Suspected duloxetine-induced restless legs syndrome phenotypic variant: a case report

BACKGROUND

Restless arms syndrome (RAS) is the most common variant of restless legs syndrome (RLS), which is easy to be ignored in clinical practice due to the lack of specific diagnostic criteria. When effective therapeutic agents induced RAS and symptoms persisted after briefly observation, clinicians will face the challenge of weighing efficacy against side effects.

CASE PRESENTATION

A 67-year-old woman was admitted to a geriatric psychiatric ward with depression. Upon admission, the escitalopram dose was reduced from 15 mg to 10 mg per day, and the duloxetine dose was increased from 60 mg to 80 mg per day. The next night before bedtime, she developed itching and creeping sensations deep inside bilateral shoulders and arms, with the urge to move, worsening at rest, and alleviation after hammering. The symptoms persisted when escitalopram was discontinued. A history of RLS was confirmed. Treatment with 40 mg of duloxetine and 0.125 mg of pramipexole significantly improved depression, and the paresthesia disappeared, with no recurrence occurring 6 months after discharge.

DISCUSSION AND CONCLUSIONS

This case suggests that psychiatrists should pay attention to RLS variants when increasing doses of duloxetine. Long-term improvement can be achieved through dosage reduction combined with dopaminergic drugs instead of immediate discontinuation.

Escitalopram-induced sinus bradycardia in coronary heart disease combined with depression: a case report and review of literature

For patients with cardiovascular disease, using the antidepressant escitalopram may lead to unexpected adverse events. Here, a rare repeated sinus bradycardia event due to escitalopram is first reported. In an 82-year-old female patient with cardiac dysfunction using digoxin, tachycardia (average heart rate of 93 beats/min) was demonstrated by electrocardiogram (ECG). She began to take escitalopram and lorazepam due to depression, but sinus bradycardia (93.7% heart rate was <60 beats/min) and sinus arrest were first detected after 3 months. Its proportion decreased to 0.1% after discontinuation of digoxin and escitalopram for 1 day, and the rhythm returned to normal 2 weeks later. After 2 months, escitalopram was prescribed again in combination with quetiapine; then, 17.1% heart rate was <60 beats/min. After escitalopram and quetiapine withdrawal, the ECG showed the heart rhythm had normalized again. No other drug changes were made during these periods. Escitalopram was deemed to be a highly possible cause of sinus bradycardia according to its Naranjo's Algorithm score. Furthermore, literature on escitalopram-mediated cardiovascular adverse events was reviewed and analyzed. Empirically, escitalopram should be discontinued immediately if iatrogenic causes cannot be ruled out. Furthermore, ECG monitoring in escitalopram-related cardiovascular adverse events is highlighted, especially in patients receiving certain drug classes simultaneously (i.e., sinoatrial node inhibitors, antipsychotics).

Frequency, risk factors, and impacts on quality of life of the restless legs syndrome and side effects among antidepressant users in a tertiary hospital: an observational cross-sectional study

Restless leg syndrome (RLS) is a common but underestimated sensorimotor disorder that significantly affects the quality of life (QoL) which can be induced by antidepressants. This study aims to investigate the frequency and potential risk factors of RLS and side effects in selective serotonin reuptake inhibitors/serotonin and noradrenaline reuptake inhibitors (SSRI/SNRI) users. This cross-sectional study included 198 outpatients who received SSRI/SNRI for 4-8 weeks. Clinical evaluation was performed using the International Restless Leg Syndrome Study Group rating scale for RLS, Udvalg for Kliniske Undersøgelser side effects rating scale, and a short form 36 (SF-36) questionnaire for QoL. The frequency of RLS was 25%. RLS significantly increased with smoking and habituality. Also, habituality increased neurologic side effects reporting. The use of antipsychotics and calcium channel blockers decreased reporting of autonomic side effects. QoL decreased with RLS, psychiatric, neurologic, autonomic, and other side effects in different domains of SF-36. These findings suggested that SSRI/SNRI use could be associated with a higher risk of RLS, especially in smokers. QoL could be influenced negatively by RLS and all side effects. However, further prospective studies are needed to confirm these associations in large samples.

