Alessandro Oldani

Validation of the International Restless Legs Syndrome Study Group rating scale for restless legs syndrome

BACKGROUND There is a need for an easily administered instrument which can be applied to all patients with restless legs syndrome (RLS) to measure disease severity for clinical assessment, research, or therapeutic trials. The pathophysiology of RLS is not clear and no objective measure so far devised can apply to all patients or accurately reflect severity. Moreover, RLS is primarily a subjective disorder. Therefore, a subjective scale is at present the optimal instrument to meet this need. METHODS Twenty centers from six countries participated in an initial reliability and validation study of a rating scale for the severity of RLS designed by the International RLS study group (IRLSSG). A ten-question scale was developed on the basis of repeated expert evaluation of potential items. This scale, the IRLSSG rating scale (IRLS), was administered to 196 RLS patients, most on some medication, and 209 control subjects. RESULTS The IRLS was found to have high levels of internal consistency, inter-examiner reliability, test-retest reliability over a 2-4 week period, and convergent validity. It also demonstrated criterion validity when tested against the current criterion of a clinical global impression and readily discriminated patient from control groups. The scale was dominated by a single severity factor that explained at least 59% of the pooled item variance. CONCLUSIONS This scale meets performance criteria for a brief, patient completed instrument that can be used to assess RLS severity for purposes of clinical assessment, research, or therapeutic trials. It supports a finding that RLS is a relatively uniform disorder in which the severity of the basic symptoms is strongly related to their impact on the patients life. In future studies, the IRLS should be tested against objective measures of RLS severity and its sensitivity should be studied as RLS severity is systematically manipulated by therapeutic interventions.

Neuropsychological assessment in idiopathic REM sleep behavior disorder (RBD): Does the idiopathic form of RBD really exist?

Objective: To evaluate the cognitive performance of patients with idiopathic REM sleep behavior disorder (RBD). Methods: The authors studied 17 consecutive patients with idiopathic RBD vs 17 age- and education-matched control subjects. Tests given to each patient and control included Mini-Mental State Examination, verbal and spatial short-term memory, visual selective attention, verbal fluency, prose memory, visuoconstructional abilities, spatial learning, and executive function tests. A self-administered depression rating scale was also used. Results: RBD patients had significantly lower scores than control subjects in two tests: copy of Rey–Osterrieth Figure and Corsi Supraspan Learning. No correlation was found between the results of neuropsychological tests and RBD duration or with polysomnographic findings. Conclusions: Visuospatial constructional dysfunction and altered visuospatial learning may be present in idiopathic RBD. A neuropsychological assessment may be indicated in RBD patients.

Nocturnal sleep study in multiple sclerosis: Correlations with clinical and brain magnetic resonance imaging findings

It has been suggested that sleep disturbances in multiple sclerosis (MS) may be related to periodic leg movements (PLM) during sleep, but to date polysomnographic studies were conducted only on small and unselected patient groups. Aim of this study was to evaluate 8-hour polysomnography in MS patients and to correlate sleep results with clinical and brain magnetic resonance imaging (MRI) data. Twenty-five clinically definite MS patients, without mood disorders and drug-free, entered the study. The patients were compared to 25 age- and sex-matched subjects. MS patients had significantly reduced sleep efficiency and experienced more awakenings during sleep. No difference was found in sleep architecture parameters between MS patients and controls. PLM was found in 9 patients (36%) and 2 controls (8%; p = 0.02). Of the six patients who complained of insomnia two had PLM and 2 others presented with PLM and central sleep apnea. In patients with PLM greater MRI lesion loads were detected in the infratentorial regions, particularly in cerebellum and brainstem. Larger studies in neurological diseases that produce focal lesions in these brain areas could provide useful information on the PLM pathogenesis.

Autosomal Dominant Nocturnal Frontal Lobe Epilepsy: Electroclinical Picture

Summary: Purpose: Nocturnal frontal lobe epilepsy is a disorder that is difficult to diagnose because its clinical presentation is often limited to motor behavior during sleep. For this reason, a misleading diagnosis of benign nocturnal parasomnias might be possible. Recently, an inherited form of nocturnal frontal lobe epilepsy was described in some families. The aim of our work was to describe the electroclinical pattern of a sample of familial cases with this syndrome.

