Endocrine Medicine 1 Flashcards
What is the extent of endocrine diseases effects?
widespread, multisystem effects
What are the two methods of failure?
control failure (secondary)
gland failure (primary)
What is an example of a dentally relevant multiple endocrine neoplasia?
what are the characteristics
MEN 2b
Medullary Thyroid, Phaeochromocytoma
Mucosal neuromas (small swelling on nerves present in tissue)
Marfanoid appearance
Where is the PG?
gland is in a small depression in the middle of the skull base called the sella turcica (turkish saddle)
What are the two types of hormones released from the hypothalamus?
primary hormones - hormones from the pituitary act directly on tissues to cause effect e.g, Thyroid, growth hormone,
trophic hormones - releasing hormones e.g. TRH, GnRH, CRH
How are the anterior pituitary and hypothalamus connected?
hypothalamic pituitary portal vessels
(vascular plexus into vascular tissue)
How are the posterior pituitary and hypothalamus connected?
via nerve axons mainly
What hormones do the anterior pituitary release?
- TSH - Thyroid Stimulating Hormone
- ACTH -Adrenocorticotrophic Hormone
- GH - Growth Hormone
- LH, FSH, Prolactin
What hormones do the posterior pituitary release?
- ADH - Anti Diuretic Hormone
- Oxytocin
What type of tumour are most pituitary tumours?
adenoma
- arise from glandular tissue
What are the two types of adenoma?
functional - produces active hormone and obstructs/impinges on other tissue
non functional - may cause pressure/obstruction
What can pituitary tumours cause in the eyes?
growth in PG can head upwards and cause pressure to optic chiasm compressing optic nerves and narrowing visual fields
What surgery is used for PG tumour removal?
trans-sphenoidal
no need to open the skull and compromise the brain
What is the pathway for GH?
hypothalamus > GHRH > anterior pituitary > GH > tissues > IGF-1 > anabolic reactions
What does insufficient growth hormone cause in children?
growth failure
What does insufficient growth hormone cause in adults?
metabolic changes in adults
- increased fat
- reduced vitality
What does excess growth hormone cause in children?
giantism
What does excess growth hormone cause in adults?
acromegaly
What is measured to assess GH?
IGF-1 - insulin growth factor 1
What are the features seen in acromegaly?
- coarse features
- enlarged hands
- carpal tunnel syndrome - finger numbness,
- type 2 diabetes mellitus - insulin resistance from increased GH
- cardiovascular disease - due to increased load from larger body
What are the dental features of acromegaly?
- enlarged tongue
- interdental spacing (diastema)
- ‘shrunk’ dentures
- Reverse overbite
What is thyrotoxicosis without hyperthyroidism usually caused by?
excess thyroid hormone drugs to promote weight loss
What is most hyperthyroidism caused by?
graves disease
auto antibodies stimulating the TSH receptor
What is toxic adenoma?
tumour within thyroid gland producing active hormone
What are the features of hyperthyroidism?
moist, sweaty skin
weight loss
tachycardia
increased blood pressure
tremors and hyperreflexia
eyelid retraction and lid lag
What is grave’s disease usually caused by?
often a family history of Autoimmune disease
What autoimmune diseases are see in family history of patient’s with graves disease?
vitiligo
pernicious anemia
type 1 DM
coeliac
myaesthenia gravis (autoantibodies against ACh receptors in muscle)
What eye conditions occur with grave’s disease?
ophthalmopthy
* scleral injection
* proptosis
* periorbital oedema
* conjuntival oedema
What neck condition occurs with graves disease?
diffuse goitre
What is hypothyroidism mostly caused by?
Autoimmune (Hashimoto’s) thyroiditis
What other reasons might hypothyroidism occur?
- Idiopathic atrophy (likely autoimmune, more in females)
- Radioiodine treatment/ thyroidectomy surgery
- Iodine deficiency
- Drugs
- Congenital
- Hypothalamic/pituitary disease
What drugs caused hypothyroidism?
carbimazole (used for hyper treatment)
amiodarone
lithium
What are the features of hypothyroidism?
dry, coarse skin
bradycardia
hyperlipidemia
psychiatric or cognitive changes
goiter (in Hashimoto’s),
delayed reflexes.
What are the associations of hashimoto’s thyroiditis?
- Middle aged & elderly women
- often a family history of Autoimmune disease
- vitiligo, PA, Type 1 DM, Addisons disease
- Down’s syndrome
How can thyroid disease be investigated?
- Blood
- TSH, T3 & T4
- Imaging
- ultrasound scan (cysts)
- radioisotope scans - gland uptake (areas producing/not producing hormones)
- Tissue
- fine needle aspirate/biopsy (FNA & FNB)
FNA VS FNB
FNA = needle stuck into gland, some cells sucked out
FNB = wide borne needle where core of tissue is trapped within needle itelf and taken away for histological examination
If the cause of hyperthyroidism is pituitary, what are the blood indications?
- RAISED TSH
- RAISED T3
If the cause of hyperthyroidism is graves or adenoma, what are the blood indications?
- LOW TSH (PG stops TSH to reverse high T3 from gland)
- RAISED T3
If the cause of hypothyroidism is pituitary, what are the blood indications?
- Low TSH
- Low T4
If the cause of hypothyroidism is hashimoto’s, what are the blood indications?
- HIGH TSH (PG tries to compensate but the gland is irresponsive)
- Low T4
What are treatments of hyperthyroidism?
- Carbimazole
- B-blockers (reduce symptoms - tremor, high BP etc)
- Radioiodine - 131I
- Surgery - partial thryoidectomy
How is grave’s ophthalmophathy treated?
no treatment as the conditions is not due to the thyroid gland activity but due to thyroid autoantibodies
controlled with immunosuppressives/ steriods
What is the treatment for hypothyroidism?
- Give T4 tablets (thyroxine)
- slow response - weeks
- increase dose slowly
What mineral deficiency can cause goitre?
iodine
What does cancer appear on a radioisotope scan?
cold nodules
What are the 3 types of thyroid cancer?
- papillary (80%) or folicular in younger
- undifferentiated in elderly
What are the dental aspects of thyroid diseases?
- Goitre detectable to the dentist
Hyperthyroid
* pain anxiety and psychiatric problems
* caution for treatment until controlled
- Hypothyroid
- avoid the use of sedatives if severe