Acute sleep interventions as an avenue for treatment of trauma-associated disorders

Scientific evidence that acute, posttrauma sleep disturbances (eg, nightmares and insomnia) can contribute significantly to the pathogenesis of trauma-induced disorders is compelling. Sleep disturbances precipitating from trauma are uniquely predictive of daytime posttrauma symptom occurrence and severity, as well as subsequent onset of mental health disorders, including post-traumatic stress disorder. Conversely, adequate sleep during the acute posttrauma period is associated with reduced likelihood of adverse mental health outcomes. These findings, which are broadly consistent with what is known about the role of sleep in the regulation of emotion, suggest that the acute posttrauma period constitutes a "window of opportunity" during which treatment of sleep disturbances may be especially effective for preventing or mitigating progression of aberrant psychophysiological processes. At this point, the weight of the scientific evidence supporting this possibility warrants initiation of clinical trials to confirm the benefits of targeted prophylactic sleep enhancement, and to establish treatment guidelines as appropriate.

CITATION

Swift KM, Thomas CL, Balkin TJ, Lowery-Gionta EG, Matson LM. Acute sleep interventions as an avenue for treatment of trauma-associated disorders. J Clin Sleep Med. 2022;18(9):2291-2312.

The effect of brain serotonin deficiency on breathing is magnified by age

Serotonin is an important mediator modulating behavior, metabolism, sleep, control of breathing, and upper airway function, but the role of aging in serotonin-mediated effects has not been previously defined. Our study aimed to examine the effect of brain serotonin deficiency on breathing during sleep and metabolism in younger and older mice. We measured breathing during sleep, hypercapnic ventilatory response (HCVR), CO2 production (VCO2 ), and O2 consumption (VO2 ) in 16-18-week old and 40-44-week old mice with deficiency of tryptophan hydroxylase 2 (Tph2), which regulates serotonin synthesis specifically in neurons, compared to Tph2+/+ mice. As expected, aging decreased VCO2 and VO2 . Tph2 knockout resulted in an increase in both metabolic indexes and no interaction between age and the genotype was observed. During wakefulness, neither age nor genotype had an effect on minute ventilation. The genotype did not affect hypercapnic sensitivity in younger mice. During sleep, Tph2-/- mice showed significant decreases in maximal inspiratory flow in NREM sleep, respiratory rate, and oxyhemoglobin saturation in REM sleep, compared to wildtype, regardless of age. Neither serotonin deficiency nor aging affected the frequency of flow limited breaths (a marker of upper airway closure) or apneas. Serotonin deficiency increased the amount and efficiency of sleep only in older animals. In conclusion, younger Tph2-/- mice were able to defend their ventilation and phenotypically did not differ from wildtype during wakefulness. In contrast, both young and old Tph2-/- mice showed sleep-related hypoventilation, which was manifested by hypoxemia during REM sleep.

Rethinking bedtime resistance in children with autism: is restless legs syndrome to blame?

STUDY OBJECTIVES

In this study we investigated the clinical correlates of restless legs syndrome in children with autism and report on our experiences with response to treatment.

METHODS

A retrospective chart review of children seen in our sleep center from 2016-2019 was performed to identify children with autism and chronic insomnia. Patients underwent clinical assessments for restless legs symptomatology. Overnight polysomnogram, serum ferritin testing, and response to clinical treatment data were collected.

RESULTS

A total of 103 children with autism and chronic insomnia were identified (age range 2-19 years). Of these, 41 children (39%) were diagnosed with restless legs syndrome. The diagnosis of restless legs syndrome was associated with significantly lower serum ferritin levels (mean 29 ± 18.62 ng/mL vs non-restless legs syndrome 56.7 ± 17.59, P < .001) and higher periodic limb movements of sleep on polysomnogram (8.12 ± 6.6 vs non-restless legs syndrome 0.06 ± 0.17). The presence of leg kicking, body rocking, or any symptoms involving the legs was highly correlated with the diagnosis of restless legs syndrome. Positive treatment response was noted in nearly all treated patients, including those treated with oral iron supplementation alone (25 children, 23 responders), gabapentin alone (12 children, all responders), and combination therapy (3 children, all responders).

CONCLUSIONS

Our findings suggest restless legs syndrome may represent an under-recognized cause of insomnia in children with autism. Initial assessment should include a thorough query of behaviors related to nocturnal motor complaints, because restless legs syndrome may be a treatable cause of sleep disruption.

