Sleep Disorders and Down Syndrome Abstracts

Arch Otolaryngol Head Neck Surg 132 (4): 432-6 (2006 April)

Obstructive Sleep Apnea. Should All Children With Down Syndrome Be Tested?

Sally R. Shott; Raouf Amin; Barbara Chini; Christine Heubi; Stephanie Hotze; Rachel Akers
Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio

Objectives. To determine the incidence of obstructive sleep apnea syndrome in children aged 2 to 4 years with Down syndrome and to determine parents' ability to predict sleep abnormalities in this patient population. Design. Prospective cohort study. Setting. Tertiary care pediatric referral center. Patients. Sixty-five children participating in a 5-year longitudinal study in which the otolaryngologic problems seen in Down syndrome were evaluated. Fifty-six completed overnight polysomnography (PSG) between 4 and 63 months of age (mean age, 42 months). Interventions. Overnight PSG was performed. Parents also completed a questionnaire regarding their impressions of their child's sleep patterns before PSG. Main Outcome Measures. Polysomnograms were classified as abnormal if the obstructive index was greater than 1, if the carbon dioxide level was greater than 45 mm Hg for more than two thirds of the study or greater than 50 mm Hg for more than 10% of the study, and/or if there was unexpected hypoxemia less than 92% during sleep or repeated intermittent desaturations less than 90%. We also identified a group of children whose PSGs findings were normal except for an arousal index greater than 10 and were associated with increased work of breathing. Results. The PSGs revealed that 57% of the children had abnormal results and evidence of obstructive sleep apnea syndrome. If we also include an elevated arousal index, 80% of the PSGs had abnormal results. Sixty-nine percent of parents reported no sleep problems in their children, but in this group, 54% of PSGs had abnormal results. Of the parents who reported sleep problems in their children, only 36% had abnormal sleep study results. Conclusion. Because of the high incidence of obstructive sleep apnea syndrome in young children with Down syndrome, and the poor correlation between parental impressions of sleep problems and PSG results, baseline PSG is recommended in all children with Down syndrome at age 3 to 4 years.
Am J Roentgenol 183: 175-181 (2004)

Causes of Persistent Obstructive Sleep Apnea Despite Previous Tonsillectomy and Adenoidectomy in Children with Down Syndrome as Depicted on Static and Dynamic Cine MRI

Lane F. Donnelly1,2, Sally R. Shott3, Connor R. LaRose1, Barbara A. Chini2,4 and Raouf S. Amin2,4
1 Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039
2 Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039
3 Department of Otolaryngology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039
4 Department of Pulmonology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229-3039

OBJECTIVE. Our purpose was to evaluate the causes of persistent obstructive sleep apnea despite previous tonsillectomy and adenoidectomy in children with Down syndrome as depicted on cine MRI. MATERIALS AND METHODS. Cine MRI studies performed to evaluate persistent obstructive sleep apnea despite previous tonsillectomy and adenoidectomy were reviewed. MRI was performed under sedation and included cine MR images (fast gradient-echo) obtained in the midline sagittal plane and in the axial plane at the base of the tongue and T1-weighted spin-echo and fast spin-echo inversion recovery images in the axial and sagittal planes. Imaging parameters reviewed included static and dynamic diagnoses made, frequency of recurrence and diameter of tonsillar tissue, and tongue morphology. RESULTS. Twenty-seven patients were identified (mean age, 9.9 years). Diagnoses included glossoptosis in 17 patients (63%), hypopharyngeal collapse in six (22%), recurrent and enlarged adenoid tonsils in 17 (63%), enlarged lingual tonsils in eight (30%), and macroglossia in 20 (74%). Of the 20 patients with macroglossia, 11 (55%) had absence of the normal median sulcus and 12 (60%) had evidence of fatty infiltration of the tongue musculature. CONCLUSION. Persistent obstructive sleep apnea in children with Down syndrome who have undergone previous adenoidectomy and tonsillectomy has multiple causes. The most common causes include macroglossia, glossoptosis, recurrent enlargement of the adenoid tonsils, and enlarged lingual tonsils.
J Pediatr 134 (6): 755-760 (1999 Jun)

