Lenise Jihe Kim

Treatment of obstructive sleep apnea syndrome associated with stroke

The association between sleep-disordered breathing and stroke has been a subject of increased interest and research. Obstructive sleep apnea (OSA) is an important risk factor for stroke incidence and mortality. Moreover, OSA is a common clinical outcome after stroke, directly influencing the patients recovery. The treatment of choice for OSA is positive airway pressure (PAP) support and the PAP appliance is considered the most recommended clinical management for the treatment of patients with cardiovascular complications. However, the implementation of PAP in stroke patients remains a challenge, considering the increased frequency of motor and language impairments associated with the cerebrovascular event. In the present study, we reviewed the main findings describing the association between stroke and OSA treatment with continuous positive airway pressure. We also discussed the types of OSA treatment, the different options and indications of PAP treatment, PAP adherence and the clinical outcomes after treatment.

Frequencies and Associations of Narcolepsy-Related Symptoms: A Cross-Sectional Study.

OBJECTIVES Narcolepsy is a disabling disease with a delayed diagnosis. At least 3 years before the disorder identification, several comorbidities can be observed in patients with narcolepsy. The early recognition of narcolepsy symptoms may improve long-term prognosis of the patients. Thus, we aimed to investigate the prevalence of the symptoms associated with narcolepsy and its social and psychological association in a sample of Sao Paulo city inhabitants. METHODS We performed a cross-sectional evaluation with 1,008 individuals from the Sao Paulo Epidemiologic Sleep Study (EPISONO). Excessive daytime sleepiness (EDS) was assessed by the Epworth Sleepiness Scale. Volunteers were also asked about the occurrence of cataplectic-like, hypnagogic or hypnopompic hallucinations, and sleep paralysis symptoms. The participants underwent a full-night polysomnography and completed questionnaires about psychological, demographic, and quality of life parameters. RESULTS We observed a prevalence of 39.2% of EDS, 15.0% of cataplectic-like symptom, 9.2% of hypnagogic or hypnopompic hallucinations, and 14.9% of sleep paralysis in Sao Paulo city inhabitants. A frequency of 6.9% was observed when EDS and cataplectic-like symptoms were grouped. The other associations were EDS + hallucinations (4.7%) and EDS + sleep paralysis (7.5%). Symptomatic participants were predominantly women and younger compared with patients without any narcolepsy symptom (n = 451). Narcolepsy symptomatology was also associated with a poor quality of life and symptoms of depression, anxiety, and fatigue. CONCLUSIONS Narcolepsy-related symptoms are associated with poor quality of life and worse psychological parameters.

Relation between body mass index and obstructive sleep apnea

Dear Editor Obstructive sleep apnea (OSA) is a multifactorial sleep disorder associated to different risk factors, including excess body weight, male gender, older age, neck circumference, body mass index (BMI), and high blood pressure [1, 2]. Considering this predisposing factors and the large reports of high risk of heart diseases in OSA patients [3, 4], the investigation of clinical features that could increase the risk for OSA occurrence assume great importance. With strong interest, we read the study of Sawanyawisuth and coworkers [5] who analyzed, by means of a retrospective study, the charts of 49 hypertensive patients with at least one report of OSA symptoms. Forty-two patients (85.71 %) were diagnosed with an apnea–hypopnea index ≥5/h by Embletta® e Stardust®. The patients were distributed in two groups: one with under 60 years of age and another with over 60 years. The authors demonstrated that the most common symptoms reported by the patients with OSAwere snoring, excessive daytime sleepiness, nocturia idiopathic, and gastroesophageal reflux. The great important finding of this study, however, was the demonstration of an inverse relationship between the BMI as a predisposing factor in elderly hypertensive Thai patients with OSA, countering most studies that observed the higher prevalence of OSA in overweight and obese patients [6]. Nevertheless, we still believe there are some additional considerations that should be mentioned. Although the study observed lower BMI in patients over 60 years of age when compared to younger patients, the authors included both genders in the comparison of the groups. The group of individuals under 60 years consisted of 55 % of men; and in contrast, the group of over 60 years of age was composed of 72.7 % of women. The no-pairing by gender may have caused the reduction of BMI average on group with over 60 years of age by the number of women in this group. This factor had significant relevance, since it is known that the prevalence of OSA in women over 60 years equals to that of men, and that the cutoff of BMI analysis differs among the genders. Finally, we would like to congratulate the authors for the great value this study has in the better understanding of the predisposing factors of OSA and of hypertension in elder Thai people. As a suggestion to improve future work, we propose the conduction of cohort and follow-up studies to control the variation of BMI of the elderly hypertensive patients and its influence on OSA as well as the separation of groups by age and sex.

