Trastornos del movimiento y de la conducta durante el sueño en el adulto / Sleep-related movement and behavioural disorders in adults

Los trastornos del movimiento y de la conducta durante el sueño pueden tener un impacto en la calidad del sueño del paciente y dar lugar a síntomas diurnos. En estos grupos de enfermedades se incluyen entidades como el síndrome de piernas inquietas, los movimientos periódicos de las piernas y las parasomnias del sueño de movimientos oculares rápidos (REM) y no REM. El conocimiento de sus características clínicas y nociones sobre su manejo es de gran importancia para el neurólogo y especialista en sueño por su frecuencia e impacto en la calidad del sujeto. Con frecuencia, estos pacientes son referidos a dichos especialistas, y es relevante conocer que ciertos trastornos del sueño pueden asociarse a otras enfermedades neurológicas

Sleep-related movement and behaviour disorders may have an impact on sleep quality and lead to daytime symptoms. These groups of conditions include diseases such as restless legs syndrome, periodic leg movements, and REM and NREM parasomnias. The knowledge of their clinical features and management is of utmost importance for the neurologist and sleep specialist. Frequently, these patients are referred to such specialists and it is relevant to know that certain sleep disorders may be associated with other neurological conditions

Validation of the Multiple Suggested Immobilization Test: A Test for the Assessment of Severity of Restless Legs Syndrome (Willis-Ekbom Disease).

STUDY OBJECTIVES: To validate the Multiple Suggested Immobilization Test (m-SIT), a symptom-provocation test measuring restless legs syndrome (RLS) severity multiple times a day while the patient is awake and resting under controlled conditions. The m-SIT was designed to overcome some limitations in measuring RLS severity with rating scales. DESIGN: Patients completed two m-SITs on 2 consecutive days while on 24-h dopaminergic medication. After treatment discontinuation, they completed one more m-SIT 3 days later. Controls performed only one m-SIT. SETTING: Sleep laboratory. PARTICIPANTS: Nineteen patients with RLS and 10 healthy controls. INTERVENTIONS: The original m-SIT consisted of seven modified 60-min SITs performed every 2 h between noon and midnight. During each SIT, the subject reclined quietly but could move his or her legs without restriction to alleviate symptoms. Every 10 min, periodic leg movements during wakefulness (PLMW) were evaluated and the m-SIT Disturbance Scale (m-SIT-DS; range 0-10) was completed. MEASUREMENTS AND RESULTS: The m-SIT, composed of 6:00pm, 8:00pm, 10:00pm, and 12:00pm SITs, discriminated patients from controls (mean m-SIT-DS: 2.68 ± 2.35 versus 0.08 ± 0.26; mean PLMW/h, P = 0.0001) and between treatment groups (on medication versus taken off medication; mean m-SIT-DS, P = 0.0001; mean PLMW/h, P < 0.01). It proved reliable on retest and covariated well with the International Restless Legs Scale (IRLS) and scales measuring daytime symptoms (Spearman ρ > 0.4). CONCLUSIONS: The m-SIT is a valid and reliable test to evaluate RLS severity and treatment response, and could be useful in the future to confirm diagnosis and identify daytime symptoms. Although it was primarily designed for clinical trials, it might be useful in clinical settings because it provides a standardized testing condition to measure RLS symptoms. CITATION: Garcia-Borreguero D; Kohnen R; Boothby L; Tzonova D; Larrosa O; Dunkl E. Validation of the Multiple Suggested Immobilization Test: a test for the assessment of severity of restless legs syndrome (Willis-Ekbom disease). SLEEP 2013;36(7):1101-1109.

Correlation between rating scales and sleep laboratory measurements in restless legs syndrome.

OBJECTIVES: The aim of this study was to test the external validity of the International Restless Legs Scale (IRLS) by assessment of the correlation between IRLS scores and objective measures of severity such as polysomnography (PSG) and Suggested Immobilization Test (SIT). DESIGNS: Correlation analysis between rating scales for RLS (IRLS and Johns Hopkins RLS Scale--JHRLSS) and sleep laboratory measurements in untreated RLS patients. METHODS: The study included 30 untreated patients diagnosed with RLS according to the criteria of the International RLS Study Group. Diagnostic procedures included physical exam, laboratory analysis, PSG and a nocturnal SIT. Statistical analysis was performed by means of Spearman's correlations and Kruskal-Wallis test. RESULTS: IRLS correlated significantly with Periodic Leg Movement of Sleep-index (PLMS), and PLMS-arousal index during PSG as well as with Periodic Leg Movement of Wakefulness (PLMW) during SIT (SIT-PLMW) (all r=0.4; p<0.01). There was no correlation between IRLS and the number of PLMW in PSG (PSG-PLMW) or any other sleep variable during PSG. Nor was any correlation found between IRLS scores and ferritin, age, duration of illness or any other clinical variables. CONCLUSIONS: This study represents the first demonstration of a correlation between IRLS and objective parameters of motor dysfunction such as PLMS-index or SIT. This finding is particularly relevant for the design of future clinical trials. Furthermore, the association between PLMS and SIT-PLMW supports the view that both PLMS and PLMW might share a common mechanism.

Circadian variation in neuroendocrine response to L-dopa in patients with restless legs syndrome.