Sleep Characteristics in Children with Down Syndrome

Levanon A, Tarasiuk A, Tal A
Sleep Wake Disorders Unit, Department of Physiology, and Department of Pediatrics and Pediatric Pulmonary Unit, Soroka Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel

BACKGROUND: Obstructive sleep apnea syndrome is common in children with Down syndrome (DS). Little is known about sleep patterns, especially arousals, awakenings, and movements during sleep in children with DS. OBJECTIVE: To determine the characteristics of sleep disorders in children with DS and to define the associations between respiratory disturbance and arousals, awakenings, and movements. METHODS: The study included 23 children with DS, compared with 13 children with primary snoring. All underwent a 6- to 8-hour sleep study. RESULTS: The respiratory disturbance index was significantly higher in the children with DS. Sleep was significantly fragmented in children with DS, who had a significantly higher arousal/awakening (A/Aw) index (24.6 ± 7.9 events/h) compared with the comparison group (17.6 ± 4.0 events/h). A higher percentage of jerks associated with A/Aw and respiratory event-associated A/Aw was observed in patients with DS (45.2% ± 25% and 8.6% ± 6.4%, respectively) compared with the control patients (10.2% ± 4.5% and 1.5% ± 2.1%). The median length of occurrences of stage 2 sleep was 27% shorter in the DS group. The number of shifts from "deeper" to "lighter" stages of non-rapid eye movement sleep was 30% greater in the DS group. CONCLUSION: Children with DS have significant sleep fragmentation, manifested by frequent awakenings and arousals, which are only partially related to obstructive sleep apnea syndrome.
J Sleep Res 7 (4): 282-7 (1998 Dec)

Heart rate variability and apnea during sleep in Down's syndrome

Ferri R, Curzi-Dascalova L, Del Gracco S, Elia M, Musumeci SA, Pettinato S
Department of Neurology, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy

Autonomic system dysfunction has been reported to occur frequently in patients with Down's syndrome (DS) and is constituted mainly by an imbalance between the sympathetic and vagal systems. The analysis of heart rate variability (HRV) during sleep is a quantitative reliable method for studying such a mechanism, but it has not yet been extensively and adequately applied in DS. In this study, HRV during sleep was evaluated in seven DS patients and in six normal controls, by also controlling for the presence of sleep apnea or arousal. The main results were an increased sympathetic function (low-frequency component of HRV) and a decreased vagal activity (high-frequency component of HRV) in DS with respect to normal controls, during apnea-free periods. Moreover, the presence of apnea, in DS, induced a further significant increase in low-frequency and very low-frequency components of HRV during sleep Stage 2. This study provides additional evidence of a brainstem dysfunctioning in DS, responsible for the abnormal imbalance between the sympathetic and vagal systems and confirms the brainstem involvement already suggested in the literature in order to explain brainstem-auditory evoked potential abnormalities and central sleep apnea in these patients.
Down's Syndrome: Research and Practice 5 (3): 105-110 (1998)

Sleep neurophysiopathology in Down syndrome

Raffaele Ferri, Lilia Curzi-Dascalova, Stefano Del Gracco, Maurizio Elia, Salvatore Pettinato, and Sebastiano Musumeci

