HYPERKINESIS IN DOWN'S SYNDROME:
A SURVEY ON 510 PERSONS.
Renato COCCHI MD,
and Marco FAVUTO MD
Summary
Among
510 Down's syndrome persons, (292 M + 218 F; M/F = 133.94; chromosomal
diagnosis: 90.39 standard trisomy 21; 3.14% mosaicisms; 3.14% translocations;
3.33% only clinical diagnosis; average age at 1st visit: 71.37 months +/-
69.71), 33.34% of them had hyperkinesis recorded during their first visit.
The hyperkinetic Downs does not differ from non-hyperkinetic ones as for the
M/F ratio, chromosomal diagnosis spreading, and average age.
As
for age, hyperkinesis ranges 25-41% up to 12 years, with a clear fall in 13-14
years, a fact related to the inhibitory action of pubertal sexual hormones.
Although
all Downs show also attention problems, we do not think that hyperkinetic Downs
have a dual diagnosis, the second being Attention Deficit Disorder with
Hyperkinesis. We noted motor hyperactivity as compared to the low motor
activity of normal Down children, but we could not match it to hyperkinesis of
non-Down children.
Key words: Hyperkinesis; Down’s
syndrome; M/F ratio; chromosomal diagnosis.
The stereotyped
image of a Down person owns also a slow and clumsy motor activity, often even
more hampered by hypotonia or joint laxity or both. It is such a common image
that sometimes answers for the pediatrician's diagnosis. So it happens that hypotonia and joint laxity go at
Down children fully without them.
Having found clearly motor hyperactive Downs
since his clinical interest in these people, so one of us hit against this
prejudice.
During the first visit, few children were more quiet than usual because of the
environment novelty. For this, the physician could have derouted with the risk
of setting out the old stereotype. But parents quickly pointed out that the
present motor behaviour of the child was unlike than at home or according to teachers and therapy professionals'
information.
So because motor hyperactivity in Downs stands for a praised feature soon related to IQ, according to Piaget's sensory-motor stage of development.
All this led one of us to a very easy recording of that datum, and now we shall try to analyse it.
Materials and method
We conducted this survey on the clinical
records related to a series of Down persons living at home. One of us visited
all them in outpatients' between January 1979 and April 1997.
The presence of hyperkinesis was recorded
during first visit according to:
- direct observation;
- information from parents, or in-home
relatives or from teachers' reports;
- presence of behaviours that the DSM
(various revisions) pointed out as signals of motor hyperactivity.
From these records, we extracted all
those about autistic or psychotic Downs, since an overlapping of a second so
heavy disease could have affected motor activity too.
From the remaining records we collected:
- sex;
- chromosomal diagnosis;
- age at 1st consultation;
- hyperkinesis, when present.
Resulted data had plain, statistical
setting and Chi Square evaluation, when suitable.
Results
Only 510 out of 548 clinical records
fitted the criteria done for this survey. We reported the data of persons whose
records refer, into Tables 1-3 and Graphic 1.
Tab. 1: Epidemiological data.
|
No. of Ss |
510 |
100.00% |
|
Males |
292 |
57.25% |
|
Females |
218 |
42.75% |
|
M/F ratio |
133.94/100 |
|
|
|
|
|
|
Chromosomal diagnosis |
|
|
|
Standard trisomy 21 |
461 |
90.39% |
|
Mosaicisms |
16 |
3.14% |
|
Translocations |
16 |
3.14% |
|
Only clinical diagnosis |
17 |
3.33% |
|
|
|
|
|
Average age at the 1st visit (months) |
|
|
|
Range |
4-510 |
|
|
Average +/- SD |
71.37 +/- 69.71 |
|
As we can observe in Table 1, the M/F
ratio shows very slight shifting from what known from born-alive Italian Downs.
The chromosomal diagnosis' spreading runs into the variance of Italian and
foreign samples. For these reasons we think our sample as a representative
sample at least of Italian Downs.
Tab. 2: Presence of hyperkinesis
|
|
No. of Ss |
% |
|
Present |
170 |
33.34 |
|
|
|
|
|
No one |
329 |
64.51 |
|
|
|
|
|
Not reported |
11 |
2.15 |
|
|
|
|
|
Totals |
510 |
100.00 |
We found hyperkinesis in about one third
of our sample.
Tab. 3: comparison between Downs without and with hyperkinesis
|
|
Without hyperkinesis |
% |
With hyperkinesis |
% |
|
|
No. of Ss |
329 |
100.00 |
170 |
100.00 |
|
|
Males |
186 |
56.53 |
99 |
58.23 |
|
|
Females |
143 |
43.47 |
71 |
41.77 |
|
|
M/F ratio |
130.86/100 |
|
139.44/100 |
|
|
|
|
|
|
|
|
|
|
Cromosomal diagnosis |
|
|
|
|
|
|
Standard trisomy 21 |
293 |
89.06 |
157 |
92.35 |
|
|
Mosaicisms |
10 |
3.04 |
6 |
3.53 |
|
|
Translocations |
12 |
3.65 |
4 |
2.35 |
|
|
Only clinical diagnosis |
14 |
4.25 |
3 |
1.76 |
|
|
|
|
|
|
|
|
|
Age at the 1st visit (months) |
|
|
|
|
|
|
Range |
4-510 |
|
4-475 |
|
|
|
Average |
71.98 |
|
69.89 |
|
|
|
SD |
68.70 |
|
72.45 |
|
|
Chi Square for M and F
spreading: 0.072 with 1 df and p = 0.788 NS
Chi Square for
diagnosis: 3.845 with 3 df and p = 0.565 NS
Chi Square for the age
at 1st visit: 0.053 with 1 df and p = 0.818 NS
From Table 3, we did not find any
significant difference between non-hyperkinetic and hyperkinetic Downs, as for
sex or chromosomal diagnosis spreading, and age at the 1st visit.