STUDY OBJECTIVE: To investigate circadian changes in dopaminergic function by means of a neuroendocrine challenge (growth hormone and prolactin responses to an acute oral administration of L-dopa) in patients with idiopathic restless legs syndrome (RLS) and controls. DESIGN: Randomized administration of the L-dopa neuroendocrine challenge. SETTING: Sleep disorders laboratory at a 500-bed academic hospital. PATIENTS OR PARTICIPANTS: Twelve patients diagnosed with idiopathic RLS and 12 age- and sex-matched healthy controls. INTERVENTIONS: Following a comprehensive evaluation that included nocturnal polysomnographic study, all participants underwent the L-dopa neuroendocrine challenge on 2 occasions (11 am and 11 pm). Subjects were previously randomly assigned to the time of first challenge (11 am or 11 pm). On each occasion, subjects took 200 mg of L-dopa (plus 50 mg carbidopa) by mouth. Blood was drawn 20 minutes and 5 minutes before administration of the drug, as well as 15, 30, 45, 60, 75, 90, 102, and 120 minutes after administration. RESULTS: Prechallenge levels of plasma values of growth hormone or prolactin did not differ in the 2 subject groups. Following only the nighttime administration of L-dopa, RLS patients manifested a more pronounced inhibition of prolactin release and an increase in growth hormone secretion. Prolactin plasma levels were significantly correlated to the periodic limb movement index on the polysomnogram. CONCLUSIONS: These findings may reflect enhanced circadian variations in dopaminergic function and support an increased sensitivity at night of dopamine receptors in patients with RLS.

Circadian effects of dopaminergic treatment in restless legs syndrome.

BACKGROUND AND PURPOSE: Although an essential diagnostic feature of restless legs syndrome (RLS) is the presence of circadian symptom variations, with an increase in the evening or at night, the mechanisms underlying this time-bound variation remain unknown. Since dopaminergic mechanisms seem to play a central role in the pathophysiology of RLS, it is likely that circadian variations in the dopaminergic system or factors affecting it cause the nightly increase. The reverse is also possible; dopaminergic medication might affect melatonin function, a key element of the circadian system. The present study investigated the effects of dopaminergic medication on melatonin secretion in RLS. PATIENTS AND METHODS: Eight previously untreated patients diagnosed with idiopathic RLS underwent a three-week, open-labeled treatment with 400 mg L-DOPA (+100 mg CarbiDOPA). Dim Light Melatonin Onset (DLMO), a marker of circadian phase, was determined before and after treatment. RESULTS: Compared to baseline, earlier DLMO was found in L-DOPA treated patients (21:00+/-1:20 vs. 18:50+/-0:55; P < 0.05). Anticipation of DLMO was more marked in the subgroup of patients showing augmentation. A positive correlation was observed between change of DLMO, sleep latency and time of onset of symptoms following treatment with L-DOPA. CONCLUSIONS: Our results suggest that L-DOPA may exert chronobiotic effects in RLS.

Parkinson's disease and sleep.

Sleep disorders are common in Parkinson's disease (PD), as almost two thirds of PD patients report them. From a clinical point of view, they can be classified into disorders of initiation and maintenance of sleep (DIMS), parasomnias, and excessive daytime sleepiness (EDS). Among the causes of DIMS are degenerative changes in the CNS affecting centers for sleep regulation, persistence into the night of daytime PD-related symptoms, concomitant medical or psychiatric disease, disruption of circadian rhythms, and effects of dopaminergic (and other) medication on sleep regulation. Parasomnias might further contribute to sleep disturbance, as they can be accompanied by motor desinhibition during REM sleep. Parasomnias can precede by several years the presence of daytime PD symptoms. EDS has been over the last years the focus of attention for both sleep and movement disorders specialists, due to the fact that it might predispose to traffic accidents. However, the so-called "sleep attacks" never occur without preexisting somnolence. Thus, a careful sleep history can be helpful to determine which patients are exposed to suffer them. Although EDS was initially attributed to the effects of dopaminergic medication, it seems likely that several disease-related factors might also play an important role. An adequate education of the PD patients in sleep hygiene measures and a skilled use of the medication seem necessary to prevent sleep disturbance.

Decreased phasic EMG activity during rapid eye movement sleep in treatment-naïve Parkinson's disease: effects of treatment with levodopa and progression of illness.

Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently associated with Parkinson's disease (PD) and may anticipate its diagnosis by several years. We assessed the presence of motor dyscontrol during REM sleep in treatment-naïve PD patients and investigated the putative effect of levodopa (L-dopa) treatment on motor activity. Overnight sleep studies were performed on 15 previously untreated PD patients and 14 controls at baseline, again after a 3- to 9-month treatment period with a low dose of L-dopa, and 2 to 5 days after treatment discontinuation (in 8 patients). No differences in sleep parameters were observed across groups or treatment conditions. None of the patients met criteria for RBD at baseline, whereas 5 patients were symptomatic at the time of the second sleep study. A quantitative analysis of electromyographic (EMG) activity during REM sleep showed a lower phasic twitching activity in untreated PD than in controls. However, an increase in both phasic twitching and tonic activity was found after treatment with L-dopa. Discontinuation of treatment resulted in a return to pretreatment values of phasic but not of tonic EMG activity. Thus, the increase in phasic activity seems to depend on the effects of L-dopa, whereas the increase in tonic EMG activity during REM sleep might be caused by other factors such as the progression of disease. Potential implications for the understanding of the relationship between RBD and PD are discussed.