In this paper, research on sleep characteristics of subjects with Down syndrome is briefly reviewed and some new data on autonomic function during sleep are reported. Subjects with Down syndrome show a significant reduction in percentage of REM sleep (probably more evident in the most severely retarded subjects), a marked delay in first REM latency and a statistically significant decrease in high-frequency rapid eye movements during REM sleep. The percentage of REM sleep in humans can be considered as an index of brain "plasticity" and the high-frequency REMs can represent an index of the brain ability to organize information; thus, these studies have provided a neurophysiological basis to a psychopedagogical approach for the treatment of learning and memory disabilities in Down syndrome. Moreover, children with Down syndrome show a clearly decreased peak amplitude of growth hormone during sleep; this causes the poor physical development in these subjects and might be related to the occurrence of sleep apnea. Obstructive sleep apnea has also been repeatedly reported in these children; however, if obvious risk factors are absent, children with Down syndrome tend to show the presence of central sleep apnea which is caused by a probable dysfunction of autonomic control at a brainstem level.
J Sleep Res 6 (2): 134-41 (1997 Jun)

Respiratory patterns during sleep in Down's syndrome:importance of central apnoeas

Ferri R, Curzi-Dascalova L, Del Gracco S, Elia M, Musumeci SA, Stefanini MC
Department of Neurology, Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy

Obstructive sleep apnoea episodes have been reported repeatedly in Down's syndrome (DS) patients as a consequence of the presence of predisposing malformations or intercurrent pathology of the upper airways. There are no data on respiratory patterns of uncomplicated Down's syndrome subjects. In order to evaluate the eventual effects of central nervous system (CNS) impairment on respiration in DS, we studied the respiratory patterns during sleep of a group of 10 DS subjects, aged 8.6-32.2 y, without relevant upper airway pathology. In order to control the possible effects of sleep structure and mental retardation on the results obtained, we compared the findings in DS with those obtained from a group formed by subjects affected by fragile X syndrome (six males and one female, aged 10.0-15.42 y) another genetically determined type of mental retardation. Sleep structure was similar in both groups; however, DS subjects showed significantly higher indices of central sleep apnoea and of oxygen desaturation than fragile X patients (P > 0.005). As far as DS individuals were considered, a significant preponderance of central, as opposed to obstructive, sleep apnoeas was found (89.4% vs. 9.4%, respectively; 1.2% were mixed) which showed a significant age-related increase. Central respiratory pauses were mostly preceded by sighs, which occurred more frequently during sleep stages 1 and REM, and were often organized in long sequences of periodic-like breathing. During REM sleep, they were less frequently preceded by sighs and by body movements than during NREM sleep. Obstructive sleep apnoeas occurred more often during REM sleep and were more rarely preceded by sighs or by body movements. Both central and obstructive apnoeas induced significant oxygen desaturation in 50-69.6%. Sleep structure was not significantly modified by apnoeas and oxygen desaturation. We hypothesize that the increase in central sleep apnoeas is related to a dysfunction of the central respiratory control at a brainstem level in DS.
Plast Reconstr Surg 99 (3): 629-37 (1997 Mar)

Down syndrome: identification and surgical management of obstructive sleep apnea

Lefaivre JF; Cohen SR; Burstein FD; Simms C; Scott PH; Montgomery GL; Graham L; Kattos AV
Center for Craniofacial Disorders, Scottish Rite Children's Medical Center, Atlanta, GA, USA

