HYPERKINESIS IN DOWN CHILDREN
AGED UP TO 12 YEARS:
A SURVEY ON 442 CASES

Renato COCCHI MD, and Marco FAVUTO MD

(Italian translation)

Summary

From the same unselected consecutive series of Down Ss already surveyed in a previous paper ( Cocchi R., Favuto M.: It. J. Intellect. Impair. 1997, 10:19-23) we extracted the clinical reports of those aged up to 144 months at first consultation. These reports pertained to 442 children, whose 251 males and 191 females, with M/F ratio = 131.41/100.

The distribution of chromosomal anomalies divided by gender was as usual, and average age at 1st consultation was about 51 months. Hyperkinetic Down girls were 34.03% and hyperkinetic Down boys were 35.86%. Epidemiological features of these hyperkinetic subgroups do not differ, like the age at 1st consultation. At least for Italian Down children, we suggest that gender do not influence the presence of hyperkinesis.

Key words: Down’s Syndrome; hyperkinesis; gender; children.

* Symptoms

* Down's syndrome

* Mental retardation

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In our previous paper on hyperkinesis in Down Ss (Cocchi and Favuto, 1997) we reached some interesting results. Hyperkinesis referred to about one third of a representative sample of 510 Ss. Hyperkinetic Down Ss did not differ from non hyperkinetic Down Ss as for M/F ratio, chromosomal anomalies' distribution, and age at 1st consultation. Being the age group up to 12 years the more stable and indicative, in this respect, we aimed to survey if in it hyperkinesis was a gender independent feature.

Materials and method

We used for this survey the clinical cards referring to an unselected consecutive series of home reared and home living Down Ss. One of the authors saw all them in outpatients' between January 1979 and April 1997, when the Ss were aged up to 144 months (12 years).

The record of hyperkinesis during 1st visits followed

- direct observation;

- reports of the parents, or in-home relatives, or teachers;

- presence of motor behaviours that the DSM pointed out as symptoms of motor hyperactivity.

From this amount we avoid using the records of PDD Down children, because we thought that a so heavy superimposed pathology could have modified also motor behaviours. Of course we did not consider the records where hyperkinesis did not have any negative or positive mention.

From so selected records we collected:

- sex;

- age at 1st consultation;

- chromosomal diagnosis;

- presence or absence of hyperkinesis.

Data collected had plain statistics and we evaluate them, when it possible, with Chi Square Test.

Results

Only 442 Ss out of 548 fitted the limits for this survey. The analysis of this sample stands in Tables 1-4.

 

Tab. 1: Epidemiological data of the sample of Down children aged up to 144 months (12 years)

No. of Ss

442

100.00%

(% of the whole series of 548 Ss)

 

80.66%)

Males

251

56.79%

Females

191

43.21%

M/F ratio

131.41/100

 

 

 

 

Chromosomal diagnosis

 

 

pure trisomy 21

407

92.08%

mosaicisms

14

3.16%

translocations

15

3.39%

only clinical diagnosis

6

1.37%

 

 

 

Age at 1st visit (months)

 

 

range

4-144

 

average +/- SD

52.55 +/- 36.76

 

 

We have to note M/F ratio and chromosomal anomalies' distribution.

According to Camera e Mastroiacovo, 1984, we can consider this sample as representative at least of the Italian Down children aged up to 144 months.

 

Tab 2: Epidemiological data of the sample, divided by gender.

 

females

%

males

%

 

 

 

 

 

No. of Ss

191

100.00

251

100.00

 

 

 

 

 

Chromosomal diagnosis

 

 

 

 

pure trisomy 21

172

90.15

235

93.61

mosaicsms

5

2.62

2

0.79

translocations

10

5.24

5

1.99

only clinical diagnosis

4

2.09

2

0.79

 

 

 

 

 

Age at 1st visit (months)

 

 

 

 

range

6-144

 

6-144

 

average +/- SD

51.42 +/-40.59

 

51.21 +/-39.09

 

 

 

 

 

 

Chi Square for chromosomal diagnoses = 4.739 with 3 df and p = 0.256 NS

The gender sharing originated two subsamples not significantly different for chromosomal anomalies' distribution, and, by evidence, for average age at 1st visit.

 

Tab. 3: Presence or not of hyperkinesis, according to gender.

Hyperkinesis

females

%

males

%

 

 

 

 

 

not present

126

65.97

161

64.14

 

 

 

 

 

present

65

34.03

90

35.86

 

 

 

 

 

 

 

 

 

 

totals

191

100.00

251

100.00

Chi Square = 0.089 with 1 df and p = 0.766 NS

The percent presence of hyperkinesis in both males and females does not clearly differ, being about 35%.