Melatonin and delayed sleep phase syndrome: Ambulatory polygraphic evaluation

THE present study objectively evaluated the efficacy of oral 5 mg day-1 melatonin in advancing the sleep-wake rhythm in patients with delayed sleep phase syndrome (DSPS). Six patients underwent ambulatory sleep monitoring for 72 h before, and 48 h after 1 month of melatonin treatment. In each patient melatonin was administered on the basis of his own estimated dim light melatonin onset (DLMO) delay. Mean advances in sleep onset time of 115 min, and in final awakening hour of 106 min were found after treatment, with no significant changes in sleep architecture parameters. Our study objectively confirms previous data obtained by a sleep-wake subjective diary on the efficacy of melatonin DSPS.

Craniofacial modifications in children with habitual snoring and obstructive sleep apnoea: a case-control study

Habitual snoring and obstructive sleep apnoea in children, which are frequently associated with adenotonsillar hypertrophy, may begin early in life and in relation with orocraniofacial features. The aim of this study was to detect the presence of early bone craniofacial modifications in young children with a long history of habitual snoring. Twenty-six habitually snoring children (mean age 4.6 yrs) were studied by nocturnal portable recording or diurnal polysomnography, cephalometry and orthodontic evaluation. A comparison of cephalometric findings was made between the studied group and 26 age-matched children (mean age 5.1 yrs) with no history of snoring or respiratory problems during sleep. The cephalometric analyses showed a significant increase in craniomandibular intermaxillar, lower and upper goniac angles with a retroposition and posterior rotation of the mandible (high angle face) and a reduction in the rhinopharynx space caused by higher thickness of adenoids in habitually snoring children compared with controls. Cross-bites and labial incompetence as well as daytime symptoms and familiarity for habitual snoring were found in most of the studied group of snorers compared with controls. The results indicate that upper airway obstruction during sleep is associated with mild but significant cephalometric and craniofacial modifications in children complaining of habitual snoring. Whether this skeletal conformation is genetically determined or influenced by the early onset of habitual snoring remains to be assessed.

Improved computation of the atonia index in normal controls and patients with REM sleep behavior disorder

OBJECTIVE The aim of this study was to evaluate the effects of a simple method of noise reduction before the calculation of the REM sleep atonia index (AI) on a large number of recordings from different normal controls and patient groups. SUBJECTS AND METHODS Eighty-nine subjects were included: 25 young controls, 10 aged controls, 31 untreated patients with idiopathic REM sleep behavior disorder (iRBD), 8 treated patients with iRBD, 10 patients with multiple system atrophy (MSA) and 5 patients with obstructive sleep apnea syndrome (OSAS). The average amplitude of the rectified submentalis muscle EMG signal was then obtained for all 1-s mini epochs of REM sleep. The new correction method was implemented by subtracting from each mini epoch the minimum value found in a moving window including the 60 mini epochs surrounding it. RESULTS Two arbitrary thresholds were established at AI<0.8 and 0.8<AI<0.9; all young controls presented AI>0.9; this was not true for aged controls, 3 of whom presented 0.8<AI<0.9 but none had AI<0.8; on the contrary 74.4% of all iRBD showed AI<0.9, with 38.5% of the whole group having AI<0.8 and only 25.6% with AI>0.9. All MSA patients showed AI<0.8. CONCLUSIONS After the introduction of this new method for noise reduction, REM sleep AI index values lower than 0.8 were strongly indicative of altered (reduced) chin EMG atonia during REM sleep; values of AI between 0.8 and 0.9 indicated a less evident involvement of atonia, and values above 0.9 characterized the majority of normal recordings.