To date, a paucity of information is available on the optimal management of obstructive sleep apnea in Down syndrome, which may have particularly important implications in this already vulnerable patient population. The objective of this study was to evaluate prospectively the results of a new surgical approach for the treatment of obstructive sleep apnea. Patients with Down syndrome and obstructive sleep apnea underwent preoperative and postoperative polysomnography and clinical and radiologic evaluation to determine prospectively the efficacy of sleep apnea surgery. Statistical testing of apnea index, respiratory disturbance index, and lowest oxygen saturation were compared by means of paired t tests. Seven children (five boys, two girls) from 3 to 12 years of age were subjected to a management protocol that included an aggressive surgical approach to the treatment of obstructive sleep apnea. Clinical symptoms and signs of obstructive sleep apnea, apnea index, respiratory disturbance index, lowest oxygen saturation, and surgical morbidity were the main outcome measures. Surgical treatment consisted of a combination of soft-tissue and skeletal alterations including tongue reduction (n = 6), tongue hyoid advancement (n = 4), uvulopalatopharyngoplasty (n = 7), and maxillary or midface advancement (n = 2). Polysomnography was obtained preoperatively and postoperatively in six patients. One patient was intubated preoperatively. Mean preoperative apnea index and respiratory disturbance index were 34.00 and 52.46 compared with mean postoperative values of 1.62 and 6.46, respectively. Clinically, all patients were improved symptomatically in terms of snoring, noisy breathing, and oxygen requirements. The one patient who had been intubated preoperatively for respiratory failure was extubated successfully but later developed recurrent tricuspid regurgitation and was found to have fixed pulmonary hypertension with cor pulmonale. This patient represented the only treatment failure and underwent tracheostomy. An aggressive surgical approach aimed at correcting all anatomic abnormalities associated with upper airway obstruction was applied successfully to the treatment of obstructive sleep apnea in Down syndrome. We suggest periodic polysomnography in patients with Down syndrome, especially if there is unexplained deterioration in mental capacity or other signs and symptoms of obstructive sleep apnea. Surgical treatment should address both the soft-tissue abnormalities and the skeletal deformities such as midface retrusion. Preoperative cardiac ultrasonography is important to determine the presence of right-sided heart failure, which may be an indication for cardiac catheterization to determine pulmonary venous pressures.
Arch Otolaryngol Head Neck Surg 112 (9): 945-950 (1996 Sept)

Upper Airway Obstruction in Children With Down Syndrome

Ian N. Jacobs, MD; Robert F. Gray, MD; N. Wendell Todd, MD
Division of Otolaryngology, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA

Objective: To analyze the complex nature of upper airway obstruction (UAO) and the response to surgery in children with Down syndrome. Design: Retrospective medical chart review of all patients with Down syndrome who had UAO during a 5-year period. Setting: Academic tertiary care children's hospital. Patients: Seventy-one pediatric patients with Down syndrome who had significant UAO. Thirty-four patients had pulmonary artery hypertension; 44 patients had multiple sites of airway obstruction. The obstructive problems included lymphoid hyperplasia, macroglossia, narrow nasopharynx, laryngomalacia, congenital subglottic stenosis, tracheobronchomalacia, and tracheal stenosis. Interventions: Children with Down syndrome and UAO underwent surgical procedures including tonsillectomy, adenoidectomy, tonsillar pillar plication, uvulopalatopharyngoplasty, anterior tongue reduction, tongue-hyoid suspension, laryngotracheoplasty, and tracheotomy. ain Outcome Measures: Postoperative symptoms found on medical chart review, or parental telephone survey, or both, and results of postoperative diagnostic tests. Patients were grouped as "improved" or having "significant residual symptoms." Results: Twenty-seven of the 55 surgical patients had mild obstructive symptoms, and most improved after tonsil or adenoid surgery, or both. The remaining patients were younger and had more severe symptoms, multiple sites of obstruction, and a high incidence of cardiac disease. Eleven (39%) of the 28 patients in this group had significant residual symptoms after surgery. Four children are tracheotomy-dependent. Five deaths occurred; 3 were attributable to the upper airway. Conclusions: Upper airway obstruction in children with Down syndrome often is a complex process with multifocal causes. Residual symptoms of airway obstruction are common after surgery. A comprehensive and individualized approach is important in the management of UAO in Down syndrome.
Down's Syndrome: Research and Practice 4 (3): 110-112 (1996)

Research on sleep problems and psychological function in children with Down syndrome: Implications for clinical practice and everyday care

Rebecca Stores and Gregory Stores

Research has been carried out in the last few years on the sleep problems of children with Down syndrome and the associations between these problems, learning, behaviour and family factors. The children studied were generally of school age and attending either mainstream or special schools. The research programme, which has involved a number of novel approaches to these neglected problems, has raised various issues which call for further investigation but the main findings already have implications for the care by both professionals and parents of children with Down syndrome. This account describes in general terms such findings and implications. Further details are available in the selected references provided.
Int J Pediatr Otorhinolaryngol 33 (2): 141-8 (1995 Oct)