Sleep pattern and spectral analysis of caregiver-mothers of sons with Duchenne muscular dystrophy, and an examination of differences between carriers and non-carriers

OBJECTIVES Sleep is essential for physical and mental well-being. However, poor sleep is a common complaint among caregivers. The aim of the present study was to determine sleep patterns of caregiver-mothers (CM group) of sons with Duchenne muscular dystrophy (DMD) and also to examine the differences between non-carriers and carriers of the gene related to DMD within the CM group. METHODS Observational case-control study. PARTICIPANTS The CM and control (CTRL) groups were matched for age, body mass index and social class. Polysomnography was conducted in a sleep laboratory for one night. The discrete fast Fourier transformation method was used to calculate the electroencephalogram (EEG) power spectrum for the entire night and sleep stages. RESULTS The CM group presented higher sleep latency and N3 sleep stage compared with the CTRL. When carrier and non-carrier CM subgroups were analyzed, increased sleep latency and time awake, as well as reduced sleep efficiency and N2, were observed in the carrier group. Regarding respiratory parameters, carriers demonstrated higher hypopnea index values compared with non-carriers. Spectral analysis showed that carriers compared with non-carrier DMD caregiver-mothers presented lower spectral power in fast waves, mainly beta, during REM sleep in some EEG derivations. CONCLUSIONS There was an impairment of sleep pattern in the CM group compared with CTRL mothers; this was possibly associated with difficulty in initiating sleep. Being a DMD gene carrying caregiver further compromised some aspects of sleep microstructure during REM sleep. The data demonstrated the importance of sleep evaluation in caregiver-mothers, and the relationship between sleep and being a carrier of the gene associated with DMD, which was demonstrated as possibly impacting sleep quality.

On the importance of polysomnography after stroke

Dear Editor, The interesting paper published by Ponsaing and colleagues entitled BPolysomnographic indicators of mortality in stroke patients^ discusses the importance of polysomnography to identify sleep disorders after stroke. The prevalence of sleep disorders after stroke is high, and there is an important association between these sleep findings and cardiovascular outcomes [1, 2]. In theory, the majority of patients after stroke should be investigated by polysomnography. Indeed, in patients after stroke, the findings of excessive daytime sleepiness and other clinical information are not reliable enough to identify sleep disturbances [3]. However, polysomnography is expensive and other alternatives have been encouraged [4]. In fact, the use of questionnaires such STOP-BANG, Berlin, and Pittsburgh to identify sleep disturbances is cheaper and easier. However, the reliability of data from these instruments depends on a minimal neurologic condition. Language and visual deficits can be important limitations for these methods of diagnosis in stroke patients. Actigraphy could be a useful alternative in this scenario. Few studies have been performed to study the utility of actigraphy in patients after stroke. We studied 17 patients for 14 days with actigraphy after ischemic stroke. Reliable data could be obtained in only 8 patients. The main problems were irregular use of actigraphy and incomplete data from diaries. The elapsed time from stroke until actigraphy ranged from 30 to 90 days depending on the patient. Of the 8 patients with adequate data, there were 4 (50 %) men; the mean age was 57.62 ± 15.25 years, and the Epworth Sleepiness Scale scores were 12.2 ± 5.16. Analysis of actigraphy data on these patients demonstrated a use time of 13.75 ± 0.46 days; wake time per 24 h was 864.01 ± 103.27 min; time of sleep per 24 h was 495.81 ± 99.41 min; nocturnal sleep efficiency was 90.80 ± 4; and latency for night time sleep was 29.10 ± 22.6 min. Many factors can explain these preliminary findings such as loss of independence after stroke, loss of attention, difficulty with memory, and apathy [5]. In our opinion, polysomnography remains the best option to identify sleep disturbances in patients after stroke. However, more studies are warranted to evaluate other strategies for cost and feasibility in patients after stroke. * Fernando M. Coelho fernandomorgadinho@hotmail.com

Sleep restriction reduces the survival time and aggravates the neurological dysfunction and memory impairments in an animal model of cerebral hypoperfusion.

Cerebral blood flow is associated with the cerebrovascular prognosis. Sleep restriction (SR) may be a limiting factor of the prognosis after a cerebrovascular event, impairing the neurological recovery. We aimed to investigate the effects of SR on mortality rate and on behavioral and histological parameters of animals submitted to permanent cerebral hypoperfusion. Sixty male Wistar rats were distributed in 4 groups, according to the protocol of common carotid artery occlusion (CCAO) and SR: nSR+nCCAO, SR+nCCAO, nSR+CCAO, and SR+CCAO. The groups SR+nCCAO and SR+CCAO were submitted to SR during 10 days. The cerebral hypoperfusion was induced by the permanent CCAO. Neurological function and memory were assessed over 14 days of cerebral hypoperfusion. Analysis of neuropathological alterations were performed in the CA1 region of hippocampus. The mortality rate was 40% in the nSR+CCAO and SR+CCAO groups. SR significantly reduced the survival time of animals submitted to CCAO. After 7 and 14 days of cerebral hypoperfusion, 11% and 33% of the nSR+CCAO and SR+CCAO animals showed severe neurological dysfunction, respectively. A significant association between a high frequency of memory impairments with the group SR+CCAO was observed. The neuropathological alterations in CA1 region of hippocampus were similar among the groups. SR potentiates the negative effects of cerebral hypoperfusion conditions, suggesting that SR could be a factor associated with a worse prognosis after a cerebrovascular event.