The impact of cyclic alternating pattern on heart rate variability during sleep in healthy young adults

OBJECTIVE Cyclic alternating pattern (CAP) consists of arousal-related phasic events while the complementary condition, non-CAP (NCAP), is characterized by a rhythmic background activity, reflecting a condition of stable arousal, during non-REM sleep. The arousal swings that accompany the appearance of CAP on the EEG are associated with transient variations of muscle tone and autonomic activities, including heart rate (HR). The aim of our study was to evaluate HR variability in relation to CAP during non-REM sleep in healthy adults. METHODS Ten healthy subjects (mean age = 28.1 years) underwent 8 h polysomnography. HR variations were measured by power spectrum analysis. The ECG signals were segmented in correspondence of the different sleep stages and different CAP conditions. RESULTS A significant difference between CAP and NCAP conditions was found in low frequency (LF) component (increased in CAP) and high frequency (HF) component (decreased in CAP). LF/HF ratio was increased in CAP. CONCLUSION Physiological fluctuations of the EEG arousal level influence cardiac autonomic activity in normal subjects. The studies on nocturnal variation in sympathetic and vagal tone should take in account the microstructural sleep changes, other than the conventional polysomnographic parameters.

Measuring the error in sleep estimation in normal subjects and in patients with insomnia

The aims of this study were to measure the error in sleep estimation in normal controls and subjects with primary insomnia to establish the minimum amount of sleep needed for reliable subjective estimation and to depict the distribution of the error in sleep estimation in both groups. A two‐step retrospective (study 1) and prospective (study 2) validation study was carried out. Study 1 included 288 normal subjects [176 females and 112 males, mean age 58.5 years, standard deviation (SD) 7.23]. Study 2 included 159 patients (98 females and 61 males; mean age 49.1 years, SD 12.71) with primary insomnia. Participants underwent a full‐night polysomnographic study, followed by a morning assessment of subjective sleep parameters. A misperception index (MI) was computed using the following formula: MI = [objective total sleep time (oTST)−subjective total sleep time (sTST)]/oTST. The statistical properties of this index were analysed in detail in both groups. In controls, the Bland–Altman test demonstrated the reliability of this index for values of oTST >120 min. Healthy subjects estimated their sleep time correctly, while insomniacs largely underestimated their sleep time. Statistical analysis of the distribution of MI in insomnia patients disclosed the presence of two subgroups, one with moderate sleep misperception (132 patients) and the other with high sleep misperception (27 patients). The latter presented MI values ≥0.9, exhibiting statistical properties different from those with MI <0.9 and from normal subjects. The MI gives a reliable and immediate description of sleep misperception in healthy and insomnia subjects. Its application supports the existence of the high misperception of insomnia as a separate pathological entity.

The macrostructure and microstructure of sleep in patients with autosomal dominant nocturnal frontal lobe epilepsy.

The electroclinical features of autosomal dominant nocturnal frontal lobe epilepsy have been recently described. Although some patients reported a poor quality of sleep, daytime tiredness, and sleepiness, their sleep macrostructure appeared to be indistinguishable from those of the control group. The aim of this study was to evaluate the macro- and microstructure of sleep in a sample of autosomal dominant nocturnal frontal lobe epilepsy patients, diagnosed by videopolysomnography. The authors selected 16 patients, 8 with daytime complaints (morning tiredness and/or excessive sleepiness) (group 1) and 8 without those complaints (group 2). The classical macrostructure of sleep and the microstructure, according to the cyclic alternating pattern (CAP) scoring rules, were compared with another group of 8 healthy controls. In group 1 the motor attacks during sleep took place more frequently during CAP and were significantly related to phase A of the CAP cycle in comparison to group 2 (P = 0.04). Group 2 had a sleep microstructure similar to the controls, whereas group 1 showed higher CAP/nonrapid eye movement sleep (CAP rate) and a higher number of CAP cycles with respect to controls (P = 0.012 and P = 0.001) and to group 2 (P = 0.05 and P = 0.04). The analysis of sleep microstructure showed an increase in sleep instability in patients with autosomal dominant nocturnal frontal lobe epilepsy and daytime sleep complaints and indicated the relationship between sleep fragmentation, nocturnal motor seizures, and daytime symptoms.