Hyperactivity in patients with narcolepsy and idiopathic hypersomnia: an exploratory study.

Introduction: Patients with either Idiopathic Hypersomnia or Narcolepsy demonstrate excessive daytime somnolence (EDS) with resultant inattention mimicking Attention Deficit Hyperactivity Disorder (ADHD). Patients with ADHD also often express sleep problems including EDS. Thus, patients with ADHD and patients with idiopathic hypersomnia or narcolepsy may share inattention and daytime drowsiness as common features. However, it is not known whether EDS patients with idiopathic hypersomnia or narcolepsy also have increased movement (hyperactivity) like ADHD patients, the determination of which is the purpose of this study. Methods: We studied 12 patients (7 Narcolepsy type 2 and 5 Idiopathic Hypersomnia) with EDS as shown by Multiple Sleep Latency Test which served as the gold standard for entry into the study. Twelve subjects without symptoms of EDS served as the control group. None of the participants had a previous history of ADHD. Each participant underwent a one-hour session laying at 45 degrees with surveys about the need to move and actigraphy as an objective measure of movement. Results: Sleep-disordered patients with EDS reported more symptoms of inattention and hyperactivity on the ADHD Self-Report Scale. At each of the time points patients with EDS had a clear trend to express the need to move more than controls on the Suggested Immobilization Test (SIT). For the total 60 minutes, a large effect size for the need to move during the SIT test was found between patients and controls (Cohen's d = 0.61, p=0.01). Patients with EDS did not express a need to move more to combat drowsiness than controls, nor did actigraphy show any difference in objective movement between patients and controls during the SIT. Conclusion: Patients with EDS express inattention and a need to move more than controls. However, hyperactivity was not verified by objective measurement, nor did the EDS patients express a need to move to combat drowsiness more than controls. Thus, a hypothesis to be further tested, is whether narcolepsy and idiopathic hypersomnia may be more a model of the inattentive form of ADHD rather than the combined or inattentive/hyperactive form of ADHD. Further studies are needed to explore the relationship between EDS and hyperactivity.

Children show individual night-to-night variability of periodic limb movements in sleep.

STUDY OBJECTIVE: Several studies have documented the occurrence of significant night-to-night variability of periodic limb movements in sleep (PLMS) in adults.The aim of this study was to investigate the night-tonight variability of PLMS in children. DESIGN AND MEASUREMENTS: Two to 4 nights of polysomnography were performed as part of a multisite, placebo-controlled study investigating the effects of carbidopa/levodopa on attention-deficit/hyperactivity disorder in children who were not taking other medications that impacted the central nervous system. Baseline polysomnograms from all children and endpoint polysomnograms from children who were randomly assigned to a placebo group were scored using International Restless Legs Syndrome Study Group criteria for PLMS. PLMS indexes from 101 sleep studies of 36 children, aged 7 to 12 years, were compared. INTERVENTIONS: N/A. RESULTS: For all 36 children as a group, PLMS index on Night 1 was predictive of PLMS index on Night 2 (odds ratio 7.0, 95% confidence interval 1.4-38.4), suggesting that overall diagnostic classification (PLMS index above or below 5/h) was accurate. In addition, for the 15 children with 5 or more PLMS per hour on either night, there was no significant group difference on Night 1 versus Night 2 for mean PLMS index (10.6 vs 8.5/h, P = 0.92) or chance of having 5 or more PLMS per hour, indicating no first-night effect. When looking at individual data, however, 9 of these 15 children (60%) had PLMS indexes over and under the 5 per hour cutoff on these 2 nights. Of these 15, 10 had clinical diagnoses of restless legs syndrome and 5 of periodic limb movement disorder (PLMD). The PLMS indexes of all children who were medication free for a third and fourth night (n = 7) or just a third night (n = 2) and had not shown a PLMS index of 5 or greater on either of the first 2 nights remained under this threshold. CONCLUSIONS: In this sample of children, considerable individual night-to-night variability of PLMS indexes was observed. This finding has important clinical relevance for the diagnosis of restless legs syndrome and PLMD and may have an impact on future studies that correlate individual PLMS severity with frequently associated symptoms, such as negative affect, fatigue, and inattention. Our data, however, also suggest that individual PLMS variability is random and not likely to skew the group-level analysis of treatment outcome studies.

