Literature search from ms 29/4/2010

Shea, S. A., L. P. Andres, et al. (1993). "Respiratory sensations in subjects who lack a ventilatory response to CO2." RESPIRATION PHYSIOLOGY 93(2): 203-19.

An urge to breath is perceived during breath hold and hypercapnia (termed 'air hunger') and during heavy exercise (often termed 'shortness of breath'). To better understand the neural mechanisms responsible for these sensations we studied five patients (8-17 years old) with congenital central hypoventilation syndrome (CCHS) who lack ventilatory response to CO2. CCHS patients reported no respiratory discomfort during CO2 inhalation or during maximal breath hold which was of much longer duration than age-matched controls. However, all 3 CCHS patients who exercised heavily reported some sensations akin to shortness of breath (they increased breathing nearly as much as controls). Our results are consistent with two possibilities. First, the air hunger of hypercapnia and breath hold is caused by projection to the forebrain of respiratory chemoreceptor afferents which bypass the respiratory centers, while exercise shortness of breath is caused by direct projections of limb afferents or locomotory center activity. Second, air hunger and shortness of breath share the same origin--projection of increased brain stem respiratory center motor activity (corollary discharge) to the forebrain.

Shields, M. (2005). "The journey to quitting smoking." HEALTH REPORTS 16(3): 19-36.

OBJECTIVES: This article outlines smoking trends over the past 10 years among the population aged 18 or older. Factors associated with smoking cessation and relapse are examined, as well as factors associated with having no intention of quitting in the next 6 months. DATA SOURCES: Data are from the household cross-sectional and longitudinal components of Statistics Canada's National Population Health Survey (1994/95 to 2002/03) (NPHS) and from the 2000/01 and 2003 Canadian Community Health Survey (CCHS). ANALYTICAL TECHNIQUES: Trends in smoking rates were calculated using cross-sectional data from the NPHS and the CCHS. Factors associated with cessation and relapsing were examined using pooling of repeated observations over two-year periods and logistic regression based on NPHS longitudinal data from 1994/95 to 2002/03. Factors associated with having no plans to quit were examined with logistic regression, based on 2003 CCHS cross-sectional data. MAIN RESULTS: In 2003, 19% of the Canadian population aged 18 or older smoked cigarettes daily, down 7 percentage points from a decade earlier. Smoking cessation, relapsing and having no plans to quit were all associated with addiction levels, notably, cigarettes smoked per day. Smoke-free homes and workplace smoking bans were associated with reduced cigarette consumption.

Shields, M. (2006). "Overweight and obesity among children and youth." HEALTH REPORTS 17(3): 27-42.

OBJECTIVES: This article describes the prevalence of overweight and obesity among Canadian children and youth aged 2 to 17, based on direct measurements of their height and weight. Data from 1978/79 and 2004 are compared, and trends by sex and age groups are presented. DATA SOURCES: Data based on direct measurements are from the 2004 Canadian Community Health Survey (CCHS): Nutrition. Other information is from the 1978/79 Canada Health Survey and the 1999-2002 National Health and Nutrition Examination Survey, conducted in the US. ANALYTICAL TECHNIQUES: The estimated prevalence of overweight and of obesity, including an overall rate reflecting both, was based on 2004 CCHS data for 8,661 children and youth whose height and weight were measured. MAIN RESULTS: In 2004, 26% of Canadian children and adolescents aged 2 to 17 were overweight or obese, and 8% were obese. Over the past 25 years, the prevalence of overweight and obesity combined has more than doubled among youth aged 12 to 17, while the prevalence of obesity alone has tripled. Children and youth who ate fruit and vegetables at least five times a day were substantially less likely to be overweight or obese than were those who ate these foods less often. The likelihood of being overweight/obese rose as "screen time" (watching TV, playing video games or using a computer) increased.

Shields, M., S. C. Gorber, et al. (2008). "Effects of measurement on obesity and morbidity." HEALTH REPORTS 19(2): 77-84.

