Prenatal hydrocephalus: outcome and prognosis

Child's Nerv Syst (1988) 4:213-222 ml]NS © Springer-Verlag 1988

Prenatal hydrocephalus: outcome and prognosis

D o m i n i q u e Renier , Chr i s t i an Sa in te-Rose , Ala in P i e r r e -Kahn , a n d J e a n - F r a n c o i s Hi r sch

Pediatric Neurosurgery, H6pital des Enfants Malades, 149, rue de Srvres, F-75730 Paris Codex t5, France

Abstract. The clinical records of 108 infants presenting with hydrocephalus at birth and operated on from 1971 to 1981 were reviewed in order to evaluate the functional results. Premature newborns and spina bifida patients were excluded. Communicated hydrocephalus (39 cases) and aqueductal stenosis (32 cases, excluding 6 X-linked hydrocephalus and 4 toxoplasmoses) were the two main types of hydrocephalus in this series. Eighty-four percent of the infants were operated on before the age o f 3 months. The mean follow-up time was 7 years (range 1 to 14 years). The survival rate, calculated by the life table method, was 62% at 10 years. The functional results were evaluated according to intellectual performance, academic level, and psychological status. Of the 75 surviving children, 28% have an I.Q. over 80 and 50% an I.Q. under 60. The mean I.Q. is 54 (range 0 to 130). Of the 52 children who have now reached school age, only 29% have reached a normal academic level. The psychological status is normal or borderline in 46% of the patients. The im- portance of head enlargement at birth, ventricular size, and the age at the time of surgery are not related to late functional results. The results were best when there were no associated malformations, no shunt infection, when hydrocephalus was due to aqueductal stenosis (excluding X-linked hydrocephalus and toxoplasmosis), or when the first developmental quotient measured at 6 months was over 80.

Key words: Prenatal hydrocephalus - CSF shunt - Outcome.

Since prenatal hydrocephalus can be recognized before birth, at 15 to 18 weeks o f gestation [5, 25], prognostic data are essential to provide counseling guidelines for parents and obstetricians. Important decisions have to be made regarding the termination or continuation of a pregnancy

Offprint requests to: D. Renier

up to preterm delivery [3] or even in utero treatment of hydrocephalus [5, 14]. These difficult decisions should be based on an accurate knowledge of the prognosis o f prenatal hydrocephalus. Until now, there has been little information published on this issue, and all o f it has been based on small series. Moreover, the conclusions of these studies differ according to authors. In Mealey's series [19], one-third o f the survivors showed a normal I.Q. whereas in that of Mc Cullough and Balzer-Martin [20], one child

• in two was intellectually normal and two-thirds attended a regular academic school.

In a series of 108 children treated for prenatal hydrocephalus, we assessed the long-term results in order to determine the prognostic factors.

Materials and methods

From 1971 to 1981, 108 children were operated on for prenatal hydrocephalus in the pediatric neurosurgical service in "Les Enfants Malades" in Paris. There were 62 males and 46 females.

Prenatal hydrocephalus was diagnosed when the head circumference at birth was at or above 37.7 cm for gifts and 38.5 cm for boys delivered at term (normal for girls: 34.4 cm, S.D. = 1.1; normal for boys: 35.2 cm, S.D.= 1.1). Premature newborns and spina bifida patients were excluded. Ventricular enlargement was assessed by air studies or CT scan. Hydrocephalus was con- sidered progressive when the head circumference was growing too fast and/or when the fontanelle was bulging.

Table 1 gives the etiologies or sites of CSF block in the series. Communicating hydrocephalus of unknown cause (36%) and aqueductal stenosis (30%, excluding 6 X linked hydrocephalus and 4 toxoplasmoses) were the two main types. The occurrence of associated malformations could be assessed in 80 cases; 25% had associated CNS malformations and 14% extra-CNS malformations.

