Rosalia Silvestri

Sleep disorders in children with Attention-Deficit/Hyperactivity Disorder (ADHD) recorded overnight by video-polysomnography

OBJECTIVE To outline specific sleep disturbances in different clinical subsets of Attention Deficit/Hyperactivity Disorder (ADHD) and to confirm, by means of nocturnal video-polysomnography (video-PSG), a variety of sleep disorders in ADHD besides the classically described periodic leg movement disorder (PLMD), restless legs syndrome (RLS) and sleep related breathing disorder (SRBD). METHODS Fifty-five ADHD children (47 M, 8F; mean age=8.9 y) were included: 16 had Inattentive and 39 Hyperactive/Impulsive or Combined ADHD subtype. Behavior assessment by Conners and SNAP-IV Scales, a structured sleep interview and a nocturnal video-PSG were administered. RESULTS Most children/parents reported disturbed, fragmentary sleep at night; complaints were motor restlessness (50%), sleep walking (47.6%), night terrors (38%), confusional arousals (28.5%), snoring (21.4%), and leg discomfort at night associated with RLS (11.9%). There is a significant difference (p value <0.05 or <0.001) in almost all the studied sleep variables between ADHD children and controls. International RLS Rating Scale scoring, Periodic Limb Movements during Sleep (PLMS) and Wake (PLMW) indexes, hyperactivity and opposition scores and ADHD subtype appear related. Different sleep disorders seem to address specific ADHD phenotypes and correlate with severity of symptoms as in sleep related movement disorders occurring in Hyperactive/Impulsive and Combined ADHD subtypes. Besides, an abnormality of the arousal process in slow wave sleep with consequent abnormal prevalence of disorders of arousal possibly enhanced by SRBD has also been detected in 52% of our sample. CONCLUSIONS This study underlines the opportunity to propose and promote the inclusion of sleep studies, possibly by video-PSG, as part of the diagnostic screening for ADHD. This strategy could address the diagnosis and treatment of different specific ADHD phenotypic expressions that might be relevant to childrens symptoms and contribute to ADHD severity.

Sleep features in Tourette's syndrome, neuroacanthocytosis and Huntington's chorea

Twenty-one patients affected by extrapyramidal disorders were polygraphically recorded during spontaneous nocturnal sleep for two consecutive nights to assess their sleep and movement patterns. The patients (pts) sample included: Gilles de La Tourette syndrome (TS, nine pts), neuroacanthocytosis (NA, six pts) and Hungtingtons chorea (HC, six pts). Sleep recording included C3/A2, 01/A2, ROC/LOC, submental EMG, EKG, nasal airflow thoracoabdominal respirogram, bilateral anterior tibialis and other EMGs, in relation to the individual distribution of the abnormal movements. According to our observations, abnormal movements always decreased but never ceased completely during sleep. Sleep efficiency (SE) was nearly always poor with a high percentage of wakefulness after sleep onset (WASO) and increased number of arousals. REM sleep was often reduced and in some cases (3 TS pts) incompletely defined as far as its microstructural aspects. Slow wave sleep (SWS) was reduced in HC, normal in NA, and increased in all TS patients with the exception of the two adult subjects more severely affected, while the percentage of stage 2 was not affected. Spindling was increased in NA, HC and in the two most severely affected adult TS patients.

Ictal and interictal EEG abnormalities in ADHD children recorded over night by video-polysomnography

In this paper we explore the prevalence of ictal and interictal epileptiform discharges (IEDs) and sleep disorders in ADHD children referred to a sleep clinic for all night video-PSG. Forty-two ADHD outpatients (35 males and 7 females) underwent video-PSG and a behavioural/neuropsychological assessment. Spearman correlation coefficients (p<0.05 criterion level) were used to assess the association between cognitive, behavioural, clinical (co-morbidity), sleep (sleep efficiency) and EEG (seizures, IEDs, localization of IEDs foci) variables. Sleep disorders were found in 86% of ADHD children; among these, 26% had RLS. 53.1% of ADHD children had IEDs (28.2% centro-temporal spikes, 12.5% frontal spikes, 9.3% temporal-occipital spikes and 2.3% generalized S-W). Nocturnal seizures were recorded in three patients: two with atypical interictal rolandic spikes and one with left frontal slow abnormalities. A significant relationship (p<0.05) emerges between nocturnal seizures and WISC-R IQ score and visual-spatial memory test and between some cognitive variables and interictal rolandic spikes. High levels of inattention, impulsivity/hyperactivity and oppositional behaviours were related (p<0.01 or 0.05) with Restless Leg Syndrome diagnosis. In conclusion, ADHD is a condition often associated with EEG epileptiform abnormalities. Seizures/IEDs presence seems to play a role on cognitive abilities, conversely sleep disorders have a stronger impact on behavioural rather than cognitive indicators.

