Fernando De Paolis

Paradoxical insomnia: The role of CAP and arousals in sleep misperception

OBJECTIVE The relationship between CAP parameters and subjective time perception during sleep in primary insomnia was investigated. PATIENTS AND METHODS Data collected from all-night PSG recordings of 20 patients with a diagnosis of paradoxical insomnia (misperceptors) were compared with those of 20 normal gender- and age-matched subjects (controls). Besides sleep staging, scoring measures included CAP parameters and EEG arousals. RESULTS Patients and controls presented non-significant differences in the amounts of objective sleep time (464 min vs. 447 min) and objective sleep latency (9 min vs. 8 min). Compared to controls, misperceptors reported a significantly shorter time of perceived sleep (285 min vs. 461 min) and a significantly longer duration of perceived sleep latency (51 min vs. 22 min). In spite of the 11 objective awakenings, misperceptors reported only 4 subjective awakenings, while controls described 2 of the 5 objective awakenings. Arousal index (31.7/h vs. 18.6/h) and total CAP rate (58.1% vs. 35.5%) were significantly higher in misperceptors. In the sleep period between objective and subjective sleep onset, CAP rate was 64.4% in misperceptors and 45.1% in controls (p<0.002). Insomniacs showed significantly higher amounts of CAP rate in stage 1 (62.7% vs. 37.5%) and in stage 2 (53.3% vs. 33.1%), but not in slow wave sleep. CAP phase A2 subtypes were significantly increased in misperceptors (31% vs. 24%). CONCLUSIONS The study points out the topical role of enhanced activation and arousal instability not only in the first part of the night (mismatch between objective and subjective sleep onset) but also in the misperception of consecutive objective awakenings which are subjectively grouped together as a single prolonged event.

Distinctive polysomnographic traits in nocturnal frontal lobe epilepsy.

Purpose:  To describe the polysomnographic features and distribution of epileptic motor events, in relation to conventional sleep measures and cyclic alternating pattern (CAP) parameters, in 40 untreated patients with nocturnal frontal lobe epilepsy (NFLE).

Polysomnographic study of intermittent zolpidem treatment in primary sleep maintenance insomnia.

Background and Purpose: Treatment of chronic insomnia with nightly hypnotics is efficacious, but discontinuation is recommended after 1 month, less than the average disease duration. This study was undertaken to determine the efficacy of intermittent administration. Patients and Methods: A double-blind study was carried out on 8 patients (age, 32.8 ± 9 years; 3 men) with primary sleep maintenance insomnia longer than 1 month. Polysomnography of conventional sleep parameters, cyclic alternating patterns (CAPs), and arousals was performed. Perception of sleep quality was assessed on a visual analog scale. After an adaptation night, baselines were recorded followed by 6 consecutive nights of alternating treatment with zolpidem (10 mg) or placebo. Results: Significant improvements on baseline values (P < 0.0001) were observed on all 3 active treatment nights for total sleep time, sleep efficiency, CAP time, CAP rate, subtype A2, arousals, and arousal index. Deep non-rapid eye movement sleep increased with the second and third doses of active treatment (P < 0.0001). Rapid eye movement sleep increased during the last 3 polysomnographic recordings (P < 0.014). Sleep quality (visual analog scale) improved on all nights after the initial dose of active treatment (P < 0.0001). There was no evidence of rebound insomnia with placebo. Conclusions: Intermittent treatment with zolpidem in primary insomnia patients improves CAP parameters and arousals, as well as sleep duration and quality, in the absence of rebound insomnia.

Effects of antiepileptic treatment on sleep and seizures in nocturnal frontal lobe epilepsy.

OBJECTIVE To study the effects of antiepileptic treatment on sleep parameters and video-polysomnography (VPSG) seizures in nocturnal frontal lobe epilepsy (NFLE). METHODS Twenty patients with a clinical and VPSG diagnosis of NFLE (baseline polysomnography [PSG]) underwent a clinical follow-up and performed a second VPSG after effective antiepileptic treatment lasting for at least 6 months. Conventional sleep measures, cyclic alternating pattern (CAP) parameters, and objective VPSG seizures were assessed in NFLE patients before and after treatment and were compared with the results of 20 age- and gender-matched control subjects. RESULTS Antiepileptic treatment determined a partial reduction of objective VPSG seizures of approximately 25% compared to baseline condition. Alterations of most conventional sleep measures recovered normal values, but nonrapid eye movement (NREM) sleep instability remained pathologically enhanced (CAP rate, +26% compared to controls) and was associated with persistence of daytime sleepiness. CONCLUSIONS Residual epileptic events and high levels of unstable NREM sleep can define a sort of objective resistance of both seizures and disturbed arousal system to the therapeutic purpose of the antiepileptic drugs in NFLE. This finding could determine the need for new therapeutic options in this particular form of epilepsy.