Preliminary study of the prevalence of restless legs syndrome in adults with attention deficit hyperactivity disorder.

Several previous studies have shown that Attention Deficit Hyperactivity Disorder (ADHD) is common in children with Restless Legs Syndrome and ADHD is more common in adults with this syndrome. This pilot study examined the prevalence of Restless Legs Syndrome in adults with ADHD, showing six of 30 adult ADHD participants (20%) had Restless Legs Syndrome. This estimate exceeds the prevalence (7.2%) for a previously published control group. These six adults had more severe ADHD symptomatology than those without Restless Legs Syndrome based on the overall Conners' Adult ADHD Rating Scale. Such results suggest that symptoms of Restless Legs Syndrome may occur often in adults with ADHD and might worsen the symptoms of ADHD. Replication with a larger sample size is in order.

An evaluation of the incremental validity of the MMPI-2 Superlative (S) scale in an inpatient psychiatric sample.

The MMPI-2 Superlative (S) scale was developed by Butcher and Han (1995) to assess individuals' tendencies to present themselves in an unrealistically positive light. The current study examined the performance of the L, K, and S scales in accurately distinguishing the MMPI-2 profiles of 379 psychiatric inpatients who produced one or more elevations on the basic scale profiles, from 82 psychiatric inpatients who produced no clinical range elevation on any of the eight basic clinical scales (excluding scales 5 and 0). The findings from the present study indicate that the S scale appears to be effective in the identification of defensiveness among psychiatric inpatients, with mean effect sizes in the moderate to large range. The optimal T-score cutoff for identifying defensive responders was 70 for both men and women. Further, results of hierarchical regression analyses showed that the S scale added incrementally to the prediction levels achieved by the optimal combination of the L and K scales.

L-Dopa improves Restless Legs Syndrome and periodic limb movements in sleep but not Attention-Deficit-Hyperactivity Disorder in a double-blind trial in children.

BACKGROUND: In a previous open-label study, dopaminergic agents improved Restless Legs Syndrome (RLS) and Periodic Limb Movements in Sleep (PLMS), as well as Attention-Deficit-Hyperactivity Disorder (ADHD) in children with both disorders. We therefore conducted a double-blind placebo-controlled trial of L-DOPA in ADHD children with and without RLS/PLMS. METHODS: Two groups of patients (total n = 29), those with ADHD only or those with ADHD and RLS/PLMS, were randomized to L-DOPA or placebo therapy. At baseline and after therapy patients were assessed with Conners' parent and teacher rating scales; polysomnography; RLS rating scale; and neuropsychometric measures of memory, learning, attention, and vigilance. RESULTS: L-DOPA improved RLS/PLMS symptoms in all patients with those disorders compared with placebo (p = .007). When assessed by the Conners' Scales before therapy, ADHD was more severe in children without RLS/PLMS than in children with RLS/PLMS (p = 0.006). L-DOPA had no effect on Conners' scales, sleep, or neuropsychometric tests when all patients treated with the drug were compared to those on placebo or when patients with ADHD only were compared to those with ADHD and RLS/PLMS. CONCLUSIONS: In this first double-blind study of a dopaminergic therapy in children with RLS/PLMS, L-Dopa significantly improved RLS/PLMS but not ADHD. These results, however, should be interpreted carefully since they may have been influenced by the relatively small sample size and the baseline differences in severity of ADHD symptoms. Further work needs to be done to elucidate the relationship between dopamine, ADHD and RLS/PLMS.