Association of proton pump inhibitor and histamine H2-receptor antagonists with restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder, which can disrupt sleep and is thought to be caused in part by low cellular iron stores. Proton pump inhibitors (PPI) and histamine H₂-receptor antagonists (H₂A) are among the most commonly used drugs worldwide and show evidence of causing iron deficiency. We conducted a case/non-case observational study of blood donors in the United States (N = 13,403; REDS-III) and Denmark (N = 50,323; Danish Blood Donor Study, DBDS), both of which had complete blood count measures and a completed RLS assessment via the Cambridge–Hopkins RLS questionnaire. After adjusting for age, sex, race, BMI, blood donation frequency, smoking, hormone use, and iron supplement use, PPI/H₂A use was associated with RLS (odds ratio [OR] = 1.41; 95% confidence interval [CI], 1.13–1.76; p = 0.002) in REDS-III for both PPI (OR = 1.43; CI, 1.03–1.95; p = 0.03) and H₂A (OR = 1.56; CI, 1.10–2.16; p = 0.01). DBDS exhibited a similar association with PPIs/H₂As (OR = 1.29; CI, 1.20–1.40; p < 0.001), and for PPIs alone (OR = 1.27; CI, 1.17–1.38; p < 0.001), but not H₂As alone (OR = 1.18; CI, 0.92–1.53; p = 0.2). We found no evidence of blood iron stores mediating this association. The association of PPI, and possibly H₂A, consumption with RLS independent of blood iron status and other factors which contribute to RLS risk suggest the need to re-evaluate use of PPI/H₂A in populations at particular risk for RLS.

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.

Drug-Induced Restless Legs Syndrome

OBJECTIVE

To review the literature on drug-induced restless legs syndrome (DI-RLS).

DATA SOURCES

The review included a search for English-language literature from 1966 to December 2017 in the MEDLINE, PubMed, and Ovid databases using the following search terms: restless legs syndrome (RLS), periodic limb movement, adverse effects, and drug-induced. In addition, background articles on the pathophysiology, etiology, and epidemiology of RLS were retrieved. Bibliographies of relevant articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION

All case reports, case series, and review articles of DI-RLS were identified and analyzed. There were only a small number of controlled clinical trials, and most data were from case reports and case series.

RESULTS

Several drugs and drug classes have been implicated in DI-RLS, with antidepressants, antipsychotics, and antiepileptics having the most evidence. In addition, RLS may be linked with a number of disorders or underlying predisposing factors as well.

CONCLUSIONS

The prevalence of RLS is variable and ranges from 3% to 19% in the general population. There are many predisposing factors to RLS, but an emerging body of evidence suggests that there is an association between numerous drugs and RLS.

Restless Legs Syndrome and Depression: Effect Mediation by Disturbed Sleep and Periodic Limb Movements

OBJECTIVE

To investigate an association between restless legs syndrome (RLS) and depression and to what extent sleep disturbance, periodic limb movements during sleep (PLMS), and antidepressant medication mediate this relationship.

METHODS

A cross-sectional analysis was conducted of the Osteoporotic Fractures in Older Men Study data in 982 men assessed for RLS (International RLS Study Group scale [IRLSS]) and depression (Geriatric Depression Scale [GDS]), who underwent actigraphy (for sleep latency/efficiency) and polysomnography (for PLMS). Men were split into three groups: no RLS (N = 815), mild RLS (IRLSS ≤ 12, N = 85), moderate-to-severe RLS (IRLSS > 12, N = 82). Depression was defined as GDS score ≥ 6. Logistic and linear regression assessed associations of RLS and depression or number depressive symptoms, respectively. Models were adjusted for age, site, race, education, body mass index, personal habits, benzodiazepine/dopaminergic medication, physical activity, cardiovascular risk factors, and apnea-hypopnea index.

RESULTS

Of 982 men, 167 (17.0%) had RLS. Depression was significantly associated with moderate-to-severe RLS after adjustment (versus no RLS: OR [95% CI] 2.85 [1.23, 6.64]). Further adjustment for potential mediators attenuated effect size modestly, most for sleep efficiency (OR: 2.85-2.55). Compared with no RLS, moderate-to-severe RLS was associated with the number of depressive symptoms after adjustment (adjusted means [95% CI]; no RLS: 1.14 [1.05, 1.24] versus IRLSS > 12: 1.69 [1.32, 2.11]). Further adjustment for potential mediators did not alter effect size. For men with PLMS index at least median, number of depressive symptoms significantly increased as RLS category became more severe.