Ninety-one infants (84%) were operated, on during the first 3 months of life: 65 (60%) during the first month, 17 (16%) between 1 and 2 months, and 9 (8%) between 2 and 3 months. The remaining 17 cases (16%) were operated on between 3 and 30 months. The initial treatment was a ventriculoperitoneal shunt in 91 cases, a ventriculocistemostomy in 10 cases, a ventriculocystostomy in 5 cases, and a direct approach for a Dandy-Walker cyst in 2 cases; a total of 248 surgical procedures were performed in the 108 cases; 38 children had only one operation whereas the remaining 70 had 2-8 procedures. Among the 75 survivors, the

214

Table 1. Etiology or sites of CSF block in 108 cases of prenatal hydrocephalus

Unknown 39 Aqueduct stenosis 32 Aqueduct stenosis, X-linked 6 Aqueduct stenosis, toxoplasmosis 4 Dandy-Walker 10 Brain cysts 10 Malformations, miscellaneous 7 Boys: 57% Girls: 43%

Table 2. Results of the first surgical procedure

n Failure %

Dandy-Walker cyst 2 2 100 (direct approach)

Ventriculocysternostomy 10 8 80 Ventriculocystostomy 5 4 80

91 shunts - Infection: 15 . . . . 16% - Malfunction: 39 . . . . 43%

Table 3. Causes of the 33 deaths

Shunt infection 12 36% Shunt malfunction 3 9% Other disease 6 18% Unknown 12 36%

Fig. 1. Ventricular surface index: VSI = s/S× 100. The normal VSI (values evaluated in 100 patients) ranges from 1 to 12; mean 5.4; standard deviation 2.8

%

t00 _ ~ e ~ o ~ o _ _ o _ _ e . ~ . e _ _ o _ _ o__e__o__ e__ e__ o__ e o ~

80 o.... °'~- O~o~.~ "

60 °--°--°"°--°--°--°

&o

20

Years 0 i I i I i I i i i i 1 i i i

2 4 5 8 1 0 1 2 1 4

Fig. 2. Actuarial survival rate in the whole series (life table method). (e) postnatal hours, n = 492; (o)prenatal hours, n= 108; log rank (Kaplan-Meier); chi 2 = 24.304; P < 0.0001

average number of operations was 2.5. Mean follow-up was 7 years (range 1 to 14 years). In 17 cases, an attempt was made to treat hydrocephalus without shunting: these approaches failed in most cases and a shunting procedure had to be done afterwards. A ventriculoperitoneal shunt was the first treatment in 91 cases. 15 of these initial shunts were colonized by bacteria and 39 had to be revised for malfunction (Table 2).

The severity of hydrocephalus was evaluated by the head circumference at birth and the size of the ventricles before treatment. The size of the ventricles was assessed using a ventricular surface index, which is the ratio of the ventricular surface to the whole brain surface at the same level, on a CT scan cut just above the foramen of Monro (Fig. 1).

The mental level of the children was tested by intelligence quotient (I.Q.) or development quotient (D.Q.). The development Brunet-Lrzine scale was used for children up to 2Y2years of age. Between 212 and 3 years of age, the complementary tests and the nonverbal scale of Brunet-Lrzine were used. Over 3years of age, the NEMI (Nouvelle Echelle Mrtrique de l'Iutelligence, a revision by Zazzo et al. of the Binet-Simon test) was used. When there were linguistic difficulties, the performance test of the Wechsler Intelligence Scale for Children (WISC) was used. Academic performance was recorded for 52 children who had reached school age.

For comparison, a control group of 492 children shunted in our department for postnatal hydrocephalus was studied. In this control group, the types of hydrocephalus were the same as in the prenatal group; spina bitida, encephaloceles, premature newborns, and tumors were excluded.

Results

Survival and functional results

Survival (Fig. 2). In the whole series the length of survival ranged from 2 weeks to 14 years (median: 50 months). The 5-year actuarial survival rate was 71% (95% confidence in terval= 10%) and the 10-year survival rate was 62% (95% confidence in te rva l= 12%). Death was related to shunt complications in almost half of the cases (Table 3). These survival rates are lower than those observed in postnatal hydrocephalus. In the control group of shunted postnatal hydrocephalic children, the 10-year survival rate was 88% (95% confidence interval = 5%).

Intellect (Fig. 3). A late postoperative I.Q. is known in 75 children. The I.Q. scores have been divided into three groups: very low I.Q. under 60; borderline I.Q. between 60 and 80; and normal I.Q. at or above 80. The I.Q. score was normal in 28%, borderline in 21%, and very low in 51%. The mean I.Q. was 55. In the control group of postnatal hydrocephalus, the mean late postoperative I.Q. was 73; 58% of the I.Q.s were at or above 80.

Nb % 16 - - 21

14 - 18

12 - - 16

10 - - 13

8 - - 10

6 - - 8

4 - - 5 .

