THERAPY OF SQUINT IN DOWN SYNDROME SUBJECTS.

 RESULTS ACCORDING TO THE LENGTH OF DRUG TAKING: REPORT ON 125 CASES

Renato COCCHI, neurologist and medical psychologist.


(Italian translation)

Summary

125 Down syndrome Ss (F = 63 and M = 62; average age at first consultation = 76.57 +/- 5.52 months, range 5 - 271 months; cytodiagnoses distribution: 93.60 % pure trisomy 21; 4.00 % mosaicisms; 2.40 % translocations) affected by various degrees of squint were assessed after different periods of drug therapy.

Although the prescription has been individualized, all the Ss took, among the other drugs, l-glutamine 90-250 mg; pyridoxine 125-150 mg; biotin 5 mg; diazepam 1-3 mg (daily doses). At T0 the squint distribution was as follows: slight: 33 Ss; moderate: 10 Ss; marked: 74 Ss; severe: 8 Ss. At Tn (finaì assessments made since up to 6 to up to 120 months of drug therapy) the distribution found was: desappearance: 42 Ss; present only following antibiotic therapies for respiratory infections: 28 Ss; present when the S is tired: 26 Ss; slight: 13 Ss; moderate: 3 S; marked: 12 Ss; severe: 1 Ss (Chi Square: 158.60; p < .00025, 6 df). Possible explanations of the drugs action and choice are suggested.

Key words: Down's syndrome; squint; drug therapy; improvement; GABAergic drugs; biotin.

 

Down's syndrome

Mental retardation

Drug therapy of stress reactions

Symptoms

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Congenital squint is very frequently encountered in children suffering from Down's syndrome. Rates vary from 21 to 44 % [1-3], being our own 27.91 % [4].

The causes are unknown and merely hypothetical, but the frequent presence of this eyes trouble in subjects affected by cerebral palsy (CP) - rated 37-60% in Harcourt review [5] and reconfirmed 52.5-62%, according to more recent investigations [6-9] - led Hugonnier and Hugonnier-Clayette to assert a common etiology [10].

Our previous investigation aimed to correlate, in Down's syndrome subjects, risk factors for CP such as prematurity and low birthweight and the presence or absence of squint produced negative results [11].

Since 1979 I have been using low dosage drug treatment on children affected by Down's syndrome. The rationale behind this therapy is that many Down's syndrome symptoms are not due to the chromosomal anomaly itself, but to the organism's response to endogenous metabolic stress.

This stress is brought about by the 50% acceleration of all the metabolisms whose control genes are found in chromosome 21 [12]. If 100% represents a metabolism controlled by the 2 genes, as it normally happens, then this will become 150% in the presence of 3 control genes as in trisomies.

This is the well-known "dosage effect" which as already been demonstrated regarding more than just one of these metabolisms [13-23].

One of the unespected results of this therapeutic practice has been its beneficial effect on nystagmus [24], confirmed also in non Down subjects [25], as well as its effect on squint.

Given these premises, a clinical survey was carried out in order to evaluate the results obtained so far with Down subjects.

Subjects, materials and methods.

All the medical records were re-examined of an unselected consecutive series of 470 Trisomy 21 patients, drawn from all over Italy who attended our outpatients' clinics between 1979 and late October 1990.

The records were extracted for all those who had shown visible evidence of squint at the first visit and who had successively undergone the prescribed treatment for at least 6 months.

At T0, the initial squint evaluation, wich was purely clinical, was based on the following criteria:

- light (+), when deviation of the ocular axis went no further than halfway of its possible movement towards the nose and, according to the parents, rarely was not present;

- moderate (++), as above but the position being permanent;

- marked (+++) with ocular axis deviation tending to occupy also the second half of the eyeball's possible movement towards the nose;

- severe (++++), as above, but with fixed marked deviation.

At Tn, final evaluation, 3 further distinctions were added:

- disappearance (0);

- very rare (--), as reported by the parents, present only after antibiotic therapies mainly carried out following respiratory infections;

- uncommon (-), as above and/or only present when the child is very tired.

Details regarding sex, age at first consultation (months) and chromosomal diagnosis were also taken from subjects with the required characteristics for this investigation.

The therapy carried out, despite being quite different from subject to subject according to the differences in individual stress responses, always involved (daily doses):

- l-glutamine: 90-250mg

- pyridoxine: 125-150mg;

- biotin: 2.5-5 mg;

- diazepam: 1-3mg.

