Nasal CPAP can greatly improve the quality of life of those with Down syndrome who have OSA.

Today, many adults with Down syndrome live in a residential or assisted care setting. In these facilities, most adult Down syndrome residents have roommates who are often bothered by loud snoring. When snoring is a disturbance, it becomes the house manager’s job to handle.

One such residence manager recently brought a patient to the Regional Sleep Center, Memorial Health Care System, Chattanooga, Tenn, for evaluation. Initially, the patient’s mother objected and refused to permit the patient to have an evaluation for OSA. After some gentle but persistent persuasion by the patient’s house manager, evaluation and treatment were arranged and the patient immediately demonstrated a remarkable improvement in daytime alertness and disposition once started in the home on nasal CPAP.

Down syndrome is associated with either an extra chromosome 21 or an effective trisomy of chromosome 21 by its translocation to another chromosome, usually chromosome 14. Down syndrome is the most common autosomal anomaly in live births and the most common single cause of mental retardation. It was first described in 1866 by Down and Seguin. In recent years, women are getting married at a later age. A higher proportion of older women bearing children has caused an increase in the incidence of this condition. Early recognition and reporting as a result of increased prenatal diagnosis have also affected the incidence. In the United States, it happens in one in 1,000 newborns. More than 30% of Down syndrome occurs in births to women aged 35 years or older. It should be noted that Down syndrome increases with maternal age and reaches an incidence of one out of 54 births in mothers aged 45 years or older. Approximately 20% to 60% of Down syndrome subjects have congenital heart disease in the atrioventricular septum. A ventricular septal defect is present in 33%. A patent ductus arteriosis is present in 10% of patients. Malformation of the spine especially the upper cervical region can occasionally produce neurologic symptoms.

Patients
An estimated 50% of persons with Down syndrome have significant OSA.^1,2 A variety of other polysomnographic changes have also been reported. Excessive sleep fragmentation, increased arousals and awakenings, and more frequent stage shifts were reported in 23 children with Down syndrome. These findings may also be related to the presence of OSA. This study reports successful experiences in treatment of OSA in seven adults with Down syndrome. This particular group of patients responded very well to nCPAP and had excellent compliance (90%). Compliance to the treatment was better than that in the average general population.

Table 1. Seven patients with Down syndrome are charted to determine compliance of nCPAP.

As depicted in Table 1, our seven patients’ ages ranged from 19 to 44 years (mean 30.4 years). All were short (mean 59.3 inches) and overweight (mean 188.3 pounds). The mean body mass index (BMI) was 38 (over 27 is overweight).

Results
The group’s OSA ranged from moderate to very severe with varying degree of O2 desaturation (Table 1). The nCPAP pressure required correlated well with BMI, respiratory distress index (RDI) (case four and seven), and O2 desaturation level. All patients tolerated nCPAP very well and voluntarily applied the nasal CPAP mask at bedtime. Daytime sleepiness, hyperirritability, and loud snoring were all abolished after nCPAP treatment. Cases one and four were most representative of the successes that Down syndrome patients can achieve when compliant with nCPAP therapy.

Case One
Case one was a 29-year-old man with Down syndrome who also suffered from a seizure disorder since he was 10 years old. He was treated with phenobarbital for his seizures, and has been treated with levothyroxine sodium 0.15 mg daily for hypothyroidism. He used to have seizures once a week. Now he has a seizure once a month. His seizures were described as generalized tonic/clonic type, which lasted for 2 to 3 minutes, after which he would quickly progress into postictal sleep.

He was born after a full-term pregnancy. The labor was short and uncomplicated. His birth weight was 6 pounds, 12 ounces. His mother did smoke cigarettes, but she denies alcohol or drug intake. There were no complications during pregnancy, labor, or delivery. At the time of his birth, the mother was a 37-year-old gravida 6, para 2 and abortus 3.

His previous hospitalizations included treatment for right tear duct repair and also an allergic reaction to a flu shot. He was diagnosed at age 2 years by chromosomal studies for Down syndrome.

On examination, the patient was overweight and with features compatible with Down syndrome. Due to the presence of excessively loud snoring during sleep, a polysomnogram was done. It showed that he had an RDI of 80 per hour associated with arousals and oxygen desaturation to SpO2 68%. A nCPAP titration at 10 cm of water with a standard CPAP mask caused the patient to report subjective improvement to the restorative nature of his sleep and increased alertness. The snoring, apnea/hypopnea, and oxygen desaturations were all abolished after the nCPAP. Now, the patient has been on nCPAP for 6 years, and uses nCPAP every night. His seizure disorder is under control with carbamazepine. His phenobarbital dosage was reduced to 60 mg at bedtime.