Tonsillectomy and adenoidectomy in patients with Down syndrome

Bower CM, Richmond D
Department of Pediatric Otolaryngology, Arkansas Children's Hospital, Little Rock 72202, USA

Tonsillectomy and adenoidectomy in patients with Down syndrome usually relieves symptoms of upper airway obstruction due to adenotonsillar hypertrophy. A retrospective review of 16 patients with Down syndrome who underwent a tonsillectomy and adenoidectomy was conducted to define early postoperative morbidity, and to evaluate the results of the procedure. Fifteen of 16 patients had upper airway obstruction manifest by adenotonsillar hypertrophy. One had adenoid hypertrophy only. Tonsillectomy and adenoidectomy (13), adenoidectomy (1), tonsillectomy (1), and UP3/adenoidectomy (1) were performed on these patients. Four patients (25%) required observation in an intensive care setting the first night. An average hospital stay of 2.1 days was noted with a range of 0 to 7 days. Significant postoperative apnea was common, and oxygen was used in over 60% of patients. Symptoms were resolved in 69% of patients at last follow up. In conclusion, tonsillectomy and adenoidectomy can be a useful procedure for children with Down syndrome and obstructive sleep apnea, however overnight hospitalization for observation and treatment of persistent apnea is appropriate.
Down's Syndrome: Research and Practice 1 (2): 72-4 (1993)

Sleep problems in children with Down syndrome: A summary report

Rebecca Stores

This article presents a summary of the findings of the first part of a research programme being carried out at The Sarah Duffen Centre in Portsmouth. The findings will be published in full in the future. It follows an article published in the last edition of the journal entitled "A preliminary study of sleep disorders and daytime behaviour problems in children with Down syndrome". The first stage of the current research programme has been an extensive survey of sleep problems in a group of children with Down syndrome compared with other children with learning disabilities and non-disabled children.The daytime behaviour of all these children and their mothers' stress levels have also been investigated. This information, as well as associations between sleep disorders, daytime behaviour problems and maternal stress will be reported in future publications.
Down's Syndrome: Research and Practice 1 (1): 29-33 (1993)

A preliminary study of sleep disorders and daytime behaviour problems in children with Down syndrome

Rebecca Stores

The recent occurrence and severity of a range of sleep disorders were determined in a group of children with Down syndrome, and compared with those in a group of non-disabled children with the same mean age and similar Social Economic Status distribution. Associations were explored between the sleep disorders in children with Down syndrome and measures of their daytime behaviour. Frequently occurring sleep problems were found to be significantly more common in the group with Down syndrome compared with the non-disabled group. The most common sleep problems showed a different pattern in the two groups. In the children with Down syndrome, various significant associations were seen between the number of frequent sleep problems and specific types of disturbed daytime behaviour. Within the Down syndrome group, boys had significantly more frequent sleep problems than girls. The findings show that sleep problems are common in children with Down syndrome and that they are linked with disturbed behaviour during the day. The requirements for possible further research are discussed.
Arch Dis Child 66 (11): 1333-8 (1991 Nov)

Sleep related upper airway obstruction in a cohort with Down's syndrome

Stebbens VA, Dennis J, Samuels MP, Croft CB, Southall DP
National Heart and Lung Institute, Royal Brompton Hospital, London