OBJECTIVES: This article compares associations between body mass index (BMI) categories based on self-reported vers measured data with selected health conditions. The goal is to see if the misclassifications resulting from the use of self-reported data alters associations between excess body weight and these health conditions. METHODS: The analysis is based on 2,667 respondents aged 40 years or older from the 2005 Canadian Community Health Survey (CCHS) who, during a face-to-face interview, provided self-reported values for height and weight and were then measured by trained interviewers. Multiple logistic regression analysis was used to examine associations between BMI categories (based on self-reported and measured data) and obesity-related health conditions. RESULTS: On average, BMI based on self-reported height and weight was 1.3 kg/m2 lower than BMI based on measured values. Consequently, based on self-reported data, a substantial proportion of individuals with excess body weight were erroneously placed in lower BMI categories. This misclassification resulted in elevated associations between overweight/obesity and morbidity.

Shields, M., S. C. Gorber, et al. (2008). "Estimates of obesity based on self-report versus direct measures." HEALTH REPORTS 19(2): 61-76.

OBJECTIVES: Based on a representative sample of the Canadian population, this article quantifies the bias resulting from the use of self-reported rather than directly measured height, weight and body mass index (BMI). METHODS: The analysis is based on 4,567 respondents to the 2005 Canadian Community Health Survey (CCHS) who, during a face-to-face interview, provided self-reported values for height and weight and were then measured by trained interviewers. RESULTS: On average, males over-reported their height by 1 cm, and females, by 0.5 cm. Females under-reported their weight by an average of 2.5 kg; males, by 1.8 kg. Reporting bias in weight was strongly associated with measured BMI category. Under-reporting of weight was high among people who were overweight, and particularly high among those who were obese, compared with people of normal weight. When based on measured rather than on self-reported values, the prevalence of obesity was 9 percentage points higher among males and 6 points higher among females.

Shields, M. and K. Wilkins (2009). "An update on mammography use in Canada." HEALTH REPORTS 20(3): 7-19.

BACKGROUND: This article updates mammography use by Canadian women aged 50 to 69, and reports trends from 1990 to 2008 among the provinces. Characteristics of non-users are examined. DATA SOURCES AND METHODS: Data from the 2008 Canadian Community Health Survey (CCHS) were used to update mammography use and to examine factors associated with non-use. Historical estimates were produced using the 2000/2001,2003 and 2005 CCHS, the 1994/1995, 1996/1997 and 1998/1999 National Population Health Survey and the 1990 Health Promotion Survey. Frequency estimates, cross-tabulations and logistic regression analysis were used. RESULTS: In 2008, 72% of women aged 50 to 69 reported having had a mammogram in the past two years, up from 40% in 1990. The increase occurred from 1990 to 2000/2001; rates then stabilized. Between 1990 and 2000/2001, the difference in participation between women in the highest and lowest income quintiles gradually narrowed-from a 26- to a 12-percentage-point difference. In 2008, the disparity widened to 18 percentage points. Non-use was high in British Columbia, Prince Edward Island and Nunavut. Non-use was associated with being an immigrant, living in a lower income household, not having a regular doctor and smoking.

Shih, H. N., C. T. Hong, et al. (2003). "Medullary Infarction with Central Hypoventilation (Ondine's Curse): A Case Report." Acta Neurologica Taiwanica 12(4): 201-204.

Ondine's curse, also termed central alveolar hypoventilation, presents as hypoventilation or total loss of automatic ventilation with progressive hypercapnia and hypoxia during sleep. This syndrome is often associated with large medullary infarction, Hirschsprung disease and ganglioneuroblastoma. We report a 75-year-old man with right lateral medullary infarction who presented with apnea and cyanosis suddenly during sleep on the third day of admission. Due to bradycardia (HR: 22) and decreased SaO2 (22%) he was intubated with ventilator support. Two and half months later, the patient could finally breathe without ventilator support, although his neurological deficit was just as that before intubation. Ondine's curse as a result of acute medullary dysfunction was the most likely etiology causing sudden cyanosis and apnea of this patient. Close monitoring and adequate ventilation support are important for patients at risk of developing Ondine's curse.

Shoba, T., S. T. Dheen, et al. (2002). "Retinoic acid influences Phox2 expression of cardiac ganglionic cells in the developing rat heart." NEUROSCIENCE LETTERS 321(1-2): 41-44.

