Abnormal motor behavior during sleep

Abnormal motor behaviors during sleep can be classified into four categories, ranging from myoclonic jerks to complex and integrated motor behaviors There have been recent developments in several of these conditions, in particular restless legs syndrome (RLS) and rapid-eye-movement sleep behavior disorder (RBD). RLS is one of the major causes of insomnia. Familial aggregation of RLS has been demonstrated by several groups, and molecular genetics studies have suggested the presence of susceptibility genes on chromosomes 12q and 14q. Pharmacologic and brain imaging studies suggest the involvement of dopaminergic mechanisms in RLS, but recent work has focused on brain iron metabolism. Studies indicate that RBD patients may eventually develop Parkinson's disease (PD). Conversely, RBD has been found in patients already diagnosed with PD. Single-photon emission computed tomography and positron emission tomography studies have shown a decrease in binding to presynaptic dopamine transporter in both idiopathic RBD and PD. Patients with RBD (associated or unassociated with PD) also have neuropsychological deficits. RBD may therefore represent the prodrome of a neurodegenerative disease leading to multiple system atrophy and Lewy body dementia. Understanding the underlying pathophysiology of abnormal sleep motor behaviors may prove useful in the management of insomnia.     

Sleep disordered breathing during REM sleep in Freeman-Sheldon syndrome

OBJECTIVES: To examine the sleep-disordered breathing in patients with Freeman-Sheldon syndrome (FSS). MATERIAL AND METHODS: One night polysomnography was performed for 2 teenage FSS patients. RESULTS: They showed frequent obstructive sleep apnea exclusively during rapid-eye-movement sleep. CONCLUSION: FSS is a risk factor for the occurrence of sleep disordered breathing.     

Further observations on sleep abnormalities in Kleine-Levin syndrome: abnormal breathing pattern during sleep

In two adolescent and two adult patients with Kleine-Levin syndrome, polygraphic sleep recording performed during somnolent and non-somnolent periods revealed various forms of abnormal breathing patterns during sleep. These included periodic breathing and hypopnoeic episodes associated with brief arousals and, in one adult patient, a full blown sleep apnoea syndrome. It is suggested that abnormal breathing in sleep in this syndrome may result from central hypoexcitability.     

Abnormal breathing in the Rett syndrome

Four girls affected with the Rett syndrome showed stereotyped hand movements and psychomotor regression beginning in the first or second year of life after initially normal development, with total loss of language, a severe gait, and chewing and swallowing disturbances. Breathing during active wakefulness was abnormal, with clusters of arrhythmic, tachypneic and irregular respiratory acts, intermixed with prolonged apneic episodes causing cyanosis and even fainting. On the other hand, breathing was regular during both NREM and REM sleep stages. Breathing impairment in the Rett syndrome is characterized by an inability to maintain normal respiratory patterns during wakefulness, and represents a functional disturbance of the behavioral control of breathing, which occurs during active wakefulness.     

Obstructive disordered breathing during sleep in patients with spinal cord injury

Little is known about respiration and sleep in spinal cord injured (SCI) patients, and yet they frequently have complaints related to sleep. Four SCI patients with various sleep complaints were evaluated with nocturnal polysomnography. All 4 had evidence of obstructive sleep apnea (disordered breathing). These findings suggest that obstructive sleep apnea may be contributing to disruptive sleep in SCI patients and may be responsible for many of their daytime symptoms.     