CONCLUSION

Depression is more common as RLS severity worsens. The RLS-depression relationship is modestly explained by sleep disturbance and PLMS.

Restless Legs Syndrome: Current Concepts about Disease Pathophysiology

Background

In the past few decades, much has been learned about the pathophysiology of restless legs syndrome (RLS). Investigators have studied neuropathology, imaging, electrophysiology, and genetics of RLS, identifying brain regions and biological systems affected in RLS. This manuscript will review RLS pathophysiology literature, examining the RLS state through consideration of the neuroanatomy, then the biological, organ, and genetic systems.

Methods

Pubmed (1966 to April 2016) was searched for the term “restless legs syndrome” cross-referenced with “pathophysiology,” “pathogenesis,” “pathology,” or “imaging.” English language papers were reviewed. Studies that focused on RLS in relation to another disease were not reviewed.

Results

Although there are no gross structural brain abnormalities in RLS, widespread brain areas are activated, including the pre- and post-central gyri, cingulate cortex, thalamus, and cerebellum. Pathologically, the most consistent finding is striatal iron deficiency in RLS patients. A host of other biological systems are also altered in RLS, including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems. Polymorphisms in genes including BTBD9 and MEIS1 are associated with RLS.

Discussion

RLS is a neurologic sensorimotor disorder that involves pathology, most notably iron deficiency, in motor and sensory brain areas. Brain areas not subserving movement or sensation such as the cingulate cortex and cerebellum are also involved. Other biological systems including the dopaminergic, oxygen-sensing, opioid, glutamatergic, and serotonergic systems are involved. Further research is needed to determine which of these anatomic locations or biological systems are affected primarily, and which are affected in a secondary response.

Selective Serotonin Reuptake Inhibitor/Serotonin-Norepinephrine Reuptake Inhibitor Use as a Predictor of a Diagnosis of Restless Legs Syndrome

OBJECTIVE/BACKGROUND

Because restless legs syndrome (RLS) is a problematic syndrome, demonstrating an association between use of selective serotonin reuptake inhibitors (SSRIs)/serotonin-norepinephrine reuptake inhibitors (SNRIs) and RLS may help direct patient care. The goals of this study were (1) to establish the incidence of RLS in mental health patients being treated with SSRIs or SNRIs in a local Veterans Affairs medical center and (2) to evaluate the frequency with which certain SSRIs or SNRIs are associated with RLS and the trend in frequency of the diagnosis since the revision of the criteria for RLS offered by the International Restless Leg Syndrome Study Group (IRLSSG), the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), and the International Classification of Sleep Disorders, Revised (ICSD-3).

METHODS

A retrospective chart review was used to evaluate the number of patients receiving SSRI/SNRI therapy with and without a diagnosis of RLS, with the date of the RLS diagnosis and initiation of SSRI/SNRI therapy noted. The frequency with which certain SSRIs/SNRIs were associated with RLS, and the frequency of RLS diagnoses since January 2012 were also noted. Descriptive statistics and logistic regression were used for data analysis.

RESULTS

A total of 254 charts were reviewed. A majority of the patients (89.8%) were male, and 14 (5.5%) were diagnosed with RLS. A logistic regression equation approached significance in predicting RLS (P=0.053). Age and sex emerged as significant predictors of RLS. The prevalence of any individual SSRI or SNRI being associated with RLS was indeterminable. No difference was seen in the number of RLS diagnoses since the refining of the IRLSSG, DSM-5, and ICSD-3 criteria.

CONCLUSIONS

The use of SSRIs/SNRIs does not seem to be associated with a diagnosis of RLS. In addition, the diagnosis of RLS does not seem to have become more common since the revision of the diagnostic criteria for the disorder.

Restless legs syndrome: clinical presentation diagnosis and treatment

Restless legs syndrome (RLS) is a circadian disorder of sensory-motor integration that may be related to genetically determined dysregulation of iron transport across the blood-brain barrier. Dopamine agonists (DAs) have been considered the first-line therapy, but with the growing appreciation of problems associated with long-term treatment, particularly augmentation and impulse control disorder, alpha-2-delta drugs, such as gabapentin, are now considered the first line of treatment in patients with troublesome RLS. Opioids can be considered as an alternative therapy, particularly in patients with DA-related augmentation. In more severe cases, a combination therapy may be required. Intravenous iron therapy may be considered on those patients with refractory RLS.