We have studied the expression of the homeodomain transcriptional neuronal regulators Phox2a, Phox2b and the non-neuronal Schwann cell response using the marker S-100 in the differentiating phase of cardiac ganglionic cells in rat embryos following exogenous retinoic acid (RA) treatment of pregnant dams. In control embryos, the expression of Phox2b (E11) preceded that of Phox2a, which, along with the terminal neuronal differentiation marker PGP9.5, was expressed from E12 onwards. Phox2b expression remained unchanged in the differentiated phase of cardiac ganglionic cell development after RA treatment, whereas the population of cells expressing Phox2a, PGP9.5 and S-100 was diminished. These results suggest that RA disrupts the differentiation of cardiac neural crest cells into ganglionic cells destined to contribute to the parasympathetic innervation of the heart, by regulating the expression of Phox2a and Phox2b. copyright 2002 Elsevier Science Ireland Ltd. All rights reserved.

Shteinberg, M. and Y. Edoute (2000). "[Central alveolar hypoventilation in adults--Ondine's curse]." HAREFUAH 138(3): 234-6.

Shuman, L. and D. Youmans (2005). "Haddad syndrome: a case study." Neonatal Network - Journal of Neonatal Nursing 24(4): 41-4.

Hirschsprung's disease (HD), also known as congenital aganglionic megacolon, is a relatively common cause of congenital obstruction of the colon. Congenital central hypoventilation syndrome (CCHS), also known as Ondine's curse, is a rare condition involving failed autonomic respiration in the absence of cardiorespiratory disease resulting in inadequate alveolar ventilation. Both conditions typically present in the newborn period and belong to a group of disorders referred to as neurocristopathies. HD and CCHS most commonly exist as discrete entities, but the coexistence of them is now called Haddad syndrome. Although few documented cases of Haddad syndrome exist in the literature, the association of CCHS and HD suggests a common etiology involving neural crest development. [References: 11]
Silvestri, J. M. (1997). "Long-term outcome of children with congenital central hypoventilation syndrome." PEDIATRIC PULMONOLOGY 23(2): 161-168.

Published data show prolonged survival of children with CCHS as well as overall good quality of life. Long-term follow-up and neurodevelopmental outcome reveal a broad range of results, with a great deal of variability. Many children demonstrate findings that may be related to sequelae of intermittent hypoxemia. Thus it is difficult to determine whether neurodevelopmental outcome is related to a diffuse central nervous system process specific to CCHS or is a sequela of intermittent hypoxemia. Therefore, it is strongly recommended that children with CCHS be managed at centers that have a broad experience with CCHS to optimize outcome. These data emphasize the importance of early diagnosis and ongoing vigilant care in the day-to-day management of these special children with CCHS.

Silvestri, J. M., M. L. Chen, et al. (2002). "Idiopathic congenital central hypoventilation syndrome: the next generation." AMERICAN JOURNAL OF MEDICAL GENETICS 112(1): 46-50.

Idiopathic congenital central hypoventilation syndrome (CCHS) is a rare disorder in which affected children have a decreased sensitivity of their respiratory centers to hypercarbia and hypoxia, as well as evidence for generalized autonomic nervous system dysfunction. A genetic origin has long been hypothesized for CCHS. Previous reports of the syndrome among twins, siblings, and half siblings, as well as an established association with Hirschsprung disease and neural crest tumors support this genetic hypothesis. Here, we present the first reported offspring born to four women diagnosed with idiopathic CCHS. Their children display a spectrum of abnormalities with one child being diagnosed with CCHS, one child with recurrent apparent life threatening events, one infant born prematurely with severe chronic lung disease and diminished ventilatory responses to carbon dioxide, and one infant who is apparently healthy with no clinical manifestations suggestive of disordered respiratory control to date. Two and potentially three of these patients illustrate transmission of altered respiratory control by CCHS patients into the next generation, furthering the evidence that CCHS is part of a broadly based inherited syndrome of autonomic nervous system dysfunction. Copyright 2002 Wiley-Liss, Inc.

