Oxcarbazepine treatment of restless legs syndrome: three case reports

Anticonvulsant Agents for Treatment of Restless Legs Syndrome: A Case Report With Lamotrigine and a Review of the Literature

INTRODUCTION

Restless Legs Syndrome (RLS) is a neurological disorder primarily treated with pregabalin and gabapentin, followed by dopamine agonists later in the process due to the risk of augmenting RLS symptoms. In addition, clinical reports have disclosed varying degrees of success employing other agents in patients unresponsive to traditional agents. Here, we present a patient who had success in the reduction of RLS symptoms with lamotrigine, a broad-spectrum anticonvulsant. Previously, lamotrigine had been used in 2 trials with successful treatment of RLS.

CASE REPORT

We present a 58-year-old right-handed lady with long-standing history of smoking, hypertension, dyslipidaemia, prediabetes, gastro-esophageal reflux disease, asthma, strabismus, uterine cancer, severe and debilitating course of RLS accompanied by unexplained deterioration. The patient initially demonstrated abnormal sensation in all her limbs, which worsened with radiotherapy treatment, and was eventually diagnosed with RLS based on the diagnostic criteria. Subsequent examinations were unremarkable and revealed no further explanation for the deterioration of the RLS symptoms. While the complexity of the patient's medical history had exposed her to a variety of medications, she reported that only lamotrigine, in addition to her original regimen of methadone and pramipexole, offered significant symptomatic relief. It must be noted that no adverse side effects, including impulse-control disorder, were reported by the patient.

CONCLUSIONS

We present a case of a woman whose deteriorating symptoms of RLS were successfully alleviated by the administration of lamotrigine. This is only the third case in the literature to have successfully utilized lamotrigine as a treatment option for RLS.

A Narrative Review of the Lesser Known Medications for Treatment of Restless Legs Syndrome and Pathogenetic Implications for Their Use

Background

There are several well-known treatments for Restless Legs Syndrome (RLS), including dopamine agonists (pramipexole, ropinirole, rotigotine), anticonvulsants (gabapentin and its analogs, pregabalin), oral or intravenous iron, opioids and benzodiazepines. However, in clinical practice, treatment is sometimes limited due to incomplete response or side effects and it is necessary to be aware of other treatment options for RLS, which is the purpose of this review.

Methods

We performed a narrative review detailing all of the lesser known pharmacological treatment literature on RLS. The review purposefully excludes well-established, well-known treatments for RLS which are widely accepted as treatments for RLS in evidence-based reviews. We also have emphasized the pathogenetic implications for RLS of the successful use of these lesser known agents.

Results

Alternative pharmacological agents include clonidine which reduces adrenergic transmission, adenosinergic agents such as dipyridamole, glutamate AMPA receptor blocking agents such as perampanel, glutamate NMDA receptor blocking agents such as amantadine and ketamine, various anticonvulsants (carbamazepine/oxcarbazepine, lamotrigine, topiramate, valproic acid, levetiracetam), anti-inflammatory agents such as steroids, as well as cannabis. Bupropion is also a good choice for the treatment of co-existent depression in RLS because of its pro-dopaminergic properties.

Discussion

Clinicians should first follow evidence-based review recommendations for the treatment of RLS but when the clinical response is either incomplete or side effects are intolerable other options can be considered. We neither recommend nor discourage the use of these options, but leave it up to the clinician to make their own choices based upon the benefit and side effect profiles of each medication.

Summary

Clinicians should first follow evidence-based reviews for RLS but when response is incomplete and side effects intolerable, other medications can be considered. We do not make a recommendation on these options but leave it up to the clinician to make their own choice based upon the benefit and side effect profiles of each medication.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

Restless legs syndrome (RLS) is a sleep-related disorder defined by an urgency to move the legs, usually combined with uncomfortable or unpleasant sensations, which occurs or worsens during rest, usually in the evening or at night, and disappears with the movement of the legs. RLS can be classified as idiopathic or primary, and secondary to comorbid conditions (eg, renal disease, polyneuropathy). The pathophysiology of RLS is still unclear. This article provides an updated practical guide for the treatment of primary RLS in adults.

Antiseizure Drugs and Movement Disorders

The relationship between antiseizure drugs and movement disorders is complex and not adequately reviewed so far. Antiseizure drugs as a treatment for tremor and other entities such as myoclonus and restless leg syndrome is the most common scenario, although the scientific evidence supporting their use is variable. However, antiseizure drugs also represent a potential cause of iatrogenic movement disorders, with parkinsonism and tremor the most common disorders. Many other antiseizure drug-induced movement disorders are possible and not always correctly identified. This review was conducted by searching for all the possible combinations between 15 movement disorders (excluding ataxia) and 24 antiseizure drugs. The main objective was to describe the movement disorders treated and worsened or induced by antiseizure drugs. We also summarized the proposed mechanisms and risk factors involved in the complex interaction between antiseizure drugs and movement disorders. Antiseizure drugs mainly used to treat movement disorders are clonazepam, gabapentin, lacosamide, levetiracetam, oxcarbazepine, perampanel, phenobarbital, pregabalin, primidone, topiramate, and zonisamide. Antiseizure drugs that worsen or induce movement disorders are cenobamate, ethosuximide, felbamate, lamotrigine, phenytoin, tiagabine, and vigabatrin. Antiseizure drugs with a variable effect on movement disorders are carbamazepine and valproate while no effect on movement disorders has been reported for brivaracetam, eslicarbazepine, lacosamide, and stiripentol. Although little information is available on the adverse effects or benefits on movement disorders of newer antiseizure drugs (such as brivaracetam, cenobamate, eslicarbazepine, lacosamide, and rufinamide), the evidence collected in this review should guide the choice of antiseizure drugs in patients with concomitant epilepsy and movement disorders. Finally, these notions can lead to a better understanding of the mechanisms involved in the pathophysiology and treatments of movement disorders.