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.

Prospective study of restless legs syndrome and risk of depression in women

Most research on the association between restless legs syndrome (RLS) and depression has involved cross-sectional data. The objective of the present study was to evaluate this issue prospectively among Nurses' Health Study participants. A total of 56,399 women (mean age = 68 years) who were free of depression symptoms at baseline (2002) were followed until 2008. Physician-diagnosed RLS was self-reported. During 300,155 person-years of follow-up, the authors identified 1,268 incident cases of clinical depression (regular use of antidepressant medication and physician-diagnosed depression). Women with RLS at baseline were more likely to develop clinical depression (multivariate-adjusted relative risk (RR) = 1.5, 95% confidence interval (CI): 1.1, 2.1; P = 0.02) than those without RLS. The presence of RLS at baseline was also associated with higher scores on the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) and the 15-item Geriatric Depression Scale (GDS-15) thereafter. Multivariable-adjusted mean differences were 1.00 (standard error, 0.12) for CESD-10 score and 0.47 (standard error, 0.07) for GDS-15 score between women with RLS and those without RLS (P < 0.0001). In conclusion, women with physician-diagnosed RLS had an increased risk of developing clinical depression and clinically relevant depression symptoms. Further prospective studies using refined approaches to ascertainment of RLS and depression are warranted.

The psychopharmacological management of RLS in psychiatric conditions: a review of the literature

BACKGROUND

Restless legs syndrome (RLS) is a movement disorder treated with dopamine agonists. RLS is often diagnosed as a comorbid condition with psychiatric disorders, which are treated with dopamine antagonists or antidepressants resulting in onset or exacerbation of RLS symptoms.

OBJECTIVES

The objectives of this article are to provide a review of the literature to (a) describe the comorbidity of psychiatric disorders associated with RLS, (b) identify the treatment of psychiatric disorders that cause or exacerbate symptoms of RLS, and (c) provide clinical recommendations for psychiatric health care providers.

DESIGN

A review of the literature of English articles included the databases of Medline, Pubmed, PsychINFO, and CINAHL for "Restless Legs Syndrome" with major psychiatric disorders including mood disorders (depression and bipolar), schizophrenia, and anxiety disorders (anxiety, panic disorder, obsessive compulsive disorder). The PRISMA guidelines were used to improve the reporting of the review of the literature.

RESULTS

There were 61 articles that met the inclusion and exclusion criteria identified for the review of the literature, including RLS with mood disorders (n = 36), schizophrenia (n = 9), and anxiety disorders (n = 16).

CONCLUSIONS

Clinical trials are lacking on the best treatment for persons with RLS and psychiatric disorders; the most rigorous research found in the literature related to depression and anxiety. Studies lack evidence to document the best practice for persons with RLS and comorbid psychiatric disorders. Psychiatric health care providers should be aware of RLS, which is influenced by psychiatric medications.

Examination of insomnia and insomnia treatment in psychiatric inpatients

Despite the high comorbidity of insomnia with psychiatric illness, few studies have examined insomnia or insomnia treatments in psychiatric inpatients. The present study had two overall goals. First, we sought to describe insomnia symptoms in 76 US veterans hospitalized for a wide-range of psychiatric illnesses. Next, we sought to examine whether participation in one session of group therapy for insomnia was associated with improvement in Insomnia Severity Index (ISI) scores for a subset of these inpatients (n = 19). Data were extracted from the clinical charts of 140 inpatients admitted into the 26-bed psychiatric ward at the New Mexico VA Healthcare System. The majority of the veterans had clinical insomnia in the moderate-to-severe range, and only 18% of the sample reported no clinically-significant insomnia. There was a significant reduction in ISI scores approximately 1 week after attendance at the group therapy session, which appears to be unrelated to the length of hospitalization, but might be related to psychiatric stabilization. This is the first study to examine insomnia symptoms in a mixed, psychiatric inpatient population. Group therapy for insomnia might be a particularly useful treatment option given polypharmacy and substance dependency issues often arising in this population.