Silvestri, J. M., B. D. Hanna, et al. (2000). "Cardiac rhythm disturbances among children with idiopathic congenital central hypoventilation syndrome." PEDIATRIC PULMONOLOGY 29(5): 351-8.

The objective of this study was to determine whether subjects with congenital central hypoventilation syndrome (CCHS) had an increased frequency of cardiac arrhythmias and decreased heart rate variability when compared to subjects without a known deficit in control of breathing, and that these abnormalities would be exaggerated by anesthesia. Continuous ambulatory Holter recordings were obtained in patients with CCHS and compared to two otherwise healthy control groups without a deficit in control of breathing: one with an intact airway (n = 11) and a second group with a tracheostomy (n = 6). Holter recordings were obtained before, during (under general anesthesia), and after bronchoscopy. Fourteen children with CCHS (age: 9.3 +/- 4.4 years mean +/- S.D.) were studied, and 7 underwent bronchoscopy. Seventeen control children were studied (age 6.6 +/- 3.6 years): 11 without a tracheostomy, and 6 with a tracheostomy who also underwent bronchoscopy. Maximum heart rate during baseline recording was significantly lower in the CCHS subjects as compared to controls (P = 0.0001). At baseline the difference in the number of arrhythmias/24 hr/subject in all CCHS vs. all control subjects was significant (P = 0.0002); for the subjects who had bronchoscopy, CCHS vs. control, the difference was also significant (P = 0.03). In addition, there was a significant decrease in the number of events/24 hr/subject among the CCHS subjects between baseline and post-bronchoscopy (P = 0.0288). The predominant arrhythmias were sinus bradycardia and transient asystole. The longest asystole in a CCHS subject was 6.50 sec, and in a control subject, 1.42 sec (at baseline the means of the longest asystole were 2.69 +/- 1.4 vs. 1.24 +/- 0.13; P = 0.003 in the CCHS vs. control groups). Other indices of heart rate variability were significantly reduced in the CCHS subjects (P < 0.05). These results substantiate our hypothesis that subjects with CCHS have more arrhythmias than controls, an increased frequency of bradyarrhythmias, and decreased cyclical sinus arrhythmia. Copyright 2000 Wiley-Liss, Inc.

Silvestri, J. M. and D. E. Weese-Mayer (1996). "Respiratory control disorders in infancy and childhood." CURRENT OPINION IN PEDIATRICS 8(3): 216-20.

Current contributions to the literature on disorders of respiratory control in infancy and childhood are reviewed. These encompass studies of cardiorespiratory control in preterm and term infants, apparent life-threatening events in infants, and obstructive sleep apnea including etiology, diagnosis, and alternatives to surgical management. In addition, alveolar hypoventilation is discussed in children with congenital central hypoventilation syndrome, myelomeningocele, and Prader-Willi syndrome. [References: 44]

Silvestri, J. M., D. E. Weese-Mayer, et al. (1995). "Congenital central hypoventilation syndrome: cardiorespiratory responses to moderate exercise, simulating daily activity." PEDIATRIC PULMONOLOGY 20(2): 89-93.

Children with congenital central hypoventilation syndrome (CCHS) lack normal awake ventilatory responses to hypoxia and hypercarbia, yet engage in daily activities typical of similarly aged children. Our patients with CCHS are assessed annually with a walking treadmill protocol to assess physiologic responses to different levels of simulated daily activity. We hypothesized that children with CCHS (compared with age- and sex-matched healthy controls) would 1) exercise for shorter durations and reach lower peak speed and incline on the treadmill; 2) become more hypoxemic, more hypercarbic, and develop less tachycardia during activity; and 3) take longer to return to baseline oxygenation, ventilation, and heart rate than normal children. Seven children with CCHS [mean age, 6.9 +/- 3.0 (SD) years] who required 24 h/day ventilatory support (diaphragm pacers while awake and mechanical ventilation asleep) and 7 controls performed a walking protocol on a treadmill with progressive increments in speed and incline. Hemoglobin saturations (SaO2), end-tidal carbon dioxide concentrations (ETCO2), and heart rates (HR) were recorded at baseline conditions, during activity and during recovery. There were no significant differences between children with CCHS and controls in baseline values, duration of activity, peak speed, and incline achieved during walking and recovery time to baseline once the treadmill had stopped. However, children with CCHS became significantly more hypoxemic and hypercarbic during activity (P < 0.05), and they had a lower percent increase in HR during treadmill walking than controls (P < 0.05). These results offer the clinician an opportunity to adjust clinical management in children with CCHS by providing specific recommendations to parents about appropriate levels of activity for their children with CCHS.(ABSTRACT TRUNCATED AT 250 WORDS)