Specific patterns of laryngeal electromyography during wakefulness are associated to sleep disordered breathing and nocturnal stridor in multiple system atrophy

BackgroundNocturnal stridor and respiratory abnormalities are important features of multiple system atrophy (MSA) with relevance to patient survival, and they are detected and evaluated mainly through video-polysomnography (video-PSG). Diurnal laryngoscopy seems to yield abnormal findings only in the presence of significant vocal cord (VC) dysfunction.AimTo assess whether specific electrophysiological patterns of diurnal EMG of VC muscles may indicate nocturnal stridor or respiratory dysfunctions in MSA patients.Materials and methodsSeventeen patients with probable MSA were examined. A full-night video-PSG to collect standard breathing parameters (apnea/hypopnea index, mean HbSAO₂, oxygen desaturation index, total sleep time with HbSaO₂ below 90%) was performed in all the patients. Laryngoscopy and EMG investigation of adductor (thyroarytenoid-TA) and abductor (posterior cricoarytenoid-PCA) muscles of the VCs were also performed.ResultsBoth the laryngeal EMG abnormalities (based on MUAP analysis and kinesiologic EMG investigation of VC muscles) and the laryngoscopic alterations correlated with video-PSG respiratory abnormalities. Specific patterns of EMG findings were consistently found in MSA subjects with nocturnal stridor detected at PSG. In particular, the following EMG findings were related to the severity of breathing abnormalities and the presence of stridor on video-PSG: neurogenic pattern on MUAP analysis of the PCA, paradoxical activation of the TA during inspiration and tonic EMG activity of the TA during quiet breathing.ConclusionsElectromyographic/kinesiologic investigation of VC muscles during wakefulness provides additional information on the pathophysiology of the respiratory abnormalities in MSA patients that could be useful for guiding the choice of the best appropriate treatment and care.     

Cleft lip and/or palate and breathing during sleep

Cleft of the lip and/or palate (CL/P) is a common defect which is associated with changes in facial structures and a smaller upper airway. As a result, infants and children with CL/P have an increased risk of sleep disordered breathing (SDB). This paper will review the anatomical and functional factors which place infants and children with CL/P at increased risk of SDB as well as review the literature which defines the magnitude of this risk. The information available on treatment of SDB in infants and children with CL/P will be presented. Finally, outstanding issues relevant to SDB in children with CL/P are discussed with direction for future research.     

Increased upper airway resistance to breathing during sleep in the cat.

At the onset of sleep, upper airway resistance shifted to higher levels which were maintained throughout sleep. With each inspiration, there was a decrease in upper airway resistance. These respiratory changes in resistance were smaller in wakefulness (on low baseline resistances) than those in nonrapid eye movement sleep (on high baseline resistances). In rapid eye movement sleep, modulations with inspiration were diminished and were intermittently absent, and baseline resistance was high.     

Sleep disordered breathing may not be an independent risk factor for diabetes, but diabetes may contribute to the occurrence of periodic breathing in sleep

