration. Iron, as a cofactor of dopamine production and a regulator of the expression of dopamine type 2-receptor, has an important role in the RLS etiology. In the management of the disease, the first step is to investigate possible secondary causes and their treatment. Dopaminergic agents are considered as the first-line therapy for moderate to severe RLS. If dopaminergic drugs are contraindicated or not efficacious, or if symptoms are resistant and unremitting, gabapentin or other antiepileptic agents, benzodiazepines, or opioids can be used for RLS therapy. Undiagnosed, wrongly diagnosed, and untreated RLS is associated with a significant impairment of the quality of life.

Parkinson disease: an update

BACKGROUND

Over the past decade, the treatment of Parkinson disease (PD) has undergone tremendous changes. New drugs have been introduced to manage the cardinal motor symptoms of PD, and other agents have been borrowed to treat the nonmotor manifestations of the illness. For neurologists faced with the task of treating PD patients, the available array of medications may be confusing and intimidating.

REVIEW SUMMARY

In this review, I summarize the newest approved medications for the treatment of PD, including the new dopamine agonists and catechol-O-methyl-transferase inhibitors. I also describe agents that are used to treat common problems in PD patients, including hallucinations, orthostasis, nausea, erectile dysfunction, depression, and memory loss. Guidelines for handling common scenarios in PD patients will be illustrated by 10 case histories. Finally, the most promising PD drugs that are currently in development will be reviewed.

CONCLUSIONS

Neurologists have a vast armamentarium to treat both motor and nonmotor manifestations of PD. Understanding this array allows the astute clinician to improve the lives of their patients with PD.