Silvestri, J. M., D. E. Weese-Mayer, et al. (1991). "Erratum: Congenital central hypoventilation syndrome: A diffuse central nervous system process (Am Rev Respir Dis)." American Review of Respiratory Disease 143(6): 1473.

Silvestri, J. M., D. E. Weese-Mayer, et al. (1992). "Neuropsychologic abnormalities in children with congenital central hypoventilation syndrome." JOURNAL OF PEDIATRICS 120(3): 388-93.

We hypothesized that intellectual, neurodevelopmental, and visual-motor tests would be able to characterize the scope and nature of central nervous system involvement in children with congenital central hypoventilation syndrome. Age-appropriate intellectual (Brazelton Neonatal Behavioral Assessment, Bayley Scales of Infant Development, Wechsler Preschool and Primary Scale of Intelligence-Revised and Wechsler Intelligence Scale for Children--Revised), neurodevelopmental (Halsted-Reitan neuropsychologic battery), and visual-motor (Beery visual-motor integration test) tests were given to 17 children with congenital central hypoventilation syndrome (age 0.1 to 14.3 years). We found a broad range in IQ and developmental quotient, from greater than the 85th percentile to less than the 5th percentile, with discrepancies noted between verbal and performance measures. Multiple asymmetries and deficiencies of motor performance, not consistently related to handedness, were also found. Significant eye-hand coordination deficits were uncommon, but general performance was well below average. Full, verbal, and performance IQs and developmental quotients greater than or equal to 70 and less than 70 were compared by chi-square analysis with other associated conditions, including hours of ventilatory support, duration of initial hospitalization, growth, pulmonary hypertension, seizures, brain atrophy, central and peripheral hearing deficits, and ophthalmologic abnormalities; no statistically significant associations were found. These results lend support to the hypothesis that congenital central hypoventilation syndrome is a diffuse central nervous system process. However, the effects of transient hypoxia and associated conditions on neurodevelopmental test results cannot be excluded with certainty.
Silvestri, R., P. De Domenico, et al. (1994). "Parasomnias as possible cause of insomnia. [Italian]." Neurologia Psichiatria Scienze Umane 14(2): 319-328.

Those parasomnias susceptible to cause insomnias are taken into account. In particular they may be subdivided into the sleep-wake transition disorders (rhythmic movements, nocturnal leg cramps), REM parasomnias (nightmares, sleep-related painful erections, REM sleep behaviour disorder) and parasomnias which are not specifically linked to any sleep phase (bruxism, sleep related abnormal swallowing syndrome, nocturnal paroxysmal dystonia and congenital central hypoventilation syndrome). All the above mentioned syndromes are briefly dealt with, regarding the etiological and clinical aspects and their possible interaction with physiological sleep, whether they might interfere with sleep onset, continuity or final awakening from sleep.

Singh, M. A., W. Ding, et al. (1999). "Insulin-like growth factor I in skeletal muscle after weight-lifting exercise in frail elders." The American journal of physiology(1 Pt 1): E135-43.