SSRI Treatment suppresses dream recall frequency but increases subjective dream intensity in normal subjects

Clinical lore and a small number of published studies report that the selective serotonin reuptake inhibitors (SSRIs) intensify dreaming. This study examines the dream effects of paroxetine and fluvoxamine in order to both increase clinical knowledge of these agents and to test an important potential method for probing the relationship between REM sleep neurobiology and dreaming in humans. Fourteen normal, paid volunteers (4 males, 10 females; mean age 27.4 year, range 22–39) free of medical or neuropsychiatric symptoms as well as of psychotropic or sleep affecting drugs completed a 31‐day home‐based study consisting of: 7 days drug‐free baseline; 19 days on either 100 mg fluvoxamine (7 Ss) or 20 mg paroxetine (7 Ss) in divided morning and evening doses; and 5 days acute discontinuation. Upon awakening, subjects wrote dream reports, self‐scored specific emotions in their reports and rated seven general dream characteristics using 5‐point Likert scales. Dream reports were independently scored for bizarreness, movement and number of visual nouns by three judges. REM sleep‐related measures were obtained using the Nightcap ambulatory sleep monitor. Mean dream recall frequency decreased during treatment compared with baseline. Dream report length and judge‐rated bizarreness were greater during acute discontinuation compared with both baseline and treatment and this effect was a result of the fluvoxamine‐treated subjects. The subjective intensity of dreaming increased during both treatment and acute discontinuation compared with baseline. Propensity to enter REM sleep was decreased during treatment compared with baseline and acute discontinuation and the intensity of REM sleep increased during acute discontinuation compared with baseline and treatment. The decrease in dream frequency during SSRI treatment may reflect serotonergic REM suppression while the augmented report length and bizarreness during acute SSRI discontinuation may reflect cholinergic rebound from serotonergic suppression.

Sleep Structure in Essential Hypertensive Patients: Differences between Dippers and Non-Dippers

The objective of this study was to determine whether the macrostructure and microstructure of sleep were altered in non-dipper essential hypertensive patients. Patients included 9 non-dipper essential hypertensive patients and 10 dippers. We measured blood pressure beat-to-beat by Finapres and all stages of sleep by polysomnografically recording simultaneously during spontaneous nocturnal sleep. We analysed blood pressure pattern for 4-min long random periods while the patients were awake and during all stages of sleep; sleep-efficiency (SE), sleep-latency (SL), delta sleep-latency (delta-SL), REM sleep-latency (REM-SL), St. 1, St.2, St.3, St.4 and REM duration and percentage (%) values, and microstructural aspects of sleep (arousal and microarousal temporisation and features). Dipper patients showed a fall in blood pressure (BP) greater than 10% in all stages of NREM sleep; in the non-dipper patients BP fell by less than 10% of waking values in all NREM stages. REM sleep as well as HR were similar in both groups during all stages of sleep. Non-dippers showed the same number of arousals but more microarousals than dippers (p < 0.001). During and after microarousals BP and HR increased in non-dippers, but showed light variation in dippers. Microarousals induced several stage shifts towards lighter sleep. For this reason non-dippers spent less time in stage 4 than dippers (p < 0.001). In conclusion, non-dipper essential hypertensive patients are a subset of patients with central sympathetic hyperactivity responsible for quantitative and qualitative alteration of sleep.

Dopamine agonists restore cortical plasticity in patients with idiopathic restless legs syndrome.

In the present work, we aimed at assessing whether patients with idiopathic restless legs syndrome (RLS) showed alterations of sensory‐motor plasticity, an indirect probe for motor learning, within the motor cortex (M1). Previous findings suggest that learning in human M1 occurs through LTP‐like mechanisms. To test our hypothesis, we employed the paired associative stimulation (PAS) protocol by transcranial magnetic stimulation (TMS), which is able to induce LTP‐like effects in the motor cortex of normal subjects. Twelve patients with idiopathic RLS and 10 age‐ and sex‐matched control subjects were recruited. PAS protocol consisted of 0.05 Hz electrical median nerve stimulation (90 stimuli), paired with 0.05 Hz TMS (90 stimuli) over the hot spot for stimulating the abductor pollicis brevis (APB) muscle given 25 milliseconds after the onset of the electrical stimulus. Corticospinal excitability recorded in APB muscle, as indexed by MEP obtained after single stimulus, was tested before and up to 30 minutes after PAS protocol. Eight of 12 patients were studied before and after 4 weeks of dopaminergic treatment. PAS protocol increased significantly corticospinal excitability as long as 30 minutes in healthy subjects. On the contrary, PAS protocol did not change the amplitude of MEPs in patients with idiopathic RLS without treatment. PAS associative plasticity was restored after 4 weeks of dopaminergic treatment. Our data demonstrated that associative sensory‐motor plasticity, an indirect probe for motor learning, is impaired in idiopathic RLS patients but may be reverted to normal after dopaminergic treatment.