Evaluating the underestimated risk factors associated with carotid artery stenosis.

Stroke is the third leading cause of premature deaths and one of the most prevalent causes of disability-adjusted lifeyears [1]. Risk factors and their motor and cognitive impairment induced mechanisms have been frequently investigated. Ischaemic strokes can be a result of cardiovascular emboli or local artery stenosis. Carotid artery diseases are responsible for 10% to 20% of strokes [2]. The study performed by Everts et al. [3] is very interesting. The authors performed a prospective exploratory study with symptomatic patients aged between 51.3 and 85.3 years with extracranial carotid artery stenosis of ≥70%. The main finding of the present study was the correlation between the carotid artery stenosis and impairments in various cognitive and emotional domains, including verbal fluency and anxiety. These results suggest that carotid artery stenosis may induce neuropsychological impairments even in patients without a previous stroke history. Thus, controlling the risk factors of atherosclerotic lesions seems to be essential to prevent prior cerebrovascular impairments. Several studies have demonstrated the association between sleep-disordered breathing, such as obstructive sleep apnoea, and cardiovascular outcomes [4, 5]. However, primary snoring is still an underestimated respiratory condition. Recently, a study discussed the possible relationship between primary snoring and carotid artery intima-media thickness [6]. The results of this study showed that the intima-media thickness of patients who snored was greater, when considering eight different points of the carotid artery, compared with those of nonsnorers. Therefore, primary snoring could be a possible mechanism for the aggravation of the carotid stenosis, leading to greater hypoperfusion and embolisation, eventually resulting in a cognitive and executive function deficit. In general, studies show that prevention is still the best and most cost-effective way to avoid cardiovascular events. Primary snoring is underestimated and understudied among sleep disorders, but it seems to be related to stroke. Therefore, we emphasise that primary snoring and cardiovascular outcomes must be studied. A higher prevalence of snoring and cultural tolerance of this symptom is a problem. It is important to study more extensively the outcomes, causes and comorbidities of primary snoring, such as neurovascular diseases that are the major causes of health expenditures and disabling sequelae.

Is it possible to prevent obstructive sleep apnea with maxillomandibular orthopedic treatment during childhood

Several conditions, comprising obesity, cervical soft tissueaccumulation, nasal obstruction, and craniofacial abnormali-ties, increase the risk for obstructive sleep apnea (OSA). Themaxillomandibularanteroposteriorandverticaldisproportionsare one of the most frequent craniofacial abnormalities andgenerally appear due to an alteration in the mandible growth.Thus, a decrease in oropharyngeal space is often observed[1]which predisposes to OSA. Although transversal alterationsalso play an important role in the OSA development and thetreatment with rapid maxillary expansion shows great results,in the present letter, we discussed only mandibulardeficiencies.In dentistry, the diagnostic classification of these craniofacialabnormalities is still controversial, ranging from the relation-ship between the first permanent molars (Angle’sclassifica-tion) to the cephalometric measurements and subjective anal-ysis of the facial morphology [2]. This absence of an optimi-zation of the diagnostic criteria for craniofacial abnormalitiesimpairsthecomparisonsamongdifferentstudiesandhampersthe evaluation of the maxillomandibular treatmenteffectiveness.In growing patients, one of the craniofacial abnormalitytreatments consists in moving the mandible forward to ananterior position by fixed or removable maxillary orthopedicappliances[3].Althoughcontroversial,thisadvancementlike-ly increases the anterior mandible position in relation to themaxilla and to the skull base by promoting mandible growthand dentoalveolar remodeling. This process also could pro-mote a soft tissue organization and a sagittal malocclusionimprovement which lead to oropharyngeal space increase,facilitating a normal air flow [3]. Hence, maxillomandibularcorrection represents an important and effective treatment tosnoreandOSA duringchildhood,aspreviouslydemonstratedin children with 4 to 10 years treated with removable oralappliances during 6 months [4, 5].Recently, it has been suggested that the therapeutic inter-vention to correct skeletal abnormalities in children and ado-lescents notonly couldtreatthecurrent problems of snore andOSA during childhood and adolescence but also could have along-term effect, preventing these obstructive events even inadulthood [6]. The mechanism of this possible associationwould be the maxillomandibular correction persistence bythe morphological stabilizationofface growth and maturation.This hypothesis, however, still lacks objective evidences. Inthe studies of Villa and colleagues (2002) and Cozza andcolleagues (2004), the authors only observed the short-termeffectoforalappliancestreatingthesnoreandOSAanddidnotinvestigate the skeletal maxillomandibular correction in chil-drenanditsstabilization.Althoughtheimmediateoutcomesofthese treatments performed in the growing face are clinicallysatisfactory for snore and OSA, including significant changesin linear and volumetric dimensions of oropharyngeal spaces[3], the long-term effectiveness of this therapy is still unclear.Another possibility is that the maxillomandibular correctionduring childhood and adolescence could not persist until adult-hood, considering that the craniofacial pattern seems to have apredominant genetic determination (Fig. 1)[7]. In this case,evenpromotingtheadvancementofthemandibleduringchild-hood for treatment of skeletal abnormalities or of OSA andsnore, the genetic determination could contribute to a progres-sive return to the initial maxillomandibular disproportions in