To assess muscle remodeling and functional adaptation to exercise and diet interventions, 26 men and women aged 72-98 yr underwent a vastus lateralis biopsy before and after placebo control condition, and progressive resistance training, multinutrient supplementation, or both. Type II atrophy, Z band, and myofibril damage were present at baseline. Combined weight lifting and nutritional supplementation increased strength by 257 +/- 62% (P = 0.0001) and type II fiber area by 10.1 +/- 9.0% (P = 0.033), with a similar trend for type I fiber area (+12.8 +/- 22.2%). Exercise was associated with a 2. 5-fold increase in neonatal myosin staining (P = 0.0009) and an increase of 491 +/- 137% (P < 0.0001) in IGF-I staining. Ultrastructural damage increased by 141 +/- 59% after exercise training (P = 0.034). Strength increases were largest in those with the greatest increases in myosin, IGF-I, damage, and caloric intake during the trial. Age-related sarcopenia appears largely confined to type II muscle fibers. Frail elders respond robustly to resistance training with musculoskeletal remodeling, and significant increases in muscle area are possible with resistance training in combination with adequate energy intakes.

Sirtori, V., D. Corbetta, et al. (2009) Constraint-induced movement therapy for upper extremities in stroke patients. Cochrane Database of Systematic Reviews Volume, DOI: 10.1002/14651858.CD004433.pub2

BACKGROUND: In stroke patients, upper limb paresis affects many activities of daily life. Reducing disability is therefore a major aim of rehabilitation programmes for hemiparetic patients. Constraint-induced movement therapy (CIMT) is a current approach to stroke rehabilitation that implies the forced use and the massed practice of the affected arm by restraining the unaffected arm. OBJECTIVES: To assess the efficacy of CIMT, modified CIMT (mCIMT), or forced use (FU) for arm management in hemiparetic patients. SEARCH STRATEGY: We searched the Cochrane Stroke Group trials register (last searched June 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2008), MEDLINE (1966 to June 2008), EMBASE (1980 to June 2008), CINAHL (1982 to June 2008), and the Physiotherapy Evidence Database (PEDro) (June 2008). SELECTION CRITERIA: Randomised control trials (RCTs) and quasi-RCTs (qRCTs) comparing CIMT, mCIMT or FU with other rehabilitative techniques, or none. DATA COLLECTION AND ANALYSIS: Two review authors independently classified the identified trials according to the inclusion and exclusion criteria, assessed methodological quality and extracted data. The primary outcome was disability. MAIN RESULTS: We included 19 studies involving 619 participants. The trials included participants who had some residual motor power of the paretic arm, the potential for further motor recovery and with limited pain or spasticity, but tended to use the limb little if at all. Only five studies had adequate allocation concealment. The majority of studies were underpowered (median number of included patients was 15) and we cannot rule out small-trial bias. Six trials (184 patients) assessed disability immediately after the intervention, indicating a significant standard mean difference (SMD) of 0.36, 95% confidence interval (CI) 0.06 to 0.65. For the most frequently reported outcome, arm motor function (11 studies involving 373 patients), the SMD was 0.72 (95% CI 0.32 to 1.12). There were only two studies that explored disability improvement after a few months of follow up and found no significant difference, SMD -0.07 (95% CI -0.53 to 0.40). AUTHORS' CONCLUSIONS: CIMT is a multifaceted intervention: the restriction to the normal limb is accompanied by a certain amount of exercise of the appropriate quality. It is associated with a moderate reduction in disability assessed at the end of the treatment period. However, for disability measured some months after the end of treatment, there was no evidence of persisting benefit. Further randomised trials, with larger sample sizes and longer follow up, are justified. CONSTRAINT-INDUCED MOVEMENT THERAPY FOR UPPER EXTREMITIES IN STROKE PATIENTS: Paralysis of an arm after a stroke makes arm movements, such as reaching, grasping, and manipulating an object difficult. In turn, this causes many difficulties in activities of daily life, such as bathing, dressing, eating, and toileting. Constraint-induced movement therapy (CIMT) is a type of rehabilitation therapy in which the patient is obliged to use the paralysed arm. The normal arm and hand are prevented from moving with a glove and a special arm rest. We found 19 studies involving 619 participants, which assessed whether CIMT could reduce disability in stroke patients with a paralysed arm. Patients were included in the studies if they had good potential for recovery but tended not to use the arm. At the end of the treatment period, compared with exercise without constraint, CIMT improved the patient's ability to manage activities of daily living, but there was no evidence that this improvement was maintained over the next six months. Further larger trials to assess whether CIMT provides lasting benefit are justified.