2 -- 2.E

0 - 0 - 20 40 60 80 100 120 140

Fig. 3. Late postoperative I.Q. distribution in the whole series

% 100

80

60

~0

20

i i

I I I I

0 1 2 3 4

Years I I I F I I

5 6 7 8 9 1 0

Fig. 4. Actuarial survival rates (fife table method) in the two main groups. (e) Aqueductal stenosis; (o) communicating hydrocephalus; log rank (Kaplan-Meier); chi 2 = 4.502; P--- 0.0339

Nb % 6 - 27 1.0.. > 80 : ~5%

5 - 22

4 - 18

3 - 1 3

2- 9.0

1- 4.5

O- 0 o 20 40 60

I I.CZ , I

80 160 120 140

Nb %

6 m 24

4~16

o o b o 20 40 60

I.CL > 80 :20%

--1• I.&. i

80 100 120 140

Fig. 5 a, b. Distribution of late postoperative I.Q. a in aqueductal stenosis (n = 22); 5 in communicating hydrocephalus (n = 25)

215

Education (Table 4). Fifty-two children have reached a school age and have been followed up. In terms of education, the results are consistent with those of the I.Q. evaluation since 29% of the children attend normal schools without significant retardation.

Neurological condition (Table 5). The neurological status is known at the last consultation in 70 patients; 41% of them have no neurological disabilities.

Behavior (Table 6). The behavioral status at the last consultation is described in 76 records. In 46% of the children, behavioral disorders are mild or nonexistent.

Prognostic factors

The predictive value of the available data in the 108 observations was tested in terms of survival and outcome.

Site of obstruction. Compar ison of the prognosis in the two main groups of prenatal hydrocephalus, communicat ing and noncommunicat ing (aqueductal stenosis, excluding X- linked hydrocephalus and toxoplasmosis), showed significant differences. The 10-year survival was 80% in aqueductal stenosis and 60% in communicat ing hydrocephalus (Fig. 4). This difference was statistically significant (Log rank: chi ~ =4.502; P < 0.04). The final mental level was different as well (Fig. 5): in aqueductal stenosis, the mean I.Q. was 67, with 46% of the children at or above 80, whereas in communicat ing hydrocephalus, the mean I.Q. was 52 with only 20% of the children at or above 80 (Mann-Whitney test, unilateral: P = 0.05).

None of the 5 X-linked aqueductal stenoses tested in the late postoperative period had a normal final I.Q. (mean I.Q.: 17; range 0 to 40). In 9 of the 10 Dandy- Walker syndromes with prenatal hydrocephalus, the final I,Q. is known: mean I.Q. 49. Seven children have severe retardation (I.Q. < 60) and only two are in the normal range. The 10-year survival in these 10 Dandy-Walker syndromes is 75%.

Table 5. Neurological findings at the last consultation

None 29 41% Seizures 21 30% Motor handicap 30 43 % Blindness 7 10%

Table 4. Academic performance in the whole series

No school 21 Special school 10 (academic failure 71%) Retardation > 2 years 6 Normal 15 (29%)

Table 6. Behavioral state at the last consultation

Disorders None 21 } Mild 14 46% Psychotic 26 34% Untestable (I.Q. # O) 15 20%

216

% I00

80

60

I 20

0 0 1 2 3 t.

Fig. 6. Relationship

• ] ~ ° " ' ~ ° ",..-.~ e ~ o ~ e ~ o ~ , - - o - - o

~ o ~ o ~ o ~ ° | ~ . . . . . . . . .

Years I I [ I I I

5 6 7 8 9 1 o

between survival and associated real- formations. (e) No mal format ion (n=51) ; (o) mal format ion (n = 29)

Nb % 4- 23

3-- 17

2--11

1--5.8

0 - ' 0

Nb % I0--23 9 -21 8- 19 7- 16 6- 14 5- II 4- 9.5 3- 7.1 2- 4.7 1- 2.3 0 O

b

20

I.~, > 80 : 18%

- - ~ - - I.CL. i

40 60 80 100 120 140

20 40 60 80

I.I1. > 80 : 33 %

I I'&" 100 120 140

Fig. 7a, b. Distribution of late postoperative I.Q. in the groups. a With associated malformations (n= 17); b without associated malformations (n = 42)