Acute shift of a case of moderate obstructive sleep apnea syndrome towards one of severe central sleep apnea syndrome after an ischemic stroke.

Article history: Received 21 December 2011 Received in revised form 12 January 2012 Accepted 27 January 2012 Available online 22 March 2012

Clinical and Polygraphic Improvement of Breathing Abnormalities After Valproate in a Case of Pitt-Hopkins Syndrome

Pitt-Hopkins syndrome is a rare genetic form of severe psychomotor delay, caused by mutations in transcription cell factor-4 gene and characterized by distinctive dysmorphic features and abnormal breathing pattern. The current report describes the polygraphic features of the syndrome’s typical breathing pattern in a patient both in wakefulness and in sleep. The control of these breathing alterations is important to prevent the neurological sequelae linked to chronic cerebral hypoxemia in early ages. No data are available on effective treatment options for breathing abnormalities of Pitt-Hopkins syndrome. The authors polygraphically documented a reduction of apneic and hypopneic phenomena, with a significant improvement in saturation values, after the introduction of sodium valproate.

Complex sleep apnea syndrome in stroke patients

Fig. 1. A profile of Tiberius Claudius Germanicus appears on the obverse of this silver denarius struck during the Imperial Roman Era (ca. first century CE; photo provided courtesy of A Pangerl of www.romancoins.info). To the Editor We would like to thank Dr. Sacchetti and co-workers for their interest in our article [1]. Sacchetti et al. raise the question whether a stroke may transform, in selected patients, an obstructive sleep apnea syndrome (OSAHS) into a complex-sleep apnea syndrome (Comp-SAS) and postulate that the appearance of central respiratory events may represent a stable consequence of stroke, and may complicate the treatment approach to sleep apnea. This hypothesis is supported by their preliminary data showing mixed (obstructive and central) apneas four months after the stroke. This high prevalence of central and mixed respiratory events in stable phase after stroke is higher than that found in other studies, about the time course of sleep breathing disorders and central periodic breathing in stroke patients [2,3]. These data also contradict in part the attenuation of central respiratory events within week or a few months after the stroke described by the same authors or in OSAHS patients with CompSAS [4]. In OSAHS patients some predictive factors for appearance of CompSAS during CPAP treatment have been proposed [5], which include atrial fibrillation, use of opioids, sleep disruption and features of initial sleep apnea syndrome (in term of severity of obstructive apneas and presence of relevant mixed/central events). The last two factors are probably strictly related to the fluctuations of ventilatory control system and CO2 levels, that we documented in our paper [1], as well as, the fluctuations of arousal system in NREM sleep that have been described as possible distinctive patterns of some patients with OSAHS [6]. Finally, in our opinion, the question is to clarify if these or other factors can tell us whether initial ‘‘complex’’ cases of OSAHS are more prone to develop a clear CompSAS after a stroke and, whether as suggestedbySacchetti andco-workers, tomerge this ‘‘pre-stroke’’ profile of sleep disordered breathing with ‘‘post-stroke’’ features. Thismay enable us to findout possible factors able to distinguish patientswith a transient CompSAS frompatientswith a persistent one.

Atypical patterns in portable monitoring for sleep apnoea: features of nocturnal epilepsy?

Atypical cardiorespiratory patterns can be found during routine clinical use of portable monitoring for diagnosis of sleep-disordered breathing (SDB). Over 1,000 consecutive portable recordings were analysed to study the potential ictal nature of stereotyped cardiorespiratory and motor patterns. Snoring, airflow, thoracic effort, pulse rate, body position, oxygen saturation and activity of the anterior tibialis muscles were quantified. Recordings showing stereotyped polygraphic patterns recurring throughout the night, but without the features of sleep apnoea (apnoea/hypopnoea index <5 events·h−1), were selected for investigation. Once included in the study, patients underwent attended nocturnal video polysomnography. A total of 15 recordings showing repeated polygraphic patterns characterised by a sequence of microphone activation, respiratory activity atypical for sleep and wakefulness, heart rate acceleration and limb movements, followed by body position change, were selected for investigation. Once included in the study, patients underwent attended nocturnal video polysomnography that showed frontal epileptic discharges triggering periodic electroencephalographic arousals, autonomic activation and stereotyped motor patterns. A diagnosis of nocturnal frontal lobe epilepsy (NFLE) was established for all patients. NFLE should be taken into consideration in patients with stereotyped and recurrent behavioural features during portable monitoring carried out for diagnosis of SDB.