Excessive sleepiness: under-recognized and essential marker for sleep/wake disorder management

BACKGROUND

Research during the past few decades has provided substantial evidence indicating that excessive sleepiness (ES) and associated sleep/wake disorders can result in significant morbidity and mortality. However, symptomatology (e.g., ES) and the relationships among common morbidities (e.g., cardiovascular disease, metabolic disorders, mood impairment) and sleep/wake disorders remain under-recognized in clinical practice, particularly in primary care. Yet assessment of sleep/wakefulness and associated symptoms can often be easily conducted in the primary care setting, providing valuable information to facilitate the diagnosis and management of sleep/wake disorders.

OBJECTIVE

To provide a conceptual and educational framework that helps primary care physicians comprehensively assess, differentially diagnosis, and appropriately manage patients presenting with ES or ES-related sleep/wake disorders.

METHODS

Comprised of six sleep specialists and six primary care physicians, the Sleep/Wake Disorders Working Group (SWG) used a modified, two-round Delphi approach to create and harmonize consensus recommendations for the assessment, diagnosis, treatment, and ongoing management of patients with common sleep/wake disorders related to ES.

RESULTS

After a review of the relevant literature, the SWG arrived at consensus on a number of clinical recommendations for the assessment and management ES and some of the most commonly associated sleep/wake disorders. Ten consensus statements – five each for assessment/diagnosis and treatment/ongoing care – were created for ES, insomnia, obstructive sleep apnea, circadian rhythm disorders, restless legs syndrome, and narcolepsy.

CONCLUSION

ES and ES-related sleep/wake disorders are commonly encountered in the primary care setting. By providing an educational framework for primary care physicians, the SWG hopes to improve patient outcomes by emphasizing recognition, prompt diagnosis, and appropriate ongoing management of ES and associated sleep/wake disorders.

Successful treatment of central pain in a multiple sclerosis patient with epidural stimulation of the dorsal root entry zone

OBJECTIVE

We report a case of central pain successfully treated by epidural placement of spinal cord stimulator electrodes. Neuromodulation of primary afferent fibers and the underlying dorsal root entry zone provided effective analgesia whereas traditional lead placement over the dorsal columns on a prior occasion had not been effective. The rationale for this technique based on current understanding of the mechanisms of central pain and the risk/benefit considerations are discussed.

CASE REPORT

A 52-year-old woman presented with a 2-year history of pain in the lateral hand secondary to a demyelinating episode in the C2-4 spinal cord secondary to multiple sclerosis. Medications, sympathetic blocks, and acupuncture had been ineffective. One year after an unsuccessful single-lead trial of spinal cord stimulation over the cervical dorsal columns, a dual-lead trial of spinal cord stimulation over the lateral cervical spinal cord and dorsal roots provided significant analgesia, prompting a successful permanent implant.

OUTCOME MEASURES

Responses on the Brief Pain Inventory short form and quantitative thermosensory testing data were collected at two timepoints 16 days apart under two conditions: no stimulation and single-lead stimulation of cervical primary afferents and underlying spinal cord.

RESULTS

The patient's questionnaire responses indicated significantly improved pain scores with lateral-lead neuromodulation that was associated with a reduction in her baseline heat hypoalgesia.

CONCLUSIONS

Lateral-lead spinal cord stimulation may be effective for some central pain syndromes through a partial restoration of homeostatic small-fiber signaling. Neuroanatomical and physiological data in a larger population of patients will be required to predict the best responders to this therapeutic modality.

Chiral toxicology: it's the same thing...only different

Chiral substances possess a unique architecture such that, despite sharing identical molecular formulas, atom-to-atom linkages, and bonding distances, they cannot be superimposed. Thus, in the environment of living systems, where specific structure-activity relationships may be required for effect (e.g., enzymes, receptors, transporters, and DNA), the physiochemical and biochemical properties of racemic mixtures and individual stereoisomers can differ significantly. In drug development, enantiomeric selection to maximize clinical effects or mitigate drug toxicity has yielded both success and failure. Further complicating genetic polymorphisms in drug disposition, stereoselective metabolism of chiral compounds can additionally influence pharmacokinetics, pharmacodynamics, and toxicity. Optically pure pharmaceuticals may undergo racemization in vivo, negating single enantiomer benefits or inducing unexpected effects. Appropriate chiral antidotes must be selected for therapeutic benefit and to minimize adverse events. Enantiomers may possess different carcinogenicity and teratogenicity. Environmental toxicology provides several examples in which compound bioaccumulation, persistence, and toxicity show chiral dependence. In forensic toxicology, chiral analysis has been applied to illicit drug preparations and biological specimens, with the potential to assist in determination of cause of death and aid in the correct interpretation of substance abuse and "doping" screens. Adrenergic agonists and antagonist, nonsteroidal anti-inflammatory agents, SSRIs, opioids, warfarin, valproate, thalidomide, retinoic acid, N-acetylcysteine, carnitine, penicillamine, leucovorin, glucarpidase, pesticides, polychlorinated biphenyls, phenylethylamines, and additional compounds will be discussed to illustrate important concepts in "chiral toxicology."