% IO0

80 o~-~. o

60 ~ ° ~ ° ~ o - - o . - . ~ ~ ° ~ o ~ 0 _ _ o

40

20

Years I I I I I I I I I 110

0 1 2 3 4 5 6 7 8 9

Fig. 8. Relationship between survival and head circumference at birth (HC). Comparison between a group with HC <4 SD (e); and a group with HC > 4 SD at birth (o)

Nb 7-

6 -

5-

4-

3-

2-

I -

0 -

% 31

27

18

- 13

9.0 I 4.5 I 0 1 1 1 ~ 1

0 10 20 30 t,O 50 60 70 80 90 t00

Fig. 9. Distribution of the preoperative ventricular surface indexes in 22 cases

Associated malformations (Figs. 6 and 7). The 10-year survival was 74% in the group without associated malformation versus 54% in the group with associated malformations (Log rank: chi2= 6.3419; P < 0.02). The final I.Q. scores were higher in the first group (mean I.Q.: 58, with 33% I.Q. > 80) than in the group with malformations (mean I.Q.: 44 with 18% I.Q. > 80). This difference was not statistically significant but was suggestive (Mann- Whitney test, unilateral: P - - 0.10).

Sex. There was no difference between boys and girls - either regarding survival or functional results.

Head circumference (HC) at birth. The series were divided into two groups: increased HC up to + 4 standard deviations (43 cases) and increased HC above + 4 standard deviations (65 cases). In terms of survival, the difference was significant (Fig. 8): the 10-year survival was 83% in the first group versus 52% in the second group (Log rank: chi2 =5.2421; P < 0.03). In terms of final I.Q., there is no statistically significant difference: mean I.Q. = 56 in the first group (I.Q. > 80=23%) and 52 in the second (I.Q. > 80=31%).

Ventricular surface index (VSI). It was possible to evaluate the Weoperative VSI in 22 cases (Fig. 9). The preoperative VSI ranged from 17 to 85 (mean: 57, median 56). As far as survival and functional results are concerned, the prognostic value of the VSI was similar to the prognostic value of the head circumference at birth. The survival rate (Fig. 10) was higher in the group with VSI < 56 than in the group with VSI > 56 (9-year survival: 76% versus 53%), but the I.Q. scores were not significantly different in the two groups.

Age at the time of surgery (Figs. 11 and 12). Early surgery was associated with higher mortality and lower final I.Q. The 10-year survival rate was 75% in the group treated after 1 month of life, versus 59% in the group treated during the first month (Log rank: chi2= 2.478; P=0.12). The mean final I.Q. was 63 (with 39% I.Q. > 80) in the group treated after 1 month versus 48 (with 19% I.Q. > 80) in the group treated during the first month (t=1.74; P < 0.09).

%

100

8o \ . ~ . . . . . . . . .

60 o--o--o--o--o

40

20

Years I I I t I I I I I I

0 1 2 3 4 5 6 7 8 9 10

Fig. 10. Relationship between survival and preoperative ventricular surface index (VSI). Comparison between a group with VSI < 56, n = 11 (e); and a group with VSI > 56, n = 11 (o)

217

% 100

80 l ~ o """ "--~ ,..._... | ~ "--- .......

60 / o~ . . . . . . .

' - - ~ ~o--o~o

40

20

Years

O0 , , , , i , , , ' 0 " 1 2 3 4 5 6 7 8 9 I

Fig. 13. Survival and shunt infection. (e) group without shunt infection (n = 78); (o) group with shunt infection (n -- 30)

% 100 ~ ,

8o ~ ~ " " . . . . . . . . ~ . . . . ° ~ ° ~ O ~ o ~

60 o o._..o__o__ °

40

20

Years I I I I I I I I I I

0 1 2 3 4 5 6 7 8 9 10

Fig. 11. Relationship between survival and age at the time of surgery. Comparison between a group operated during the ftrst month of life, n =65 (o); and a group operated on later, n=43 (e)

Nb % 10 T 23 9 + 2 1 8 + 1 9 7 + 1 6 6 + 1 4 5 + 1 1

4 t 9 " 5 3 71

2 4.7 1 23 1~-0

a 0

Nb %

5 15

4 12

3

2

1

b

20 40 60

LOt. > 80 : 19%

1.0.. i

80 100 120 140

0 20 40 60

1.0.. > 80 : 39 %

L0..

