“Dreams are not what we get while we are sleeping but dreams are those we do not sleep before we achieve”

PUBERTY & PRECOTIOUS PUBERTY

Dickson Cv BNS3 {BISHOP STUART UNIVERSITY}

Physiologic Changes with Puberty

physiologic transition from childhood to sexual and reproductive maturity.

10 sexual characteristics of the hypothalamus, pituitary, and ovaries initially undergo an intricate maturation process 20 sexual x-tics involving the breast, sexual hair, and genitalia, in addition, to a limited acceleration in growth.

Hypothalamic-Pituitary-Ovarian Axis

A cascade of events unfolds in the neuro-endocrine system .

In utero, GnRH neurons develop in the olfactory placode. These neurons migrate through the forebrain to the arcuate nucleus of the hypothalamus by 11 weeks of gestation.

They form axons that extend to the median eminence and to the capillary plexus of the pituitary portal system.

Gonadotropin-releasing hormone is influenced by higher cortical centers .

Released in a pulsatile fashion into the pituitary portal plexus .

Cont…

GnRH "pulse generator" stimulates secretion of gonadotropins, FSH and LH, from the anterior pituitary by mid-gestation

stimulates ovarian synthesis and release of gonadal steroid hormones.

Concurrently, accelerated germ cell division and follicular development begins, 6 to 7 million oocytes by 5 months' gestation.

Cont…

By late gestation, gonadal steroids exert a negative feedback upon both the pituitary gonadotropins and hypothalamic GnRH secretion.

During this time, the oocyte number decreases through a process of gene-related apoptosis to reach 1 to 2 million by birth.

Cont…

At birth, FSH and LH levels rise abruptly in response to the fall in placental estrogen.

And gradually decline within the first few months of life to reach prepubertal levels by age 1 to 4 years.

This transient rise in gonadotropin levels vs gonadal steroid levels, is thought to explain instances of neonatal breast budding and minor bleeding from endometrial shedding.

Cont…

Childhood years are thus characterized by low plasma levels of FSH, LH, and estradiol. However, studies suggest that the GnRH pulse generator is exquisitely sensitive to minute amounts of gonadal steroids.

True central precocious puberty may develop as a result of premature activation of the GnRH pulse generator.

Cont…

During childhood, the ovary increases in size and undergoes active follicular growth and atresia.

As a result of this attrition, by puberty only 300,000 to 500,000 oocytes remain.

Pubertal Changes

Initial pubertal changes occur between the ages of 8 and 13 years in North America.

Changes before or after are categorized as either precocious or delayed puberty and warrant evaluation.

At approximately age 10 to 12 years, breast budding, termed thelarche.

This is followed by pubic hair growth, known as pubarche and then Menarche.

Following breast and pubic hair growth, adolescents, during a 3-year span from ages 10.5 to 13.5 years, undergo an accelerated increase in height, termed a growth spurt.

Precocious Puberty

Early pubertal development may be seen in both sexes.

For girls, precocious puberty has historically been defined as the development of breast or pubic hair in girls younger than 8 years.

Cont…

Premature pubertal development may result from a variety of etiologies.

These causes have been categorized based on the site of pathogenesis and include:

central precocious puberty peripheral precocious puberty heterosexual precocious puberty variations of normal puberty.

Central/true Precocious Puberty (Gonadotropin-Dependent)

Early activation of the hypothalamic-pituitary-

ovarian axis leads to GnRH secretion, increased gonadotropin formation, and in turn increased gonadal sex steroid levels.

Central precocious puberty is rare and affects one in 5,000 to 10,000 individuals in the general population.

The most common cause of central precocious puberty is idiopathic, however, central nervous systems lesions must be excluded.

Common Etiologies of Precocious Puberty

Central(GnRH-dependent)   Idiopathic   Central nervous system (CNS) tumors   CNS infection   Head trauma   Iatrogenic Radiation Chemotherapy Surgical  

Cont…

 Malformations of the CNS Arachnoid or suprasellar cysts

Septo-optic dysplasia Hydrocephalus Empty sella syndrome

Peripheral (GnRH-independent)   Congenital adrenal hyperplasia   Testosterone/estrogen-producing tumors Adrenal/ovarian carcinoma or adenoma Granulosa cell tumor Theca cell tumor Leydig cell tumor   Gonadotropin/hCG-producing tumors Choriocarcinoma Dysgerminoma Hepatoblastoma   

Cont…

Exogenous exposure to androgen or estrogen

  Familial male-limited precocious puberty

  McCune-Albright syndrome  Ovarian cysts  Hypothyroidism (Van Wyk-Grumbach

syndrome)  Aromatase excess syndrome

Symptoms of central precocious puberty are similar to those of normal puberty, with breast development, growth spurt, and eventual menses.

However, these are seen at an earlier age

.

DIAGNOSIS

Signs of sexual maturationBlood and urine levels Hormone levelsX-ray to show Bone maturationCT/MRI to detect tumors in the

brain/ovary/testicle.

TREATMENT

There are 2 approaches 1) Treat the underlying cause or

disease 2) Lowering the high levels of sex

hormones with medication to stop the progression of sexual development

LHRH- synthetic hormones that block the body production of sex hormones.

LHRH

Synthetic hormonesDramatic results and no side

effects In boys penis and testicles

shrink back to the normal size or no further development.

In girls breast size may decrease / at least there is no further development seen

Growth and behavior of the child will return to normal and will reach an appropriate level.

CARING

More compulsory than treatment and is very necessary for the emotional support of the child.

Important points at school1. Poor grades2. Problems at school3. Loss of interest in daily activities4. Depression

SUPPORT

To create a supportive environment, try not to focus your comments on your child's appearance; instead, offer praise for achievements in school or sports and support your child's participation in other activities.