The prevalence of sleep related upper airway obstruction (UAO) was studied in a cohort of 34 children with Down's syndrome from a geographically defined area. Thirty two (94%) of the children, ranging in age between 0.1 and 4.9 years (median 1.4), underwent full clinical assessment for UAO including parental questionnaires and overnight tape recordings of chest wall movements and arterial oxygen saturation (SaO2). Compared with controls, children with Down's syndrome had (a) an increased incidence of stridor and chest wall recession during sleep, (b) an increased frequency of a pattern on inspiration indicating increased upper airway resistance, (c) a reduced baseline oxygen saturation (having excluded recordings on four children with potential for right to left intracardiac shunting), and (d) an increased number of episodes with SaO2 less than or equal to 90% despite continued chest wall movements. At their initial assessment seven children (22%) had evidence of UAO. The 18 youngest children (less than or equal to 1.7 years) underwent repeated recordings and clinical assessment until they had all reached 2 years of age. A further three were found to have developed UAO. Sleep related UAO is a common problem in children with Down's syndrome, occurring in 10 of 32 (31%) of this population based sample.
American Journal on Mental Retardation 88 (1): 132-139 (1991 Jul)

Obstructive Sleep Apnea in Children with Down Syndrome

CL Marcus, TG Keens, DB Bautista, WS von Pechmann, SL Ward
Division of Neonatology and Pediatric Pulmonology, Childrens Hospital of Los Angeles, CA 90027

Children with Down syndrome have many predisposing factors for the obstructive sleep apnea syndrome (OSAS), yet the type and severity of OSAS in this population has not been characterized. Fifty-three subjects with Down syndrome (mean age 7.4 ± 1.2 [SE] years; range 2 weeks to 51 years) were studied. Chest wall movement, heart rate, electroculogram, end-tidal PO2 and PCO2, transcutaneous PO2 and PCO2, and arterial oxygen saturation were measured during a daytime nap polysomnogram. Sixteen of these children also underwent overnight polysomnography. Nap polysomnograms were abnormal in 77% of children; 45% had obstructive sleep apnea (OSA), 4% had central apnea, and 6% had mixed apneas; 66% had hypoventilation (end-tidal PCO2 greater than 45 mm Hg) and 32% desaturation (arterial oxygen saturation less than 90%). Overnight studies were abnormal in 100% of children, with OSA in 63%, hypoventilation in 81%, and desaturation in 56%. Nap studies significantly underestimated the presence of abnormalities when compared to overnight polysomnograms. Seventeen (32%) of the children were referred for testing because OSAS was clinically suspected, but there was no clinical suspicion of OSAS in 36 (68%) children. Neither age, obesity, nor the presence of congenital heart disease affected the incidence of OSA, desaturation, or hypoventilation. Polysomnograms improved in all 8 children who underwent tonsillectomy and adenoidectomy, but they normalized in only 3. It is concluded that children with Down syndrome frequently in have OSAS, with OSA, hypoxemia, and hypoventilation. Obstructive sleep apnea syndrome is seen frequently in those children in whom it is not clinically suspected. It is speculated that OSAS may contribute to the unexplained pulmonary hypertension seen in children with Down syndrome.
Monatsschr Kinderheilkd 138 (12): 817-22 (1990 Dec)

Obstructive sleep apnea syndrome in a child with trisomy 21

Bloch K, Witztum A, Wieser HG, Schmid S, Russi E

Medizinische Klinik, Universitatsspital Zurich

Pulmonary hypertension without any cardiovascular malformation was diagnosed by heart catheterization in a 4 year old girl with trisomy 21. A suspected obstructive sleep apnea syndrome was confirmed by polysomnography which revealed numerous obstructive apneas and hypopneas (apnea-index 23/h) with marked oxygen desaturation and a disturbed sleep pattern. Three months after adenotonsillectomy the mother reported her daughter having a quiet sleep without snoring. Polysomnography did not show any apnea nor any oxygen desaturation below 90%. A decrease of the pulmonary artery pressure was documented. Facial dysmorphias and muscle hypotonia predispose patients with trisomy 21 to obstructive sleep apnea, especially if hypertrophy of tonsills and adenoids coexist. Frequent arousals and hypoxia during sleep can result in failure to thrive and pulmonary hypertension. These consequences can be prevented by early diagnosis and treatment.
J Otolaryngol 17 (7): 398-403 (1988 Dec)