 

Tab. 4: Analysis of the epidemiological data of hyperkinetic children divided by gender.

 

females

%

males

%

 

 

 

 

 

No. of Ss

65

100.00

90

100.00

 

 

 

 

 

Chromosomal diagnosis

 

 

 

 

pure trisomy 21

62

95.38

84

93.33

mosaicisms

0

0.00

5

5.56

translocations

3

4.62

0

0.00

only clinical diagnosis

0

0.00

1

1.11

 

 

 

 

 

Age at 1st visit (months)

 

 

 

 

range

6-144

 

6-144

 

average

48.48

 

56.85

 

SD

40.69

 

41.41

 

 

 

 

 

 

(Chromosomal diagnoses: Chi Square = 0.504 with 3 df and p = 0.047)

Age at 1st visit: Chi Square = 0.111 with 1 df and p = 0.739 NS

As we can observe in Table 4, both subgroups of hyperkinetic Down children, divided by gender, seem ignificantly differ as for chromosomal anomalies' distribution. They do not differ as for average age at 1st visit.

Discussion

This second survey on hyperkinesis in Down children was easier to do, because we used data already computed in the previous one (Cocchi and Favuto, 1997). We could have previewed the results, as far as an essential element was accounted, such as the presence of hyperkinesis in about one third of the original sample.

Now we can confirm hyperkinesis in about 35% of this new sample, without gender difference. We cannot deserve particular attention to a significant gender difference in chromosomal anomalies' distribution that we found in this second survey. It is enough to watch at the figures of either distribution. There is evidence of no differences as for pure trisomy 21, the percentage of which is as usual.

To have not found hyperkinetic girls with mosaicisms or the sole clinical diagnosis, and hyperkinetic boys with translocations, led to nearly sure wrong statistic significance. The percent rates of mosaicisms and translocations are very low as per se (normally 2-4%). It is not difficult to find samples of less than 100 Ss, without any one who carries mosaicism or translocation. The same we can say for the contingent category of "only clinical diagnosis" the rate of which was already 1.36% in the initial gender mixed sample.

Already in the larger sample previously surveyed, we did not find any difference between hyperkinetic and non hyperkinetic children, as for chromosomal anomalies' distribution (Cocchi and Favuto, 1997).

So we suggest as a highly possible hypothesis that hyperkinesis is not related to gender. Even if Down males and females had significantly different chromosomal anomalies' distributions - a fact that we believe hardly to find - this hypothesis should not be damaged.

Conclusion

In this second survey dealing with hyperkinesis in Down children aged up to 12, we found it in about 35% without any gender preference.

We can ask where it is coming this hyperactive behaviour that characterizes one third of the Down children. Surely pregnancy and delivery risk factors, with their noticeable prevalence in Downs (Cocchi, 1987; Cocchi and Branchesi, 1987, Cocchi and Branchesi, 1988, Cocchi, 1992) are first liable to suspicion.

This will be our next target.

 

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

Cocchi R.: Presenza di scavengers e incidenza di paralisi cerebrali infantili da prematurita' e basso peso alla nascita in 381 soggetti Down allevati in famiglia. Giorn. Neuropsichiat. Eta' Evol. 1987, 7: 317-323.

Cocchi R.: Alcuni dati epidemiologici su una serie consecutiva di 490 soggetti Down. Riv. It. Disturbo Intellet. 1992, 5: 107-112.

Cocchi R., Branchesi R.: Strabismo e disturbi pre-, peri- e neonatali in soggetti affetti da sindrome di Down. Indagine epidemiologica su 215 casi. Rass. Studi Psichiat. 1986, 75: 504-512.

Cocchi R., Branchesi R.: Is there a causal non-connection between squint and cerebral palsy through prematurity and/or low birthweight in Down syndrome children? It. J. Intellect. Impair. 1988, 1: 141-144.

Cocchi R., Favuto M.: Hyperkinesis in Down’s syndrome. A survey on 510 persons. It. J. Intellect. Impair.1997, 10: 19-23

 

Paper printed on It. J. Intellect. Impair 1997, 10: 25-28.

 

Author’s address: Renato COCCHI MD, via Rabbeno, 3
42100 Reggio Emilia (Italy)

 renatococchi@libero.it

 

Italian translation

Symptoms

Down's syndrome

Mental retardation

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