Increased cerebrospinal fluid concentrations of soluble Fas (CD95/Apo-1) in hydrocephalus

BACKGROUND AND AIMS

The ventricular enlargement observed in children with chronically raised intracranial pressure (ICP) causes a secondary loss of brain tissue. In animal studies of hydrocephalus, programmed cell death (apoptosis) has been found as a major mechanism of neuronal injury. One of the regulators of the apoptotic cell death programme is the receptor mediated Fas/Fas ligand interaction.

METHODS

The apoptosis regulating cytokines soluble Fas (sFas) and soluble Fas ligand (sFasL) were studied in the cerebrospinal fluid (CSF) of 31 hydrocephalic children undergoing shunt surgery for symptomatic hydrocephalus and 18 controls.

RESULTS

High concentrations of sFas were observed in children with hydrocephalus (median 252 ng/ml); in controls sFas was below the detection limit (0.5 ng/ml). sFasL was undetectable in all but one sample.

CONCLUSION

High concentrations of sFas in the CSF of children with hydrocephalus suggest intrinsic sFas production, potentially antagonising pressure mediated Fas activation.

One-year treatment with recombinant human growth hormone of children with meningomyelocele and growth hormone deficiency: a comparison of supine length and arm span

Growth retardation and precocious puberty are frequently found in children with meningomyelocele (MMC). Lower limb contractions, spasticity and kyphoscoliosis may lead to disproportionate short stature. Most of these patients have structural brain defects or hydrocephalus which can cause growth hormone deficiency. In this study, 19 children aged between 3.5 and 12.8 years with MMC and growth hormone (GH) deficiency were treated with recombinant human GH for a period of 12 months. Supine length, arm span and growth velocity were compared before, and after 6 and 12 months of treatment with rhGH (daily dose 2.0 IU/m2 BSA s.c.). Mean supine length standard deviation score (SDS) increased by +0.8 SDS after 6 months and +1.2 SDS after 12 months of therapy. Mean arm span standard deviation score increased by +0.9 SDS and +1.3 SDS. Growth velocity increased in supine length from 3.3 cm/yr (-2.1 SDS) to 8.4 cm/yr (+2.4 SDS) and in arm span from 4.8 cm/yr (-1.3 SDS) to 8.6 cm/yr (+3.1 SDS) in the first 6 months and was 8.1 cm/yr (+2.4 SDS) and 8.3 cm/yr (+2.6 SDS) after 12 months of therapy. Linear correlation between SDS growth velocity supine length and SDS growth velocity arm span during one year of treatment was excellent (r = 0.65, p < 0.0025). We surmise that body proportions do not deteriorate when growth velocity is stimulated in MMC patients. Both supine length and arm span measurements are necessary to document growth in children with spinal dysraphism.

Auxological and endocrinological evaluation of children with hydrocephalus and/or meningomyelocele

Short stature and precocious puberty are frequently found in children with hydrocephalus and/or meningomyelocele (MMC). However, aetiology and pathophysiology have not been well characterized. In this study, 108 patients aged between 3 and 17.8 years were evaluated. Growth was documented on the basis of arm span measurements. Short arm span was found in 47 (43.5%) children with hydrocephalus and/or MMC. Mean arm span was -2.0 standard deviation score (SDS) (-6.4 to +0.8) in 43 girls and -14 SDS (-5.6 to +1.3) in 65 boys. When growth deficiency (more than -2.0 SDS) was diagnosed by arm span measurement (24 F, 23 M) or when early sexual maturation was found (6 F, 9 M), endocrine evaluation followed. Levels of serum insulin-like growth factor and insulin-like growth factor binding protein-3 were low in 22 of 62 (33.8%) patients. In 9 of 62 (14.5%) patients, insulin-like growth factor-1 and insulin-like growth factor binding protein-3 levels were found to be increased. Growth hormone (GH) deficiency was diagnosed by means of two different stimulation tests (clonidine and arginine) in 7 of 62 (11.3%) patients. In another 3 of 62 (4.8%) children, 12 h night time GH sampling showed low maximum peak levels and decreased area under the curve values, suggesting neurosecretory GH dysfunction. Precocious puberty or early onset of puberty associated with elevated luteinising hormone and follicle stimulating hormone concentrations after stimulation with luteinising hormone releasing hormone was found in 13 of 108 (12.0%) patients (age 7-9 years). Free thyroxine was abnormally low in 2 of 62 (3.2%) patients. Cortisol was within the normal range in all 62 (100%) tested patients.

CONCLUSIONS

Short arm span in children with hydrocephalus and/or MMC is frequently accompanied by GH deficiency or neurosecretory GH dysfunction. Early onset of puberty is another frequent finding. Both hormonal disorders may be the consequence of damage to the hypothalamus or the pituitary gland caused by increased intracerebral pressure or increased mass of cerebrospinal fluid.