80 100 120 140

Fig. 12a, b. Distribution of late postoperative I.Q. a In early (before 1 month) surgery group (n=42); b late (after 1 month) surgery group (n = 33)

Nb % 5 - - 26

4--21

3 -- 15

2-l- 10

1 F5.2

0 - - 0 a o 20 40

Nb %

10 17

60

1.0.. > 80 : 5%

- - ] I.&. I

80 100 120 140

8- 14

6 10

4- 7.1

2 3.5

O- O b 0 20 40 60

1.0.. > 80 : 36°/o

- - 1 I.(1.

80 100 120 140

Fig. 14a, b. Distribution of late postoperative I.Q. in the groups. a With shunt infection (n -- 19); b without shunt infection (n = 56)

Number of operations. Among the 75 children who had a late postoperative I.Q. evaluation, 25 had undergone only one operation and 50 had two or more. The functional results were similar in the two groups (one operation: mean I.Q. 54; more than one operation: mean I.Q. 56).

Shunt infection (Figs. 13 and 14). Shunt infections were associated with a poor prognosis in terms of survival as well as in terms of functional results. Out of 108 children and 248 operations, 78 did not have any shunt infections whereas 30 had at least one infection. The 10-year survival was 71% in the noninfected group, versus 51% in the infected group (Log rank: chi2=8.1835; P < 0.005). The mean late postoperative I.Q. was 40 in the infected group (I.Q. > 80=5%) versus 60 in the noninfected group (I.Q. > 80 = 36%) (Mann-Whitney: P < 0.04).

218

% 100

80

60

40

20

O,

~ - - o - - o - - o - - • - - • - - o - - o - - o - - o

~

°~°~°--O~o__o__o__o__o

Years [ I I I I I I I T I

I 2 3 4 5 6 7 8 9 10

Fig. 15. Relationship between survival (life table method) and the first D.Q. at six months. Comparison between (e) group with D.Q. >80 (n= 15); and a group (o) with D.Q. <80 (n=29); log rank (Kaplan-Meier) chi 2 = 6.9589; P = 0.0083

Nb %

7- 3 3

6" -28

5- • 23 /

4 1 9 ~7 ~ 3" 1 4

2 - 9 . 5

I " -4.7

0 - 0 0 20

Nb % 5 - 33

4 - 26

3 - 20

2 - 13

I - 6.6

0 - 0 b ;

~ . _ I.G. J

40 60 80 100 120 140

20 40 60 80 100 120 140

Fig. 16a, b. Relationship between late postoperative I.Q. and developmental quotients at 6 months, a First D.Q. <80, n=41; b first D.Q. > 80, n = 95

Prognostic value of the first L Q. assessment. The first development quotient (D.Q.) is usually evaluated at about 6 months o f age since its reliability before this age is questionable. Thus, in almost all cases the first D.Q. assessment is not preoperative. The first D.Q. is of good prognostic value, either for survival (Fig. 15) or final I.Q. (Fig. 16). Fifteen infants had a developmental quotient (D.Q.) measured at or above 80 during the first year o f life, and 29 were under 80. No deaths occurred in the normal group whereas the 10-year survival was 68% in the retarded group (Log rank: chi 2 = 6.9589; P < 0.01).

D.Q. in the first year o f life and late I.Q. can be compared in 36 children. In 21 cases, the first D.Q. was below 80: in this group, the mean final I.Q. was only 41 with 5% I.Q. over 80. In 15 cases, the first D.Q. was at or

I/,0

120 /

100 ..." ": 60

40 • •

20 •

0 • P I I i l l I I I I I l

120 Initial 1.0..

Fig. 17. Relationship between final I.Q. and first D.Q. score (n--36 pairs). Regression curve; r--0.78; P<0.0001. Final I.Q. = initial I.Q. - 20

Nb % 21 - - 37

18 -" 32

15 -" 26

12 ~- 21

ii -10

5.3

0 '0 10 20 30 40 50 60 70 80 90 100

Fig. 18. Distribution of the late postoperative ventricular surface indexes in 56 cases

Nb % 10 37 9 33 8 29

- 25 6 - 22 5 - 18 4 - 14 3 -11 2 -7 .4 1 - 3.7 0 - 0 ,

a 0

Nb % 6 T 2 3

5 + 19

4 + 1 5

3 + 1 1

2 + 7.6

I + 3 . 5

0 ~ - 0 b

? 20 40 60

1.0.. i

80 100 120 140

- - I . D .