Case Four
Case four was a 29-year-old woman who was seen in the Sleep Disorder Center due to difficulty breathing during sleep. At night she would sit up during sleep. She snored loudly at night and had excessive daytime sleepiness. During the daytime, she would drink 16 ounces of caffeinated soda per day to stay awake. Over the past 12 months before she was seen, she had gained about 17 pounds. She reported swelling of the ankles and feet. She lives at a residential care unit with seven other residents of various ages. She had an Epworth Sleepiness Scale of 15 (over 10 is abnormal). On examination, the patient’s height was 58 inches and her weight was 278 pounds; the oral cavity showed a low soft palate position and enlargement of the uvula. Her mandible was not recessed. She had a short neck. Her thyroid was not palpable. Her abdomen was obese. There was mild pretibial edema bilaterally in the legs. She has all the features of Down syndrome. An overnight polysomnography showed adequate stage III/IV, but the REM sleep was reduced to 1.7%. Her total apneas and hypopneas were 698 during 5 hours’ sleep. Her RDI was 136.5/hour. During REM sleep, the RDI was 83.1 per hour. During NREM sleep, the RDI was 136.5/hour, total arousals were 698, and arousal index was 136.5/hour. Moderately loud snoring was heard in all sleep positions with gasping and snorting on recovery. The lowest SpO2 was 64%. The longest respiratory event was a 46-second obstructive hypopnea with an SpO2 of 70% during REM sleep. During REM sleep, there was a 14-second obstructive apnea with SpO2 of 79%. There were no parasomnias noticed. With nasal CPAP titration at 15 cm water pressure using an full-faced medium CPAP mask, the patient’s respiratory problem was totally eliminated. Sleep architecture showed some improvement with the return of REM sleep to 12.6% and rebound of stage III/IV sleep to 19.2. The patient reported remarkable improvement after nCPAP treatment. At follow-up appointments at 2 months, 4 months, and 6 months, she showed steady improvement with weight loss down to 258 pounds and she now sleeps soundly only on rare occasions.

The clinical picture of Down syndrome is variable and consists of an unusual combination of anomalies. The birth weight of Down syndrome infants is less than normal. There is a higher incidence of breech presentations. The mental age that is ultimately achieved varies considerably. It is related in part to environmental factors, including the age at institutionalization and to the degree of intellectual stimulation. The older patients as reported here with Down syndrome have an IQ between 25 and 49 with the average approximately 43.

During overnight polysomnography, one needs to search for evidence of epileptogenic discharges. During infancy they may associate with infantile spasms. These seizures sometimes may persist to adulthood. Children with Down syndrome sometimes may have atlantoaxial instability and develop neurologic signs that require surgical stabilization of the joint. It may be risky for these children to participate in sports activities.

Sixty four percent of patients with Down syndrome have bilateral hearing loss. Sometimes they are not able to cooperate with sleep studies because of hearing loss.

The diagnosis of Down syndrome is usually made by the presence of the characteristic physical anomalies and then confirmed by cytogenetic analysis. Management of a patient with Down syndrome may include treatment of hypothyroidism, treatment and prevention of infections, and treatment of hearing and visual deficits. Additionally, congenital heart disease or other significant malformations that are found can be treated either medically or surgically as indicated.

The causes of the high incidence of OSA in Down syndrome have been postulated as: midfacial and mandibular hypoplasia, a large tongue, and abnormally small upper airway with superficially placed tonsils and relative tonsillar and adenoid encroachment, obesity, and generalized hypotonia with a result in the collapse of airway during sleep especially during inspiration.^3,4 Two of our patients have hypothyroidism, which may worsen OSA. In patients with a varying degree of neurological development, disorders, and multiple medical problems such as Down syndrome, without a thorough history OSA may be missed. Patients often do not communicate well about their symptoms, and in such cases, undiagnosed chronic hypoxemia may cause pulmonary hypertension, congestive heart failure, and even death.

Conclusion
Early diagnosis and treatment of OSA with nCPAP in persons with Down syndrome have significantly improved the quality of life in the group of patients cited from the local group home. The abolishment of their snoring certainly was appreciated by other clients in the residential facility, and ultimately led to improved daytime functioning and interaction between staff and other residents.

As with so many educational challenges we face in sleep medicine, promoting awareness in the community and among physicians about the nature of sleep in our Down syndrome population is very important. Improved sleep and daytime function in the lives of this group can make the difference between leading an active life versus a very sedentary and less active life.

Lawrence T. Chien, MD, ABSM, is a pediatric neurologist, Robert Lindsey, MS, RPSGT, is director of Neuromedical Services, and Michael L. Dunn, RRT, RPSGT, is patient care manager of Neuromedical Services, all at Regional Sleep Centers, Memorial Health Care System, Chattanooga; Anne P.Y. Chien, MSN, APN, NP-C, is clinical associate professor at the University of Tennessee, Chattanooga, School of Nursing; and Kelly L. Phillips, MSN, APN, BC, FNP, is a family nurse practitioner in Chattanooga.

References
1. Marcus CL, Keens TG, Bautista DB, von Pechmann, Ward SL. Obstructive sleep apnea in children with Down syndrome. Pediatrics. 1991;88:132-139.
2. Marcus CL, Ward SL, Mallory GB, et al. Use of nasal continuous positive airway pressure as treatment of childhood obstructive sleep apnea. J Pediatr. 1995;127:88-94.
3. Pueschel SM. Young people with Down syndrome: transition from childhood to adulthood. Mental Retardation and Developmental Disabilities. 1996;2:90-95.
4. Smith DS. Healthcare management of adults with Down syndrome. Am Fam Physician. 2001;64:1031-1040.