Augmentation in restless legs syndrome: an eye tracking study on emotion processing

Emotion Recognition in Multiple System Atrophy: An Exploratory Eye-Tracking Study

OBJECTIVE

Emotional processing is a core feature of social interactions and has been well studied in patients with idiopathic Parkinson's disease (PD), albeit with contradictory.

RESULTS

. However, these studies excluded patients with atypical parkinsonism, such as multiple system atrophy (MSA). The objective of this exploratory study was to provide better insights into emotion processing in patients with MSA using eye tracking data.

METHODS

We included 21 MSA patients, 15 PD patients and 19 matched controls in this study. Participants performed a dynamic and a static emotion recognition task, and gaze fixations were analyzed in different areas of interest. Participants underwent neuropsychological testing and assessment of depression and alexithymia.

RESULTS

MSA patients were less accurate in recognizing anger than controls (p = 0.02) and had overall fewer fixations than controls (p = 0.001). In the static task, MSA patients had fewer fixations (p < 0.001) and a longer time to first fixation (p = 0.026) on the eye region. Furthermore, MSA patients had a longer fixation duration overall than PD patients (p = 0.004) and longer fixations on the nose than controls (p = 0.005). Alexithymia scores were higher in MSA patients compared to controls (p = 0.038).

CONCLUSION

This study demonstrated impaired recognition of anger in MSA patients compared to HCs. Fewer and later fixations on the eyes along with a center bias suggest avoidance of eye contact, which may be a characteristic gaze behavior in MSA patients.

Giving Rest to the Restless Leg: A Case Report of How Self-Education Prepending Web-Based Interventions Can Ameliorate Restless Leg Syndrome

Restless leg syndrome (RLS) is a neurological disorder characterized by an irresistible urge to move one's leg sporadically. The pathogenesis of RLS, also known as Willis Ekborn disease, is not fully understood; however, scientists note a complex interplay between multiple neuronal pathway-related genes with endogenous and exogenous factors. We report a case of a previously healthy 27-year-old man complaining of a continuous urge to move his right leg, notably at night. Laboratory evaluation proved negative for secondary causes of RLS; hence the condition was labeled as "primary idiopathic." The patient was started on appropriate pharmacotherapy and was advised to self-educate regarding his ailment. The patient began internet-based self-education and displayed excellent improvements on the International Restless Leg Syndrome Scale (IRLS). Mental exercises, such as self-education using web-based intervention and pharmacotherapy, could alleviate factors in patients with primary idiopathic RLS. Further research is needed to clarify self-education's role in managing RLS.

Restless legs syndrome: Over 50 years of European contribution

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterised by an urge to move the limbs with a circadian pattern (occurring in the evening/at night), more prominent at rest, and relieved with movements. RLS is one of the most prevalent sleep disorders, occurring in 5%-10% of the European population. Thomas Willis first described RLS clinical cases already in the 17th century, and Karl-Axel Ekbom described the disease as a modern clinical entity in the 20th century. Despite variable severity, RLS can markedly affect sleep (partly through the presence of periodic leg movements) and quality of life, with a relevant socio-economic impact. Thus, its recognition and treatment are essential. However, screening methods present limitations and should be improved. Moreover, available RLS treatment options albeit providing sustained relief to many patients are limited in number. Additionally, the development of augmentation with dopamine agonists represents a major treatment problem. A better understanding of RLS pathomechanisms can bring to light novel treatment possibilities. With emerging new avenues of research in pharmacology, imaging, genetics, and animal models of RLS, this is an interesting and constantly growing field of research. This review will update the reader on the current state of RLS clinical practice and research, with a special focus on the contribution of European researchers.

Eye Tracking in Patients with Parkinson’s Disease Treated with Nabilone–Results of a Phase II, Placebo-Controlled, Double-Blind, Parallel-Group Pilot Study

The topic of the therapeutic use of cannabinoids in Parkinson’s disease (PD) is broadly discussed and frequently comes up in the outpatient clinic. So far, there are only a few randomized clinical trials assessing the effects of cannabinoids in PD. We are able to demonstrate a reduction in non-motor symptom (NMS) burden after the administration of nabilone. As impairment of attention and working memory have been described earlier as possible side effects, we assess cognitive performance using saccadic paradigms measured by an eye tracker. We do not observe a significant difference in any of the saccadic paradigms between PD patients on placebo versus those treated with nabilone. We, therefore, conclude that top-down inhibitory control is not affected by the tetrahydrocannabinol analogue. Nabilone did not significantly worsen cognitive performance and appears to be safe to use in selected PD patients who suffer from disabling NMS.

