Prevalence of neuroleptic-induced restless legs syndrome in patients taking neuroleptic drugs

The Parkinson's disease and restless legs syndrome/Willis-Ekbom disorder link: evidences, biases and clinical relevance

Parkinson's disease (PD) and restless legs syndrome/Willis-Ekbom disorder (RLS/WED) are relatively common diseases in the realm of movement disorders. The fact that both may, as expected, co-occur and typically share a similar remarkable response to dopaminergic treatment raised the interest in exploration of additional shared features that throughout the years cruised fields as diverse as phenomenology, epidemiology, genetics, pathology, and clinical studies. In this review, we describe and critically examine the evidence and biases of a conceivable overlap of these two disorders, trying to shed light onto two main sources of confusion: (1) are PD and RLS/WED reciprocal risk factors? and (2) what are the main mimics of RLS/WED in PD?

Clinical Study of Restless Leg Syndrome Accompanied by Psychological Symptoms Induced by High-Dose Treatment With Madopar

Objectives: Some neurological disorders demonstrate indistinguishable psychological symptoms at an early stage, especially when accompanied by jitters similar to those in Parkinson's disease. During dopamine replacement therapy, some patients display restless leg syndrome (RLS)-like symptoms. Therefore, we aimed to analyze treatment strategies and the prognosis of RLS caused by high-dose Madopar. Methods: Nine patients who were misdiagnosed with Parkinson's disease, taking a high dose of Madopar, and showed symptoms of anxiety, depression, and somatization were recruited. Clinical data were collected, and strategies of treatment and prognosis were analyzed. Results: Seven patients demonstrated varying degrees of anxiety and depression, and the other two cases were misdiagnosed as Parkinson's disease. During Madopar treatment, patients gradually showed aggravated symptoms, including swelling, numbness, pain, and other sensory abnormalities in both lower extremities, which spread to both upper extremities in a few patients. Among the seven patients, symptoms of anxiety, depression, insomnia, and somatization significantly worsened during the observation period. The average time from taking Madopar to the appearance of RLS was 2.6 ± 0.6 months, the average time to clinical diagnosis was 18.17 ± 9.40 months, and the average dosage of Madopar was 1.44 ± 0.21 g per day. Gradually reducing the Madopar dosage and administering a small dose of long-acting dopamine preparation greatly alleviated the symptoms after 3 months. Conclusion: A high dose of Madopar can cause RLS-like symptoms accompanied by anxiety, depression, insomnia, and other mental health symptoms. These symptoms should be more closely monitored by clinicians.

French consensus: Pharmacoresistant restless legs syndrome

Dopaminergic agonists, α2δ ligands and opioids are, as single-drug therapy, the first line treatment for restless legs syndrome (RLS/Willis-Ekbom disease). However, despite treatment efficacy, exacerbations of RLS may occur with overall worsening in symptoms severity, development of pain and symptoms spreading to other parts of the body, without meeting augmentation syndrome criteria. This development of "drug-resistant" RLS can cause pain, severe insomnia and psychiatric disorders that affect considerably patients' quality of life. The lack of French recommendations for this form of RLS leave physicians with few options to help patients with physical and emotional distress. Our group of neurological experts and sleep specialists proposes a diagnostic and therapeutic strategy to provide better care and appropriate treatment through searching for the organic, psychiatric and/or iatrogenic causes of drug resistance. Once a drug-resistant RLS diagnosis has been confirmed, we recommend an obligatory work-up including: a video-polysomnogram, a biological evaluation including iron status, standard numeration and C-reactive protein level. Treatment will be comorbidity-dependent: dopaminergic agonist would be recommended in case of depression or associated periodic leg movements, α2δ ligand in case of insomnia, complaint of pain, or general anxiety, in association with low-dose opioids if necessary. Strong opioids should be preferred for multiresistant RLS.

Association of Restless Legs Syndrome With Incident Parkinson's Disease

Study Objectives

The association between restless legs syndrome (RLS) and Parkinson's disease (PD) has been extensively studied with inconclusive results; therefore, we prospectively examined the associations of the presence of RLS with development of incident PD.

Methods

From a nationally representative prospective cohort of almost 3.5 million US veterans (age: 60 ± 14 years, 93% male, median follow-up time of 7.8 years [interquartile range: 6.4-8.4 years]), we created a propensity-matched cohort of 100882 PD-free patients and examined the association between prevalent RLS and incident PD. This association was also assessed in the entire cohort. Associations were examined using Cox models.

Results

There were 68 incident PD events (0.13%, incidence rate 1.87 [1.48-2.37]/10000 patient-years) in the RLS-negative group, and 185 incident PD events (0.37%, incidence rate 4.72 [4.09-5.45]/10000 patient-years) in the RLS-positive group in the propensity-matched cohort. Prevalent RLS was associated with more than twofold higher risk of incident PD (hazard ratio [HR]: 2.57, 95% confidence interval [CI]: 1.95-3.39) compared to RLS-negative patients. Qualitatively similar results were found when we examined the entire 3.5 million cohort: Prevalent RLS was associated with more than twofold higher risk of incident PD (multivariable adjusted HR: 2.81, 95%CI: 2.41-3.27).