OBJECTIVE(S): (a) To determine if self-reported diabetes mellitus is independently associated with sleep-disordered breathing (SDB); (b) to determine if diabetes mellitus is specifically associated with central sleep apnea including periodic breathing (Cheyne-Stokes breathing pattern) during sleep. STUDY POPULATION: The study population reflected participants in the on-going Sleep Heart Health Study (SHHS). Analyses were conducted utilizing data obtained from 4872 SHHS participants without prevalent cardiovascular disease (CVD) and 1002 participants with self-reported CVD, defined as hospitalization for non-fatal coronary heart disease, congestive heart failure, myocardial infarction, coronary artery bypass graft, and stroke. METHODS: SHHS methodologies have been previously reported and include performance of overnight, in-home polysomnography (PSG), which recorded variables reflecting sleep architecture and breathing, permitting identification of obstructive and central apneas, hypopneas, periodic breathing and oxyhemoglobin saturation (SpO(2)). Anthropomorphic metrics as well as systemic blood pressure measurements were obtained at the time of PSG. Other health data were available from questionnaires and the data sets of the parent cohorts from whom SHHS participants were recruited. The investigators assessed and compared breathing parameters, sleep architecture and CVD variables in diabetic and non-diabetic participants. The relationships between diabetes and the various study parameters, independent of potential confounders, were examined by multivariable modeling. Linear regression modeling was employed to examine the relationship between continuously distributed variables such as respiratory disturbance index log (RDI). The relationships between diabetes and dichotomous outcome variables such as central apnea index (CAI), obstructive apnea index (OAI), periodic breathing and the percentage of time spent at various levels below SpO(2) 90% were examined by the logistic regression model. Age, gender, race, BMI and neck circumference were forced into all multivariable analyses since these factors are associated with both diabetes mellitus and SDB. RESULTS: The investigators reported that the prevalence of CVD risk factors including increased BMI, waist circumference, neck circumference, triglycerides, reduced HDL cholesterol and hypertension was greater in diabetic than non-diabetic participants. Native Americans represented a disproportionately high percentage of the diabetic population. Unadjusted data obtained from participants without prevalent CVD indicated that the mean RDI was higher in the diabetic participants. Moreover, there was a greater percentage of diabetic participants in the higher RDI categories (e.g. 23.8% of the 470 diabetics and 15.6% of the 4402 non-diabetics had RDI>15, P<0.001). Similarly, the unadjusted data indicated that a significantly greater proportion of the diabetic participants spent >5% and >10% of sleep time below SpO(2) 90%, compared with the non-diabetic participants. The unadjusted data from participants without prevalent CVD indicated that the diabetic and non-diabetic participants did not differ with regard to distribution by category of OAI severity (e.g. > or =2 events/h, > or =3 events/h, or > or =4 events/h). On the other hand, although the prevalence of central apneas was low, a significantly greater proportion of diabetic participants were in the CAI categories (> or =2 events/h and > or =3 events/h) than non-diabetic subjects. There was no difference between diabetic and non-diabetic individuals with regard to CAI prevalence in the > or =4 events/h category. Of note, a greater percentage of diabetic patients exhibited periodic breathing (3.8% vs. 1.8%, diabetic and non-diabetic participants, respectively, P=0.002). Repeating the above analyses with inclusion of the participants with prevalent CVD did not change these relationships, and in fact, the differences between diabetic and non-diabetic participants with respect to central events and periodic breathing became more evident (the data forre evident (the data for this were not provided in the paper). Linear regression analyses demonstrated that BMI, age and male gender were independently related to increased RDI among participants without prevalent CVD. Furthermore, after adjusting for age, gender, race, BMI and neck circumference, there was no difference in geometric mean RDI between the diabetic and non-diabetic participants. The adjusted odds of having RDI> or =15 and the adjusted odds for spending> or =5% or > or =10% of sleep time with SpO(2) <90% did not differ between the diabetic and non-diabetic individuals. The investigators also examined sleep architecture in the study cohort. There were no differences between the diabetic and non-diabetic groups with regard to the adjusted proportion of time spent in non-REM sleep stages, although the mean percent time spent in REM sleep was 1.1% less in the diabetic individuals. The findings were the same with or without inclusion of participants with known CVD. Even after adjustment for potential confounders, in a sample without or with prevalent CVD, diabetic participants had increased adjusted odds for periodic breathing odds ratio (1.8, 95% confidence interval (CI) with a range of 1.02--3.15 in diabetic participants without prevalent CVD vs. 1.74, 95% CI with a range of 1.16--2.62 in diabetic participants with prevalent CVD). There was a suggestion of increased odds for CAI in diabetic subjects when analyzing populations with and without prevalent CVD. CONCLUSION: The authors concluded that diabetes mellitus is associated with sleep apnea but that this association is largely explained by risk factors in common for both disorders, most notably obesity. After adjusting for confounding factors there was no difference between diabetic and non-diabetic participants with regard to obstructive events. However, even after adjusting for potential confounders, there was a greater prevalence of periodic breathing in diabetic subjects. Although not reaching statistical significance, there was a suggestion of an increased prevalence of central events in the diabetic population, particularly when the sample included participants with known CVD. The investigators believed it unlikely that the findings were attributable to underlying congestive heart failure in as much as the diabetic subjects without prevalent CVD exhibited increased prevalence of periodic breathing and possibly increased central events. The authors proposed that diabetes mellitus might be a cause of SDB, mediated through autonomic neuropathy that may alter ventilatory control mechanisms. In this context, the authors commented that autonomic neuropathy may cause perturbations in ventilatory control by altering chemoreceptor gain or altering cardiovascular function (although the authors discounted underlying congestive heart failure as an explanation for the higher prevalence of periodic breathing in diabetic participants). To reinforce their conclusions, the authors cited the literature indicating increased prevalence of sleep apnea in diabetic patients with autonomic dysfunction, as well as the association between Shy--Drager syndrome, in which autonomic insufficiency is a constitutive element, and central sleep apnea.     