Graph.1 shows a quite constant
rate of hyperkinesis (range: 25-41.17%) up to the twelfth year, a cut-down at
the thirteenth year, its absence at the fourteenth year, and a reduced rate at
the fifteenth year.
Discussion
This survey, perhaps one larger in this
field, needs to have a soon warning. We must clarify what we mean about
hyperkinesis in Downs, to avoid mistaking it with that of Attention Deficit
Disorder with Hyperkinesis (ADHD) in non-Down children.
If we may use a mathematical analogy,
the hyperkinetic Down child is to the Down child as the ADHD child is to the
non-Down child. In other words, the direct related term for the hyperkinetic
Down child is not the non-Down child, but the normal Down child. Hyperkinetic
Down children show a very lively motor activity as compared with normal Down
children.
This difference in quantity of motion
could depend on refraining factors of the syndrome itself, but this is only a
hypothesis.
As for the present casuistry, the M/F
ratio is very close to what Camera and Mastroiacovo 1984 found for born-alive
Italian Down children. The same happens for the chromosomal diagnosis
spreading, which overlaps what usually reported both in Italian and foreign
countries' studies (Camera and Mastroiacovo, 1984; Hook, 1981).
The share of persons with only clinical
diagnosis comes from two places. Often they were yet adults at first visit
time, born when the chromosomal diagnosis did not stand or did not have a usual
run. In few cases they were infants born in small country hospitals where
obstetricians thought the clinical evidence to be enough for the diagnosis.
These latter ones had only the 1st visit
during which we noticed the parents on the need of the chromosomal diagnosis. So
they could avoid the genetic risk of a hidden translocation coming out from a
balanced one in one parent. Not having they come back for checkup, although the
parents had our advice followed, we could not correct our lacking datum.
According to the warning done above, we
defined one third out of 510 Down persons as hyperkinetic. Moreover in our
experience we rarely saw hypotonia, or joint laxity or both in that people, if
not all those fully lack out of the first year of life.
Furthermore, as checked by us or
indirectly heard by specific professionals, these children have poor or null
need of motor rehabilitation, at least for gross motor skills.
One third hyperkinetic Down children
could appear a high figure, when L. Leichtman (personal communication, 1997)
found only 10% of them out of 300 people about. Probably we used a wider
criterion to evaluate hyperkinesis than Leichtman did.
In comparison with non-hyperkinetic Down
children of the same sample, the hyperkinetic ones do not differ as for the M/F
ratio, chromosomal diagnosis spreading or the first visit's age. This fact led
us to at least think that the hyperkinesis is not a feature linked to the
chromosomal anomaly.
Finally, its presence up to 12 years and
its 13-14 year fall suggest that hyperkinesis have the same nature of that in
ADHD, which runs in a similar way. The age of this fall seems coincident with
sexual development, and with the "antidepressant" action - in a
broader sense - of the pubertal sexual hormones incretion.
Now, can we speak of ADHD in Down'
syndrome? Someone did it (Green et al., 1989; Pueschel et al., 1991), but we
ask caution to avoid bringing an analogy into an identity. It is true that
hyperkinetic Down children lack in attention, but this fact is common to
non-hyperkinetic Downs.
So we cannot choose the attention
trouble to distinguish the hyperkinetic Down children from non-hyperkinetic
ones. In facts we can found both ADD and ADHD in non Down children, but also
children without any attention's trouble. As for attention, we do not find any
partition in Downs, but we can split non-Downs into two shares, with or without
attention disorder.
On the other hand, this time too,
hyperkinesis seems a non-essential added feature of ADD. In our hyperkinetic
Downs' series, only one child fitted the criteria for a diagnosis of ADHD/DS,
with some hyperactive and impulsive behaviours reported in the DSM.
Other hyperkinetic Downs did not show any impulsiveness, while we can easily
see it in psychotic Down children. But we excluded them from this survey.
Conclusion
Our survey on clinical records of 510
Downs all taken by one of us, found a notice of hyperkinesis in about one third
of them.
When compared with non-hyperkinetic Downs of the same sample the probands did
not differ as for M/F ratio, chromosomal diagnosis
spreading, and average age at the 1st visit. Being split up according to age,
hyperkinesis ranges 25-41.17% up to 12 years with a clear fall in 13-14.
We related such a fact to the inhibitory
action of pubertal sexual hormones. We
got to further research to better evaluate this symptom.
References
Camera G., Mastroiacovo P.: Epidemiologia
della sindrome di Down. In. Ce.Pi.M. (ed): Aspetti epidemiologici, genetici,
clinici, riabilitativi e sociali della sindrome di Down. Ce.Pi.M., Genova 1984:
225-230
Green, J.M. et al. Attention disorder in a
group of young Down's syndrome children. J. Mental Defic. Res.,
33:105-122, 1989.
Hook E.B.: Down syndrome: Frequency in human
popolation and factors pertinent to variation in rates. In: De la Cruz F.F.,
Gerald P.S. (eds): Trisomy 21 (Down Syndrome) research perspe ctives.
University Park Press, Baltimore, 1981.
Pueschel, S.M. et al. Behavioral
observations in children with Down's syndrome. J. Mental Defic. Res.,
35:502-511, 1991.
Printed on It. J. Intellect. Impair. 1997, 10: 19-23
Author’s address:
Renato COCCHI MD, via Rabbeno,
3
42100 Reggio Emilia
(Italy)
renatococchi@libero.it
Symptoms
* Down's syndrome
* Mental retardation
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