20 40 60 80 100 120 140

Fig. 19a, b. Distribution of late postoperative I.Q. according to the postoperative ventricular surface index (VSI). a Children with VSI < 21; b children with VSI > 20

above 80: in this group, the mean final I.Q. was 95, with 80% I.Q. over 80. These differences are highly significant (Mann-Whitney: P < 0.0001).

The final I.Q. correlates well with the first D.Q. assessment ( r=0.78; P < 0.0001) but is overvalued by 20 points. Therefore, the relationship is the following: final

Table 7. Summary of the prognostic factors (for statistical significance, see text)

219

Factor Final I.Q.

Mean > 80 60-80 (%) (%)

Survival

<60 Me.an(m) 5-year (%) (%)

10-year (%)

Whole series 55 28 21 Aqueduct stenosis a 67 46 27 Communicating 52 20 24 Dandy-Walker 49 22 0 Boys 53 22 26 Girls 57 38 14 Associated 44 18 17 malformations No associated malformation 58 33 24 HC at birth 52 31 15

>4 SD HC at birth 56 23 28

<4 SD VSI > 56 67 37,5 25 VSI < 56 59 40 10 Operated < 1 month 48 19 24 Operated > 1 month 63 39 18 Shunt infection 40 5 26 No shunt infection 60 36 20 1st D.Q. < 80 41 5 28 1st D.Q. > 80 95 80 20 > 1 operation 56 27 24 Only 1 operation 54 32 20

51 50 71 62 27 57 86 80 56 57 69 60 78 75 75 52 65 77 69 48 39 61 61 65 38 60 54

43 67 77 74 54 37 59 52

49 72 87 83

37,5 37 53 53 b 50 41 76 76 b 57 39 65 59 43 72 79 75 69 34 58 51 44 54 76 71 67 58 73 68 0 62 100 100

49 48

a Excluded: X-linked aqueduct stenosis and toxoplasmosis b 9-year survival

I.Q. = initial D.Q. minus 20 (Fig. 17). Table 7 summarizes the prognostic factors studied in this series.

Postoperative ventricular surface index (VSI). A late postoperative CT scan is available in 56 patients (Fig. 18). The postoperative VSI ranged from 0 to 75 (mean: 23, median: 20). The final I.Q. was significantly higher in children with normal /subnormal ventricles than in those with remaining dilated ventricles (Fig. 19). The postoperative VSI was measured at 20 or less in 28 children; in these children, the mean I.Q. is 75 with 41% I.Q. >80. In children with postoperative VSI > 20, the mean I.Q. is 51 with 27% I.Q. > 80 (chi2=5.7387; P--0.057). The I.Q. o f children with slit ventricles (VSI < 5) was similar to the I.Q. o f children with normal /subnormal ventricles (VSI: 5-20): mean I.Q. 76 versus 75.

D i s c u s s i o n

q-he results of this series (one-third of the patients dead by 10 years of age and only one-third o f the survivors having a normal I.Q. and regular schooling) are rather pessimistic. The first question is to assess their validity and meaning. It should be pointed out that since ultrasonog- raphy was not easily available between 1971 and 1981, the sampling criterion in this study was increased head

Table 8. Survival and functional results in shunted prenatal hydrocephalus

n Survival Mental level

Normal Border- Re- fine tarded

Mealey et al. [19] 34 47% 31% 31% 38% Mc Cullough and 37 86% 53% 19% 28% Balzer-Martin [20] Present series 108 62% 28% 21% 51%

circumference over 3 S.D. at birth. All patients with enlarged ventricles and bulging fontanelles, but with normal head circumferences, i.e., those infants who were at an earlier stage of the disease, were excluded. There- fore, the results do not concern them. It is likely that the results would have been slightly less pessimistic if these cases had been included in the series, although in most publications the head circumference at birth is not correlated with the functional results [6, 12].