Can we improve stroke rehabilitation after a circadian preference study

Individual circadian preferences represent the rhythmic expression of biological and behavioral patterns, such as the sleep– wake cycle (1). Several physiological parameters follow this intrinsic tendency. For instance, increased body temperature near the circadian acrophase is associated with improvement in motor and cognitive performances (2). In stroke patients, the possible trend of behavioral and motor-disability oscillations during daytime has been less studied. Data indicate that morningpreferring patients with cognitive impairments performed the worst when tested in the evening (nonpreferred time) during rehabilitation (3). Motor performance also exhibits a circadian pattern. Among inpatients in rehabilitation with neuromuscular disorders, longer durations of motor activity such as writing and walking were observed at 8 am, 11 am, and 11 pm (4). These findings suggest a possible influence of the circadian clock on cognitive performance and physical exercises during rehabilitation. Although the role of the circadian pattern in the onset of stroke is already well established (5), studies investigating the effectiveness of performing rehabilitation sessions during the preferred circadian time of patients after stroke are still warranted. We believe that individual circadian features could affect the motor and cognitive performances of stroke patients, influencing the time of recovery during rehabilitation. We strongly recommend that rehabilitation sessions should occur during the preferred period of stroke patients. Unfortunately, this is not always possible. Indeed, our public rehabilitation system is overloaded, and patient’s followup depends on the center’s availability. Thus, further investments and studies must be done to clarify the relationship between circadian preference and rehabilitation status in stroke patients. A rehabilitation schedule following circadian preferences may improve the stroke patient’s recovery, which could decrease treatment duration and lead to greater cost-effectiveness in the rehabilitation system.

New perspectives of iron deficiency as a risk factor for ischemic stroke.

Dear Editor, Stroke is the third leading cause of premature death in general population [1]. In childhood, the occurrence of stroke is less frequent than in adulthood; however, the mortality rate reaches 20 % in infants [2]. For instance, sickle cell disease, congenital cardiac disorders, traumatic lesions, and infections contribute to increase the odds for childhood stroke [3]. Recently, iron-deficiency anemia (IDA) has been also suggested as an important risk factor to ischemic cerebrovascular events [4, 5]. In this context, Azab et al. [6] performed a case–control study with 21 stroke children with median age of 36 months. They found a significant effect of IDA predicting stroke. The patients with IDA showed higher median platelet count compared to control and stroke with normal iron parameters groups. Consequently, children with IDA had 2.5-fold greater odds for ischemic stroke. These results suggest that IDA could be a more potent risk factor for perinatal stroke with similar magnitude than the others widely reported. The authors deserve congratulations for this study mainly for two reasons. Firstly, effective stroke treatments must be continuously investigated since the prevention of reversible risk factors is the most indicated therapy to avoid the occurrence and recurrence of stroke. Secondly, these findings may contribute to elucidate the different pathophysiological mechanism involved in the association of stroke and other disorders, such as the periodic limb movements (PLM) [7], for example. PLM is characterized by repeated movements of arms and/ or legs during sleep whose possible etiology comprises an iron deficiency and a consequent dysfunction in dopaminergic transmission [8]. Indeed, children with sickle cell disease showed a higher PLM prevalence than healthy patients [9]. PLM also increase the risk of ischemic stroke. The high prevalence of PLM after stroke may indicate a concomitant pathway of iron deficiency [7]. Indeterminate etiology of stroke can constitute approximately 37 % of all diagnosed patients [10]. Thus, further studies should be performed to analyze underestimated risk factors for stroke. New and common pathophysiological mechanisms of different diseases with stroke must be better understood. The investigations may contribute to elucidate part of the indeterminate stroke.