[Restless legs syndrome, periodic limb movements, and psychopharmacology]

Restless legs syndrome (RLS) and the often associated periodic limb movement disorder in sleep (PLMD) frequently occur in the general population as a primary disorder. In addition to organic disease, secondary forms are caused by psychotropic medication. Several antidepressants, antipsychotics, lithium, and opioid withdrawal have been shown to induce or exacerbate RLS and PLMD, while several antiepileptics used as mood stabilizers and some benzodiazepines demonstrate therapeutic potential for treating RLS/PLMD. Systematic or controlled studies for evaluating these side effects still do not exist. Among the antidepressants at higher risk of inducing this disorder are selective serotonin reuptake inhibitors, venlafaxine, and some tetracyclic antidepressants. Under medication with some tricyclic substances, periodic limb movements were observed more often. For some antidepressants with differing transmitter profiles such as bupropion RLS/PLMD ameliorating effects or at least neutral effects (Trazodon, Nortriptylin) have been described in small studies. In case of continued of or newly occurring insomnia a thorough history should be taken to identify a possible RLS/PLMD as an intolerable side effect of treatment. A change in medications should be considered if clinically feasible. In case of RLS/PLMD occurring in psychotic patients switching the antipsychotic and additionally using a second line medication such as antiepileptics or a benzodiazepine should be considered.

[Restless-legs syndrome]

Restless-legs syndrome (RLS) is a sensorimotor disorder, characterized by an irresistible urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations. It begins or worsens during periods of rest or inactivity, is partially or totally relieved by movements and is exacerbated or occurs at night and in the evening. RLS sufferers represent 2 to 3% of the general population in Western countries. Supportive criteria include a family history, the presence of periodic-leg movements (PLM) when awake or asleep and a positive response to dopaminergic treatment. The RLS phenotypes include an early onset form, usually idiopathic with a familial history and a late onset form, usually secondary to peripheral neuropathy. Recently, an atypical RLS phenotype without PLM and l-DOPA resistant has been characterized. RLS can occur in childhood and should be distinguished from attention deficit/hyperactivity disorder, growing pains and sleep complaints in childhood. RLS should be included in the diagnosis of all patients consulting for sleep complaints or discomfort in the lower limbs. It should be differentiated from akathisia, that is, an urge to move the whole body without uncomfortable sensations. Polysomnographic studies and the suggested immobilization test can detect PLM. Furthermore, an l-DOPA challenge has recently been validated to support the diagnosis of RLS. RLS may cause severe-sleep disturbances, poor quality of life, depressive and anxious symptoms and may be a risk factor for cardiovascular disease. In most cases, RLS is idiopathic. It may also be secondary to iron deficiency, end-stage renal disease, pregnancy, peripheral neuropathy and drugs, such as antipsychotics and antidepressants. The small-fiber neuropathy can mimic RLS or even trigger it. RLS is associated with many neurological and sleep disorders including Parkinson's disease, but does not predispose to these diseases. The pathophysiology of RLS includes an altered brain-iron metabolism, a dopaminergic dysfunction, a probable role of pain control systems and a genetic susceptibility with nine loci and three polymorphisms in genes serving developmental functions. RLS treatment begins with the elimination of triggering factors and iron supplementation when deficient. Mild or intermittent RLS is usually treated with low doses of l-DOPA or codeine; the first-line treatment for moderate to severe RLS is dopaminergic agonists (pramipexole, ropinirole, rotigotine). In severe, refractory or neuropathy-associated RLS, antiepileptic (gabapentin, pregabalin) or opioid (oxycodone, tramadol) drugs can be used.