PRECOCIOUS PUBERTY

Precocious puberty traditionally is Tanner stage II breast development before age 8 years and testicular enlargement before age 9.5 years (134). Precocious puberty is associated with an accelerated growth velocity and early epiphyseal fusion (134).

Individuals with spina bifida and precocious puberty can have marked short stature if untreated. Their short stature results from abnormalities of the hypothalamic-pituitary axis, the Chiari II malforma­tion, and hydrocephalus (135). These abnormalities are thought to cause premature pulsatile secretion of gonadotropin-releasing hormone (GnRH) (134).

Screening lab tests for girls include a luteinizing hormone and estradiol or testosterone level. For boys, morning testosterone values in the pubertal range are diagnostic with an elevated luteinizing hormone level. For both boys and girls, if the luteinizing hormone level is not clearly elevated, this should be retested fol­lowing stimulation with a GnRH agonist before treat­ment is begun (134). Bone age should also be tested and will likely be advanced.

Treatment with growth hormone leads to desen­sitization of the pituitary gonadotrophs, decreasing the release of luteinizing hormone. Treatment may be associated with menopausal symptoms such as hot flushes and may be associated with headaches. In a recent study in the spina bifida population, near adult stature, improved BMI, better reported self-esteem, and better gross motor skills were reported after treat­ment with GnRH (135).