Abnormal palatopharyngeal muscle morphology in sleep-disordered breathing

The aim of the present study was to investigate whether histopathological changes can be detected in two soft palate muscles, the palatopharyngeus and the uvula, in 11 patients with long duration of sleep-disordered breathing (SDB). Muscle samples were collected from patients undergoing uvulo-palatopharyngoplasty (UPPP). Reference samples from the corresponding areas were obtained at autopsy from five previously healthy subjects. Muscle morphology, fibre type and myosin heavy chain (MyHC) compositions were analysed with enzyme-histochemical, immunohistochemical and biochemical techniques. The muscle samples from the patients, and especially those from the palatopharyngeus, showed several morphological abnormalities. The most striking findings were (i) increased amount of connective tissue, (ii) abnormal variability in fibre size, (iii) increased proportion of small-sized fibres, (iv) alterations in fibre type and MyHC compositions, (v) increased frequency of fibres containing developmental MyHC isoforms. Our findings point towards a pathological process of denervation and degeneration in the patient samples. Conclusively, the morphological abnormalities suggest a neuromuscular disorder of the soft palate in SDB patients.     

Respiratory patterns during sleep in mitochondrial myopathies with ophthalmoplegia

Nocturnal polygraphic recordings (electroencephalography, electro-oculography, submental and intercostal muscle electromyography, electrocardiography, respiration by thoracic strain gauges and oronasal thermistors) with continuous monitoring of arterial oxyhemoglobin saturation by pulse oximeter were performed in 8 patients with ophthalmoplegia plus. All patients except 1 had normal blood gas values and normal lung volumes associated with a diminished ventilatory response to inhaled CO2 during wakefulness. Four patients showed pathological sleep-related breathing patterns consisting of sleep apneic polygraphic tracings mainly of the central type or of REM-related hypoventilation episodes. It is suggested that these disorders in patients with ophthalmoplegia plus may have a central origin and be related to the underlying metabolic disturbance.     

Effect of respiration on heartbeat-evoked potentials during sleep in children with sleep-disordered breathing

ObjectiveHeartbeat-evoked potentials (HEPs) in electroencephalogram (EEG) provide a quantitative measure of cardiac interoception during sleep. We previously reported reduced HEPs in children with sleep-disordered breathing (SDB), indicative of attenuated cardiac information processing. The objective of this study was to investigate the link between HEP and respiration.Patients/MethodsFrom the overnight polysomnograms of 40 healthy children and 40 children with SDB, we measured HEPs during epochs of stage 2, slow-wave and rapid eye movement (REM) sleep free of abnormal respiratory events. HEPs were analysed with respect to respiratory phase.ResultsWe observed a marked association between respiratory phase and HEP in children with SDB during REM sleep, but not in normal children. In children with SDB, HEP waveforms were attenuated during expiration compared to inspiration. Following adenotonsillectomy, expiratory HEP peak amplitude increased in the SDB children and was no longer different from those of normal children.ConclusionsThe expiratory phase of respiration is primarily associated with attenuated cardiac information processing in children with SDB, establishing a pathophysiological link between breathing and HEP attenuation.     