The same criterion for selection, i.e., an increased head circumference over 3 S.D. at birth, has been used in the two largest series reported in the literature (Table 8). Mealey et al. [19] found that only one-third of the sur-

220

Table9. Survival and functional results in untreated hydrocephalus

n Survival Normal intelligence

Hadenius et al. [6] 180 47% 49% Hagberg and Sjogren [7] 63 37% Laurence and Coates [16, 17] 182 45% 45% Jansen [13] 219 45% 4270 a

"SocioeconomicaUy independent"

Table 10. Survival and functional results in shunted hydrocephalus

n Survival Normal intelligence

Hemmer and Wessenfels [9] 237 67% 60% a Keucher and Mealey [15] 228 84% Mazza et al. [18] .' 165 82% Amacher and Wellington [1] 170 82% 64% Young et al. [26] . 147 51% Shurtleffet al. [241 ' " 222 56% Present series: 492 88% 58%

control group

a "Normal professional life"

vivors showed a normal I.Q., a result in complete accordance with ours. However, Me Cullough and Balzer- Martin [20] were more optimistic since more than 50% of the survivors in their series had a normal I.Q. This difference is most likely due to patient selection differences. Mc Cullough and Balzer-Martin [20] included children with meningomyeloceles in their study, whereas they were excluded in ours. Four o f the seven good results in Mc Cullough's series concern infants with myelo- dysplasias, and it is well known that the prognosis of hydrocephalus is better in cases associated with myelo- meningocele than in other hydrocephalic patients. In cases with spina bifida aperta, Hemmer and Wessenfels [9] have reported a mean I.Q. of 94, and Raimondi and Soare [22] a mean I.Q. of 83.6. In the series of spina bifida patients with hydrocephalus operated on at "Les Enfants Malades" in Paris, the mean I.Q. was 88 and 74% of the patients had an I.Q. over 80 (Hirsch et al. unpubhshed data). The fact that these results are better might be due to the natural CSF drainage afforded in utero by the spina aperta. Their inclusion in the study of Mc Cullough and Balzer-Martin [20] explains the differences between their results and ours. The results of our series do not include infants with hydrocephalus and spina bifida aperta.

It is also difficult to compare our series with those in which the diagnosis was made before birth [2, 21] since they include spina bifida aperta and ventriculomegalies without head enlargement. Moreover, it has been demon-

strated that antenatal ventriculomegaly is not synonymous with hydrocephalus; 6 of the 11 patients reported by Glick etal. [5] did not require postnatal shunting. In those studies in which the diagnosis was made before birth (Chevernak et al. [2]; Pretorius etal. [21]), the mortality was very high, varying from 62% to 81%. However, these mortality rates do not mean very much since they are largely a function of the methods used for delivery. More important is the fact that once myelomeningoceles are excluded, the functional results are poor as far as I.Q. is concerned.

The prognosis of prenatal hydrocephalus (excluding myelomeningoceles for I.Q. values) is more pessimistic than that for postnatal hydrocephalus: a survival rate of 66% compared to 80% in postnatal hydrocephalus; normal I.Q. in 28% of the patients as compared to 51% to 64% in the recent published series of postnatal hydrocephalus (Table 10). The prognosis of prenatal hydrocephalus should actually be compared to the prognosis of untreated hydrocephalus (Table 9). However, these overall results should be closely examined in order to give a more precise prognosis in each individual case.

The site of the CSF pathway obstruction affects the prognosis. In our series (excluding toxoplasmosis and X- linked hydrocephalus), infants with aqueductal stenosis did better than those with communicating hydrocephalus. The same observation has been made in postnatal hydrocephalus due to aqueductal stenosis: inour series [11], 59% of the patients with aqueductal stenosis showed an I.Q. over 80 versus 48% in communicating hydrocephalus. These better results were probably attributable to the group of patients with late hydrocephalus in aqueductal stenosis; in these cases the obstruction responsible for the slow evolution is probably incomplete and the final I.Q. values are higher. The same explanation might be valid for prenatal hydrocephalus, with at least some cases of aqueductal stenosis progressing more slowly than those of communicating hydrocephalus. However, among these cases of noncommunicating hydrocephalus, three types deserve special attention.

In our series the Dandy-Walker malformation had a poor prognosis since only two patients out of nine had an I.Q, in the normal range. Since we have shown in a previous study [10] that 80% of the patients presenting with a Dandy-Walker malformation were not hydrocephalic at birth and that 59% had a normal I.Q., the poor results of the prenatal hydrocephalic caSes must be related to the hydrocephalus and not to the Dandy Walker lesion itself.

Aqueductal stenosis due to toxoplasmosis also had a poor prognosis. This is in accordance with the findings of Couvreur and Filler [4] who showed, in a series including pre- and postnatal cases, that only 43% of the patients had an I.Q. over 80. Thus, in toxoplasmosis the poor results are not only related to the precocity of hydrocephalus but also to its etiology, i.e., to the cerebral lesions that it produces.