Conclusion

RLS and PD share common risk factors. In this large cohort of US veterans, we found that prevalent RLS is associated with higher risk of incident PD during 8 years of follow-up, suggesting that RLS could be an early clinical feature of incident PD.

Gabapentin treatment in clozapine-induced restless legs syndrome: two cases and a review of the literature

Restless legs syndrome (RLS) is a neuro-sensorimotor disorder affecting 2-4% of adults. It is characterized by intense urges to move the legs, associated with unpleasant sensory disturbances in the legs occurring at rest and manifests mostly in the evening and night, relieved by movement. Diagnosis is primarily based on clinical presentation and the consensus criteria for the diagnosis have been established. Antipsychotics, the dopamine antagonists, have been reported to induce RLS. Dopamine agonists, the effective first-line treatment of RLS, carry the risk of inducing or worsening psychosis. Many nondopaminergic agents including antiepileptic medications have also been used in the treatment of primary RLS. In this report we describe clozapine-induced RLS in two patients with schizophrenia and its successful treatment with gabapentin, a nondopaminergic agent. In addition, we have reviewed the available literature on clozapine-induced RLS and its management.

Transcranial magnetic stimulation for evaluation of motor cortical excitability in restless legs syndrome/Willis-Ekbom disease

There is no consensus about mechanisms underlying restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). Cortical excitability may be abnormal in RLS. Transcranial magnetic stimulation (TMS) can provide insight about cortical excitability. We reviewed studies about measures of excitability to TMS in RLS. Original studies published between January 1999 and January 2015 were searched in PubMed, Scopus, and Web of Science databases. Inclusion criteria were as follows: original studies involving primary RLS in patients from both sexes and ages between 18 and 85 years; TMS protocols clearly described; and they were written in English, in peer-reviewed journals. Fifteen manuscripts were identified. TMS protocols were heterogeneous across studies. Resting motor threshold, active motor threshold, and amplitudes of motor-evoked potentials were typically reported to be normal in RLS. A reduction in short-interval intracortical inhibition (SICI) was the most consistent finding, whereas conflicting results were described in regard to short-interval intracortical facilitation and the contralateral silent period. Decreased SICI can be reversed by treatment with dopaminergic agonists. Plasticity in the motor cortex and sensorimotor integration may be disrupted. TMS may become a useful biomarker of responsiveness to drug treatment in RLS. The field can benefit from increases in homogeneity and sizes of samples, as well as from decrease in methodological variability across studies.

Medications associated with restless legs syndrome: a case-control study in the US Renal Data System (USRDS)

OBJECTIVE

The objective of this study was to determine the association between the usage of four classes of "at-risk" medications (antidepressants, neuroleptics, antihistamines, and antiemetics with dopamine blockade) and restless legs syndrome (RLS) in dialysis patients within the United States Renal Data System (USRDS).

METHODS

This was a case-control design within a national (United States) patient registry of all patients with end-stage renal disease (ESRD) in the USRDS anytime during the period of 1 October 2006 to 31 December 2010, inclusive. A total of 16,165 ESRD patients (3234 cases; 12,931 age-, sex-, and race-matched controls) were studied.

RESULTS

All four classes of "at-risk" medications see widespread use among patients in the USRDS. All were associated with increased odds of an RLS diagnosis (range of odds ratios, 1.47-2.28; all p < 0.0001) during the period of observation. Results were unchanged when controlling for time on hemodialysis. Usage of more than one class of medication increased the odds for having RLS.

CONCLUSIONS

ESRD patients often receive medication intended for relief of conditions associated with their disease, such as depression and psychological issues, pruritus, and gastroparesis; however, such medications may increase the risk of RLS. Given the high prevalence of RLS in ESRD patients, these medications should only be used when their benefits clearly outweigh the risk of development of the troubling and distressing symptoms of RLS.

Olanzapine and clozapine differently affect sleep in patients with schizophrenia: results from a double-blind, polysomnographic study and review of the literature

Schizophrenia is associated with impaired sleep continuity. The second generation antipsychotics clozapine and olanzapine have been reported to improve sleep continuity but also to rarely induce restless legs syndrome (RLS). The aims of this randomized double-blind study were to compare the effects of clozapine and olanzapine on sleep and the occurrence of RLS. Therefore, polysomnographies were recorded and RLS symptoms were assessed in 30 patients with schizophrenia before and after 2, 4 and 6 weeks of treatment with either clozapine or olanzapine. Treatment with both antipsychotics increased total sleep time, sleep period time and sleep efficiency and decreased sleep onset latency. These changes were similar in both groups, occurred during the first 2 treatment weeks and were sustained. For example, sleep efficiency increased from 83% (olanzapine) and 82% (clozapine) at baseline to 95% at week 2 and 97% at week 6 in both treatment groups. Sleep architecture was differently affected: clozapine caused a significantly stronger increase of stage 2 sleep (44%) than olanzapine (11%) but olanzapine a significantly stronger increase of REM-sleep. Olanzapine caused an 80% increase of slow wave sleep whereas clozapine caused a 6% decrease. No patient reported any of 4 RLS defining symptoms at baseline. During treatment, 1 patient of each group reported at one visit all 4 symptoms, i.e. met the diagnosis of an RLS. In conclusion, sleep continuity similarly improved and sleep architecture changed more physiologically with olanzapine. Neither of the antipsychotics induced RLS symptoms that were clinically relevant.