Abnormal breathing patterns in stroke: relationship with location of acute stroke lesion and prior cerebrovascular disease

Objective

To determine whether central periodic breathing (CPB) is associated with acute involvement of any particular part of the brain, or the extent of total damage in patients with acute stroke.

Methods

CPB was identified using portable monitoring equipment in patients with stroke on admission. A neuroradiologist classified acute stroke lesions and prior cerebrovascular disease on brain images.

Results

Among 134 patients with acute stroke, those with CPB were more likely to have a large acute stroke lesion in a cerebral hemisphere (p = 0.01) and more mass effect (p = 0.03). There was no association between CPB and severe prior cerebrovascular disease on imaging (p = 0.76).

Conclusion

CPB is related to the acute (not old) lesions, particularly large acute cerebral hemispheric lesions with mass effect. A relationship between lesions in any discrete brain location (unilateral or bilateral) and CPB could not be shown.Central periodic breathing (CPB), including Cheynes–Stokes respiration, during wakefulness has been reported to occur in 53% of patients with acute stroke.¹ Limited information suggests a possible relationship between the site and size of the stroke lesion and the presence of CPB. Previous studies suggested that the presence of bilateral hemispheric or brain stem stroke lesions might be crucial for the presence of CPB after stroke.^2,3 However, these were small studies (n = 28, n = 49) predating computed tomography, which found that hospitalised patients with intermittent CPB during wakefulness had bilateral hemispheric or brain stem lesions on autopsy. More recent studies have failed to find any association between the location of brain lesion on imaging and CPB while patients were awake¹ (n = 32) or asleep^4,5 (n = 93, n = 39).We reported previously that CPB was associated with a poor functional outcome at 3 months after stroke, even after accounting for clinical stroke severity, but the mechanism linking CPB with poor outcome was unclear.⁶ Therefore, we aimed to determine, using data from the same cohort, whether CPB was related to features of the acute stroke lesion on brain imaging or to prior cerebrovascular disease (ie, previous infarcts, haemorrhages and/or periventricular white matter lesions (PVWML)/leucoaraiosis).     

The influence of sleep disordered breathing in REM sleep behavior disorder

Objectives/backgroundBecause both REM sleep behavior disorder (RBD) and Obstructive Sleep Apnea (OSA) can present with similar symptoms, it is important to understand the influence of OSA in the clinical manifestations of RBD and whether RBD modulates OSA severity. Our objectives were to compare: 1. the intensity of non-motor symptoms between RBD patients with (RBD-OSA) and without OSA (RBD-non-OSA), and 2. polysomnographic features between RBD-OSA and OSA without RBD (OSA-non-RBD) patients.Methods32 RBD cases were divided in two groups according to the presence of moderate to severe OSA [Apnea Hypopnea Index (AIH) > 14] (RBD-OSA vs. RBD-non-OSA). Non-motor symptoms were assessed with Montreal Cognitive Assessment Scale, SCOPA-Sleep and the Non-Motor Symptom Scale (NMSS) for Parkinson's disease. RBD-OSA patients were compared to 20 OSA-non-RBD patients matched for age, AHI and gender.ResultsCompared to RBD-non-OSA (n = 22) patients, RBD-OSA patients (n = 10) showed significantly higher scores in SCOPA-Sleep Daytime and NMSS Attention/Memory, Gastrointestinal and Urinary domains, as well as higher sleep fragmentation, more oxygen desaturation and higher AIH in NREM sleep. RBD-OSA patients presented with less O₂ desaturation, snoring, and BMI when compared to OSA-non-RBD patients.DiscussionOur data suggests that OSA contributes to hypersomnolence, gastro-intestinal, memory, and urinary complaints in RBD patients. RBD patients seem to have a milder OSA phenotype (possible reflecting a protective role conferred by the maintenance of muscle tone during REM sleep) and to be less prone to obesity and snoring than non-RBD patients.