Finally, the poorest results in noncommunicating hydrocephalus were found in X-linked hydrocephalus.

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This is actually well known since the syndrome includes mental deficiency in its description. In a series published by Halliday et al. [8], none of the surviving X-linked patients was normal. In these cases, hydrocephalus is only partly responsible for the very low I.Q. Factors other than the site of obstruction can affect the prognosis.

It is obvious in our study that associated malformations imply a low survival rate and poor functional results. Shurtleff et al. [24] reached a similar conclusion in a study on infantile hydrocephalus. However, our results should be accepted cautiously since we found CNS malformations in only 25% of the children and systemic malformations in 14%. In other studies, the real incidence of associated malformations in prenatal hydrocephalus has been observed to be as high as 84% [2, 21, 25].

In our series, the head circumference at birth and the size of the ventricles before treatment correlated with the survival rate: the larger the head and ventricles, the bigger the overall mortality. This observation is in accordance with that of Laurence and Coates [16], who found that the survival rate was lower in infants seen soon after birth than in children seen after 1 year of age since it can be assumed that in our series, the cases with the largest head circumferences and ventricles were referred earlier than the others.

Even though not completely statistically significant (P around 10%), the correlation between early surgery and a higher overall mortality should be understood in the same way. It suggests that the cases referred and operated on early are the more severe; obviously, it does not mean that surgery should not be performed as early as possible.

We did not find in our series any correlations between head circumference, size of the ventricles at birth, and functional results. Jackson and Lorber [12] and Hadenius et al. [6] made the same observation. However, Shurtleff et al. [24] found a relationship between brain mass and intellectual outcome, at least when there were no asso- dated malformations. Comparisons between these series and those involving prenatal hydrocephalus are difficult. In the latter group not only are associated malformations frequent, but the duration of the ventricular dilatation, which might be one of the most important prognostic factors, is unknown. Moreover, the absence of correlation in our series between head enlargement and functional results might be the consequence of a bias: the mortality of the children with larger preoperative ventricles being significantly higher, the late functional results are mainly based on patients with smaller ventricles.

In contrasts, this study shows a correlation between the final postoperative ventricular size and the final I.Q., children with normal ventricles doing better than the others. This correlation demonstrates that to ta l and normal postoperative reexpansion of the cerebral mantle means the absence of irreversible lesions of the brain. Remaining postoperative ventricular enlargement could be due either to a more precocious in utero onset of hydrocephalus or to an underlying brain defect: in the first hypothesis, the postnatal shunting is too late and treat-

ment in utero should be proposed; in the second hypothesis prenatal treatment would not be effective. The effectiveness of the prenatal treatment of hydrocephalus is debatable. Discussing this point, Glick et al. [5] stated that "most fetuses with ventriculomegaly do not require inter- vention before birth", the selection being difficult between "those fetuses with true hydrocephalus that is neither so severe that the fetus cannot be saved nor so mild that the fetus will do well with less risky forms of treatment."

Shunt infections carry a very poor prognosis in terms of both survival and intellectual outcome. The rate of infection in the present series is very high. It has been shown in another study that the rate of infection is highly correlated with the age at therapy: the youngest children carry the highest risks of infection [23].

In conclusion, our study on infants without meningomyeloceles presenting at birth with increased head circumferences and enlarged ventricles allows the following predictions. Regarding the preoperative factors, 66% of the patients will be alive at t0 years of age; one-third of the survivors will have a normal I.Q. and will attend regular schools. These results are slightly better in noncommunicating hydrocephalus (excluding Dandy-Walker, toxoplasmosis and X-linked hydrocephalus). The results are worse when head enlargement is severe at birth or when there are associated malformations.

After surgery, shunt infection carries a poor prognosis whereas normal reexpansion of the cerebral mantle is an indication of a good final I.Q. Moreover, there is a good correlation between the developmental quotient measured at 6 months of age and the final I.Q. When this D.Q. was over 80 in our series, no death occurred and 80% of the patients had a final I.Q. of over 80. These data provide guidelines for the dialogue between pediatric neuro- surgeons and families when dealing with an infant showing prenatal hydrocephalus.

References

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Received December 28, 1987; in revised form March 8, 1988

Prenatal hydrocephalus: outcome and prognosis

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