(This article first appeared in MIMS Magazine weekly on
September 1st 1992. It has been brought up to date in 2001 and is reproduced
with permission of the Journal)
What medical help can GPs give families who have a child with Down's
syndrome?
Dr Jennifer Dennis. Director of Information and Research. DSMIG
Many children with Down's syndrome are fit and healthy but one way in
which General Practitioners can help people with Down's syndrome is by
being aware of those medical problems which are over-represented among
this population. Most of these are readily remedied but can cause extra
handicap if unrecognised.
Congenital heart disease. Fifty percent of children with Down's syndrome
have congenital heart disease, 15 per cent of these have a full atrioventricular
canal defect. Full corrective surgery is now offered to nearly all children
with the syndrome. This is usually carried out by age 6 months. The perioperative
mortality is around 5%.
Irreversible pulmonary hypertension, usually a contra-indication to full
corrective surgery, develops more rapidly than in other children. Hence
the cardiac status of every child must be established before age 6 weeks.
Other first-year emergencies. Duodenal atresia or web and Hirschsprung's
disease all occur more often than in the general population. Hirschsprung's
disease poses diagnostic problems because constipation is common in children
with Down's syndrome.
Weight in early childhood. For young children with the syndrome the 50th
centiles for height and weight are only just above the 3rd centile for
the general population. Thus children may appear small for their age if
charted on standard charts. UK
Down's specific growth charts should be used. These are available
in A4 format and are also included in the Down's syndrome PCHR
insert.
Underfeeding and failure to thrive. Even an experienced mother can have
difficulty assessing how a child with Down's syndrome is feeding at the
breast. If weight gain is poor (as assessed on Down's specific charts)
and there are green runny stools, underfeeding should be considered. Test
weighing may be the only way to resolve the issue. Older children may
fail to thrive because of feeding difficulties associated with impaired
oral-motor function.
Hearing loss. Conductive hearing loss secondary to glue ear affects many
children with Down's syndrome, developing as early as the first year of
life. If unrecognised it can be a major cause of extra handicap. A child
with learning disability is less able to compensate for this, so it is
important that the condition is recognised early and corrected by hearing
aids or grommets. Babies and young children may also have sensorineural
hearing problems but these are more common in teenagers and adults. Hearing
should be checked annually until age 5, and 2 yearly thereafter for life.
Vision problems. These affect 60-70 percent of children with Down's syndrome
before the age of seven. Some have quite high myopia and many have hypermetropia,
which may be signalled by the onset of a squint. Hypermetropia is not
picked up by routine screening; refraction by an optician or ophthalmologist
is needed. Children with Down's syndrome should have vision checks at
least once a year from the ages of two to four, then every two years for
life.
Nuisance problems. Nasal congestion, persistent catarrh, sticky eyes,
blocked tearducts, dry skin, friable nails, constipation and/or toddler
diarrhoea all seem to crop up more in Down's syndrome patients. With catarrh,
a vicious circle of poor postnasal drainage, and repeated secondary infection
and exacerbation can set in. A serious empirical trial of a dairy-free
diet is worthwhile as this sometimes reduces the amount of mucus production.
Thyroid problems. By adolescence 15 to 20 percent of those with Down's
syndrome will have become hypothyroid, usually an autoimmune type of thyroiditis
which is difficult to detect clinically. Regular screening is essential.
Fingerprick blood spot testing for TSH is available in some areas. This
should be repeated annually For venous blood screening programmes thyroid
function, including antibodies, should be checked at age 1 year and 2
yearly thereafter for life. If antibodies are present, annual checks are
needed because 50 percent of those with antibodies develop frank hypothyroidism.
A diagnosis of hypothyroidism should always certainly be kept in mind
if a teenager or adult slows down intellectually or physically, or gains
excess weight.
Cervical spine instability. This is a contentious area. The problem most
frequently addressed is that of atlantoaxial instability which is due
to laxity of the transverse ligament of the atlas vertebra. This may predispose
to dislocation and neurological damage. Serious sequelae can undoubtedly
occur but are very rare. DoH guidelines issued in 1986 which recommended
that all people with Down's syndrome have cervical spine X-rays before
taking part in sports have been withdrawn because radiological screening
has proved unreliable in detecting those at risk. A review of the literature
suggests that sports injuries leading to death or disability directly
due to atlantoaxial instability are rare. Clinical vigilance is the only
effective screening approach. Symptoms of spinal cord compression secondary
to atlantoaxial instability frequently precede dislocation. Torticollis,
pain behind the ear, deterioration of manipulative skills, altered gait
and incontinence may all signal this complication and urgent referral
to a specialist spinal surgeon is needed. Cervical spine fusion may be
effective but complications occur more frequently than in the general
population.
Sleep-related upper airway obstruction. This is an often unrecognised
complication of Down's syndrome at all ages. It affects quality of life
and can be life threatening, particularly if congenital heart disease
coexists. A floppy tongue falls back during sleep into an already narrow
postnasal space, which may be further compromised by adenotonsillar growth.
Frequent waking with a start, snoring, lower sternal recession, daytime
sleepiness and swallowing difficulties are clinical indicators. Children
often adopt strange pre-sleep positions to maintain airway patency. The
condition requires specialist appraisal and may be improved by adentonsillectomy.
Early dementia. Around 50% of those with Down's syndrome develop Alzheimer-type
dementia which may begin as early as age 35. The first signs may be deterioration
in self-help skills, particularly the ability to feed neatly and cleanly
and to maintain personal appearance. The person may also appear unduly
lethargic and depressed. Differentiation from affective disorder can be
difficult. However, it is well worth remembering that some people with
Down's syndrome remain alert and fit into their sixties or seventies
see also
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