Endocrinology Flashcards
What are the clinical features of neonatal hypothyroidism?
In neonatal period: there is may be
1- Prolonged physiologic jaundice
2- Lethargy; cry little, sleep much.
3- Poor feeding; Lack intrest, chocking spells during feeding.
4- Wide posterior fontanel
5- Noisy breathing due to large tongue.
6- Distended abdomen , constipation with umbilical hernia.
7- Heavy at birth
8- Subnormal temperature But baby may be asymptomatic (why?), so neonatal screening is mandatory.
What are the clinical features of hypothyroidism in the 3 to 6 months of age?
Delayed growth => proportionate short stature * Delayed mental milestones * Delayed motor milestones * Physical features may include:
Head - Hair is coarse, brittle with low anterior hair line
- Delayed closure of anterior fontanel
- Eyes are puffy, narrow palpebral fissure
- Broad nose & depressed bridge
- Delayed teething
- Thick large protruding tongue
- Hoarse cry Neck - Short neck with supraclavicular pad of fat
- Thyroid is enlarged in:
- Endemic goiter.
- Dyshormonogenesis
- Pseudohypothyroidism Cardiac - Bradycardia
- Pericardia! effusion.
- Cardiomegaly Abdomen - Protruding with umbilical hernia
- Constipation Genitalia - Delayed sexual maturation
- Rarely precocious puberty Limbs - Short broad hands
- Generalized hypotonia
- Occasional reversible generalized pseudohypertrophy most prominent in calf(Kocher Debre Semelaigne Syndrome) Skin -Cold
- Dry (t myxoedematous tissue)
- Pale (resistant anemia)
- May be yellow(t carotene)
What are the x ray findings of congenital hypothyroidism?
a- Delayed bone age :
- At birth~ absent distal femoral epiphysis (by knee x-ray)
- Later~ delayed appearance of ossific centers (by wrist x-ray)
b- Epiphyseal dysgenesis: multiple foci of ossification in heads of femur & humerus.
c- Beaking of anterior part ofT 12 & L 1 vertebrae.
d- Skull X-ray~ intrasutural (Wormian) bones, large fontanels, delayed teething.
d- Chest x ray ~ may show cardiomegaly
What are the causes of transient hypothyroidism?
~ Transplacental passage of maternal:
- TSH receptor blocking antibodies.
- Drugs e.g.:- Anthyroid drugs.
- Excessive iodine.
~Neonatal iodine containing antiseptics.
How to follow up the patient with hypothyroidism and monitor response to drugs?
- Clinical~ monitor activity,”milestones & growth.
- Laboratory~ monitor T 4 and TSH (should kept in normal range).
- Radiologic ~ monitor bone age
What are the Causes of deafness & hypothyroidism:
1- Pendred syndrome ~ organification defect , goitrous hypothyroidism & positive perchlorate discharge test (perchlorate discharge 40-90% of radioiodine, in contrast to I 0% in normal subjects)
2- Endemic goiter
3- Neglected hypothyroidism
4- Congenital rubella syndrome.
What are the possible Causes of congenital Goitre?
1- Pendred syndrome.
2- Endemic goiter.
3~ Dyshormonogenesis (but goiter may be delayed for months).
4- Transplacental antithyroid drugs.
5- Maternal Grave’s disease.
How to investigate a patient with aquired hypothyroidism?
As before but:
a- Search for auto antibodies for Hashimoto thyroiditis e.g.
- Thyroid anti peroxidase antibody
- Anti thyroglobulin antibody.
- TSH receptor blocking antibodies b- Check for associated auto immune disorders e.g. auto immune hepatitis, diabetes
What is endemic goiter?
It’s maternal iodine deficiency leading-to transient congenital hypothyroidism.
What is the provnosis of congenital hypothyroidism?
Diagnosis & treatment before 3 months ~ good mentality.
- Diagnosis & treatment at 3-6 months ~ variable response.
- Diagnosis & treatment after 6 months ~ permanent MR.