Factors associated with augmentation in patients with restless legs syndrome

Background and purpose

Augmentation is a paradoxical reaction mainly to dopaminergic medication in patients with restless legs syndrome (RLS), but the exact pathomechanism remains unclear. The aim of this study was to identify factors associated with augmentation in RLS patients.

Methods

RLS patients with and without current or previous augmentation were recruited. Demographic characteristics, history of smoking, questionnaires for depression, alexithymia, and impulsivity, and RLS severity were obtained.

Results

We included 122 patients, of whom half had a history of augmentation. Patients with augmentation had a longer disease duration (p = 0.001), had higher RLS severity scores (p = 0.013), had higher levodopa equivalent doses (p < 0.001), had higher scores for alexithymia (p = 0.028), had higher prevalence of impulse control disorders (p < 0.001), more often had a history of smoking (p = 0.039), were more often currently smoking (p = 0.015), and had more average pack‐years (p = 0.016).

Conclusions

Here, we describe several factors commonly associated with augmentation in RLS. These may help clinicians to screen and treat patients carefully to avoid the challenging side effect of augmentation.

Cognitive profile in Restless Legs Syndrome: A signal-to-noise ratio account

Restless legs syndrome (RLS) is a common neurological disorder characterized by a sensorimotor condition, where patients feel an uncontrollable urge to move the lower limbs in the evening and/or during the night. RLS does not only have a profound impact on quality of life due to the disturbed night-time sleep, but there is growing evidence that untreated or insufficiently managed RLS might also cause cognitive changes in patients affected by this syndrome. It has been proposed that RLS is caused by alterations in the signal-to-noise ratio (SNR) and in dopamine (DA) neurotransmission in the nervous system. Based on this evidence, we propose the “SNR-DA hypothesis” as an explanation of how RLS could affect cognitive performance. According to this hypothesis, variations/reductions in the SNR underlie RLS-associated cognitive deficits, which follow an inverted U-shaped function: In unmedicated patients, low dopamine levels worsen the SNR, which eventually impairs cognition. Pharmacological treatment enhances DA levels in medicated patients, which likely improves/normalizes the SNR in case of optimal doses, thus restoring cognition to a normal level. However, overmedication might push patients past the optimal point on the inverted U-shaped curve, where an exaggerated SNR potentially impairs cognitive performance relying on cortical noise such as cognitive flexibility. Based on these assumptions of SNR alterations, we propose to directly measure neural noise via “1/f noise” and related metrics to use transcranial random noise stimulation (tRNS), a noninvasive brain stimulation method which manipulates the SNR, as a research tool and potential treatment option for RLS.

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Restless legs syndrome (RLS) is a common neurological disorder.

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RLS is caused by alterations in the SNR ratio and in DA neurotransmission.

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The SNR- DA hypothesis how RLS affects cognitive performance is presented.

The Frontal Assessment Battery in RLS patients with and without augmentation

OBJECTIVE

We assessed frontal executive functions in patients with RLS/WED with and without augmentation and compared the results to healthy controls.

METHODS

We recruited 38 patients with RLS/WED. A total of 23 patients were treated with dopaminergic therapy and showed no signs of augmentation and 15 patients had a history of augmentation (AUG). Results were compared to 21 healthy controls. All individuals were assessed by the Frontal Assessment Battery (FAB) and the MMSE. Furthermore, impulsivity was assessed during a semi-structured interview.

RESULTS

Patients with AUG performed worse in the FAB than healthy controls and RLS/WED patients without AUG (p = 0.001, η² = 0.201). When we assessed the subtests of the FAB separately, we found a significant difference in the subtest assessing inhibitory control (p = 0.008, η² = 0.138).

CONCLUSIONS

Our findings suggest an impaired executive function in RLS/WED patients with augmentation compared to RLS/WED patients without augmentation and healthy controls. Long term neuroplastic changes within the prefrontal cortex may be the underlying cause for these results. However, further studies in a larger sample size and with a more extensive neuropsychological test battery are needed to confirm our preliminary results.