Restless leg syndrome prevalence in epilepsy patients and its impact on quality of sleep

This study aimed to determine the frequency of restless leg syndrome (RLS) and other sleep-related movement disorders and their effects on sleep quality in epilepsy patients. One hundred and twenty-seven epilepsy patients were compared with 115 age-and gender-matched healthy controls. RLS was determined from the clinical characteristics of the patients according to the International RLS Study Group's (IRLSSG) diagnostic criteria. Sleep bruxism was diagnosed based on the International Classification of Sleep Disorders, Third Edition (ICSD-3) criteria. Subjective sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was more common in the epilepsy group than in the control group (42.5% versus 26.1%; p = 0.007). The epilepsy group had significantly higher PSQI total scores than the control group (p = 0.003). The frequency of RLS was higher in epileptic patients than in the control group (13.4% versus 5.2%; p = 0.024). There were no significant differences between the patient group and the control group regarding limb movement and bruxism frequency during sleep. The PSQI scores were high in epilepsy patients with RLS compared to those without RLS (p = 0.009). The frequency of habitual snoring, bruxism, and repetitive leg movement in sleep was also high in epilepsy patients with RLS compared to those without RLS (p < 0.05). The prevalence of poor sleep quality and RLS in epilepsy patients is higher than in healthy controls. Our results also show the negative impact of RLS on sleep quality in epilepsy patients. Further confirmatory studies using objective sleep tests are needed to identify the mechanisms underlying the current findings.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

This article provides an updated practical guide for the treatment of primary restless legs syndrome (RLS). Articles that appeared after the American Academy of Neurology guideline search were reviewed according to the same evidence rating schedule. We found limited evidence for nonpharmacologic treatment options. In moderate to severe primary RLS, pharmacologic options may be considered, including iron suppletion, an α2δ ligand, a dopamine agonist, a combination of an α2δ ligand and a dopamine agonist, or oxycodone/naloxone. This article includes treatment options in case of augmentation.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

This article provides an updated practical guide for the treatment of primary restless legs syndrome (RLS). Articles that appeared after the American Academy of Neurology guideline search were reviewed according to the same evidence rating schedule. We found limited evidence for nonpharmacologic treatment options. In moderate to severe primary RLS, pharmacologic options may be considered, including iron suppletion, an α2δ ligand, a dopamine agonist, a combination of an α2δ ligand and a dopamine agonist, or oxycodone/naloxone. This article includes treatment options in case of augmentation.

Restless legs syndrome and pregnancy: a review

Restless legs syndrome (RLS) is a common sensorimotor neurological disorder that is diagnosed according to the revised criteria of the International RLS Study Group (IRLSSG). The pathophysiology of RLS is still unknown and its prevalence is influenced by ethnicity, age, and gender. RLS is divided into two types by etiology: primary or idiopathic and secondary. Primary RLS is strongly influenced by a genetic component while secondary RLS is caused by other associated conditions such as end-stage renal disease or peripheral neuropathy. Another common condition associated with RLS is pregnancy. The prevalence of RLS during pregnancy is two to three times higher than in the normal population and is influenced by the trimester and the number of parity. The main mechanisms that may contribute to the pathophysiology of RLS during pregnancy are hormonal changes and iron and folate status. Standard medications for treating RLS during pregnancy are not established. Most medications have been used according to the evidence from non-pregnant patients. Therefore, consideration of the medical treatment for treating RLS during pregnancy should be balanced between the benefit of relieving the symptoms and maternal and fetal risk. In general, the prognosis of RLS during pregnancy is good and symptoms are usually relieved after delivery.

Strategies for the treatment of restless legs syndrome

Restless legs syndrome (RLS) is a common neurological disorder of unknown etiology that is managed by therapy directed at relieving its symptoms. Treatment of patients with milder symptoms that occur intermittently may be treated with nonpharmacological therapy but when not successful, drug therapy should be chosen based on the timing of the symptoms and the needs of the patient. Patients with moderate to severe RLS typically require daily medication to control their symptoms. Although the dopamine agonists, ropinirole and pramipexole have been the drugs of choice for patients with moderate to severe RLS, drug emergent problems like augmentation may limit their use for long term therapy. Keeping the dopamine agonist dose as low as possible, using longer acting dopamine agonists such as the rotigotine patch and maintaining a high serum ferritin level may help prevent the development of augmentation. The α2δ anticonvulsants may now also be considered as drugs of choice for moderate to severe RLS patients. Opioids should be considered for RLS patients, especially for those who have failed other therapies since they are very effective for severe cases. When monitored appropriately, they can be very safe and durable for long term therapy. They should also be strongly considered for treating patients with augmentation as they are very effective for relieving the worsening symptoms that occur when decreasing or eliminating dopamine agonists.

Use of antiepileptic drugs for hyperkinetic movement disorders

Many studies investigated the use of antiepileptic drugs (AEDs) in several neurological diseases other than epilepsy. These neurological disorders, usually, involve neuronal excitability through the modulating of ion channels, receptors and intracellular signaling pathways, and are the targets of the AEDs. This article provides a review of the clinical efficacy of both conventional and newer AEDs in hyperkinetic movement disorders. Some of these indications for AEDs have been established, while others are under investigation. The modulation of GABAergic transmission may explain the neuronal hyper-excitability that underlies some forms of hyperkinetic movement disorders. So, AEDs able to increase GABAergic neurotransmission may play a role in hyperkinetic movement disorders treatment. Therefore, AEDs could represent a useful therapeutic option in the management of hyperkinetic movement disorders where the available treatments are ineffective.