Impairment of sensory-motor integration in patients affected by RLS

Much evidence suggests that restless legs syndrome (RLS) is a disorder characterized by an unsuppressed response to sensory urges due to abnormalities in inhibitory pathways that specifically link sensory input and motor output. Therefore, in the present study, we tested sensory-motor integration in patients with RLS, measured by short latency afferent inhibition (SAI) and long latency afferent inhibition (LAI). SAI and LAI were determined using transcranial magnetic stimulation before and after 1month of dopaminergic treatment in RLS patients. Ten naïve patients with idiopathic RLS and ten healthy age-matched controls were recruited. Patients with secondary causes for RLS (e.g. renal failure, anaemia, low iron and ferritin) were excluded, as well as those with other sleep disorders. Untreated RLS patients demonstrated deficient SAI in the human motor cortex, which proved revertible toward normal values after dopaminergic treatment. We demonstrated an alteration of sensory-motor integration, which is normalized by dopaminergic treatment, in patients affected by RLS. It is likely that the reduction of SAI might contribute significantly to the release of the involuntary movements and might account for the sensory urge typical of this condition.

Clozapine-Induced Seizures and EEG Abnormalities in Ambulatory Psychiatric Patients

OBJECTIVE: To examine the seizure characteristics and electroencephalogram (EEG) abnormalities in psychiatric patients taking clozapine, given the estimate of a 10% cumulative risk of generalized seizures in this population. DESIGN: We reviewed all consecutive EEGs of ambulatory psychiatric patients taking clozapine performed at our laboratory during 1996 and 1997. SETTING: A university-affiliated urban teaching hospital. SUBJECTS: Twelve patients (4 F/8 M; mean age 40.1 y, range 20–63) had either presented with de novo ictal events within the first month of clozapine therapy (n = 8) or had EEGs recorded to assess seizure risk (n = 4). RESULTS: According to clinical history and interictal EEG findings, the patients were subdivided as follows: three patients with generalized tonic–clonic seizures, two with generalized myoclonic jerks (1 associated with simple partial seizures), two with complex partial seizures, and one with simple partial seizures. The EEGs revealed interictal epileptiform abnormalities (IEDs) in eight patients, two of whom had not had seizures. IEDs were focal or multifocal, with a predominance of left temporal foci. One patient showed a paroxysmal response to photic stimulation. CONCLUSIONS: Patients taking clozapine may be prone to partial seizures and focal EEG abnormalities as well as to generalized seizures and EEG abnormalities, as previously reported.

Rebound insomnia after abrupt discontinuation of hypnotic treatment: double-blind randomized comparison of zolpidem versus triazolam

Rebound insomnia is a transient intense worsening of sleep usually appearing within 3 days from the abrupt discontinuation of benzodiazepines (mainly short‐acting), following long term use and abuse of these hypnotics. Zolpidem is an imidazopyridine, that binds selectively at ω1‐receptor subtypes within the GABAA receptor supramolecular complex. It has a rapid onset of action and short‐elimination half‐life; it reduces the latency of sleep and prolongs the duration of sleep in patients with insomnia, without any major effects on sleep stages and rebound effects upon discontinuation.

Aging, drugs and sleep

Elderly subjects are infrequently selected as subjects to evaluate the effects of medication. In combination with increasing age and sleep, certain drugs may lead to unsuspected and undesirable secondary effects which may be life-threatening or at least very disturbing to the well-being of the elderly subject. Medications administered during the daytime may affect sleep or lead to sleep-related pathology. Administration of cardiovascular medications, corticosteroids, tricyclic antidepressants, and antiparkinsonian drugs have been found to induce significant problems during sleep in patients, leading to investigation and polygraphic testing in our clinic at Stanford. Benzodiazepines are frequently prescribed in elderly subjects to control nocturnal sleep disturbances. However, long-lasting benzodiazepines, such as flurazepam, may induce confusion, disorientation, daytime sleepiness, or may impact on breathing and its control during sleep.