Surgical management of obstructive sleep apnea in children with Down syndrome

Donaldson JD, Redmond WM
Department of Otolaryngology, Izak Walton Killam Hospital for Children, Halifax, Nova Scotia, Canada

Obstructive sleep apnea (OSA) is relatively common in children with Down Syndrome due to anatomical and immunological variations which place them at particular risk. Secondary cardio-respiratory complications of upper airway obstruction may be found at the time of initial diagnosis; these require medical therapy before surgical correction of the OSA is attempted. The selection of appropriate surgical therapy is influenced by the anatomical structure of the individual child. Tonsillectomy and adenoidectomy alone infrequently provide lasting relief of obstruction for these children. We have found that uvulopalatopharyngoplasty (UPPP), with or without simultaneous anterior reduction of the tongue, alleviates this form of airway obstruction. This paper describes the procedures and reports our experience of six patients with Down syndrome.
Dev Med Child Neurol 29 (6): 734-42 (1987 Dec)

Upper airway obstruction with hypoxaemia and sleep disruption in Down syndrome

Southall DP, Stebbens VA, Mirza R, Lang MH, Croft CB, Shinebourne EA
Department of Paediatrics, Brompton Hospital, London

Six of 12 children with Down syndrome (DS) tested by means of long-term tape-recordings of oxygen saturation, breathing movements and expired CO2 were found to have previously undetected and severe upper airway obstruction during sleep. In five cases the obstruction occurred in the pharynx and in the sixth it was due to bilateral choanal stenosis. When compared with age-matched controls, overnight tape-recordings showed episodes of abnormal arterial hypoxaemia and an abnormally elevated end-tidal CO2. Episodes of obstruction were most marked during sleep associated with a non-regular breathing pattern. Abnormal episodes of hypoxaemia were associated with continued breathing movements. Sometimes there was no airflow (complete obstruction); at other times airflow continued normally or was reduced in amplitude (partial obstruction). During episodes of partial or complete airway obstruction the inspiratory waveform showed a characteristic shape. These results show sleep-related upper airway obstruction to be an often undetected complication of DS and all necessary measures should be taken to overcome the obstruction when it reaches the stage of producing abnormal hypoxaemia. Choanal dilatation and tracheostomy were successful in treating two of the children. Tonsillectomy and adenoidectomy were successful for one child, but only of marginal benefit for two others.
J Ment Defic Res 31 (1): 31-9 (1987 Mar)

Nocturnal periodic breathing in adults with Down's syndrome

Telakivi T, Partinen M, Salmi T, Leinonen L, Harkonen T

Nineteen adults with Down's syndrome were studied with the static charge sensitive bed (SCSB) method. A single whole-night recording was made of each subject. Two different periodic breathing indices (PBIf and PBI%) were calculated from a computerized analysis of these recordings. A polygraphic recording was also made of one subject, a 52-year-old male. The EEG, the EOG, the EMG, nasal and oral airflow, and diaphragmatic movement were recorded, the latter with an abdominal strain gauge and with the SCSB-method simultaneously. Good correlation was found between the recording with the SCSB and the strain gauge. The apnoea index (AI) calculated from the polygraphic recording was 23.3, while the PBIf of this patient recorded on another night and analysed automatically was 45 and the PBI% was 78.6. The patient group was divided into those aged 40 or older (n = 10) and those aged 39 or younger (n = 9). The mean PBI% of the older group was 24.0 while that of the younger group was 5.4 (t = 2.23; P less than 0.05). The mean PBIf of the older group was 16.7 and that of the younger was 3.6 (t = 2.70; P = less than 0.02). The mean body mass index (BMI) of the younger group was significantly higher than the mean BMI of the older group. The mean BMI of those patients, whose PBI values were considered to be normal (PBI% less than 3, PBIf less than 7), did not significantly differ from the BMI of those patients, whose PBI-values were abnormal.