The results taken pertained to the last visit made, i.e. results at six months pertain to subjects having made only six months of drug therapy.

A statistical analysis of the results was carried out using the non-parametric Chi Square test.

Results.

Only 125 subjects were eligible for this study, out of 470. This group compri-sed 63 females and 62 males; sex ratio (M/F) = 98.41. Average age and SD at first consultation: 76.57 +/- 5.52 months; range: 5-271.

The chromosomal diagnoses were as follows:

pure trisomy 21: 117 Ss = 93.60%;

mosaicisms: 5 Ss = 4.00 %;

translocations: 2 Ss = 1.60 %

unknown: 1 S = 0.80 %.

Results are shown in table 1.

Table 1: distribution of squint grades at T0 and Tn, according to the length (months) of the drug taking.

 

 

 

Tn (months of drug taking)

Value

T0

%

6

7-12

13-24

25-36

37-60

61-84

85-120

totals

%

0

 

 

2

4

4

7

20

5

0

42

33.60

(--)

 

 

1

1

2

8

15

1

0

28

22.40

(---)

 

 

5

3

8

6

2

2

0

26

20.80

(+)

33

26.40

6

2

1

0

0

2

2

13

10.40

(++)

10

8.00

0

1

1

0

0

0

1

3

2.40

(***)

74

59.20

3

2

5

1

1

0

0

12

9.60

(++++)

8

6.40

0

0

0

0

1

0

0

1

0.80

Totals

125

100.00

17

13

21

22

29

10

3

125

100.00

Chi Square: 158.60; df = 6; p < .00025.

 

Discussion.

As regards selectional criteria for the presence of squint, the symptom was only considered in those subjects who showed evidence of it during the first visit.

The use of spectacles to correct squint was not taken into account because young Down children do not tolerate them, and more aged subjects with squint and spectacles are the proof that they had scarce helpful by using them.

The distribution of chromosomal anomalies parallels with Italian anä International limits [26-30].

The M/F ratio which was, on the contrary, found to be equal in this selected male and female groups. This ratio differs from that usually found regard trisomy 21, which in Italy ranges from 134/100 [27] to 136/100 calculated in the first 366 cases of this series [28].

As for the results, the casuistry here presented, often backed up by photographic and filmed documentation, is by now so strong that it is difficult to attribute all this to chance. If the relationship between squint and CP in Down subjects is highly improbable [11], the present results after drug therapy lead to a new suggestion. Convergent squint in 21 trisomics, when not due to refraction problems, could be a symptom of biochemical inbalance concerning oculomotor nuclei of the midbrain and of the pons, vestibular area and reticular paramedian formation of the pons, added to which, an interferring cerebellar dysfunction seems likely [31].

Such a dysfunction, ex adjuvantibus, seems mainly due with GABA and glutamate.

In fact among the drugs used, glutamine is the main precursor of glutamate and GABA in the brain [32]; pyridoxine, in the form of pyridoxal-phosphate, is the co-factor of all the decarboxylases, as well as the glutamic-acid-decarboxylase (GAD) [33]; diazepam is the sensitizer of type A post-synaptic GABAergic receptor [34-36].

All three of these drugs have a precise anti-stress function [37].

Pyridoxine and biotin have been found to be strongly present in midbrain, pons and cerebellum in normal subjects [38]. This last finding led me to suppose that their supply, in Down subjects, could improve the neurochemical functioning of these areas. In my opinion, this seems the least improbable explanation to justify the results obtained.

These same rusults also lead to infer that when squint in Down subjects responds to an antistress therapy it is almost certainly one of the many stress symptoms of the Down syndrome.

Biotin excluded, the medical correction of squint does not involve the use of any different drugs other than those used as basic for stress response correction in Down's syndrome. Apart from helping to avoid any eventual surgical intervention on the eyes, the improvement of squint in the Down child, by itself improves motor confidence as well as scholastic performances. 

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Paper presented at the First Europ. Conference on Mental Handicap and Medical Care, Leeuwenhorst, april 21-24, 1991. 

Printed on It. J. Intellect. Impair. 1991, 4: 9-14.

Author's address: dr Renato COCCHI, via Rabbeno,3

42100 Reggio Emilia (Italy)

renatococchi@libero.it


Testo in italiano

Down's syndrome

Mental retardation

Drug therapy of stress reactions

Symptoms

Home Page